Sections

Division 23


23 00 00 HEATING, VENTILATING, AND AIR-CONDITIONING (HVAC)

23 00 01 Owner General Requirements and Design Intent

.01 HVAC Design General Requirements
  1. General:  HVAC Design Professional services and documentation shall include the following:
    1. Comply with Design Phase Submittal Requirements (Design Deliverables) in 00 51 00 MISCELLANEOUS FORMS.
    2. Develop the HVAC component of the Basis of Design document to meet Owner’s Project Requirements and update at each design phase submission.
    3. Perform all necessary design analysis and calculations. 
      1. Submit load summaries. Provide breakdowns for zones, major areas, subsystems and equipment loads.  Include common engineering check figure ratios such as cfm/sq. ft., heating BTUH/sq.ft, and cooling sq. ft./ton.
      2. Sound and Vibration control analysis:  Perform calculations and selection of attenuation provisions for HVAC systems to maintain sound and vibration within acceptable levels for each application.
      3. Economic / Life Cycle Cost Analysis:  Perform and submit as required to confirm selection of base systems and potential options for alternate bids.
    4. Performance Requirements Compliance Documentation:  Coordinate with lead Design Professional to submit application portions.  Comply with requirements in 01 80 00 PERFORMANCE REQUIREMENTS.
    5. All drawing sets shall include:
      1. Coordinated single line diagrams shall include both existing and new work as applicable.
        1. Overall building airflow diagram(s) showing interrelationships of air handling units, exhaust fans, duct risers and mains, primary dampers and air balance / pressure relationships.
        2. Overall building hydronic and steam system diagrams showing  interrelationships of main heating/cooling plant equipment or central utility source, heat exchangers, pumps, pipe risers and mains and primary isolation and control valves.
        3. Diagrams shall include connected and cumulative design capacities and flow rates which can be toggled on during design phase for review purposes and off if desired for final construction documents.
      2. Clear delineation between demolition, existing to remain, and new work on plans and riser diagrams.
      3. For areas with special pressure relationship requirements that must be properly controlled, the Design Professionals shall include plans in the construction set of drawings showing simplified pressure relationships and tabular summaries of overall air balance for each pressure controlled space and summaries of system airflows.
        1. These plans shall be the basic floor plan (clearly identifying all room names/use - not just numbers) with easily recognizable tags for any room that is not neutral pressurization.  The tag would indicate airflow direction (e.g. + and - or POS and NEG) and airflow (cfm).
        2. The drawing would also have a table indicating system level summaries of airflows per floor.  (i.e. System SA (max/min),  RA (max/min), General Lab Exhaust (max/min), Fume Hood Exhaust (max/min), General Exhaust, Transfer Air (including intended source - adjacent system), and any other special exhaust systems).
        3.  The purpose is to have easy to follow summaries to help everybody involved understand the design intent during all phases of the project and for the record set for future operation and maintenance reference.  Showing transfer air on a complicated duct drawing does not work well.  The concept is similar to having simple Life Safety Plans for accurate and quick understanding.
    6. DESIGN FOR COMPLETENESS:  All projects are expected to be complete at their conclusion, meaning that the project generates no need for additional efforts beyond the planned scope.   Any expansion or renovation of conditioned space must include an assessment of the adequacy of the utilities infrastructure.  Above all, the campus maintenance staff is not available to complete projects or provide remedies to problems caused by the project.
  2. Architectural Coordination:
    1. Space Planning:  Comply with requirements in 01 05 05 Space Planning, .01 Planning for Engineered Building Systems
      1. Coordinate generous space programming allowance for equipment and shaft space for M/P/E distribution systems, including future flexibility for future expansion.
      2. Plan for and clearly label any future equipment space needs on drawings.
      3. Drawings shall include equipment sizes and locations, showing locations of all required service areas to be kept clear, including coil and tube pull and adequate space for major component replacement,
      4. Coordinate locations of supplementary structural steel above and/or clear space above and around equipment for portable gantry crane for rigging of large component replacement.
    2. Thermal Comfort:  Comply with ASHRAE 55 Thermal Environmental Conditions for Human Occupancy.    Coordinate with Architect to integrate thermal envelope design and HVAC design iteratively such that thermal comfort criteria is met in the section 5.2 Method for Determining Acceptable Thermal Conditions in Occupied Spaces.   Perform calculations and analysis for representative spaces.
      1. Criteria to be evaluated with respect to thermal envelope design includes:
        1. Operative Temperature (average air temperature and Mean Radiant Temperature)
        2. Allowable Radiant Temperature Asymmetry
        3. Allowable Vertical Air Temperature Difference
        4. Allowable Range of Floor Temperature
      2. Notify the Project Manager if comfort criteria is jeopardized due to impact of thermal envelope and/or if HVAC systems are being expected to overcompensate for lack of high-performance of the thermal envelope.
    3. Coordinate outdoor and rooftop HVAC equipment locations and screening requirements per 01 05 01 Site Requirements
    4. Inform and help guide space planning when applicable with respect to efficient equipment zoning for efficient operation and accommodating unoccupied shutdown.
  3. High-Performance Energy-Efficiency:  Professional shall design each HVAC system and equipment application for optimal operating efficiency, and flexibility with the lowest life cycle cost.
    1. General:  Comply with requirements in 01 80 00 PERFORMANCE REQUIREMENTS 
      1. 01 81 13 Sustainable Design Requirements
      2. 01 83 00 Facility Shell Performance Requirements
    2. Equipment Selection:  Design Professional shall carefully evaluate and properly select the most effective equipment type and to best suit the needs of the application with emphasis on minimizing operating and life cycle cost, rather than minimizing size and first cost.  
    3. Part Load Operation:  Carefully evaluate system turndown requirements. Consider modular, multiple unit configurations where effective and practical for proper and efficient low part load operation and to help prevent complete system or building shutdown upon failure of a single primary HVAC system component.
    4. Primary and Terminal Equipment Zoning:  The simplest and most effective method of energy conservation is to turn things off when not in use.  To this end, zones with similar uses, environmental conditions, fresh air ventilation rates and occupancy schedules should be grouped together, to the extent possible, on the same HVAC system, to accommodate unoccupied shutdown.  
      1. In general, general offices should be grouped together, but separate from classrooms and both should be separate from lab/research zones requiring 24/7 operation and/or 100% outside air.
      2. Define and keep separate special use zones with continuous process cooling loads such as main TNS and College Server rooms or audio-visual closets with high load densities that require independent cooling systems to accommodate unoccupied shutdown of central systems.
  4. Reliability and Redundancy: Professional shall determine the adequate amount of redundancy for each application of mechanical equipment to meet the Owner’s Project Requirements.
    1. Confirm Owner requirements for redundancy are clearly defined.
    2. Install fully redundant (N+1) stand-by chillers for extremely critical applications (such as critical research laboratories and computer centers) and/or as otherwise defined specifically in the Owner’s Project Requirements.
    3. For non-critical applications (such as general office spaces, general purpose classrooms, general commercial type spaces) full redundancy/complete standby is typically not required. 
    4. Determine and specify applicable emergency power requirements. (research,  process or other specific critical application).
    5. Check with Failure analysis to determine weak links in system and revise as necessary.
  5. Flexibility: Consider potential future expansion. Extent of expansion will be determined on a case-by-case basis. Consult with the University Project Leader and Engineering Services.
  6. Utilities / Infrastructure Coordination:
    1. General:  Comply with requirements in 33 00 00 UTILITIES
    2. Perform analysis of existing utilities and/or existing HVAC infrastructure and submit summary of required upgrades to support new work.
    3. Utility Demand and Consumption Form:  Submit and update throughout design phase.
    4. UTILITIES IMPACT POLICY: Each project is responsible for funding all utility infrastructure upgrades made necessary by that project. 
    5. UTILITY DESIGN: 
      1. Designer shall consult with current drawings, planning connections, and upgrades.
      2. University is in the process of developing master plans.  Contact Project Manager.
  7. Mechanical Identification:  Coordinate identification nomenclature with University Standards per 23 05 01.06 Mechanical Identification.
  8. HVAC Controls / Building Automation Systems:  
    1. Comply with requirements in 25 00 00 INTEGRATED AUTOMATION
    2. Coordinate control design with OPP, Environmental Systems, Building Automation System (BAS) Application Engineering.
    3. 25 90 00 GUIDE SEQUENCES OF OPERATION:  Designers shall use guide sequences of operation, whenever available.  These “master” guide sequences have been developed and implemented at University Park in conjunction with existing BAS vendors and shall form the basis of the main sequences to maintain overall uniformity.  Guide sequences shall be edited as necessary to meet project specific requirements.  Fundamental modifications shall be reviewed and approved by the manager of the OPP BAS group.  Do not cut and paste portions into designer’s “office standard” sequences.
  9. Variable Frequency Drives for HVAC Motors:  Designers shall use guide specification in 26 29 23 Variable-Frequency Motor Controllers.  Guide specification shall be edited only as required to meet project specific requirements.  Proposed modifications shall be reviewed with OPP Engineering Services.
  10. Miscellaneous OPP Additional Resources and Links:  
    1. Engineering Resources
      1. Building Mechanical & Electrical Systems
.02 Related Documents
  1. The general requirements of the Penn State Office of Physical Plant Design and Construction Standards, including the Introduction, General Notes to the Professional and Contract Administration Division and General Conduct of the Work and Special Requirements apply to the work specified in this Division.
  2. For convenience, other sections with additional University-specific associated requirements related to HVAC work, include, but are not necessarily limited to, the following:
    1. 01 00 00 GENERAL REQUIREMENTS
    2. 01 56 10 Temporary Protection of Outdoor Air Intakes
    3. 02 00 00 EXISTING CONDITIONS
    4. 13 00 00 SPECIAL CONSTRUCTION:  HVAC requirements for special purpose spaces such as Classrooms, Bookstores, Labs, etc.
    5. 14 00 00 CONVEYING EQUIPMENT:  ventilation and environmental requirements for elevator machine rooms
    6. 27 00 00 COMMUNICATIONSMinimum Standards for Telecommunications Facilities, 5.1.2 Environmental requirements
.03 Definitions
  1. BTU Conversion Factor: The following energy source to BTU conversion factors have been established for general University use:
    1. Coal -------------------- 25 x 106 BTU/ton
    2. #2 Fuel Oil ------------- 140 x 103 BTU/gal.
    3. Electricity ------------- 3.412 x 103 BTU/k.w.h.
    4. Steam ------------------- 1 x 103 BTU/lb.
    5. Air Conditioning -------- 12 x 103 BTU/ton
    6. Natural Gas ------------- 1030 BTU/ft.3
  2. These values are modified from time to time.  The Professional shall consult the University for the most recent revisions. 
.04 Submittals
  1. Design Calculations:  The University requires calculations to be submitted for all projects. 
.05 Standard of Quality/Quality Assurance
  1. General (Reserved)
  2. Pressure Vessels
    1. All pressure vessels shall be in accordance with the requirements of the Commonwealth of Pennsylvania, Department of Labor and Industry Code for Unfired Pressure Vessels.
    2. Tanks and pressure vessels shall be inspected, stamped and certified to be constructed in accordance with the above code and the ASME Code for Unfired Pressure Vessels.
    3. Operating certificates shall be turned over to the University upon completion of the project.
.06 Coordination and Space Planning
  1. General:  Refer to Space Planning requirements in the Introduction of the Design and Construction Standards. 
  2. Mechanical Rooms:
    1. Mechanical rooms shall be designed in accordance with the most current version of all applicable codes.
    2. Mechanical rooms shall be planned with sufficient size and equipment laid out to provide adequate maintenance clearances for all equipment; (i.e. for filter changes, tube and coil pull spaces, repair of components, etc.).  Adequate means of access shall be provided for replacement of largest piece of equipment without removing general construction or moving other equipment.   Minimize the need to do maintenance from ladders.  Provide overhead structural steel with portable chain hoists to lift heavy motors, compressors, fans, etc. Provide adequate lighting.
    3. Mechanical rooms shall be provided with an automatic ventilation system.
    4. Mechanical rooms shall be provided with a minimum of one floor drain.  Floor drains shall be piped to sanitary system.
    5. Provide mechanical rooms with minimum one hose bibb with backflow preventer in supply piping.
    6. All equipment drains, blow down lines, etc. shall be piped to a floor drain with an approved air gap fitting.
    7. Mechanical rooms shall be located to provide access directly from the building exterior.  Mechanical rooms shall not be located where vibration and/or noise would be objectionable.
  3. Janitor Rooms
    1. Janitor rooms are not accessible to maintenance employees.  Therefore, mechanical equipment, valves, electric panels, thermostats, etc. are not to be placed in these rooms.
    2. Refer to Division 23 00 10.03 for janitor room ventilation requirements.
  4. Equipment Locations
    1. Terminal units and air handling equipment shall not be located above an occupied space unless prior approval is received from the University.  All equipment must be readily accessible for maintenance. 
    2. Floor mounted equipment shall be installed on concrete housekeeping pads.  Pads shall be isolated from the surrounding slab if vibration requirements warrant.
    3. All equipment installed on grade outdoors shall be installed on reinforced concrete pads.  Foundation requirements shall be analyzed for large pad-mounted equipment.
    4. Locations of mechanical equipment which affect the aesthetics of the building and Campus shall be approved by the Environmental Quality Board.  Discuss approval procedures with the Project Manager.
    5. Equipment above the finished floor level or roof level shall be provided with access platforms or walkways suitable for maintenance activities.
    6. Equipment accessible to the general public shall be provided with screens, fences, or enclosures to deter vandalism and to prevent access to dangerous conditions.

23 00 10 Systems Selection and Application

.01 General
  1. Construction documents shall clearly record all pertinent information and criteria related to the design, construction and intended operation of the HVAC systems.  Such information shall include, but not necessarily be limited to:
    1. Critical space temperature and pressure relationships to be maintained.
    2. Construction phasing planning as required to minimize disruption to existing facilities and occupancies.
    3. Future provisions including:
      1. Intentional oversizing of equipment or distribution systems and intended future connection points.
      2. Floor Space to be kept clear for future additional equipment.
      3. Provisions for major equipment replacement such as removable louvers or knock-out panels, etc.
    4. Special operating instructions of systems, special purpose valves, dampers or manual/emergency type controls.
    5. Shut-down and emergency instructions.
    6. Intended summer and winter operating and change over instructions.
    7. Any other special operating or maintenance instructions.
  2. Equipment (Non-typical)or Process Load Criteria: Design criteria for specialized, non-typical equipment or process heat gains (excluding people, lights, conduction, and solar loads), in critical and special areas such as computer rooms, microcomputer labs, research labs, etc. shall be scheduled on the drawings by room number for future reference.
.02 Design Conditions
  1. The following are general design guidelines for inside and outdoor design conditions.

    Area Description
    Season Indoor Outdoor Comments
    Comfort Areas
    Summer
    Winter
    75°F DB/50%
    72°F DB/25%
    90°F DB  74°F WB
    0°F DB
    1, 4 5

    Labs & Critical Areas
    Summer
    Winter
    Consult w/User
    Consult w/User
    92°F DB  74°F WB
    0°F DB
    Note 5

    Animal Rooms
    Summer
    Winter
    Note 3
    Note 3
    95°F DB  75°F WB
    -10°F DB
    2,  5
    2
    Cooling Tower Selection
    Summer
    Winter
      77°F WB

     
    Notes:

 

  1. Consideration shall be given to morning warm-up cycle.
  2. Typically these systems are required to be 100% outdoor air systems, therefore, the outdoor design conditions are altered for these and any other 100% outside air systems.  Specified discharge air temperatures shall be maintained at all times.
  3. As specified in the latest edition of "Guide for Care & Use of Laboratory Animals".
  4. Operating control setpoints shall be as follows:
    1. Comfort Areas such as general office/classrooms
      1. Occupied: 70 heating, 75 cooling
      2. Unoccupied:  60 heating, 85 cooling
      3. Holiday Setback:  50 heating, 85 cooling
  5. The University Park Campus chilled water system distributes chilled water at a supply temperature of 43°.  Therefore, all chilled water coils must be selected to function at a supply chilled water temperature of 43° with a minimum Symbol 1 of 12°.  The exception to this requirement is chilled water coils that are expected to provide cooling year-round to isolated zones that are not practical to serve via airside economizer (examples: telecom/data closets, elevator equipment rooms).  These chilled water coils must be selected to function at a supply chilled water temperature of 48°, which is the winter “free cooling” maximum supply water temperature.
.03 General Pressure Relationship and Ventilation Requirements for Certain Areas                   
  1. General:  Ventilation systems shall be designed to achieve high indoor air quality by providing adequate amounts of fresh air to maintain adequate and safe breathing air, control odors, and associated exhaust to remove contaminants from occupied spaces for each application.  Proper pressure relationships shall also be maintained where required with adequate differential airflow between adjacent spaces in the direction from most clean (positive) to most dirty (negative). 
  2. Codes, Standards and Guidelines:  In addition to minimum requirements of the Building Code, ventilation systems shall be designed in accordance with the following current editions of industry standards and design guidelines.
    1. ASHRAE 62.1- Ventilation for Acceptable Indoor Air Quality
    2. ASHRAE HVAC Applications Handbook:  Follow the guidelines for the General, Comfort, and specialty Industrial/Process/Research Applications associated with the project scope
    3. ANSI/AIHA Z9.5 - Laboratory Ventilation
      1. The purpose of this standard is to establish minimum requirements and best practices for the design and operation of laboratory ventilation systems to protect personnel from overexposure to harmful or potentially harmful airborne contaminants generated within the laboratory. This standard:
        1. Sets forth ventilation requirements that will, combined with appropriate work practices, achieve acceptable concentrations of air contaminants.
        2. Informs the designer of the requirements and conflicts among various criteria relative to laboratory ventilation.
        3. Informs the User of information needed by designers.
      2. This standard does not apply to the following types of laboratories or hoods except as it may relate to general laboratory ventilation:
        1. Explosives laboratories
        2. Radioisotope laboratories
        3. Laminar flow hoods (e.g., a clean bench for product protection, not employee protection)
        4. Biological safety cabinets
    4. Standards used by the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC) International for Accreditation of Animal Facilities:
      1. Guide for the Care and Use of Laboratory Animals, Institute of Laboratory Animal Resources
      2. Guide for the Care and Use of Agricultural Animals in Research and Teaching
  3. Special Requirements from Users:  Determine any project-specific research or process ventilation or pressure relationship requirements with the University User’s representative and review with Operations staff at OPP.  Requirements may vary.
  4. Cooling of Utility Spaces:  Use ambient/outside air for cooling of general mechanical and electrical distribution and elevator equipment rooms to the fullest practical extent.
    1. The preferred typical temperature range for these spaces is 55°F minimum (heating) and 85°F maximum (cooling) to provide acceptable temperatures for equipment and service personnel yet balanced with goal of requiring minimal heating and cooling energy.  Care must be taken in establishing a minimum temperature in order to avoid the risk of condensation in electrical equipment.  It is permissible for seasonal, short-term (partial day) operation at a maximum of 10°F above the 99.6% Summer Outdoor Design DB temperature, but not to exceed the most stringent maximum ambient operating temperature ratings of any installed equipment.
    2. For applications that cannot otherwise maintain acceptable operating conditions per the above in a practical, cost-effective manner using either outside air or air transferred from adjacent conditioned spaces, provide mechanical cooling as required.  Mechanical cooling systems shall be designed to operate only minimally as required to maintain recommended upper temperature limits for equipment expected to operate for extended periods at those conditions, in order to optimize service life.  For spaces requiring continuous cooling, do not rely solely on central air systems serving multiple spaces with scheduled occupied/unoccupied periods.  Design shall accommodate shutdown of central systems during unoccupied periods.
    3. Centralized battery banks, equipment with large batteries such as centralized Uninterruptible Power Supplies and/or other similar battery applications shall be in spaces with temperature maintained for optimum battery capacity and service life – generally between approximately 65 and 80°F (confirm with battery equipment manufacturer’s recommendations).  Ventilation of centralized battery rooms must be designed to limit any hydrogen concentration to lowest levels specified by accepted industry standards.
    4. Where fuel-fired equipment uses room air for combustion, do not use exhaust fans that will make the mechanical space negative and thus adversely affect proper combustion or venting of flue gases.
    5. Openings to the outdoors shall be screened/ minimally filtered to keep out insects, dust, pollen, etc.  Air for the main station switchgear and motor control center rooms should be relatively clean.  Any makeup air supplied from outdoors shall be filtered with minimum 30% efficient air filters.
.04 Standby Equipment for Critical Areas
  1. Standby equipment requirements shall be discussed with the Project Manager for systems serving critical areas such as:
    1. Labs
    2. Research Buildings
    3. Animal Rooms
    4. Main Frame Computer Rooms
  2. Contract documents shall indicate equipment which is intended for standby service.
  3. Animal Rooms, in addition to being tied into the main building chilled water system, shall have a totally independent air-cooled, chilled-water system to serve as backup during summer operation and to provide a year round supply of chilled water.
  4. Auto changeover shall be provided for all standby equipment.  Changeover shall be alarmed to CCS.  Refer to Division 23 09 00.
.05 Emergency Shutdown
  1. All systems shall be arranged for emergency shutdown requirements outlined in the applicable codes.
  2. Emergency shutdowns shall be alarmed to CCS.
.06 Central Heating and Cooling Plant
  1. CAMPUS CHILLED WATER:
    1. Much of University Park Campus is, or will be, served by a campus loop chilled water system.  The chilled water system of each new building must be designed so as to be compatible with the characteristics of the campus chilled water system.  New buildings shall have chilled water pumps (in a booster arrangement from the campus distribution loop with check valves and automatic control valves).  Refer to Campus Chilled Water System Building Service Entrance Details (with our without heat exchangers as applicable).
    2. Buildings served by a central chiller plant shall NOT have an automatic water make-up connection.  Make provision for flushing and initial filling of the chilled water system using domestic water.
    3. Expansion tanks shall not be installed in any part that directly connected to the campus chilled water system.  Buildings provided with a heat exchanger will require an expansion tank (bladder type) in the building side of the heat exchanger, but NOT in the campus side.
    4. Refer to Chilled Water System Sequence of Operation posted for the general requirements relating to Building Chilled Water Control Systems.  Review and coordinate project specific modification requirements with University Chilled Water Utility Engineer.
    5. All buildings shall be provided with shut-off valves at the building entrance (inside the building) with manual air vents and drains on the plant side of the shut-off valves.  Refer to Building Wall Penetration Detail. 
    6. All isolation valves shall be high performance butterfly valve, lug style.
    7. Provide thermometers in thermal wells. Provide manifold pressure taps to a single gauge.  Automatic air vents shall have isolation valves for replacement/maintenance.  Manual air vents to consist of ¾” ball valves and necessary pipe/fittings to clear valve handle of insulation.  Discharge from manual air vent valve to turn out horizontally from carrier pipe and be provided with hose bibb connection and cap on chain.  Low point system drains are to be installed in similar fashion with ball valve, piping, hose bibb connection and cap.  Provide air/water separators with a combination of manual and automatic air vents at all high points in system and drains at low points.
    8. Emergency chilled water tie-in points shall be provided on air conditioning critical buildings such as animal facilities, computing centers, medical facilities, etc.  Discuss with Project Manager for application.
.07 Zoning
  1. Zoning of the systems shall be done in accordance with sound engineering judgment relating to varying load conditions, function of space, occupancy schedules, etc.  Final zoning shall be discussed at conceptual design stage with the Project Manager.  Rooms shall be individually controlled.
  2. All Classrooms are to be separately zoned to allow cooling all year long, including those times when building air conditioning is turned off for the season.  Refer to Division 13 for further references to General Purpose Classroom document that includes information on HVAC needs related to Classrooms. 
.08 Water Systems
  1. Glycol Dry Coolers
    1. Utilize free cooling option for computer room systems when it is cost effective.
    2. Refer to Detail [23 xx xx .xx].  Details are not yet available in WEB-based manual.
  2. Process Cooling Water Systems
    1. City water is not permitted to be used in "once through cooling" applications.
    2. Laboratory equipment and other applications requiring specialized process cooling water shall be appropriately designed by the Professional.  Specialized process cooling equipment or heat exchangers and pumps connected to other building condenser water loops may be utilized, if applicable.
    3. The Professional's approach should be reviewed with the University early in the design process.
.09 All-Air Systems (General)
  1. Ducted supply and return systems are required.  Return plenums are not permitted unless prior approval is received.
  2. One hundred percent shutoff VAV systems are not permitted.  Minimum airflow must be maintained to satisfy ventilation requirements.  Reheat shall be provided for all interior and exterior zone VAV boxes.
  3. Economizer cycle (temperature controlled) shall be utilized on all systems for areas requiring year-round cooling.
  4. For all systems five tons and over utilizing economizer cycles a separate return or exhaust fan must be utilized to provide positive relief and also standby capacity in the event of supply fan failure.
  5. All sheet metal shall be specified to be constructed in accordance with the latest edition of SMACNA's HVAC duct construction standards.
  6. It is the intent that duct leakage tests will not be necessary since the Professional will be specifying a high quality duct joint and seam sealant or sealing system to be installed on all ductwork constructed to static pressure classifications of 1" and greater.
    1. The Engineer shall specify a duct static pressure construction classification, a duct seal classification and a duct leakage classification (when required) for all duct systems.  All values shall be as recommended by SMACNA in "HVAC Air Duct Leakage Test Manual", First Edition-1985.
    2. Duct Leakage Tests shall only be required for air systems with a 4" or greater duct static pressure construction classification.
    3. Duct systems constructed to static pressure classes lower than 4" shall be inspected for leaks by a representative of the Professional’s office or the University prior to insulation of the duct system.  All sources of audible noise shall be identified and sealed in accordance with the project specifications. 
.10 Computer Room Air-Conditioning Systems
  1. Main frame computer room air conditioning systems shall be package computer room units, glycol cooled, with free cooling option.  In raised floor rooms, distribution shall be under the floor.  Raised floor shall be high enough to provide adequate air circulation but in no case less than 12".
  2. Units shall be equipped with trouble indicators, audible alarms with silencers and auxiliary contacts for shutdown upon detection of fire.  All alarms shall be interconnected with CCS and the Contractor shall be required to demonstrate to a University Representative that each alarm is fully functional and connected to CCS.
  3. Humidification shall be provided to satisfy computer requirements using building steam.  Electronic steam generators shall not be used except where building steam is not available.  Discuss exceptions with Project Manager.
  4. Standby equipment shall be discussed with the Project Manager.
  5. Refer to Detail [23 xx xx .xx] for piping.  Details are not yet available in WEB-based manual. 
.11 Micro and Personal Computer Lab Air Conditioning
  1. See Paragraph 23 00 10.10.A, except that raised floors are not normally installed and distribution may be ducted overhead.
  2. Humidification is not normally required.
  3. Standby equipment is not required.
.12  Laboratory Ventilation Systems
  1. General:
    1. Comply with other general requirements of Section 23 00 10.
    2. Ensure needs of scientific research and life safety are satisfactorily met.
      1. Review all design parameters with the scientific staff and PSU Environmental Health and Safety.
      2. Establish the desirable operating conditions (temperature, humidity, rate of change, pressure relationships, air quality) and determine limits that should not be exceeded.  These characteristics shall be clearly defined in the construction documents so contractors, Commissioning Agency and operating staff clearly understand intent and initial settings on room-by-room basis.
      3. For areas requiring variable temperature or humidity, these parameters must be carefully reviewed with the users to establish a clear understanding of expected operating conditions and system performance.
      4. Determine need for standby equipment and emergency power to achieve system reliability and life safety.  Note:  In general, EH&S recommends that ventilation systems (exhaust and adequate makeup) serving fume hoods be on emergency power.  A major concern is about toxic gas and flammable vapor build-up in the event of a power outage.  This has already caused a fire on campus.  However, it is not an absolute requirement for all cases.  Each project specific application shall be assessed among the scientific staff, EH&S and the capabilities of and/or implications to the electrical infrastructure.
      5. Determine and define alarming requirements.
    3. Operable window systems are prohibited for use in laboratory spaces due to loss of proper pressurization control in the facility.
      1. Operable windows in fully conditioned, pressure controlled laboratory spaces have the potential to cause serious life safety and energy issues, as well has having a negative impact on research.  All laboratory air should be controlled and discharged in a safe manner.  Operable windows inhibit our ability to achieve that goal.
      2. Life Safety Issues:
        1. Random crossflows (drafts) in a space, created by wind, adversely affect a hood's ability to capture, resulting in an unsafe working environment.
        2. A windward (positively pressurized) opening in a laboratory space has the potential to over-pressurize an individual room, reversing pressures and forcing laboratory air into the egress corridor in lieu of being safely managed and exhausted at the designated discharge points.
        3. A leeward open window can draw a significant quantity of air out of a lab.  This causes multiple issues:  reduced hood capture, "stealing" of pressurization air through one location which causes adjacent labs to be positive in respect to the corridor, and affecting pedestrians outside the building.
      3. Energy Consequences:
        1. Air in or out of a window reduces the energy recovery capability of the exhaust system.
        2. A window left open might (and often does) arbitrarily drive the HVAC system to extremes, increasing energy usages, and potentially adversely affecting adjacent spaces.
        3. Window seals break down over time, leading to leakage and comfort issues.
      4. Research - Loss of controlled conditions:
        1. HEPA filters installed in most research AHUs filter to 99%, catching viruses, bacteria and pollen.  An open window allows all these things into the airspace, completely circumventing the filtration system, and essentially corrupting all research in the space.
        2. Accurate temperature and humidity control cannot operate properly with a "rogue zone".  Therefore, systems may not be able to operate within the user's tolerances for temperature and humidity.
        3. Humidity cannot be controlled with an open window.  Vapor pressure will always equalize, and quickly, regardless of wind directions.
    4. Mechanical infrastructure serving laboratory spaces shall be flexible and adaptable.
      1. Research objectives frequently require changes in laboratory operations and programs.  Thus, laboratories must be flexible and adaptable, able to accomodate these changes without significant modifications to the infrastructure.
      2. Therefore the utilities and distribution infrastructure system design shall be flexible enough to supply ample cooling to support the addition of heat producing equipment without requiring modifications to the central HVAC system.
      3. Adaptable designs shall allow programmatic research changes that require modifications to the laboratory's infrastructure within the limits of the individual laboratory area and/or interstitial and utility corridors.
    5. Design Professionals shall include plans in the construction set of drawings showing simplifieid pressure relationships and tabular summaries of overall air balance for each pressure controlled space and summaries of system airflows.
      1. These plans shall be the basic floor plan (clearly identifying all room names/use-not just mumbers) with easily recognizable tags for any room that is not neutral pressurization.  The tag would indicate airflow direction (e.g. + or - or POS and NEG) and airflow (cfm).
      2. The drawing would also have a table indication system level summaries of airflows per floor.  (i.e. System SA(max/min), General Exhaust, Transfer Air (including intended source - adjacent system), and any other special exhaust systems.
      3. The purpose is to have easy to follow summaries to help everybody involved understand the design intent during all phases of the project and for the record set for future operation and maintenance reference.  Showing transfer air on a complicated duct drawing does not work well.  The concept is similar to having simple Life Safety Plans for accurate and quick understanding.
  2. Codes, Standards and Guidelines:
    1. In addition to minimum requirements of the Building Code, laboratory ventilation systems shall be designed in accordance with the followng current editions of industry standards and design guidelines.
      1. The basic design of laboratory spaces shall be in accordance with the guidelines in the current edition of the ASHRAE Applications Handbook including, but not necessarily limited to, the chapters for Educational Facilities and Laboratories.
      2. Comply with ANSI/AIHA Z9.5-(current) Laboratory Ventilation.
    2. Other Laboratory Design Resources:
      1. National Institute of Building Sciences (NIBS) - Whole Building Design Guide - Research Facilities
      2. A Design Guide for Energy-Efficient Research Laboratories - Version 4.0, http://ateam.lbl.gov/Design-Guide/Index.htm
  3. PSU Environmental Health and Safety, Lab Safety Requirements:
    1. Coordinate and review all laboratory designs with PSU Environmental Health and Safety, Laboratory Safety Program, http://www.ehs.psu.edu/occhealth/labsafety.cfm
    2. Work with representatives of University's scientific staff and PSU EH&S to perform a hazard assessment to determine risk level for each lab application.
    3. Use definitions and associated occupied/unoccupied minimum lab ventilation rates being developed within PSU Environmental Health and Safety “Lab Banding” guidelines. Minimum ventilation rates shall be established and clearly defined/scheduled on the construction documents on a room-by-room basis considering the hazard level of materials expected to be used in the room and the operation and procedures to be performed.
    4. Be advised that the company EH&S has retained to develop methodology for laboratory hazard assessment and associated ventilation rates (i.e. lab banding) is also developing a Laboratory Ventilation Management Plan, based on ANS/AIHA Z9.5.  Contact EH&S to request current document.
    5. Comply with the following fume hood guidelines from EH&S.
      1. Review and confirm most current requirements with EH&S during the Design Phase.
      2. The following shall be included with regards to low flow/high performance hoods.
        1. Low Flow or Velocity Hoods - At a 12” vertical sash height, the minimum face velocity should be 60 fpm.
        2. Existing hoods shall not be adapted to function as low flow/high performance hoods.  Low flow/velocity hoods shall be purchased as hoods designed for high performance at low flow operation.
      3. Other considerations for fume hoods:
        1. Fume hoods should not be situated directly opposite normally occupied work stations.
        2. Air distribution devices shall be carefully located within the laboratory to avoid turbulence and cross currents at the fume hood face that can negatively affect the fume capturing performance of the fume hood.
        3. Note: The 2008 National Institutes of Health (NIH) Design Requirements Manual for Biomedical Laboratories and Animal Research Facilities (DRM), formerly called the NIH Design Policy and Guidelines, is the only detailed design requirements and guidance manual for biomedical research laboratory and animal research facilities in the U.S. Compliance to the DRM, which promulgates minimum performance design standards for NIH owned and leased new buildings and renovated facilities, ensures that those facilities will be of the highest quality to support Biomedical research. 
        4. The DRM requirement that fume hood face velocity never falls below 80 feet per minute applied to buildings that are constructed using NIH funding, and also applied to NIH funded renovations if the entire building is renovated, or if more than 50% of the building is renovated.
  4. Energy Saving Strategies and OPP Preferences:
    1. Laboratory spaces typically use far more energy and water than most typical office or classroom spaces.  Therefore, as part of meeting the Performance Requirements and Sustainability goals of the University, careful attention must be given to the design, construction and continued operation of Laboratory spaces.  Refer to the U.S. EPA and DOE sponsored Labs for the 21st Century (Labs21) Tool Kit, including the Best Practices Guides.  Apply them to best fit each specific project scope giving consideration to the University’s local operating staff to achieve high performance and the lowest long term total life cycle costs.
    2. Be careful to define and segregate non-hazard type spaces (i.e. offices, non-lab workspaces, classroom-use “teaching labs” or “dry labs” – those that contain primarily physics and/or electronic equipment) that could otherwise be recirculated because they do not have hazardous or noxious contaminants and thus do not require fume hoods from actual “wet lab” spaces that do have requirements for fume hoods that require 100% exhaust and 100% outside air makeup.
    3. Maintaining the proper pressure relationships for laboratory spaces shall not require the continuous operation of mechanical systems serving non-laboratory spaces when they could otherwise be scheduled off during unoccupied periods.  For instance, an air handling system serving adjacent regular office spaces and/or corridors shall not be required to run 24/7/365 in order to provide makeup /transfer air into the lab spaces. That does not preclude the mutually beneficial transfer of air when it can be used beneficially during shared occupied periods.  Rather, it may require alternately serving the transfer zone/corridor with the lab system makeup air during unoccupied periods.
    4. The architectural and engineering design of labs shall segregate equipment and process cooling loads wherever possible from the ventilation requirements so that the heat gain from the equipment can be cooled separately with process cooling systems and/or recirculating space cooling equipment in lieu of 100% makeup air systems.  Consult with scientific staff to inform and guide them to select water-cooled process equipment in lieu of air-cooled units that reject heat to lab space whenever possible.
    5. Work with representatives of scientific staff to minimize use of hoods while still meeting their needs.  Eliminate/decommission unnecessary existing hoods wherever practical.  Use local / snorkel exhaust devices strategically to capture applicable noxious, non-hazardous odors as close to source as possible to maintain overall high indoor air quality while keeping general lab ventilation rates as low as practical.
    6. The design of lab ventilation and fume hood systems shall be carefully integrated to strive to continuously and optimally match the general minimum ventilation rates (during occupied and unoccupied periods wherever applicable) and specific exhaust hood and makeup air and pressure relationships needed to maintain a healthy and safe work environment for the occupants. Refer to Labs 21 Best Practice Guides Optimizing Laboratory Ventilation Rates
    7. Apply variable air volume to exhaust and supply air makeup systems to the fullest extent practical within the project constraints.
      1. When considering fume exhaust systems and related equipment or changes to an existing system, the designer should first consider whether the labs served are fume hood driven or air change driven with respect to airflow. There may be little or no energy saving advantage for applying low flow hoods in a lab that is driven by minimum air change rates.
      2. Also, consider whether the project specific location will have the commitment to have the adequate training and staff available to keep more sophisticated systems operating as designed.
      3. Applying variable geometry discharge dampers to fume hood exhaust fans can be a value-added option that allows modulating the fan speed to control exhaust duct static pressure and to maintain constant stack velocity / effective plume discharge height rather than requiring modulating a bypass damper on a constant speed fan assembly.  This technology should be evaluated and applied where it offers the lowest life cycle cost.  Consider developing as an additional energy conservation measure alternate bid option with an estimated payback analysis as appropriate.
    8. Apply space occupancy sensors to achieve demand based minimum ventilation strategies applicable to laboratories.  Disable in control settings of individual lab spaces defined to not allow reductions due to risk type.
    9. In applications with multiple exhaust devices, generally connect into a common manifold exhaust system with the recommended better multiple fan lead/lag/standby assembly (3 fans each @ 50% maximum capacity) to achieve the benefits listed below (see Labs 21 Toolkit, Manifolding Laboratory Exhaust Systems):
      1. Ability to take advantage of exhaust system diversity and fume dilution
      2. Ability to provide a redundant exhaust system by adding one spare fan per manifold and thus increasing personnel safety (lab user’s and maintenance staff)
      3. Opportunity for energy recovery
      4. Design Flexibility and adaptability
      5. Fewer pieces of equipment to operate and maintain
      6. Centralized locations for exhaust discharge
      7. Fewer roof penetrations and exhaust stacks
      8. Lower ductwork cost
    10. Laboratory exhaust air systems shall be designed to minimize pressure drops through each component, fitting, and the total system to minimize associated fan energy.  This is especially important for manifolded systems.  Refer to Labs 21 Best Practice Guides Low-Pressure-Drop HVAC Design for Laboratories.
      1. Review and optimize exhaust device selection for lowest pressure drop with lab consultant (as applicable).  Be careful to not allow hoods or snorkels with high individual pressure drops that end up causing the whole system to have to operate at the higher pressure, which can have a huge impact on the fan energy.
      2. Minimize length of duct runs and number of elbows, transitions, fittings and abrupt changes and combinations of all of the above that contribute to high pressure drops.
    11. Apply Air to Air Energy Recovery equipment in safest and most cost-effective manner:
      1. General lab exhaust:  Enthalpy wheels are typically recommended to maximize total energy recovery from non-contaminated/non-hazardous general lab exhaust airstreams.  Non-recirculated air drawn from general lab spaces (not through fume hoods) may be treated as spill/relief air in the sense that regular VAV exhaust fans and discharge louvers at normal velocities located far enough away from other intakes are acceptable and preferred rather than forcing all that air through the more energy-intensive high-plume type fume hood exhaust fans.
      2. Fume Hood Exhaust:  In general, in teaching or research laboratories with fume exhaust devices manifolded together, the concentration levels of potentially hazardous materials at the main header/discharge point are typically below the threshold that the Mechanical Code would prohibit the application of heat recovery.  Therefore, Glycol Runaround coil systems  (in separated airstreams so no chance of cross contamination) are recommended where applicable and cost effective depending on capacity and frequency of use.  All associated aspects of the design and construction shall include special emphasis for specifying materials of construction of coils and filters/housing and provisions for safe inspection, cleaning and maintenance of these systems.
      3. Any special purpose containment devices dedicated to toxic or flammable hazardous exhaust systems classified as such, shall be prohibited from applying heat recovery, per the Mechanical Code.
      4. Air Filtration:  Appropriate particle filtration shall be included at the entering sides of all air to air heat recovery equipment to keep surfaces free of dirt and debris to extend cleaning periods as long as practical.  Filter housings shall be convenient and safe to routinely access to inspect and change filters.
  5. Laboratory fume hoods:
    1. Shall be the current state of the art, high-performance designs to achieve optimal fume capture with minimal airflow requirements.    This requirement shall supersede other, older references in 11 53 13 Laboratory Fume Hoods to constant volume, bypass type hoods until that section is updated in the future.
    2. Generally, in applications with multiple hoods, fume hoods shall be variable air flow type, based on sash position.  Some exceptions may apply but review with OPP Engineering Services and EH&S.
    3. The operating mechanisms for vertical and horizontal sashes shall be high quality and well-engineered so the sashes can easily be adjusted by users. 
      1. Hoods with poor quality cables, pulleys, and sliding mechanisms that allow the sashes to bind up and require a lot of effort to move them are prohibited.  If such conditions are encountered on a project, hoods must be repaired or replaced at no additional cost to the University.
    4. The sash positioners should be “non-contact” type for reliable long service life when using VAV hood systems.
      1. Variable resistance pressure activated type shall be prohibited.
    5. Specify protective screens at lower exhaust inlets of fume hoods to prevent pulling debris such as paper towels or lab wipes into the exhaust system and cause clogging problems on VAV airflow stations,  duct turning vanes and fan blades.
      1. Recommending something like 1/2”x1/2” stainless steel welded wire mesh covering inlet slots that would be prone to sucking in materials from the working surfaces within the hood.  This would be preferable as a factory-installed option for best fit and finish.
    6. Consider proximity occupancy sensors at each hood that could allow reduced airflows when nobody is working in front of the hood.  Review with EH&S.
    7. If the hood is VAV then some device measures the face area for air flow control.  Not all hood face velocity monitor/alarms are equal.   In the VAV case the face velocity monitor/alarm can use that info and other control data to report FPM and alarms.  If a constant volume hood, then the face velocity monitor/alarm is typically a stand-alone device.  Currently we do not have a recommendation regarding who makes a high-quality, long-term reliable device, but this needs to be looked at closely.
  6. Laboratory Controls:
    1. For specialized lab ventilation system controls, avoid use of independent LONworks LAB controller that requires a gateway interface to BACnet BAS.  Preference is for the lab controls to be part of the overall BAS Contract responsibilities and shall be fully integrated into the BAS system.  Installation shall be by the BAS vendor.
    2. At this time, our BAS Department approves Phoenix, Siemens and Waddell as Lab Control Manufacturers.
    3. Review and confirm most current requirements with OPP Environmental Systems, Building Automation System (BAS) Application Engineering.  Clearly specifying adequate instrumentation, sensors and the ability to trend data will improve the odds that the system will be successful.
  7. Specialized Commissioning: 
    1. In order to ensure all lab spaces are constructed and operating effectively, laboratory ventilation systems shall include detailed specifications for specialized commissioned according to industry best practice guides for laboratories. 
    2. Refer to Labs 21 Toolkit Commissioning Ventilated Containment Systems in the Laboratory.  Complicated systems must be commissioned per the above guidelines prior to turnover to owner.  They also need to be recommissioned over the life of the system to assure that they are still operating safely and saving energy.  Those recommendations and requirements shall be included in the Operating and Maintenance manuals and Owner Training at turnover.
  8. Facility Asset Management System: 
    1. The University has a computerized facility asset management and preventive maintenance system.  All laboratory ventilation system equipment shall be planned and fully coordinated with the University’s Preventive Maintenance (PM) Group to be included in the asset database with recommended operating and maintenance procedures defined for each component to ensure continued safe and effective operation.  Contact:  Richard L. Phillips, rlp163@psu.edu - PM Quality Assurance Coordinator, Phone:  (814) 865-4837.
       

 23 01 00 OPERATION AND MAINTENANCE OF HVAC SYSTEMS

.01 General
  1. Operation and Maintenance Information for Preventive Maintenance and Training:

    The Office of Physical Plant implements a computerized preventive maintenance (PM) program of every new system or improvement.  In order to have the PM program in place when OPP assumes responsibility for maintenance, the project information pertinent to the preventive maintenance must be provided considerably prior to project completion.  Forty-five days before project completion is the minimum unless specified differently by the Project Manager.  This information will be in the form of a bound document or three ring binder with copies of the pages from the manufacturers O & M manuals detailing the preventive and predictive maintenance routines and schedules for each piece of equipment or other entity requiring preventive maintenance.  This document will also include a list of the room numbers of the restrooms and classrooms.

    Operation and Maintenance information must be provided to Facilities Services prior to training.

    This information may also be required when beneficial occupancy has been granted in the course of phased construction.
.02 Maintenance Manuals
  1. Three (3) complete copies of the maintenance manual labeled as described herein shall be submitted to the University for approval in as many three (3) ring loose leaf binders as required.  The copies shall be submitted a minimum of two weeks prior to any instructions and demonstrations to University personnel.
  2. The manuals shall be typewritten and include a table of contents.  The information shall be arranged in a logical order for use by the University in maintaining the projects.
  3. The manuals shall include but not be limited to the following:
    1. Table of Contents.
    2. Materials list with place of purchase.
    3. List of normally replaced items, such as filters, fuses, belts, seals, screens, etc., indicating style, rating, size, etc., and place of purchase.
    4. Installation, servicing, maintenance and operating instructions for all systems and components with place of original purchase, and name, address and phone number of person servicing system.
    5. Manufacturers guarantees and warranties.
    6. Approved copies of shop drawing, including component wiring diagrams and ATC wiring piping diagrams of all installed systems indicating all connections, color coding, functions, locations, etc.  Approved as noted shop drawings submittals shall be corrected to incorporate all approval notes prior to inclusion in Maintenance Manuals.
    7. Schedule of all motors, starters and controllers under this contract with the following information included:
      1. Location
      2. All Nameplate data
      3. Overload rating, and manufacturer's number
      4. Actual full load amperes
      5. Over-current protection
    8. System and equipment start-up, seasonal changeover, and seasonal shut-down with pre-start checklists and precautions.
    9. System and equipment troubleshooting guides.
    10. Reference documents which shall include construction drawings list, record set of drawings list, test and balance records.
    11. Testing and balancing procedures for each system(s) and system(s) components.
    12. Copies of all inspection certificates and approvals from all inspection agencies.
    13. Copy of an approved testing and balancing report.
    14. Copy of all Mechanical Vibration Analysis and Alignment Verification Reports.
.03 Tour/Instruction/Demonstration
  1. Maintenance Manuals
    1. Maintenance manuals shall be furnished a minimum of two weeks prior to any instructions and demonstrations to University personnel.  See Paragraph 23 01 00.02 for manual content.
  2. Tours for University Personnel
    1. At the completion of the work, immediately after Substantial Completion, the Contractor shall conduct a walk-through tour of the project work areas.  The purpose of the tour shall be to introduce the University personnel who will have charge of the equipment or use of the space to the new areas.  Generalities of the type of equipment installed shall be discussed during the tour.
  3. Instructions to University Personnel
    1. At the completion of the work, after the University has taken over use of the Building or work area, the Contractor shall instruct those University employees who will have charge of the equipment, the care, adjustment, and operation of all parts of the system.  Such instruction shall cover a minimum period as specified, eight (8) hours per day, and shall be arranged for at the University's convenience.
  4. Demonstration to University Personnel
    1. In addition to the instruction period mentioned above, the Contractor shall demonstrate the automatic temperature control cycle, on a point-by-point basis, at every piece of controlled equipment to a specially designated University representative.  Following this, the Contractor shall instruct maintenance personnel on all automatic temperature control equipment in the presence of this representative.
  5. Maintenance and Operations personnel shall be given a minimum two-week notice of each of the above scheduled tour or instruction dates. 
.04 Start-Up
  1. The Contractor shall arrange for special start-up service from the equipment manufacturer, or his appointed agent, for the following equipment:
    1. Chillers
    2. Boilers
    3. Pumps
    4. Air Handling Units
    5. Cooling Towers
    6. ATC Systems
  2. The start-up shall include, but not necessarily be limited to:
    1. Alignment and Balance
    2. Lubrication
    3. Electrical Connections, Voltage, Rotation
    4. Motor Amperage Readings
    5. Pump Discharge and Suction Readings
    6. Chiller Head and Suction Pressures
    7. Condenser Water Flow and Temperature
    8. Chilled Water Flow and Temperature Chiller Lock,
    9. Sequences and Safety Controls
    10. Water Systems
    11. Supervise Flushing and Cleaning
    12. Take pH Readings
    13. Water Treatment-heating systems, cooling systems, and condenser water systems
    14. Combustion Analysis
    15. BAS tuning and calibration
  3. Maintenance and Operations personnel shall be given minimum two-week notification of scheduled start-up date to observe procedures.  This does not preclude the requirements for operating instructions.
  4. Following start-up, the manufacturer shall submit a report on his findings to the Contractor with a copy to the University.  If the project is State funded, include a copy of the report for the Department of General Services.
.05 Warranties
  1. The specifications shall be prepared to include a one-year guarantee for the entire installation.  The following components or systems shall be specified with an extended warranty period:
    1. Compressors - Five (5) years
    2. BAS Systems - Two (2) years
  2. The warranties shall cover parts and labor for the duration of the warranty period.
  3. Routine preventive maintenance shall not be included as part of the warranty service.

23 05 00 COMMON WORK RESULTS FOR HVAC

23 05 01 Mechanical General Requirements

.01 Motors and Drives
  1. Motors
    1. All motors over 1/2 hp shall be ball bearing unless otherwise noted.
    2. All ball bearing motors shall be equipped with lubricating type bearings, and provided with one (1) grease fitting per bearing and one (1) removable plug per bearing in the bottom of the grease sump to provide for flushing and pressure relief when lubricating.  Motors shall be permanently marked that bearings are lubricating type bearings.  Where motor grease fittings are not accessible, extend 1/8" steel or copper tubing from fitting to an accessible location.
    3. Motors 3/4 hp and larger to be three phase, 60 hertz.
    4. Motors smaller than 3/4 hp to be single phase, 60 hertz, 120V and shall have built in thermal protection.
    5. All motors above 1 hp shall be the low loss - high efficiency type.  Motors shall be tested in accordance with NEMA standard MG1 1.536 and name plate shall indicate the index letter.
    6. All 3-phase motors larger than 5 hp shall have power factor correction capacitors as recommended by the manufacturer.
    7. Motor inrush current must not create a voltage sag in excess of 3 percent without specific University approval.
    8. A voltage sag report shall be completed by the Professional on selected projects as determined by the University.  Report shall include backup calculations and expected building voltage sag when motor or motors in question are started.
    9. The University has experienced widespread premature motor shaft bearing failures due to fluting from electrical arcing on motors equipped with Variable Frequency Drives.  The Design Engineer must specify appropriate technologies and/or include provisions in the system design to prevent electrical fluting induced premature bearing failure from occurring. 
  2. Drives
    1. All belt driven equipment shall include properly selected adjustable sheaves and matched V belts, all rated for 150% of motor horsepower.  Proper expanded metal guards should be provided for safety protection and to allow for proper ventilation for cool operation of belts.  Solid sheaves and band belts shall be used to minimize vibration in multiple V-belt driven equipment.
    2. Motor grease fittings shall be extended so belt guards do not need to be removed.
    3. All adjustable sheaves shall be replaced with suitable fixed sheaves prior to final acceptance by the University. 
.02 Valves
  1. General
    1. Locate valves for easy access and provide separate support where necessary.
    2. Install valves in position to allow full handle and/or stem movement.
    3. Install valves in horizontal piping with stem at or above center of pipe.
    4. Coordinate with pipe insulation requirements.
      1. Provide extended-stem valves, arranged in proper manner to receive specified insulation thickness.  Insulation cut away to receive standard stems is not acceptable.
      2. For ball valves on piping systems requiring up to 2" of insulation, specify valve manufacturer's optional thermally insulated, extended tee-handles (similar to Apollo "therma-Seal").  Features shall include a high strength, reinforced polymer body, fabricated to maintain vapor seal, internal insulation plug for enhanced thermal and vapor sealing, position indicators, formed holes for identification tag, tested and classified to UL 2043 for air plenum service, convenient valve packing maintenance - all without disturbing the insulation.  Piping insulation shall be secured directly onto the integrated plastic sleeve without being disturbed during valve operation.
        1. Caution:  Handle should not be used in applications where its temperature will exceed 275°F (confirm limits with specific manufacturer).
      3. Refer to 23 07 00 HVAC INSULATION for requirements for valve manufacturer's optional preformed 2-piece insulation kit covers (similar to products offered by TA Hydraulics) for balance valves.
    5. Operators:
      1. Provide handwheels, fastened to valve stem, for valves other than quarter-turn.
      2. Provide lever handle for quarter-turn valves, 4" and smaller, other than plug valves.
      3. Provide one wrench for every 10 plug valves.
      4. Provide gear operators for quarter-turn valves 6" and larger (weatherproof on exterior valves).
      5. Provide chainwheel operators for all valves mounted more than 10 feet above floor in equipment rooms (or otherwise beyond convenient and safe reach of person safely using a 6’ stepladder).   Extend chains to to be reachable and convenient yet avoid being a nuisance, approximately 76-80 inches above finished floor.
        1. Exceptions:
          1. If valves are intended for routine, frequent use, provide chainwheel operators if mounted more than 7 feet above floor in equipment rooms, with chains extended to approximately 60-72” above finished floor.  Review such applications with OPP.
    6. All valves of the same type on any one project shall be the product of one manufacturer.
    7. Valves shall have right hand threads. 
    8. Where possible, valves shall be installed with valve bonnet in an upright position to prevent deterioration or corrosion of bonnet and packing.
    9. Valve body materials shall be compatible with piping system materials.
      1. Do not use cast iron body shut-off valves on steam systems.
  2. Shutoff Valves
    1. General:  Install positive shut-off valves throughout the distribution piping system to facilitate shutdown and draining of smallest segment as practical for repairs while keeping the rest of the system operational.
    2. Locations:  Refer to location requirements in Section 23 21 00 HYDRONIC PIPING AND PUMPS, .01 General Requirements and Design Intent.
    3. Types and typical service schedule:
      1. Ball valves (full port): for hydronic and steam systems, up to 2”, (or up to 4” as an alternative to high performance butterfly valves for critical shut-off applications).
      2. Butterfly valves: for hydronic systems, greater than 2”.
        1. General:
          1. Specify only lug or flange style so valves can be a future point of disconnection on one side yet stay in service and not require entire draining of system.  Wafer style is prohibited.
          2. Butterfly valves shall be capable of closing tight after long periods of inactivity.  Butterfly valves shall be designed with internal, non-wetted connections to eliminate external disc-to-stem connections such as screws or taper pins.  OPP often finds butterfly valves that fail to hold or that those connections have corroded and disc rotates on stem internally after years of service, which is unacceptable.
        2. Resilient Seat Butterfly Valves: typically use where standard bubble-tight shut-off service is intended but critical, zero leakage isolation is not absolutely essential.
          1. Must be a high quality valve that complies with the general requirements above.
          2. Resilient seats must be properly selected for best longevity for each application.  Seats for valves in closed loop hydronic applications shall be rated for a minimum of 250 degrees and completely compatible with service fluid.  Seats for valves in open systems shall be selected to resist abrasive wear.
        3. High Performance Butterfly valves:  use where long term bi-directional zero leakage isolation is absolutely essential (building connections to central utility systems, pipe mains exiting central/primary mechanical rooms, bases of main system risers, main branch takeoffs from risers).
      3. Gate: for steam systems, greater than 2”.
  3. Balancing Valves
    1. See Section 23 21 13 - Hydronic Specialties.
  4. Check Valves
    1. Where check valves are required, check valves shall be installed on the equipment side of all shutoff valves to facilitate servicing the check valve.
  5. Drain Valves
    1. 1.    General:  Hydronic piping systems shall be designed and installed to permit all sections of the system to be properly and fully drained.  Provide drain valves at all low points of systems, at bases of riser, and at lowest points at equipment runouts, typically on downstream side of shut-off valves.
    2. Drain valves shall be a minimum of 3/4" with hose end connection.
  6. Pump Valves
    1. See Section 23 21 23 - HVAC Pumps.
.03 Pipe Hangers and Supports
  1. Provide an adequate pipe suspension system in accordance with the current version of the International Mechanical Code, recognized engineering practices, using standard, commercially accepted pipe hangers and accessories.  The use of pipe hooks, chains, or perforated iron for pipe supports will not be accepted. 
  2. Contractor shall submit Data sheets for approval on all pipe hanger items prior to installation.
  3. All piping shall be arranged to maintain the required pitch and provided for proper expansion and contraction.
  4. No holes are to be drilled or burned in structural building steel for hanger rod supports.
  5. Vertical runs of pipe shall be supported with riser clamps made specifically for pipe or for tubing.
  6. Where concentrated loads of valves and fittings occur, closer spacing may be necessary.  Hangers must be installed not more than 12 inches from each change in direction of pipes.
  7. All hangers for piping shall be provided with a means of vertical adjustment.  If adjustment is not incorporated in the hangers, use turnbuckles.
  8. Provide piping suspension systems with vibration isolation capability as required.  For vibration isolation requirements of piping suspension systems, refer to Sound and Vibration Control, 23 05 01.05.
  9. Copper clamps and hangers shall be used on copper piping.
.04 Sound and Vibration Control
  1. Vibration Control Requirements
    1. Mechanical and electrical equipment and associated piping and duct work shall be mounted on vibration isolators as specified and shown in equipment schedules and as required to minimize transmission of noise and vibration to the building structure or spaces within.
    2. All rotating equipment shall be balanced both statically and dynamically.  The equipment supporting structure shall not have any natural frequency within plus or minus 20% of the operating speed.  The equipment, while operating, shall not exceed a self-excited RMS radial velocity of greater than 0.10 inches/second.  Vibration pick-ups shall be placed on the bearing caps in the horizontal, vertical, and axial directions, or on the equipment supporting structure if the bearing caps are concealed.
      1. Accelerometers shall be permanently placed on all pieces of equipment in hard to reach or unsafe areas.  The University has standardized on 100 milli-volts/(g) with an accuracy of plus and minus 5 to 10 percent and BNC connections.  The University is currently using Wilcox or SKF accelerometers and an SKF Microlog CMVA60 detection monitor.
      2. Critical areas should be discussed with the University.  Tighter tolerances may be desired in certain circumstances.
    3. The specifications shall require the Contractor to hire a third party vibration analyst to conduct baseline vibration signature tests of specified pieces or classes of equipment.  The Professional shall review the proposed equipment for the project with the University and agree upon which type of equipment to include in the specifications for vibration analysis.  This process should be accomplished as early during the design phase as possible.  The specifications shall also state that the University's Commissioning Contractor shall witness and/or verify the accuracy of the Vibration Contractor's test results.  If an abnormal amount of equipment fails the Commissioning Contractor's verification (% to be determined on a project basis), the vibration tests by the Contractor must be repeated for all equipment.
    4. Where equipment vibration exceeds manufacturer’s recommendations or levels specified, the Contractor shall make corrections to reduce vibration frequencies and amplitude to within specified limits.  If this cannot be accomplished, the equipment shall be replaced with equipment that will meet all requirements of the specifications.
    5. The Contractor shall be required to submit a report for approval by the University and the Professional.  The report shall include vibration analysis and alignment data of all specified rotating equipment.  The report shall be submitted in paper and electronic format.  The electronic data shall be submitted in a form that may be imported to SKF's Prism 4 Solutions software program.
  2. Equipment Isolation
    1. Isolation shall be stable during starting and stopping of equipment.  Lateral thrust restraint isolators shall be provided where necessary to prevent excessive lateral movement under equipment start-up and stop conditions.  Lateral thrust isolators shall not interfere with vertical isolation.
    2. Isolation shall be selected for the operating speed of the equipment.  Where the equipment is controlled by a variable frequency drive, the isolator shall be sized for the lowest expected operating speed.
    3. Isolators located outdoors shall be hot-dipped galvanized.
    4. Isolators shall be selected and located to produce uniform loading and deflection even when the equipment weight is not evenly distributed.
    5. Base type, isolator type, and required minimum (not nominal) deflection shall be part of all equipment schedules shown on drawings and/or in specifications.
    6. Unless otherwise specified, said base types, isolator types, and deflections shall be taken from the “Selection Guide for Vibration Isolation” table in the Sound and Vibration Control chapter of the ASHRAE Applications Handbook, current edition.
      1. Fan and motor assemblies in air handling units may be internally spring isolated.  In which case, external isolation shall not be provided.
      2. Packages containing other rotating equipment, such as compressors and pumps, shall be externally isolated.
  3. Piping and Ductwork
    1. Vibration isolation shall be provided for piping and ductwork as follows:
      1. All high pressure ducts (over 6” wg) for 50’ from vibration isolated air handling equipment.
      2. All piping located in mechanical rooms, or for a distance of 50’, whichever is greater.  Pipe hanger isolators shall have the same deflection as that supplied for equipment to which the piping is attached.
      3. The vibration isolator units selected shall not deter the thermal movement of the piping or the expansion compensator from performing its required task.
  4. Flexible Connections
    1. Flexible duct connections shall be provided adjacent to air handling equipment.
    2. Flexible piping connections shall be provided at piping connections to all rotating mechanical equipment mounted on vibration isolators.
    3. Flexible conduit, equal to 150% of the distance between motor connection and adjacent attachment point, shall be provided for electrical connections to all vibration isolated equipment.
  5. Interior Sound Pressure Level Requirements
    1. The maximum interior sound pressure levels, due to installed HVAC equipment, shall not exceed those shown in the table of design guidelines for HVAC-related background sound in rooms in the chapter of Sound and Vibration Control, ASHRAE Application Handbook, current edition, unless otherwise specified.
      1. While these guidelines are labeled as RC values, they shall be interpreted as NCB guidelines (per ANSI Standard S12.2).
      2. The RC Mark II method shall be used for investigating room noise problems in the field, per the above noted ASHRAE Handbook chapter.
  6. Exterior Sound Pressure Level Requirements
    1. Equipment installed outside the building, at grade, in areaways, attached to walls, and on the roof, such as cooling tower fans, air conditioning units, refrigerant condensers, fans, exhaust silencers, air intakes, etc. shall comply with all local, city, state, and federal requirements.
.05 Mechanical Identification
  1. By Professional
    1. All Mechanical drawing symbols used shall be in accordance with standards of accepted practice. 
      Document Version Date
      Description
      Equipment Acronym List  May 2011  List of equipment abbreviations and identification numbering conventions.
    2. All equipment shown on Contract Documents shall conform to University's abbreviations and numbering connections defined in the Equipment Acronym List found in Division 01: 01 01 00 PROJECT DOCUMENTATION FORMAT.
    3. By Contractor
    4. Equipment
      1. All equipment, including associated electrical devices, shall be tagged in accordance with the University's CCS numbering guidelines.  Tags shall be engraved, black, laminated, micarta tags with white reading symbols secured to equipment (not motor), usually inside access door for equipment in finished areas and exposed in all other areas.  Tags should be mechanically fastened to equipment.  DO NOT USE GLUE OR WIRE.
    5. Piping and Ductwork
      1. Three-fourth-inch wide, adhesive-backed vinyl cloth labels shall be used on all piping 2" and smaller.  Label lettering shall identify both the medium being conveyed and the direction of flow.
      2. Two-inch-wide, adhesive-backed vinyl cloth labels shall be used on piping greater than 2" and on all ductwork.  Label lettering shall identify both the medium being conveyed and the direction of flow.
      3. Labels shall be spaced maximum 15' centers. Position labels for easy viewing.
      4. Identification of piping and ductwork may also be stenciled in a neat manner following the size and spacing guidelines as previously listed.
    6. Valves
      1. Valve tags - 1" x 2" laminated, black micarta attached by 10 gauge brass "S" hook.  Valve numbers to be engraved as large as possible and to read white.
      2. Valve charts shall be typewritten on white bond paper and mounted in a glass-front frame.  Charts shall indicate service, number and location.
      3. On renovation projects, contractor shall be directed to revise existing valve charts as required.
  2. University Mechanical Color Code
    1. Follow current industry ANSI/ASME A13.1 Standard for color coding scheme and piping system identification.  Comply with standard for lettering size, color scheme based on classification of contents, length of color field, locations and intervals, and visibility.
      1. General Requirements for Manufactured Pipe Labels:  Preprinted, color-coded, with lettering indicating service, and showing flow direction.
      2. Pipe Label Contents:  Include identification of piping service using same designations or abbreviations as used on Drawings, pipe size, and an arrow indicating flow direction.
      3. Markers shall be located so that they are readily visible to plant personnel from the point of normal approach.
      4. Locate pipe labels where piping is exposed or above accessible ceilings in finished spaces; machine rooms; accessible maintenance spaces such as shafts, tunnels, and plenums; and exterior exposed locations as follows:
        1. Near major equipment items and other points of origination and termination.
        2. Adjacent to all valves and control devices.
        3. Near each branch connection, excluding short takeoffs for fixtures and terminal units.  Where flow pattern is not obvious, mark each pipe at branch.
        4. Near penetrations through walls, floors, ceilings, and inaccessible enclosures.
        5. Adjacent to changes in directions.
        6. At access doors, manholes, and similar access points that permit view of concealed piping.
        7. Spaced at maximum intervals of 50 feet along each straight run.  Reduce intervals to 25 feet in areas of congested piping and equipment or otherwise difficult to access areas such as attics, crawl spaces, tunnels, and above suspended ceilings.
    2. Other Requirements
      1. Painting Coordination: The painting of exposed heating and ventilating work, fire protection work, and plumbing work, in finished rooms shall be specified to be included by the General Contractor under General Construction Painting Section in Division 9.  The installation of color coded identification, labels where the piping enters and leaves the finished areas after painting is completed shall be the responsibility of the respective mechanical systems Contractors. 
.06 Access Panels
  1. Access panels are required in each situation where items requiring maintenance are located above a concealed ceiling.
  2. Use screwdriver actuated locks.
  3. Access panel sizes shall be suitable for application.
  4. Access panel locations shall be indicated on contract drawings.
  5. Access panels are not required in lay-in ceilings, but identify appropriate tile with color button, cleated through, located on the adjacent ceiling grid.  Use color code of principal service.

23 05 19 Measuring Instruments for HVAC

.01 General
  1. Provide all measuring instruments as required to achieve proper balancing, calibration of electronic sensors, and routine inspection, maintenance and troubleshooting of mechanical systems.
    1. Provide permanent gauges and thermometers on all central equipment and temperature / pressure control zones in all mechanical and utility rooms.
    2. Provide pressure and temperature test plugs adjacent to all electronic pressure or temperature BAS sensors in hydronic systems (for testing/calibration purposes), on all terminal heating and cooling equipment, and at temperature/pressure control zones in hydronic systems in non-occupied spaces, such as above ceilings or below raised floors.
    3. Provide permanent venturi flowmeters on pumps; and on primary / dedicated hydronic flow control zones where flow/gpm point is scheduled on control sequences.  (Review specific applications with OPP Engineering Staff).
    4. Refer to Division 33 00 00 - Utilities for Utility meters (campus chilled water, steam, gas).
  2. Provide instruments with scale ranges selected according to service.
  3. Quality Assurance:  Comply with applicable portions of ANSI, ASME and Instrument Society of America (ISA) standards pertaining to construction and installation of meters and gauges.
  4. Submittals: 
    1. Product Data:  Submit manufacturer's technical product data for each type of measuring instrument.  Submit schedule showing manufacturer's model number, scale range, location, and accessories for each type and application. 
    2. Submit maintenance data and spare parts lists for each type of measuring instrument.  Include this data and product data in Maintenance Manual.
  5. RELATED DOCUMENTS
    1. 23 21 13 Hydronic Piping
    2. 23 21 23 HVAC Pumps
    3. 25 00 00 INTEGRATED AUTOMATION
    4. 33 60 00 HYDRONIC AND STEAM ENERGY UTILITIES
    5. 33 63 00 STEAM ENERGY DISTRIBUTION          
.02 Products
  1. PRESSURE GAUGES
    1. General:  Provide pressure gauges of materials, capacities, and ranges indicated, designed and constructed for use in service indicated.
    2. Type:  General HVAC grade, 1% accuracy, ANSI B40.1 grade A, glycerine filled phosphor bronze bourdon type, rotary brass movement with front recalibration adjustment bottom connection.
    3. Case:  Aluminum or nylon, glass (or acrylic) lens, 4½" diameter typical
    4. Connector:  Brass with ¼" male NPT.  Provide protective syphon when used for steam service.
    5. Scale:  White coated aluminum, with permanently etched black markings.
    6. Set Hands:  Where pressure gauges are indicated for use across pump suction diffusers or straining / filter devices, provide adjustable set hands to indicate recommended pressure ranges of system.
    7. Range:  Select for normal operating pressure to be approximately mid range of scale with full scale range shall be selected to be approximately 1.5 to 2.5 times the normal maximum operating pressure. The following typical ranges are suggested.  The Professional shall select/specify final per specific system requirements:
      1. Vacuum:  30" Hg - 30 psig (Compound)
      2. Water: 
        0 - 15 psig (between 2 to 10 psig max operating pressure)
        0 - 30 psig (between 10 to 20 psig max operating pressure)
        0 - 60 psig (between 20 to 40 psig max operating pressure)
        0 - 100 psig (between 40 to 60 psig max operating pressure)
        0 - 160 psig (between 60 to 100 psig max operating pressure)
        0 - 200 psig (between 100 to 130 psig max operating pressure)
        0 - 300 psig (between 130 to 200 psig max operating pressure)
      3. Steam: 
        0 - 200 psig (High Pressure – up to 125 psig max operating)
        0 - 100 psig (Medium Pressure – up to 50 psig max operating)
        0 - 30 psig (Low Pressure – up to 15 psig max operating)
    8. GAUGE ATTACHMENTS
      1. Snubbers:  ASME B40.100, brass; with ¼” NPT, ASME B1.20.1 pipe threads and  porous-stainless steel filter-type surge-dampening device.  Include extension for use on insulated piping.
      2. Siphons:  Loop-shaped section of brass (for normal operating pressure/temperature up to 200 psi, 325  F) or stainless-steel (for normal operating pressure/temperature greater than for brass) pipe with ¼” NPT pipe threads.
      3. Valves:  Brass body, stainless ball, selected for working pressure suitable for application, with ¼” NPT, ASME B1.20.1 pipe threads.
    9. Manufacturers:  Subject to compliance with requirements, available manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following:
      1. Ashcroft Inc.
      2. Ernst Flow Industries
      3. Marsh Instruments
      4. Miljoco Corporation
      5. Trerice, H.O. Co.
      6. Weiss Instruments Inc.
      7. Weksler
  2. LIQUID-IN-GLASS THERMOMETERS
    1. General:  Provide stem type glass thermometers, per Standard ASME B40.200, of materials, capacities, and ranges indicated, designed and constructed for use in service indicated. 
    2. Case:  Die cast aluminum finished in baked epoxy enamel, glass front, spring secured, 9" long, acrylic or glass window face.
    3. Adjustable Joint:  Die cast aluminum, finished to match case, 180 adjustment in vertical plane, 360 adjustment in horizontal plane, with locking device.
    4. Tube and Capillary:  Glass with magnifying lens, blue or red organic liquid (non-mercury), 1% scale range accuracy, shock mounted.
    5. Scale:  Satin faced, non-reflective aluminum, permanently etched markings.
    6. Stem:  Copper-plated steel, aluminum, or brass, for separable socket, length to suit installation.
      1. Design for Thermowell Installation:  Bare stem.
      2. Design for Air-Duct Installation:  With ventilated shroud.
    7. Accuracy:  Plus or minus 1 percent of scale range or one scale division, to a maximum of 1.5 percent of scale range.
    8. Range:  Full scale range shall be selected to be approximately 1.33 to 2.0 times the normal maximum operating temperature.  The following typical ranges are suggested.  The Professional shall select/specify final per specific system requirements:
      1. Chilled Water (40-75  F max):  0 - 100 F with 1 F scale divisions.
      2. Condenser-Water Piping:  0 to 160 F with 2 F scale divisions.
      3. Hot Water (120-180  F max):  30 - 240 F with 2 F scale divisions.
      4. Steam and Steam-Condensate Piping:  50 to 400 F with 5 F scale divisions.
      5. Conditioned Air Ducts:  0 to 160 F with 2 F scale divisions.
    9. Thermowells:
      1. Standard:  ASME B40.200.
      2. Description:  Pressure-tight, socket-type fitting made for insertion into piping tee fitting.
      3. Material for Use with Copper Tubing:  Brass
      4. Material for Use with Steel Piping:  Brass or Stainless Steel.
      5. Bore:  Diameter required to match thermometer bulb or stem.
      6. Insertion Length:  Length required to match thermometer bulb or stem.
      7. Lagging Extension:  Include on thermowells for insulated piping and tubing.
      8. Bushings:  For converting size of thermowell's internal screw thread to size of thermometer connection.
      9. Heat-transfer compound:  Shall be used to improve thermal transfer and to eliminate condensation forming within the thermowell.  Compound shall consist of synthetic, efficient thermally conductive ceramic or metal oxides in a homogeneous, non-hardening paste with negligible bleed and evaporation loss.  Compound shall not cause catalytic corrosion between probe material and thermowell).
    10. DUCT-THERMOMETER MOUNTING BRACKETS Description:  Flanged bracket with screw holes, for attachment to air duct and made to hold thermometer stem.
    11. Manufacturers:  Subject to compliance with requirements, available manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following:
      1. Ashcroft Inc.
      2. Ernst Flow Industries
      3. Marsh Instruments
      4. Miljoco Corporation
      5. Trerice, H.O. Co.
      6. Weiss Instruments Inc.
      7. Weksler
  3. PRESSURE/TEMPERATURE TEST PLUGS
    1. Construct of brass, equip with NPT fitting, with self-sealing, dual valve core type Nordel gasketed orifice suitable for inserting 1/8" O.D. probe assembly from dial type insertion thermometer or pressure gauge. Test plugs shall be pressure rated for 500 psi and 275F.  Equip orifice with gasketed screw cap and chain.  Provide extension of length equal to insulation thickness for insulated piping.
    2. Acceptable Manufacturers:  Subject to compliance with requirements, manufacturers offering pressure/temperature test plugs which may be incorporated in the work include; but are not limited to, the following:
      1. Peterson Equipment Co.
      2. Sisco
      3. Watts Regulator
  4. Venturi Flowmeters:
    1. Description:  flowmeter assembly shall be commercial HVAC grade, venturi type, calibrated flow-measuring element including, hoses or tubing, fittings, valves, indicator, and conversion chart.  All Venturi meters shall be manufactured under an ISO 9001:2000 certified quality program.
    2. Flow Range:  Sensor and indicator shall cover operating range of equipment or system served.
    3. Sensor:  low pressure loss venturi-type, calibrated, flow-measuring element; for installation in piping.
      1. Design:  Differential-pressure-type measurement for suitable for HVAC hydronic fluids, gases and steam.
        1. The Venturi inlet section shall be cylindrical with a pressure sensing tap and of the same diameter as the incoming pipe section and followed by a precise smooth contoured radius section causing a uniform change in fluid velocity, and to maintain a low permanent low pressure loss.
        2. Accuracy: shall be within ±2.0 uncalibrated (±0.5% calibrated) with a repeatability of ±0.1% and turndown of 10:1
      2. Construction:  Bronze, brass, or factory-primed steel, or as otherwise required to meet the intended service conditions if atypical, with extensions on sensing taps allowing for pipe insulation thickness and brass ball valve connections suitable for connection of tubing to flow indicating assembly.
      3. Provide permanent, stainless steel tag with pipe size, manufacturer’s nameplate and flow conversion data on chain as required so that tag remains visible and not covered by insulation.
      4. Minimum Pressure Rating:  250 psig or not less than 1.5 times maximum system working pressure, whichever is greater.
      5. Minimum Temperature Rating:  250 deg F.
      6. End Connections for 2” and Smaller:  Threaded.
      7. End Connections for 2-1/2” and Larger:  Flanged or grooved.
      8. Flow Range:  Flow-measuring element and flowmeter shall cover operating range of equipment or system served.
    4. Flow indicating assembly:  Shall consist of:
      1. Three valve manifold
      2. local direct reading gauge suitable for wall or bracket mounting, calibrated for connected flowmeter element, 4” min. diameter dial with threaded fittings
        1. Scale:  Gallons per minute (verify and coordinate any special requirements to adjust for use with glycol solutions).
        2. Accuracy:  Plus or minus 1 percent between 20 and 80 percent of scale range.
      3. DP/Flow Transmitter (Where applicable - coordinate requirements with 25 00 00 INTEGRATED AUTOMATION )
        1. When applicable, a DP transmitter with calibrated local electronic display of gpm may be used in lieu of direct read dial gauge. 
      4. Additional P/T ports at each tap for local independent verification without disassembling tubing.
      5. Copper tubing for connecting components together and to flowmeter taps.
    5. Operation and Maintenance Data:
      1. Conversion Chart:  Flow rate data compatible with sensor.  Include all data for each meter clearly recorded in Manual.
      2. Operating Instructions:  Include complete instructions with each flowmeter.
    6. Manufacturers:  Subject to compliance with requirements, available manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following:
      1. ABB; Instrumentation and Analytical.
      2. Gerand Engineering Co.
      3. Hyspan Precision Products, Inc.
      4. Preso Meters; a division of Racine Federated Inc.
      5. S. A. Armstrong Limited; Armstrong Pumps Inc.
      6. Victaulic Company.
.03 Execution
  1. General: 
    1. Install gauges and thermometers in locations where they are easily read from normal operating level.
    2. Coil and conceal excess capillary on remote element instruments.
  2. Pressure Gauges:  Install pressure gauges with snubber in piping tee with pressure gauge valve(s), located on pipe at most readable position.  Install siphon for steam pressure gauges. Extend nipples and siphons to allow clearance from insulation. Install pressure gauges in the following locations:
    1. Inlet and Discharge of each pressure-reducing valve.  One gauge on common inlet may be used for pressure reducing stations with multiple reducing valves.
    2. Single gauge with isolation valves across inlet and outlet of each of the following:
      1. Chiller chilled-water and condenser-water connection.
      2. Hydronic heat exchangers.
      3. Hydronic pumps.
      4. Major strainers and filter housings (include adjustable set hands to indicate upper limit when service is required).
      5. Exception: Individual gauges are permitted if length of tubing would be excessive or impractical for the preferred single gauge method.
    3. Connection to expansion tank
    4. Single gauge with isolation valve manifold across supply and return at each piping system remote differential pressure sensor/transmitter (used to control VFD).
  3. Thermometers:  Install thermometers in the following locations:
    1. Inlet and outlet of each hydronic boiler.
    2. Inlets and outlets of each chiller (chilled water and condenser water supply and return).
    3. Two inlets and two outlets of each hydronic heat exchanger.
    4. Inlet and outlet of each hydronic zone (each secondary or tertiary loop with independent temperature control)
    5. Inlet and outlet of each hydronic coil in air-handling units.
    6. Inlet and outlet of each thermal-storage tank.
    7. Each inlet and outlet of air to air heat recovery device.
    8. Outside-, return-, supply-, and mixed-air ducts.
      1. Install thermometers in air duct systems on flanges.
      2. Locate duct mounted thermometers minimum 10 feet downstream of mixing dampers, coils, or other devices.
  4. Thermometer Wells:  Install thermometers in piping systems in wells in short couplings.  Enlarge pipes smaller than 2-1/2 inch for installation of thermometer wells.  Ensure wells allow clearance from insulation.  Fill voids between thermowell and thermometer and BAS sensor stems with heat conducting compound before installing in wells.
  5. Install pressure/temperature test plugs in piping tee, located on pipe at most accessible and readable position.  Secure cap.  Install where required to allow for balancing and troubleshooting without requiring permanent pressure gages and thermometers, including but not necessarily limited to the following locations:
    1. Adjacent to all pressure or temperature BAS sensors in hydronic systems (for testing/calibration purposes).
    2. At inlet and outlet of each hydronic terminal heat transfer device, such as:
      1. air handling coils
      2. terminal heating and/or cooling units
      3. temperature control zones
      4. At each location where major return streams mix (for troubleshooting)
        1. In common pipe, approximately 10 pipe diameters downstream of mixing point.
        2.  In each upstream pipe section
    3. At inlet and outlet of each variable pressure change device, such as:
      1. Strainers at minor/zone pumps and central air handling equipment coils.  Not required at strainers of small terminal heating/cooling units.
      2. Manual and automatic calibrated balancing valves (specify as manufacturer’s options factory fabricated on valves).
  6. Adjust gages and thermometers to final angle, clean windows and lenses, and calibrate.
    1. Adjusting:  Adjust faces of meters and gauges to proper angle for best visibility. 
      1. For gauges on straining/filtering devices, adjust set hands on pressure gauges to accurately indicate when service is required (approximately 50% above pressure differential when clean (or as otherwise recommended by strainer/filter manufacturer).
      2. After installation, zero and/or calibrate meters and gauges according to manufacturer's written instructions.
    2. Cleaning:  Clean windows of meters and gauges and factory-finished surfaces.  Replace cracked or broken windows, repair any scratched or marred surfaces with manufacturer's touch-up paint.
  7. Venturi Flow Meters: 
    1. Assemble and install connections, tubing, and accessories between flow-measuring elements and flowmeters according to manufacturer's written instructions.
      1. Example:  http://www.preso.com/resources/tech/VenturiInstructions8.5-11.pdf
    2. Install flowmeter elements in accessible positions in piping systems.
    3. Install differential-pressure-type flowmeter elements, with at least minimum straight lengths of pipe, upstream and downstream from element according to manufacturer's written instructions.
    4. Install permanent indicators on walls or brackets in accessible and readable positions. 
    5. Install connection fittings in accessible locations for attachment to portable indicators.

23 05 93 Testing, Adjusting, and Balancing for HVAC

.01 Testing and Balancing
  1. All testing and balancing shall be done in accordance with the National Environmental Balancing Bureau (NEBB) or Associated Air Balance Council (AABC).
  2. On major construction projects, as determined by the University, the balancing subcontractor must be certified by AABC or NEBB.
  3. Procedures
    1. The environmental systems including all equipment, apparatus and distribution systems shall be tested and balanced in accordance with the AABC or NEBB Procedural Standards. 
    2. Fume hood testing shall be in accord with the procedure outlined in the AABC manual.
    3. All instruments used for measurements shall be accurate, and calibration histories for each instrument shall be available for examination.  Calibration and maintenance of all instruments shall be in accordance with the requirements of AABC or NEBB.
    4. Accuracy of measurements shall be in accordance with AABC or NEBB Standards.
    5. During the operating tests of the chilled water system, provide, if necessary, a false load equal to full capacity on the chiller and submit data on gpm flow, pressure drop, inlet and outlet temperatures of chilled water, amperage of chiller and ambient air temperature at condenser.
    6. In addition, the Contractor shall check the operation of all automatic temperature control equipment; verify all thermostat, aquastat, airstat, etc., set-points and operations; and enlist the aid of the control Subcontractor to make necessary adjustments where required.
  4. Reports
    1. Eight copies of the final reports shall be submitted on applicable AABC or NEBB Reporting Forms for review and approval by the Professional and University.
    2. Each individual final Reporting Form submitted must bear the signature of the person who recorded the data and the signature of the testing and balancing supervisor of the performing firm.
    3. If more than one certified firm performs the TAB work, all final reports shall be submitted by that certified firm having managerial responsibility.
    4. Identification of all types of instruments used and their last dates of calibration will be submitted with the final report.
    5. The final test report shall include appropriate reference to all problems regarding the system(s) encountered prior to, during and after testing and what action taken to correct the problem(s), including noise and vibration.
    6. Each report shall include a print, (or sketch) reduced in size, showing all supply, return, and exhaust air outlets for easy reference to report data.
    7. An approved copy of the balancing report shall be included in the Maintenance Manual submittal.
  5. Fan Sheaves
    1. It is unacceptable for a balancing contractor to indicate that a system has been balanced as far as the existing sheaves permit.  Change pulleys, belts, sheaves, etc., as required.
    2. All adjustable sheaves shall be replaced with suitable fixed sheaves prior to final acceptance by the University.

23 07 00 HVAC INSULATION

.01 General Owner Requirements and Design Intent
  1. General
    1. Professional shall use industry best practices and professional engineering judgment to design and select HVAC Insulation to be the most appropriate for long service life for its intended application and service temperature.  Insulating systems shall be durable and allow ease of maintenance and provide the lowest life cycle cost.  
    2. Include all necessary insulation to satisfy the following objectives:  Energy Conservation, Personnel Protection, Condensation Control, Freeze Protection, Noise Control, Fire Safety, and Process Control (where present).
    3. Design and construction of insulation systems shall comply with the following industry standards and guidelines:
      1. ASHRAE Fundamentals Handbook – Insulation for Mechanical Systems.
      2. Mechanical Insulation Design Guide by the National Mechanical Insulation Committee (NMIC).
    4. Ancillary materials used for weatherproofing (e.g., sealants, caulks, weather stripping, adhesives, mastics) should be appropriate for the application, and be applied following the manufacturer’s recommendations. 
    5. Thicknesses greater than the optimum economic thickness may be required for other technical reasons such as condensation control, personnel protection, or noise control.
  2. Energy Conservation:
    1. Minimum insulation R-value shall comply with the most stringent requirements in current editions of the International Energy Conservation Code, ASHRAE Standard 90.1 - Energy Standard for Buildings Except Low-Rise Residential Buildings, or as superseded by ASHRAE Standard 189.1 - Standard for the Design of High-Performance Green Buildings, Chapter 7: Energy Efficiency.
    2. Providing Optimum economic insulation thickness should be evaluated to minimize the total life cycle cost and alternate bids developed where the estimated payback is expected to meet the threshold criteria of the University.
  3. Personnel Protection
    1. In general, provide adequate insulation on hot systems to ensure a maximum temperature of 140°F for surfaces that may be contacted by personnel. 
    2. In locations where personnel would be routinely expected to be in close proximity to hot surfaces for prolonged periods, the insulation shall be increased appropriately to maintain a safe working environment.
  4. Condensation Control
    1. Systems operating below ambient condition shall have adequate insulation to keep the surface temperature above the ambient air dew point temperature.
    2. For outdoor applications, there are times when the ambient air conditions are saturated or very nearly so.  Therefore the goal above would not be fully achievable.  For outdoor applications and mechanical rooms vented to outdoor conditions, it is suggested to design for a relative humidity of 90% at the project’s design dew-point temperature to cover most hours of the year.  Appropriate water-resistant vapor-retarder jacketing or mastics must then be specified to protect the system from the inevitable surface condensation and to prevent condensation from getting trapped behind any outer weather protective coverings.
  5. Freeze Protection
    1. Review any unusual conditions with Engineering Services in which it would be impractical to maintain freeze protection with anti-freeze, flow or adequate insulation.  Electrical heat trace (on normal/standby power) should typically only be used as a last resort.
  6. Noise Control
    1. Where needed to maintain acceptable noise criteria levels in occupied spaces, apply combinations of absorptive insulation with mass-loaded jacketings or mastics on the pipe or duct exterior to reduce radiating breakout noise.
    2. Refer to 23 31 00 HVAC DUCTS AND CASINGS for limitations of use and allowable type of internal acoustic duct lining. 
  7. Fire Safety
    1. All insulation materials and applications must comply with building code requirements for fire and smoke safety ratings.
  8. Corrosion Under Insulation Control
    1. The design and installation of all insulation systems shall be such to minimize conditions that contribute to Under Insulation Corrosion.
      1. Designs and installations shall conform to the current edition of NACE SP0198-Control of Corrosion Under Thermal Insulation and Fireproofing Materials.
      2. Comply with recommendations and guidelines in ASHRAE Fundamentals Handbook, Insulation for Mechanical Systems, “Corrosion Under Insulation”.
      3. Steel pipe, fittings and welds shall be primed with an epoxy coating under the insulation.
  9. Abuse Resistance
    1. Where insulated systems are subject to high risk of damage due to proximity to foot traffic or routine access points for maintenance, select insulating materials with adequate compressive resistance and rigid jacketing to provide adequate protection from mechanical abuse.
  10. Weather Protection
    1. HVAC insulation in outdoor applications must be protected with weather barriers of superior workmanship, installed by highly experienced, knowledgeable and skilled craftspeople in order to maintain the expected service life of the insulated systems.
  11. Coordinate piping layout/installation to ensure adequate clearances to allow for Inspection, Repair and Replacement
    1. Even with vapor-retarding insulation, jackets, and vapor sealing of joints and fittings, moisture inevitably accumulates in permeable insulations.  Therefore the routing of insulated distribution systems shall be designed and constructed to be adequately accessible for periodic inspection and insulation replacement.
    2. Maintenance staff shall be able to monitor for and immediately repair compromises in the protective jacketing system. Because water may infiltrate the insulation system, inspection ports shall be strategically used to facilitate inspection without requiring destructive insulation removal. This is particularly important on subambient systems.
    3. Items regularly accessed for inspection, repair, or balancing must be insulated to either allow access to all required components, or insulated with a manufactured, removable insulation system.  Examples of these devices are: balance valves, control valves, piping ports, isolation valves, strainers, check valves.  These systems must be insulated with a removable access section, preformed insulation system, or insulated jacket.  Adjacent insulation should be sealed to maintain the system vapor barrier.
  12. Contract Documents:
    1. Include construction specifications, plans, elevations, sections, and typical details to properly convey the HVAC insulation scope of work, which shall conform to at least the minimum requirements of this section. 
    2. Specify the following required Shop Drawings:
      1. Include summary schedule of application, insulation product, material thickness, R-value, finishes, jacket, and accessories.
      2. For special coordination to avoid or minimize conflicts in the field on an as-needed basis, include plans, elevations, sections, details, and attachments to other work.
      3. Detail application of protective shields, saddles, and inserts at hangers for each type of insulation and hanger.
      4. Detail attachment and covering of heat tracing inside insulation.
      5. Detail insulation application at pipe expansion joints for each type of insulation.
      6. Detail insulation application at elbows, fittings, flanges, valves, and specialties for each type of insulation.
      7. Detail removable insulation at piping specialties.
      8. Detail application of field-applied jackets.
      9. Detail application at linkages of control devices.
      10. Inspection ports used to facilitate moisture inspection without requiring insulation removal.
.02 Product Requirements
  1. General
    1. Products that come in contact with stainless steel shall have a leachable chloride content of less than 50 ppm when tested according to ASTM C 871.
    2. Likewise, any ancillary weatherproofing materials should have low chloride content.
    3. Insulation materials for use on austenitic stainless steel shall be qualified as acceptable according to ASTM C 795. 
  2. Select materials for low environmental impact during manufacturing and installation and to not negatively impact indoor environmental air quality.
    1. Supply fiber glass products that are manufactured using a minimum of 60% “post-consumer” recycled material.
    2. Supply fiber glass products that are manufactured using a bio-based binder rather than non-renewable petroleum-based chemicals and with a binder that does not contain phenol, formaldehyde, or acrylics; whenever possible.
    3. Products shall not contain asbestos, lead, mercury, or mercury compounds, or formaldehyde-based binders; or will be third-party certified for conformance with GREENGUARD or Indoor Advantage Gold.
    4. Foam insulation materials shall not use CFC or HCFC blowing agents in the manufacturing process.
  3. Fire Hazard Ratings
    1. Insulation materials shall comply with the International Mechanical Code flame spread and smoke-developed index and testing requirements, appropriate for the application (piping, ducts, materials within plenums).
    2. Accessories such as adhesives, mastics, cements, and cloth for fittings shall have the same component ratings as listed above.
    3. Paper laminate jackets shall be permanently fire and smoke resistant.  Chemicals used for treating paper in jacket laminates shall not be water soluble and shall be unaffected by water and humidity.  The only exceptions to the above are flexible foamed plastic insulation.
  4. Duct Insulation Products
    1. Glass fiber materials shall comply with all basic requirements above.
    2. All duct insulation in mechanical rooms shall be rigid fiberglass board, minimum density 6 lb/ft3. 
    3. For typical concealed ducts, insulation shall be blanket-type insulation wrapped on the outside of the ductwork.
    4. Exposed ductwork in occupied, finished spaces shall have insulation that is selected to be the most appropriate for the round or rectangular ductwork to provide a professional, durable, quality fit and finish.  Double wall ductwork might be an alternative.  But any insulation exposed to the airstream shall not be fibrous.  Refer to prohibitions of fibrous duct liner above.
  5. Pipe Insulation Products
    1. Glass fiber materials shall comply with all basic requirements above.
    2. In general, refrigerant piping systems shall be insulated with flexible, closed-cell elastomeric pipe insulation.
    3. In general, all other piping systems shall be insulated with mineral wool/glass fiber piping insulation with a high-performance All-Service Jacket (ASJ).
      1. The high-performance jacket shall have an outer film surface with no exposed paper, be tougher than standard ASJ, puncture resistant, moisture and mold resistant, dimple and wrinkle resistant, easily cleanable with soap and wet cloth, able to accept mastic and painting.
      2. Manufacturers:  Knauf “ASJ+”, Owens Corning “Evolution Paper-Free ASJ”, or approved similar.
      3. On chilled water piping, a pipe insulation wicking system (similar to Owens Corning “VaporWick”) designed for use on below-ambient temperatures (but only above freezing pipe temperatures) services located in humid climates can be an alternative method to remove condensed water from the surface of the cold piping to the outer surface of the insulation where it can be evaporated by the ambient air.  However, dripping is avoided only if ambient conditions allow for adequate evaporation, so proper application depends on location and controlled ambient conditions.
    4. Fittings, flanges, and valves shall be insulated with fiberglass inserts and premolded polyvinyl jackets.
    5. Special insulation protection shall be selected and specified for areas subject to abuse, moisture, etc. (i.e. outside, wash down areas).
    6. Insulation Protection Shields:
      1. Insulation protection shields fabricated from galvanized steel shall be installed at all pipe hangers and supports.  Shields shall span an arc of 180°.
      2. Provide shield lengths and thicknesses as outlined in the latest version of the International Mechanical Code or MSS-SP69.
      3. High Density Inserts, capable of resisting the crushing effect of the hydraulically loaded piping, shall be placed under each shield.  Insulating material shall be suitable for the planned temperature range.  Jacketing material shall be wrapped around rigid insulation and adjacent top and butt sections to maintain the jacketing continuity.
        1. On copper/non-ferrous piping  - Single-piece thermally insulated pipe hanger with self-adhesive closure.  Similar to Armafix IPH/NPH series.
        2. On steel piping (2-1/2” and up) -  rigid cellular glass insulation is recommended.
        3. Inserts shall be the same thickness as the adjacent insulation.
      4. An 18 gauge stainless steel shield shall be installed on insulated piping located on the roof.  The shield shall be a minimum length of 36 inches and field located to prevent damage to the insulation while walking over the piping.
  6. Equipment Insulation
    1. In general, equipment shall be insulated with flexible, closed-cell elastomeric or mineral fiber insulation.  All equipment handling a medium below ambient temperature shall be additionally provided with a sealed vapor barrier.
    2. For portions of packaged equipment that are factory insulated, insulation thicknesses shall be coordinated to comply with the Energy Conservation, Personnel Protection, Condensation Control, Noise Control requirements above for the associated duct or pipe application and location.  If manufacturer’s available options for factory installed insulation do not meet requirements, then specify field-installed supplemental insulation as required.
.03 Execution
  1. General Installation Requirements
    1. All materials shall be installed by skilled labor regularly engaged in this type of work.  All materials shall be installed in strict accordance with manufacturer’s recommendations, building codes, and industry standards.
    2. Keep insulation materials dry during application and finishing. 
      1. Any fiber glass insulation that becomes wet or damaged shall be replaced at no additional cost. 
      2. Air handling insulation used in the air stream must be discarded if exposed to water.  No exceptions.
    3. Verify that all piping, ductwork, and equipment have been fully inspected, pressure or leak tested and approved prior to applying paint or insulation installation. 
    4. All surfaces to be insulated shall be thoroughly cleaned as required to remove all oil, grease, loose scale, rust, and foreign matter and verified to be acceptable before applying paint and insulation materials.  Piping shall be completely dry at the time of application of primer paint.  Painting on piping where condensation is occurring on the pipe surface is strictly prohibited.
    5. Install insulation materials, accessories, and finishes with smooth, straight, and even surfaces; free of voids throughout.
    6. Insulation on all cold surfaces must be applied with a continuous, unbroken vapor seal.
    7. Flexible Elastomeric Insulation: After adhesive has fully cured, apply two coats of insulation manufacturer's recommended UV-resistant protective coating.
  2. Pipe Insulation Installation
    1. Even with vapor-retarding insulation, jackets, and vapor sealing of joints and fittings, moisture inevitably accumulates in permeable insulations.  Therefore the piping installation shall be adequately accessible for periodic inspection and insulation replacement.
    2. Surface Preparation: Clean and prepare surfaces to be insulated.
    3. Corrosion Under Insulation Protection:  Before insulating, apply a corrosion-resistant coating to insulated surfaces as follows:
      1. Carbon Steel: Coat carbon steel operating at a service temperature below ambient with an epoxy coating. Consult coating manufacturer for appropriate coating materials and application methods for operating temperature range.
      2. Provide primer coat on all steel piping field welds. 
      3. The corrosion resistant coating shall be completed and approved prior to installation of insulation.  Coating shall be applied in accordance with the coating manufacturer’s instructions, environment, and pipe surface temperatures and shall be the responsibility of the Mechanical
        Contractor/piping installers, not the insulation installers.
    4. On piping systems operating below ambient air conditions, provide dams in insulation to prevent migration of condensation or fluid leaks.  At a minimum, dams shall be formed at every fourth 3’ section (intervals not to exceed 12 feet) and at each butt joint of insulation at fittings, flanges, valves, and at insulation support inserts and shield assemblies at hangers.  Include clear visual indicators where the dams are located for maintenance personnel to identify.   
    5. Edges of vapor barrier insulation at valve stems, instrument wells, unions and other raw edges must be adequately sealed to prevent moisture from penetrating the insulation.
    6. All pipe insulation and vapor barriers (when present) shall be continuous through walls, partitions, ceiling openings and sleeves where fire and smoke ratings permit such penetration.
      1. Where insulated pipes pass through fire-rated floors, walls, or partitions, the use of a UL approved system, specific for each insulation type, is required.  Comply with requirements in "Penetration Firestopping" for firestopping and fire-resistive joint sealers to maintain the rating of the system in accordance with the through penetration sealant manufacturer's recommendations.
      2. The General and Mechanical trades are responsible for coordinating the correct UL approved firestopping of these penetrations.  The primary trade that requires the penetration is responsible for the proper firestopping.  The insulation trade is not responsible for firestopping/firecaulking.
    7. Hangers shall support the load of the insulated pipe section on the outside of the insulation and shall not be in direct contact with the pipe.  Supporting the pipe directly on hanger and attempting to insulate around the pipe and hanger is prohibited.  Professional shall include necessary details on construction drawings.
    8. Where vapor barrier is indicated, seal joints, seams, and penetrations in insulation at hangers, supports, anchors, and other projections with vapor-barrier mastic.
      1. Install insulation continuously through hangers and around anchor attachments. 
      2. For insulation application where vapor barriers are indicated, extend insulation on anchor legs from point of attachment to supported item to point of attachment to structure. Taper and seal ends at attachment to structure with vapor-barrier mastic.
      3. Install insert materials and install insulation to tightly join the insert. Seal insulation to insulation inserts with adhesive or sealing compound recommended by insulation material manufacturer.
      4. Cover inserts with jacket material matching adjacent pipe insulation. Install shields over jacket, arranged to protect jacket from tear or puncture by hanger, support, and shield.
    9. Piping Coupon Rack Insulation:
      1. The University provided coupon racks are causing a problem in the field in regards to insulation.  Some of the projects calling for thicker insulation, or fiberglass insulation make it very tough to perform a clean job based on the clearance between the pipes.  Furthermore, the access needed for testing is not conducive to fiberglass insulation.  Standardizing the insulation and handing methods will ensure more consistent installations.
      2. Therefore, Flexible Elastomeric Cellular (1” thick) is the preferred insulation method for the coupon racks only.  This is recommended based on the following conditions/criteria:
        1. The coupon rack is constructed of stainless steel.
        2. Insulated caps are provided at the coupon access points (plugs).
        3. Rigid Armafix IPH series hangers (only available up to 1” thick) are used to secure the rack. 
        4. Armaflex and adjacent insulation systems are sealed at the junction point to prevent under-insulation condensation.
  3. Equipment Insulation Installation
    1. Before insulating steel surfaces, prepare surfaces for paint, and prime and paint as indicated for other painted components.  Do not insulate unpainted steel surfaces.
    2. Construct insulation on parts of equipment such as chilled water pumps and heads of chillers, convertors and heat exchangers that must be opened periodically for maintenance or repair, so insulation can be removed and replaced without damage. 
    3. For equipment with surface temperatures below ambient, apply vapor barrier mastic to open ends, joints, seams, breaks, and punctures in insulation.  Seal between flanges with replaceable gasket material to form a vapor barrier.
    4. All Equipment identification labels must be readily accessible.   On equipment where the nameplate data is obscured by the insulation requirements, a stamped steel nameplate shall be permanently affixed to the equipment in a visible location.  DO NOT REMOVE THE ORIGINAL NAMEPLATE.
    5. The following equipment must be insulated to be covered to fullest extent practical.  
      1. On Steam Systems:
        1. Valves, strainers, pressure reducing valves, pressure relief valves, traps, and condensate receivers/pumps, flash tanks, heat exchangers
        2. Removable “Hot Cap” insulation must be provided for those items or portions that will require insulation removal for periodic maintenance or inspection.
      2. On Hot water Systems:
        1. Valves, strainers, pumps, air/dirt eliminators, heat exchangers, storage tanks.
        2. Removable “Hot Cap” insulation must be provided for those items or portions that will require insulation removal for periodic maintenance or inspection.
      3. On Chilled water Systems:
        1. Pumps, air/dirt eliminators, valves, heat exchangers.
        2. Insulation on pumps and other equipment operating below ambient dew point requiring routine service shall be insulated with flexible,
          closed-cell elastomeric insulation to conform to the shape of the equipment, with all joints and penetrations completely sealed to maintain vapor barrier.
        3. Provide removable insulation sections of smallest, most appropriate size to cover parts of equipment and specialties that must be accessed periodically for maintenance (i.e. – strainer ends, to access grease fittings and inspect bearings for proper lubrication, vent/drain plugs or valves, p/t ports) without damaging insulation or compromising vapor barrier.  Removable sections shall be constructed to provide a removable or replaceable yet adequate vapor barrier seal at the interface between the permanent and removable sections that still allows the section to be removed and replaced on a regular, continued basis.   Note:  A room temperature, pressure-sensitive, permanently-tacky, vapor-barrier adhesive/tape (similar to carpet square adhesive) that would be compatible with the insulation material is a possibility being investigated at time of this writing.  Review currently available options with OPP Engineering Services.
        4. Main joints and splits shall coincide with flange/splits of the equipment to minimize extent of removing and replacing insulation for major, non-periodic access for repairs.
        5. Ensure that the bearing assembly grease fittings remain accessible and visible. Any vent slots on the sides and bottom of the bearing assembly should remain uncovered and completely open.
        6. Balance valves, control valves, piping ports, isolation valves, strainers, check valves on low-temperature systems must be insulated either with a removable access section as described above; or of valve manufacturer’s optional preformed 2-piece insulation kit covers (similar to products offered by TA Hydronics – verify fire resistance ratings meet application specific requirements); or precision-cut,  2-piece insulation covers pre-formed to custom fit the contour of the valve/fitting shapes, similar to products as fabricated by Extol).  Adjacent insulation shall be sealed to maintain the system vapor barrier.

23 09 00 INSTRUMENTATION AND CONTROL FOR HVAC

.01 General
  1. Refer to "Building Automation and Control Systems" web sites on the Penn State Design & Construction Standards Page.

23 20 00 HVAC PIPING AND PUMPS

23 21 00 HYDRONIC SYSTEMS

.01 General Requirements and Design Intent
  1. Summary: Section includes basic design requirements for hydronic heating and cooling systems in HVAC applications.
  2. General:  Professional shall design each hydronic system for optimal operating efficiency throughout capacity range, reliability, flexibility, and ease of maintenance with the lowest life cycle cost.
    1. ASHRAE/IESNA Compliance:  Comply with applicable high-performance building requirements in ASHRAE/IESNA 90.1 or ASHRAE 189.1 per 01 81 13 Sustainable Design Requirements.
    2. Follow the Hydronic Heating and Cooling System Design guidelines in current edition in current edition of ASHRAE Systems and Equipment Handbook.
    3. Strive to keep systems simple to understand and operate.
  3. Systems Design Criteria:
    1. Design for low flow, high temperature differences and variable flow distribution systems to minimize pump energy.
    2. Selection of cooling coils in typical HVAC applications is recommended with a minimum 14-16°F rise at peak conditions.
    3. Terminals shall be “right-sized” for both part load and partial load performance.
    4. Minimum full load design flow at any terminal device shall not be less than 0.5 gpm for effective flow measurement and heat transfer.
  4. Shut-Off Valves:  Design and indicate positive shut-off valves throughout the distribution piping system to facilitate shutdown and draining of smallest segment as practical for repairs while keeping the rest of the system operational.
    1. Clearly show locations of all shut-off valves on construction drawings to be able to properly isolate the systems for service.
    2. Locations:  Shutoff valves shall be installed at:
      1. All locations required by the current building Mechanical Code.
      2. Each piece of central or terminal equipment.  All valves shall be installed such that valve remains in service without shutting down system when downstream piping or equipment is removed for service, alterations or repairs.  Provide arrangement of unions or flanges and removable sections of pipe at final equipment connections to allow easy dismantling and pulling of associated equipment past remaining pipe assemblies without cutting pipe or breaking sweat or press-joint fitting connections.
      3. Secondary / tertiary loops off of primary/secondary piping systems.
      4. Pipe mains at points exiting mechanical rooms, located accessibly within the mechanical room.
      5. Any pipes at points exiting the building or running under slab or underground, located accessibly within the building interior.
      6. Base of each riser.
      7. Each horizontal branch takeoff of each riser.
      8. Each branch takeoff serving groups of multiple terminals arranged to create hydronic modules to achieve strategically divided sections that can be isolated for service, modifications, and troubleshooting while the rest of system can remain in service.
      9. Main or branch strainers or filters (on entering and leaving sides to allow for pulling screen).
      10. Any thermal control zone, (i.e. perimeter finned tube zones controlled by exterior orientation0).
      11. Any 3 valve bypass around devices as required maintaining continuous flow for critical applications while servicing device.
      12. Tees for future connections.  Review with OPP – in some cases valves might be unnecessary and/or undesirable.
      13. Pipe expansion compensating devices that would otherwise require extraordinary effort for system shutdown and drainage to be able to service or replace.  Review with OPP.
    3. Refer to section on Shut-Off Valves for types.
  5. Bypasses:
    1. Three valve bypasses shall be installed around control valves and pressure-reducing stations serving critical areas. Areas deemed to be critical shall be reviewed with the Project Manager. No other equipment is to be provided with a bypass unless approved by the Project Manager.
    2. In all applications, use ball valves for shut-off purposes and globe valves for throttling purposes in the bypass line.
    3. Gate valves may be used for shut-off purposes in large line sizes.
    4. Ball valves equipped with “characterizing discs” may be used for throttling purposes in lieu of globe valves.
  6. Freeze Protection:
    1. Hydronic systems subject to freezing conditions shall be protected with separate piping loops with antifreeze solution, heat exchangers, pumps, expansion tanks, as required to prevent freezing in the event of extended electrical power outage and to minimize and isolate portions of systems requiring antifreeze from the main hot and chilled water loops.
    2. Glycol anti-freeze systems shall be considered when outside air at a temperature below 20 degrees exceeds 50% of the total air stream.  However, the professional shall not specify Glycol systems until specifically approved by the University.
    3. See 23 25 00 for more information.
.02 Flow Balance and Differential Pressure Control
  1. General:  Professional shall design the layout and components of each hydronic distribution system to deliver the specified comfort level using minimal energy with optimal operating stability, serviceability, and future flexibility with the lowest life cycle cost.
    1. To enable systematic balancing with absolute minimum pressure drop result, distribution piping must be subdivided into hydronic modules within a hierarchical tree.
    2. At any node between multiple units, consider the direction of the larger flow and place a flow balancing / DP control device on the lower flow side.
    3. Do not use multiple self-regulating DP controllers in series. For example, do not use a DP controller at a main, riser, or branch and then also use a pressure independent control valve at individual terminals.
  2. Isolation and Flow Measurement:
    1. General:  In all hydronic systems, provide combination positive drip-tight shut-off and precision flow measuring devices at heat transfer terminals as required for service isolation and means to quickly, conveniently and accurately measure flow.
      1. Combination shut-off/balancing valve shall provide multi-turn 360° adjustment with precise position indicators located on the ergonomically designed handwheel.  Valves shall have a minimum of four full 360° handwheel turns.  Valve handle shall have hidden memory feature, which will provide a means for locking the valve position after the system is balanced.  Valves shall have P/T ports for connecting standard differential pressure meter, extended type as required to be accessible without having to remove primary finished insulation.  90° 'curcuit-setter' style ball valves are not acceptable.
      2. Optional:  Provide manufacturer's optional insulation covers with a flame spread rating of 25 or less and a smoke development rating of 50 or less.  Coordinate installation with piping insulation installer to ensure that complete vapor barrier is maintained on systems operating below ambient dew point.
      3. Install in accordance with manufacturer's recommendations of upstream and downstream pipe diameters from any fitting.  Install with flow in the direction of the arrow on the valve body.  Locate with easy and unobstructed view and access to the valve handwheel, position indicator, and metering ports for adjustment and measurement.  Mounting of valve in piping must prevent sediment build-up in metering ports.
      4. Acceptable Manfacturers:
        1. Armstrong CBV
        2. Tour Andersson STA series
    2. Constant flow applications:
      1. Generally use only for smallest systems (under 300,000 Btu/h output capacity) – verify and conform to most stringent of current Energy Conservation Code, ASHRAE 90.1 and ASHRAE 189.1 High Performance Building Standard.
        1. Exceptions:  Limited modifications to existing systems.  Review with OPP.
      2. The Isolation/balance valves shall be:
        1. Throttled as little as possible.
        2. Always fully open at terminals at ends of hydronic modules.
      3. Consider potential for future conversion to variable flow systems if part of a larger facility.  Include provisions for main, riser or branch Adjustable Self-acting Differential Pressure Controllers as discussed in variable flow systems below.
    3. Variable flow applications:
      1. Generally use on most systems to minimize energy usage.
      2. The Isolation/balance valves are intended primarily for isolation and flow diagnostics. They shall be:
        1. Fully open, except for very minor balancing of a group of terminals in a balancing “module” downstream of a shared dynamic pressure independent control device.
        2. Always fully open at terminals at ends of hydronic modules.
        3. Used on individual coil modules in stacked coil configurations for flow equalization to each coil.  One in common to all the coils is not required for total flow measurement.
  3. Differential Pressure Control:  Maintain differential pressure within acceptable range to achieve stable operation of automatic control valves in most energy-efficient and lowest-life cycle cost effective manner.
    1. Control valves of circuits subject to high pressure differentials and thus susceptible to overflow will tend to short cycle.  This dramatically reduces their actuator life.  Therefore differential pressure across control valves must not vary too much.
    2. Avoid cavitation:  Ensure control valves are selected to avoid cavitation due to combination of low static pressure in the system, large pressure drop across valve, high fluid temperature and/or poor valve design.
      1. Cavitation causes vibrations in the valve, wears down cone and valve seat in a very short time.
      2. Rule of thumb to prevent cavitation at control valves:  Static pressure at valve inlet > 2 times pressure drop across control valve.
    3. Maintain superior control valve authority range for stable operation, close temperature control, and actuator longevity.
      1. Control valve authority:  a ratio that indicates the relationship of the pressure drop of the fully open control valve at design flow vs. the overall differential pressure in the system at that point with the control valve fully shut.  Its value indicates how effectively the control valve can reduce the flow while it is closing.  The lower the authority, the larger the pressure differential variations on the control valve and the larger the distortion of the valve control characteristics.
        1. In a variable flow distribution, the authority of the control valve is variable.  Therefore dynamic differential pressure stabilization may be required depending on the system operating characteristics.
        2. Evaluate differential pressures throughout hydronic system between minimum and maximum operating ranges. To achieve good control performance, select control valve and DP control device to ensure design control valve authority of at greater than or equal to 0.5, and minimum authority of at no less than 0.25.
    4. Strategically locate self-regulating differential pressure controllers throughout distribution system, only as needed, to stabilize wide variations in differential pressure.  Determine the most cost effective combination that will ensure recommended control valve authority at all operating conditions. Depending on size and complexity of system, various pressure independent control components may be applied:
      1. On large mains or risers (greater than approximately 220 gpm):
        1. Adjustable Self-acting Differential Pressure Controller: Similar to:
          1. Tour Andersson DA 50 Series
        2. Combine with manual balance valves for terminals downstream.
      2. On Branches serving multiple similar terminals (up to total of approximately 220 gpm):
        1. Adjustable Self-acting Differential Pressure Controller:  Similar to:
          1. Flow Design DA516
          2. Tour Andersson DA516
        2. Combine with manual balance valves for terminals downstream.
      3. On smaller individual terminals (up to approximately 100 gpm, 2” and under):
        1. Pressure Independent Characterized Control Valves (PICCV).
          1. For specifications and acceptable manufacturers, see Div 25 - Building Automation Systems (BAS)  Guidespec.
          2. For selection criteria, see Div 25 -  Pressure Independent Control Valve Selection
          3. These combination valves are more costly than regular characterized control valves and are not needed at the more hydraulically remote parts of system.  Use them strategically only as needed to maintain control authority criteria based on careful analysis of anticipated pressure differentials throughout the system.
          4. Control valves must be characterized ball type.  Globe style control valves are not permitted.
      4. On larger individual terminals (greater than approximately 100 gpm):
        1. Adjustable Self-acting Differential Pressure Controller same as above for DP stabilization, with separate regular characterized control valve.  See Div 25 Building Automation Systems (BAS) Guidespec for control valve. Or,
        2. No more than 2 paralleled PICCVs (for up to approximately 200 gpm).  Or,
        3. Medium or Large Pressure Independent Control valves with internal mechanical pressure regulator in addition to the characterized disk control valve.  Similar to:
          1. Flow Control Industries, DeltaPValve.
          2. These combination valves are more costly than regular characterized control valves and are not needed at the more hydraulically remote parts of system.  Use them strategically only as needed to maintain control authority criteria based on careful analysis of anticipated pressure differentials throughout the system.
        4. Valves using flow sensors controls to reposition the characterized ball or disk without a mechanical pressure regulator are not acceptable.
  4. Maintain proper balance of flows in primary (production) loops vs. secondary (distribution) loops.
    1. Correct Method:  When using primary/secondary pumping, ALWAYS ensure secondary loops are designed, balanced and controlled to have less flow than primary to avoid mixing of secondary return with primary supply and thus secondary supply temperature degradation.
    2. Ineffective methods:
      1. Increasing secondary flow beyond primary only increases the flow imbalance and therefore mixing worsens making the condition worse.
      2. Producing colder primary chilled water or warmer hot water can compensate only a little but at a higher energy cost.  Mixing will still occur, only shifted slightly.
  5. Miscellaneous Coordination:
    1. Minimize pump energy with Optimized pump DP reset based on terminal heating/cooling requests.  Coordinate with BAS sequence of operations.
      1. Locate system remote DP sensor on the most probable index branch/circuit, prior to any self-regulating DP controller or PICCV.
      2. Never place remote DP sensor for pump speed control downstream of any self-regulating DP controllers or PICCVs in the system.
    2. Ensure each control valve/actuator combination has sufficient close-off pressure rating for application within distribution system.
.03  Air and Dirt Elimination
  1. All closed loop hydronic systems shall have effective means for elimination of air and dirt that are safe and convenient to access and service.

  2. Primary air eliminator shall be located at the point of lowest solubility in the system main, that being where the pressure is the lowest (on suction side of main pumps) and the temperature is the highest.

  3. Primary dirt separation on discharge side of main pumps is best.  That will allow constant blow down through a side-stream bag filter using pump pressure.

  4. For primary air eliminator and dirt separator, refer to 23 21 13 Hydronic Piping.

  5. Manual vents shall be installed at high points to remove all air trapped during initial operation. Manual vents are standard but automatic vents will be considered in special situations and locations.  Shutoff valves should be installed on any automatic air removal device to allow servicing without draining the system.  Where vent location is high or otherwise inaccessible, install valve at vent chamber, then extend 3/8" tubing to nearest janitor sink or mechanical room floor drain and terminate with ball valve.

  6. If pumps and primary air/dirt eliminators are not at the bottom of the system, provide additional dirt separator(s) as required to collect and remove sediment at the bottom of the system.

  7. System Cleaning and Flushing Bypass assemblies:

    1. Provide bypass valve and piping assemblies at all central plant heating and cooling sources and at all distribution terminal units.  The purpose is to be able to isolate all equipment and bypass around it to prevent circulating dirt through equipment strainers, control valves or heat transfer surfaces while performing main piping system cleaning and flushing.

    2. Bypasses shall be of adequate size to achieve the minimum velocities required to effectively clean and flush system mains and branches out to each piece of equipment.

    3. Provide bypasses at ends of main risers and branches as required on new or existing systems to achieve the minimum velocities required to effectively clean and flush system main risers and branches without having to rely on flows through small runout branches.

.04 Hydronic Plant Design
  1. Makeup Water Systems:
    1. Use automatic makeup assembly to maintain positive pressure at the highest point of at least 4 psig for system operating temperatures up to 210°F.
      1. Exception:  Cold water make-up piping is not to be directly connected to any system that utilizes glycol.  Refer to 23 25 00 HVAC WATER TREATMENT for mix and fill tank assembly for automatic makeup in lieu of direct makeup water connections on glycol systems.
    2. Reduced pressure principal back flow preventers shall be installed on all make-up water lines.
    3. Make-up water connection shall be located along with the expansion tank at the point of no pressure change and pumps shall pump away from that point.  Keep pressure drop low between pump suction and make-up water/expansion tank connection location.
    4. Install water meter on makeup water lines.  Tracking makeup water use is needed to correctly maintain chemical levels and to detect leaks.  If project budget   permits, the meter should include transmitter and be connected to the building BAS / campus CCS system to monitor readings and alarm abnormal conditions.
  2. Primary Heating and Cooling Production Equipment:
    1. Ensure primary production equipment is circuited and piping system is arranged to achieve maximum efficiency.
    2. Ensure the manufacturer’s recommended range of water flow through equipment is maintained.
    3. Connect piping so that all return water and any water from a bypass are thoroughly mixed before any of the water enters production equipment.  After the tee, there should be at least 10 pipe diameters to the nearest unit. This is to help avoid the possibility of having stratification in the primary return line, which can lead to unmixed water to the nearest unit. This can lead to control cycling.
    4. Arrange piping such that all production equipment obtains equal return water temperature.
      1. Exception:  in systems where “backloading” or “preferential” loading of chillers is advantageous by design to maximize the operating performance of different types of chillers.
  3. Pumping Arrangement and Configuration:
    1. General:  Refer to 23 21 23 HVAC Pumps.
    2. Chilled and Condenser Water Systems:
      1. In general, arrange pump assemblies to pump into chilled water heat exchangers, chiller evaporators, and condenser bundles.
      2. Locating the chilled water pump and associated air separator on the building chilled water return provides the warmest temperature along with the lowest pressure for most effective air removal.  This location also helps to minimize potential pump cavitation problems resulting from pressure buildups in fouled strainers or heat exchangers.
    3. Hot Water Systems:
      1. In general, arrange pump assemblies to pump away from low pressure, low temperature heating sources (low pressure boilers or gasketed-plate water to water heat exchangers).
      2. Locating the hot water pump and associated air separator on the leaving side of the heat source provides the warmest temperature along with the lowest pressure for most effective air removal.
      3. However, specify pump construction and seals to be rated for a minimum of 250°F to improve the longevity of the useful life at higher operating temperatures.
      4. Provide strainer on return of each heat sources to prevent system dirt from collecting in low velocity inner heat transfer surfaces of heating equipment.  Also, a sediment dirt leg with blow down valve is recommended as near to inlet as possible (local low point).
      5. Steam to hot water heat exchanger systems:
        1. Controls on steam heat exchangers have a higher risk of routinely overshooting supply water setpoint.  By placing the pumps on the return side, the advantage is that lower operating temperatures on the pumps will better ensure and enable longer useful life on pump internals such as seals.
        2. The difference in solubility of air in water due to the entering hot water return temperature vs. leaving supply temperature is relatively minor with respect to the difference due to pump pressure differential.  With the air removed by the air separator on the suction side of the pump (lowest pressure point), the solubility after the pump will be much higher so air will not come out of solution as it is heated going through the heat exchanger.
        3.  Pumping into heat exchangers also allows the pump strainer and system dirt eliminator to be before the heat source to better protect it without having to add an additional strainer.
  4. Primary-secondary systems:
    1. The system must be piped and controlled so that water never flows in the reverse direction in the decoupler bypass during normal operation.
    2. The supply tee connecting the building supply distribution loop to the primary loop shall be arranged such that the secondary loop is the side branch and the bypass is the straight through direction.  This directs the primary loop water’s energy into the decoupler bypass and requires the secondary loop to pull the water out of the tee.
    3. The return tee connecting the secondary return loop to the primary return shall be arranged such that the bypass is the side branch and the secondary return to the primary return loop is the straight through direction.
    4. The secondary loop return must not be connected too closely to the supply pipe with a bullhead tee in which the velocity head rams into the decoupler bypass which can encourage migration.
    5. Although in theory there should be no pressure drop in the decoupler, in order to avoid thermal contamination in actual systems the decoupler should be at least 10 pipe diameters in length (per ASHRAE Systems Handbook). Longer decouplers tend to increase the pressure drop.
    6. Size decouplers for the flow rate of the largest primary pump. This may be more than the design flow rate of the largest individual piece of production equipment if overpumping is being considered. The pressure drop should not exceed 1.5 ft. As the pressure drop through the decoupler increases, it tends to make the primary and secondary pumps behave like they are in series.
.05 Building Automation System Performance Monitoring
  1. Return Water Temperature – Heat Transfer:  Provide return water temperature transmitters at individual terminals and in main building return to continuously monitor heat transfer performance and alarm abnormal conditions when adequate temperature differential is not maintained.
  2. Energy Consumption of Water Distribution:  Provide flow, temperature difference and watt transmitters to measure operating parameters, programming and trending/reporting to continuously monitor pumping system effectiveness through the BAS and alarm abnormal conditions.  Include pump system efficiency ratios based on system type (such as kW/100 tons for chilled water and kW/1000 MBH for hot water).
.06 Ground-Coupled Heat Pump Well Field Systems
  1. The University encourages the use and application of equipment that reduce the energy consumption of building systems. However, the installation of ground-coupled or geothermal wells have groundwater contamination risks that must be addressed prior to design of any geothermal or ground-coupled systems.
  2. Prior to the start of design, the Design Professional shall review any proposed geothermal or ground-coupled systems at any University location with the Office of Physical Plant, Engineering Services and obtain written consent to proceed prior to any further design development or installation. No geothermal or ground-coupled systems shall be installed at any University location without written approval of the Office of Physical Plant, Engineering Services.
  3. Where approved, well systems shall be designed and constructed in accordance with 23 81 00.03 and 33 20 00.

23 21 13 Hydronic Piping

.01 General Requirements 
  1. Hydronic Piping Design:
    1. General:  Follow the Hydronic System Pipe Sizing guidelines in current edition of ASHRAE Fundamentals Handbook.
    2. Design to keep system pressure drop low to minimize pump energy and long-term operating costs.
      1. Use pipe fittings with low pressure drop characteristics such as long radius elbows, 45° laterals and Tee Wyes in main branches, tapered concentric/eccentric reducers, and bell-mouth inlets.
      2. Do not use fittings with abrupt changes that cause high pressure drops such as non-tapered reducing flanges or couplings, or bullhead tee connections (either two streams connected to each end of a tee with the discharge on the branch, or the main flow coming into the branch connection and discharging at each end).
    3. Pipe sizes shall be indicated on the plans at each change in direction and at all branch take off locations.
    4. Minimum distribution pipe size shall be ¾”, except ½” runout piping may be used after shut-off valves to individual terminals.
    5. Piping systems shall be designed and installed with adequate pitch to permit all sections of the system to be properly and fully drained.  All supply water piping shall be graded up and return graded down in the direction of flow.  Provide sediment leg and hose end ball drain valves at all low points of systems, at bases of riser, and at lowest points at equipment runouts, typically on downstream side of shut-off valves.
    6. Avoid running piping in such a way that will create air traps at local high points or tend to accumulate dirt legs at low local low points.  If otherwise unavoidable, provide automatic air vents at high points and blow down drain valves on dirt legs at low points.
    7. Differential pressure control of system pumps shall never be accomplished at the pump.  The pressure bypass shall be provided near the end of the system.
    8. All piping run within the building shall be run concealed in the finished portions of building in pipe spaces, ceilings or furred chases and exposed only in mechanical rooms and where shown on the drawings.
    9. No pipe shall pass in front of or interfere with any openings, door or window. Head room in front of openings and doors shall in no case be less than the top of the opening.
    10. Piping shall not pass exposed through electrical rooms or be erected over any switchboard or other electrical gear.
    11. Provide 2-inch clearance between insulated piping and other obstructions.
  2. Unions:
    1. No union shall be placed in a location which will be inaccessible.
    2. Unions shall be installed adjacent to all equipment for repair and replacement.
  3. Electrolysis Control:
    1. Electrolysis control between dissimilar materials shall be achieved through the use of dielectric nipples and a non-dielectric union.
    2. Dielectric unions are prohibited.
  4. Sleeves:
    1. All pipes passing through wall or floor construction shall be fitted with sleeves.  Each sleeve shall extend through its respective floor, wall or partition and shall be cut flush with each surface unless otherwise specified. Sleeves shall be two pipe sizes larger than the pipe when un-insulated and of sufficient size to allow for the insulation without binding. Floor sleeves in mechanical rooms shall extend 4 inches above finished floor, all other spaces minimum one inch above finished floor.
    2. Sleeves in bearing walls, masonry walls, masonry partitions, and floors shall be standard weight steel pipe finished with smooth edges. For other than masonry partitions, through suspended ceilings and for concealed vertical piping, sleeves shall be No. 22 USG galvanized steel.
    3. Where pipes pass through waterproofed floor or walls, design of sleeves shall be such that waterproofing can be flashed into and around the sleeves.
    4. Sleeves through exterior walls below grade shall have the space between pipes and sleeves caulked watertight.
    5. Install one-piece chrome-plated escutcheon plates with set screw at sleeves for all pipes exposed in finished areas.
    6. The annular space between sleeves and pipe shall be filled with fiberglass insulation and caulked in non-fire rated situations.
    7. Where pipes pass through fire-rated floors, walls, or partitions, the use of a UL approved system for through penetrations is required. The annular space around the pipes shall be packed with mineral wool or other noncombustible material and sealed at each exposed edge to maintain the rating of the system in accordance with the through penetration sealant manufacturer's recommendations.
  5. System and Equipment Drains:
    1. Where sectionalizing valves are installed, a drain shall be installed on downstream side of valve to drain that section of the system.
    2. All cooling tower drains and overflow are to be piped to sanitary system (not onto roof).
    3. All system and equipment drains are to be piped to a floor drain.
  6. Welding:
    1. All welding shall be done in accordance with the AWS.
    2. All boiler, pressure vessel, and hydronic piping welding must be done by certified welders must be done by certified welders as required by applicable codes.
    3. All welding must be done with portable welding machines.
  7. Pressure Tests:
    1. Tests shall be in accordance with Guide Specification.
    2. All piping must be tested prior to receiving insulation.
    3. Pressure tests must be witnessed and acknowledged in writing by a University representative.
  8. Piping System Cleaning:
    1. All hydronic systems shall be chemically cleaned after all items of equipment have been connected to the system and all piping has been complete.  Cleaning shall be done prior to installing chemical treatment of glycol, and prior to acceptance by the University.  See 23 25 00 for more information.
    2. Notify the University at least one week in advance of the date and time that system cleaning is to take place.  The University shall observe the system cleaning process.
.02 Gauge Piping
  1. All gauge piping on hydronic systems shall be extra-strong IPS red brass piping federal specification WW-P-351, Grade A, with threaded joints.
  2. For high pressure steam systems, pressure gauge connections shall be suitable for the maximum allowable working pressure and temperature, but if the temperature exceeds 406°F, brass or copper pipe or tubing shall not be used.  The minimum size syphon shall be 1/4" inside diameter.  For low-pressure steam systems, all gauage piping shall be ono-ferrous.
  3. Provide gauge cocks (low pressure or gate valves (high pressure) for isolations.
.03 Cooling Coil Condensate Drain Piping
  1. Refer to Guide Specifications
  2. Condensate drain piping shall not be less than 1" in diameter.
  3. Provide cleanouts at traps and other locations as required.
.04 Guide Specifications:
  1. Design Professional shall carefully review and edit the guideline specifications below, adapting them as needed to achieve application-specific, fully developed specifications for each project.
  2. These shall be edited using the process described in the instructions contained at the beginning of the document.  Proposed modifications shall be reviewed with OPP staff.
  3. Finalized version shall be included in the project contract documents.  Use of other specifications is not acceptable.
    Document Version Date
    Description

    23 21 13 Hydronic Piping Guide Specification

    July 6, 2012

    OPP minimum specification requirements for HVAC Hydronic Piping.

23 21 16 Hydronic Piping Specialties

.01 General Owner Requirements and Design Intent
  1. General Requirements:
    1. Professional shall design each hydronic piping application with all the required specialties to achieve the functional intent of effictive and safe operation, high reliability, and minimizing maintenance costs on those systems.
    2. Construction documents shall include all drawings and specifications necessary to clearly define the scope of work for the contractor to furnish and install all the hydronic piping specialties required to meet the functional intent above.
      1. Ensure details comply with manufacturer’s installation instructions.
      2. Locate in safe and convenient area and provide convenient means for frequently inspecting and cleaning.  Maintain manufacturer's recommended clearances.
      3. Coordinate requirements between Specifications and Drawings.
    3. Hydronic piping specialties work includes the following:
      1. Special Purpose Valves
        1. Pressure Reducing/Regulating Valves
        2. Safety Valves
        3. Combination Shut-off /Balancing Valves
        4. Differential Pressure Control Valves
        5. Packaged Coil Hook-up Sets
      2. Air Vents
        1. Manual Air Vents
        2. Automatic Air Vents
      3. Expansion Tanks
      4. Air and Dirt Removal Devices
        1. Air Separator
        2. Dirt Separators
        3. Strainer
        4. Side Stream Water Filters
        5. Open Systems Solids Separator Systems
      5. Flexible Pipe Connectors
  2. Applications and Selection Criteria:
    1. Flow Balancing Valves
      1. Refer to guidelines in 23 21 00 HYDRONIC SYSTEMS, .02 Flow Balance and Differential Pressure Control.
      2. Balancing valves shall be sized to allow accurate and reliable measurement for the specified flow rates, which may not necessarily be the same as the line size.
    2. Packaged Coil Hook-up Sets
      1. Piping system longevity is important, so hard piping is required.  Flexible neoprene/EPDM hoses are not to be used due to much shorter expected life of resilient material failing due to combination of effects of heat, chemicals, and dry rotting of rubber.
    3. Air Eliminator and Dirt Separators:
      1. General:  Refer to guidelines in 23 21 00 HYDRONIC SYSTEMS, .03 Air and Dirt Elimination
      2. High Performance Coalescing type air eliminator and dirt separators shall be installed in each closed hydronic system.
      3. The following types of air separator units shall NOT be used:
        1. Tangential type that depend on vortex action
        2. In-line type that depend on internal weir
        3. Units using PALL rings
        4. Units with strainer type screens requiring routine removal and cleaning.
      4. Select units at the point of peak efficiency per the manufacturer’s recommendation.  Units shall be selected for low system pressure drop, not to exceed maximum of 4 feet of head at maximum design flow rate.
      5. Dirt separator only and combination air/dirt separator units shall include removable bottom and mounted with sufficient clearance for accessing, pulling media and cleaning of interior of unit.
      6. Include detail and specifications to require a separate ball isolation valve of same inlet pipe connection size as auto air vent .
        1. This may not be a standard feature offered by manufacturers.    However, auto air vents have float and small orifice mechanism that can clog or stick (especially with glycol fluids).  These isolation valves are an important OPP requirement to enable quick and cost effective repair or replacement of auto air vent without shutting off and/or draining the main system.
      7. Refer to Guideline Details descriptions later in this section and select the best fit for each specific application.  Review and coordinate application with OPP Engineering Services and Water Treatment Supervisor.
        1. Exception:  If main piping distribution system uses all non-ferrous piping materials, then a single combined air and dirt eliminator model installed prior to the pump is recommended.
      8. Do not retrofit coalescing air eliminators to existing air control type systems with open (air cushion in direct contact with water) type expansion tanks without also upgrading the expansion tank to closed, pressurized type (bladder or diaphragm).
    4. Strainers:
      1. Strainers shall be strategically applied as necessary to protect system elements, but sparingly and with screens/mesh size appropriate to the location in the system to enhance energy efficiency.
      2. Piping systems shall be designed in a way to most effectively trap the bulk of the particles coming from the main and large branches of the piping distribution system in as few strainers as practical (particularly during cleaning and flushing operations) and to minimize the need for continually servicing individual strainers while still providing adequate protection of terminal coils and control valves.
        1. In general, subdivide the branch piping to serve groups of terminals that do not exceed 2” (the typical upper limit for use of copper pipe sizes) and provide a strainer assembly in the branch supply pipe with mesh size to protect each group of terminals downstream.
        2. Coordinate and combine the branch strainer with self-regulating pressure regulator as applicable for subdivided branches serving hydronic modules of similar terminal loads.  Refer to 23 21 00 HYDRONIC PIPING AND PUMPS, .02 Flow Balance and Differential Pressure Control for additional information.
        3. The individual strainers at each heating/cooling terminal unit shall still be installed.  They are required to protect the small orifices in terminal unit characterized control valves that are susceptible to trapping any soldering flux or other small debris that would initially be in the piping downstream of the branch strainers during cleaning and flushing operations.  However, the intent would be to remove the screens after the system has been properly cleaned and flushed but kept with the strainer body to reinsert if/when needed for future system chemical cleaning/flushing.
        4. Include a flushing bypass valve assembly across the terminal runouts of each device protected by strainers and at the branch strainer assemblies to allow for main system chemical cleaning/flushing circulation without clogging downstream device or strainer assemblies with materials intended to be removed by the process back at the central plant dirt removal equipment.  Coordinate with requirements in Water Treatment Standards and Guidespec sections.
        5. Coordinate these requirements for Branch strainers for groups of multiple small terminal units with the Guidespec and well-defined drawing plans and details.
      3. Do not apply fine mesh strainers in suction side of pumps serving open cooling tower condenser loops or other open systems that can quickly clog.
        1. Not only will pressure drop quickly increase, dropping performance in increasing energy cost, but cavitation will occur which will quickly damage equipment.
    5. Side Stream Water Filters
      1. Refer to HVAC Water Treatment design standard 23 25 00 and guidespec section to coordinate requirements.
    6. Open Systems Solids Separator Systems
      1. Solids separator systems (similar to HVAC options offered by LAKOS)  that minimize maintenance and reduce energy, water and chemical consumption and that do not impose a varying pressure drop to the primary loop shall be engineered for each open application for lowest life-cycle cost. 
      2. Include automatic means to purge solids while minimizing makeup water requirements.
      3. Coordinate with Water Treatment for Open Hydronic Systems.
.02 Guide Specifications:
  1. Design Professional shall carefully review and edit the guideline specifications below, adapting them as needed to achieve application-specific, fully developed specifications for each project.
  2. These shall be edited using the process described in the instructions contained at the beginning of the document. Proposed modifications shall be reviewed with OPP staff.
  3. Finalized version shall be included in the project contract documents. Use of other specifications is not acceptable.
    Document Version Date Description

     23 21 16 Hydronic Piping Specialties Guide Specification

     

     November 15, 2013

     

    OPP minimum specification requirements for HVAC Hydronic Piping Specialties.

 
 .03 Guideline Details
  1. Professional shall carefully review and edit the guideline installation details below, adapting them as needed to achieve application-specific, fully developed details for each project.
    Document Version Date Description
     

    Detail # 232113-D01

    Hydronic Plant Piping Schematic (AutoCAD)

    Hydronic Plant Piping Schematic (PDF)

    November 9, 2011 This schematic detail indicates general requirements and arrangement of hydronic specialties associated with each closed hydronic plant system with a combined air and dirt eliminator.  This is NOT the preferred arrangement, due to the undesirable complexity of the blowdown arrangement and associated procedures.  However, in cases where a combined air and dirt eliminator has been installed relatively recently (determined to be in excellent to good condition and working satisfactorily), or when existing space constraints do not allow separate units, then this arrangement may be considered.  Review these specific cases with OPP.
     

    Detail # 232113-D02

    Hydronic Plant Piping Schematic #2 (AutoCAD)

    Hydronic Plant Piping Schematic #2 (PDF)

    June 5, 2012 This schematic detail indicates general requirements and arrangement of hydronic specialties associated with each closed hydronic plant system with separate air and dirt eliminators.  This is the strongly preferred arrangement for all new construction and where it can be applied cost effectively to upgrades of existing systems.

  

23 21 23 HVAC Pumps

.01 Owner General Requirements
  1. HVAC Pumping Systems - Application Requirements
    1. Professional shall design each application for optimal operating efficiency, reliability, and flexibility with the lowest life cycle cost.
      1. General:  Comply with Hydronic System Design and Control requirements in current ASHRAE Standard 90.1 supplemented by University requirements below.
        1. 01 81 13 Sustainable Design Requirements
        2. 23 00 01.01 Summary of Design Intent
        3. 23 00 10.06 Central Heating and Cooling Plant
        4. 25 90 00 GUIDE SEQUENCES OF OPERATION
        5. Design Phase Submittal Requirements
      2. Design for efficient and stable system operation:  Professional shall determine the anticipated minimum and maximum loads for each pumping system and evaluate most appropriate number, combination and arrangement of pumps for optimal efficiency and stable operation of pumps over entire operating range.
        1. Overall pumping system shall be capable of operating effectively in extreme part load without deadheading or shutting off pumps entirely.  For large systems with broad range of loads, evaluate the application of an additional low load pump arrangement if minimum operating point would routinely be less than minimum staged or speed control capabilities of heating/cooling pump(s) sized for full load
          1. Professional shall determine this minimum pump flow for each application. As a general guideline, this is often expressed as a percentage (20-25%) of the best efficiency point (BEP) flow rate, but shall be reviewed to comply with the pump manufacturers’ recommendations.  On variable speed pump applications, this minimum flow is a function of the pump BEP at the minimum speed which will maintain the system control head, NOT merely based on the BEP flow rate of the full design capacity impeller/speed curve.
        2. Do not use automatic bypass valve installed in mains (directly across the pump) to ensure minimum flow.  These are often set up incorrectly or malfunction and contribute to poor system performance and yet are hard to detect as functioning improperly.
          1. If otherwise unavoidable to assure stable operation at very low flows (avoiding deadheading) and/or to maintain temperatures in the loop, small bypass control valves may be located out at the end(s) of the distribution piping system.  The sizing of these valves shall be based on the absolute MINIMUM flow requirements of the pump operating at its minimum speed (as described above), not just an arbitrary “rule of thumb” percentage of the full design flow.  In these cases, the bypass shall be normally closed and open only when pump/VFD is at minimum speed and DP setpoint is exceeded for a specified minimum period of time (5 minutes (adj.).
      3. Reliability:  Professional shall determine the consequences of system failure and provide for adequate system redundancy for each application. 
        1. Install fully redundant (N+1) stand-by pumps for extremely critical applications (such as critical research laboratories and computer centers) and/or as otherwise defined specifically in the Owner’s Project Requirements.
        2. Three (3) pumps in parallel, each sized for 50% of maximum load, with two operated in staged lead-lag control with the third in standby, offers the advantages of greater system turndown, three chances to total system failure, duty-standby ability, and smaller individual motors and pumps.
        3. For non-critical applications (such as general office spaces, general purpose classrooms, general commercial type spaces) full redundancy/complete standby is typically not required.  In such cases two (2) pumps in parallel, each sized for 50% of maximum load may be considered.  This arrangements offers greater turndown and still provides for approximately 70% of total system capacity in the event of a single pump failure.
      4. Flexibility: Consider potential future expansion of pumped systems. Extent of expansion will be determined on a case-by-case basis. Consult with the University Project Leader and Engineering Services.
  2. Selection Criteria:
    1. For HVAC Pump Systems (Chilled Water, Condenser Water, Hot Water Heating):
      1. Use end suction, double suction or in-line pumps as described in Equipment Requirements.
        1. Typically, use base mounted pumps for all applications over 10HP.
      2. Match pump curve characteristics to system application. 
        1. Flat characteristic pumps - closed systems with modulating two-way control valves.
        2. Steep characteristic pumps -  open systems, such as cooling towers where higher head and constant flow are usually desired.
      3. Select and specify pumps and motors to be non-overloading (not into the motor service factor), as the pump operates throughout any point along its flow/pressure curve.
        1. This must be carefully considered, particularly in multiple/parallel pump applications to avoid overloading in single pump operation.
      4. Select each pump as closely as possible to its best efficiency range, depending on application:
        1. Constant-speed pumps:  pick pump such that conservative design conditions are close to and just left of, peak pump efficiency (to allow for safe and efficient operation at actual operating point that are typically at lower head/higher flow).
        2. Variable-speed pumps:  pick pump such that conservative design conditions are close to and just right of peak pump efficiency (this allows for the pump to operate closer to the best efficiency curve as the speed is reduced to minimum since the actual system control curve is shifted up and thus to the left.)
      5. Select for quiet operation.  In order to minimize potential for internal noise generation, pumps shall be selected so that the ratio of impeller radius to cutwater radius shall be no greater than 0.85.
      6. Include additional gpm in pump capacity for bypass filter (approximately 10% of system capacity -  refer to bypass/sidestream filter requirements in chemical treatment section).
      7. Pumps shall be rated for minimum of 175 psi (12 bar) working pressure or higher as otherwise required to provide rated working pressure of at least 1.5 times maximum operating pressure.
      8. In general, specify pumps with 1750/1800 rpm motors, unless design condition necessitates alternate motor speed.
        1. Motors shall meet NEMA Premium efficiency levels.
        2. Comply with other special requirements for motors (shaft grounding) on variable speed drives indicated in 23 05 01.01 Motors and Drives
    2. Seals:  The Professional shall follow industry best practices and the recommendations of the pump manufacturer to select and specify the most appropriate seals for minimizing long term maintenance and the lowest life cycle cost.  Refer to the following general guidelines and review with OPP.

      Seal Type

      Typical Application Temperature Range (°F) Max. Working Pressure (psi) PH Limits
      Standard Mechanical (BUNA) Open or closed clear water systems (heating hot water, chilled water, closed loop condenser water). -20 to +225 175 7-9
      Standard Mechanical (EPR) Open or closed clear water systems (high temp hot water, special process, high temp, high PH). -20 to +250 175 7-11
      FLUSHED SINGLE SEALS (Stuffing Box Design) Closed or open systems where the temperature or pressure requirements exceed the limitations of the standard seal. -20 to +300 175 or 250 7-11 
      FLUSHED DOUBLE SEALS (Stuffing Box Design) Closed or open low pressure systems which may contain a high concentration of abrasives.  An external flush is required. 0 to +250 175  7-9
      PACKING (Stuffing Box Design) Open or closed systems which require a large amount of make-up water, as well as systems which are subjected to widely varying chemical conditions and solids buildup (open condenser water). 0 to +190  - 7-9
    3. Documentation:  The Professional shall schedule all pump performance data and project/application specific requirements on the drawings (not within project specifications).  Pump schedules shall indicate identification tag, system served, operation (Duty or Standby), pump type (i.e. end suction, double suction), service fluid (i.e percentage of glycol, operating temperature, etc.) gpm, pump head, rpm, minimum pump efficiency (or maximum brake horsepower), motor horsepower, location, manufacturer and model number (basis of design), and electrical characteristics including starter/speed drive type, and whether on normal/emergency standby power (where applicable).
      1. It is imperative to define minimum pump efficiency/max bhp to ensure final pumps submitted by contractor meet actual optimized design performance, not just within nominal motor horsepower.
      2. Where remote start-stop, or status monitoring is required, use combination magnetic starter or variable speed drive (not manual starter).
      3. Professional shall follow University Equipment Acronym List and Equipment numbering policy defined in Mechanical Identification in developing equipment tags and schedules.
    4. Equipment Layout:  Comply with all Space Planning Requirements indicated in 01 05 05.02 Planning for Engineered Building Systems.  Maintain minimum recommended service clearances around pumps of 24”.
    5. Quality Assurance and Uniformity:  
      1. All pumps shall be constructed and tested in accordance with current ANSI/HI Standards for centrifugal pumps.
        1. Small pumps (under 10 hp) shall meet at least level B performance of ANSI/HI 1.6 Standard.
        2. Large pumps (10 hp and greater) shall be factory tested and certified to level A performance of ANSI/HI 1.6 Standard.
      2. Pump manufacturer shall be ISO-9001 certified. Pumps shall be of U.S. manufacturer.
      3. Provide pumps of same type by same manufacturer.
  3. Related Standards Sections
    1. 23 00 01 Owner General Requirements and Design Intent
    2. 23 00 10 Systems Selection and Application
    3. 23 01 00 OPERATION AND MAINTENANCE OF HVAC SYSTEMS
    4. 23 05 01 Mechanical General Requirements
    5. 23 05 93 Testing, Adjusting, and Balancing for HVAC
    6. 25 00 00 INTEGRATED AUTOMATION
    7. 25 90 00 GUIDE SEQUENCES OF OPERATION
    8. 26 29 23 Variable-Frequency Motor Controllers
.02 Equipment Requirements
  1. Base Mounted, Flexible Coupled, End Suction Pumps
    1. Base mounted end suction circulating pumps shall be of the centrifugal, single stage type, with back pull-out design.
    2. Pump and motor shall be connected through a flexible drive coupling (per requirements below), with safety guard.
    3. Pumps shall be bronze fitted, with bronze impeller, statically and hydraulically balanced.
    4. A replaceable bronze shaft sleeve shall completely cover the wetted area under the seal.
    5. Volute shall have gauge tappings at the suction and discharge nozzles and vent and drain tappings at the top and bottom.
    6. Pump bearing housing shall have heavy duty regreasable ball bearings.
    7. Pump and motor shall be properly mounted and aligned on a common, welded, rigid structural steel or cast iron base, with an enclosed perimeter with opening for grouting in place. Base shall be grouted in place.
  2. Base Mounted, Flexible Coupled, Double Suction Circulating Pumps
    1. Base mounted double suction circulating pumps, shall be centrifugal, single-stage type with horizontal split case design for servicing the impeller without disruption of the piping.
    2. Pump and motor shall be connected through a flexible drive coupling (per requirements below), with safety guard.
    3. Pumps shall be bronze fitted, with bronze impeller, statically and hydraulically balanced.
    4. A replaceable bronze shaft sleeve shall completely cover the wetted area under the seal.
    5. Volute shall have gauge tappings at the suction and discharge nozzles and vent and drain tappings at the top and bottom.
    6. Pump bearing housing shall have heavy duty regreasable ball bearings.
    7. Vertical split case design is also acceptable, where floor space is at a premium.
    8. Provide rigid steel grout base and grout as described for End Suction Pumps section above.
  3. In-Line (horizontal or vertical) Circulating Pumps
    1. In-line circulating pumps shall be centrifugal, single stage; with cast iron body and bronze impeller and trim construction, unless special fluid handling dictates otherwise.  Impeller shall be both hydraulically and dynamically balanced.
    2. The motor shaft shall be connected to the pump shaft via a replaceable flexible or split coupler with guard.
      1. Coupler shall permit seal maintenance without disturbing pump or motor.
      2. Motors shall be industry standard shaft and mounting for readily available and cost effective replacement, not close-coupled that have special shaft/motor mount requirements.
    3. The pump internals shall be capable of being serviced without disturbing piping connections.
    4. A replaceable bronze/non-ferrous shaft sleeve shall completely cover the wetted area under the seal.
    5. Pump shall be of a maintainable design and for ease of maintenance should use machine fit parts, not press fit components.
    6. Comply with manufacturer’s installation instructions for supporting pump to maintain proper shaft alignment.
  4. Pumps - Close Coupled
    1. Close coupled pumps are not permitted.
      1. Although they may save space and have lower first cost, close-coupled pumps are typically undesirable from a maintenance perspective regarding repairing seals or replacing special order motors with special shaft or base mounting hole requirements.
      2. Will consider exceptions for very small, in-line, booster pump applications in which it is more economical to replace pumps in entirety rather than service parts.
  5. Pump Flexible Couplings
    1. Pump flexible couplings shall be the elastomer-in-shear toothed or donut element type.  Coupling assembly shall have 4-way flexing action that can absorb torsional, angular parallel and axial shock, vibration and misalignment. 
      1. Toothed element type shall be comprised of three parts, two metal flanges with internal teeth that engage an elastomeric flexible element (sleeve) with external teeth. Each flange is attached to the respective shaft of the driver and driven and torque is transmitted across the flanges through the sleeve. As manufactured by TB Woods “Sure-Flex” or equivalent.
      2. Donut elastomer element type shall be comprised of three components, two shaft hubs and a lightweight, splin-in-half elastomer donut element with bonded attachment collars that are bolted to the hubs for easy replacement without removing the hubs..  Each hub is attached to the respective shaft of the driver and driven and torque is transmitted across the shafts through the element.  As manufactured by TB Woods “Dura-Flex” or equivalent.
    2. Couplings shall be center drop-out, spacer type to allow disassembly and removal without removing pump shaft or motor.
    3. Select suitable sleeve material for each application depending on maximum load, constant or variable speed/torque, and operating conditions for most trouble-free and longest service life. 
    4. “Jaw” type couplings shall not be permitted.
.03 Execution
  1. Installation and Start-up/Commissioning
    1. Install pumps and accessories in strict accordance with the manufacturer's requirements for maintaining optimum hydraulic performance and lowest accessory pressure drop.
    2. Base mounted pumps installed on slab-on grade shall typically be mounted on a concrete housekeeping pad with anchor bolts.  Base mounted pumps installed above grade shall be provided with concrete inertia bases with spring vibration isolators.
      1. Exception:  For sensitive applications, such as experimental research that could be affected by mechanical system vibrations, provide inertia bases and spring vibration isolation regardless of floor construction.
      2. In general, the housekeeping pad shall be at least 4 in. thick and 6 in. wider than the pump base plate on each side.  Vibration type bases shall also include a minimum 2” pad underneath to prevent water from reaching and corroding vibration spring mountings.
      3. Steel pump frame bases shall be leveled on housekeeping pad or inertia sub-base, rigidly anchored, and completely filled with non-shrink grout formulated for equipment bases in accordance with pump manufacturer’s installation instructions.  Grout prevents the base from shifting, fills in irregularities, and further stiffens the base to maintain long-term alignment.
      4. Sound and Vibration Control Requirements:  Comply with the following:
        1. Standard 23 05 01.05 Sound and Vibration Control. Which also references the ASHRAE Handbook—HVAC Applications; Vibration Isolation and Control.
    3. All piping connections to pumps shall be independently supported so that no strain is imposed on the pump casing flanges.
      1. Support suction diffusers and piping directly in contact with pump from housekeeping pad (for slab on grade) or inertia base (above grade).
    4. Install line-sized, low pressure drop shutoff valves (typically butterfly) in the suction and discharge piping of each pump to permit servicing the pump and strainer without draining the system. In multiple pump arrangements, install a non-slam check valve in each pump discharge to prevent reverse flow in a non-running pump.
    5. Provide low pressure drop, flow-measuring station (venturi flowmeter per 23 05 19 Measuring Instruments for HVAC) located in the pump discharge.  Allow adequate length of straight pipe between the pump discharge and the flow station for measurement accuracy.  Install flow measuring devices in strict accordance with manufacturer requirements to ensure proper performance.
      1. In general, do not use manual balance valves on pump discharge. See Hydronic System Balancing requirements below.
      2. Multi-purpose (triple duty) valves are not permitted because:
        1. Their pressure drop is usually greater than separate check and butterfly shutoff; 
        2. they are often inaccurate and particularly at lower pressure drops,
        3. the check valve portion cannot be repaired without draining the system unless an additional shut off valve downstream
    6. Provide flexible pipe connectors on suction and discharge sides of base-mounted pumps between pump casing/suction diffuser and isolation valves for effective vibration isolation.  
      1. Exception:  Flexible connectors are typically not required on in-line pumps (allowing pumps to be supported from adjacent piping.  However, special noise or vibration requirements in sensitive applications may overrule and still require the isolators.
      2. Rubber Spherical Type:  shall be peroxide cured EPDM throughout with Kevlar® tire cord reinforcement.
        1. End connections shall be threaded or flanged.  The assembly shall encase solid steel rings molded within the rubber to prevent pull out.  Flexible cable wire is not acceptable.
        2. Minimum tempature rating shall be 250°F.
        3. Sizes 3/4" through 2" may have one sphere with bolted threaded flange assemblies.
        4. Sizes 2-1/2" through 14" shall have a ductile iron external ring between the two spheres.
        5. Sizes 16" through 24" may be single sphere.
        6. Include control rods or cables as recommended by manufacturer for the application.  The piping gap shall be equal to the length of the expansion joint under pressure.  Control rods passing through 1/2" thick neoprene washer bushings large enough to take the thrust at 1000psi of surface area may be used on unanchored piping where the manufacturer determines the condition exceeds the expansion joint rating without them.
        7. Strictly follow all of the manufacturer's installation instructions.
        8. Documented performance:  Submittals shall include test reports by independent consultants showing minimum reductions of 20 DB in vibration acceleration and 10 DB in sound pressure levels at typical blade passage frequencies on this or a similar product by the same manufacturer.
        9. Shall be SAFEFLEX series as manufactured by Mason Industries, Inc.
        10. Substitutions must have certifiable equal or superior characteristics.
      3. Do not use braided metal pipe connectors.   They do not provide adequate vibration isolation.
      4. All flexible connectors shall be installed on the quipment side of the shut off valves so they can be easily isolated from main system for future inspection and replacement.
    7. Pump suction piping shall be kept free of air traps and pockets.
    8. Install long-tapered reducers and increasers on suction and discharge lines to smoothly transition the pipe size and pump flanges with minimum pressure drop.  Abrupt transitions, bushings and reducing flanges are not permissible.
    9. Install a strainer (coarse mesh) in the suction pipe to remove foreign particles that can damage the pump.  Final piping connection to pump suction shall be as direct and as smooth as possible to ensure uniform flow distribution.  Follow pump manufacturer’s installation instructions to ensure performance.   Eccentric reducers shall be used at the pump suction flange to reduce the potential formation of air pockets.
      1. On base mounted pumps, install a long radius elbow and straight section of piping at least 5 pipe diameters long (or as otherwise recommended by pump manufacturer’s installation instructions) at the pump inlet to ensure uniform flow distribution.  Suction diffusers (combination elbow, flow straightening vanes and strainer) are recommended in lieu of the straight pipe requirement where spacing is a constraint.
      2. Do not use strainers/suction diffusers on pumps for open condenser water systems pulling directly from cooling towers, as they can become quickly blocked, resulting in severely reduce system capacity, pump cavitation and damage.
      3. Be sure to remove any temporary fine mesh start-up screen after cleaning/flushing and commissioning and replace with normal screen to protect the pump and minimize the suction pressure drop in normal operation.
      4. Pump applications with a suction lift shall have an eccentric reducer or a long-sweep reducing elbow at the suction to avoid air pockets.
    10. Provide a purge cock on top of the casing, a hose end drain valve on the bottom, and a hose end drain valve on blow-off side of the strainer/suction diffuser.
    11. Install a single pressure gauge with ¼” ball valves and interconnecting piping from the suction to the discharge sides of the pump and upstream of the strainer shall be provided on each pump in order that each pressure and/or difference can be observed from a single gauge.
    12. For vibration testing requirements, refer to Section 23 05 01 .05 Sound and Vibration Control.
      1. Final Alignment: All base-mounted, flexible-coupled pumps shall have final alignment of motors, couplings and pump shafts performed by an independent HVAC Vibration Analyst, using precision laser equipment.
        1. The Contractor shall coordinate and contract the services of the University’s HVAC Vibration Analyst (At University Park, arranged through the Supervisor of Refrigeration and Mechanical Services) whenever available.  Otherwise (and at Commonwealth Campus locations) the Contractor shall hire an independent, third party Vibration Analyst meeting the approval of the University. 
        2. Align the pump shaft couplings properly and shim the motor base as required to be within tolerances recommended by pump manufacturer, and/or by specific coupling type, and/or University HVAC Vibration Analyst - whichever is most stringent.
        3. Measured results of vibration testing and final alignment shall be recorded and coordinated to be entered into University’s Preventative Maintenance Software at time of start-up AND included in final report to be submitted as part of TAB/O&M submittals.
        4. IMPORTANT:  Incorrect alignment causes rapid coupling and bearing failure.  This work must be completed to the satisfaction of the University as part of the criteria determining Substantial Completion.
    13. Hydronic System Balancing;  Hydronic systems shall be proportionately balanced in a manner to first minimize throttling losses; then the pump impeller shall be trimmed or maximum pump speed shall be adjusted to meet design flow conditions at actual minimum pressure required to satisfy critical zone(s).
      1. On constant speed pumps, the amount of overpressure shall be determined at time of system balance and the impeller trimmed to eliminate as much of the overpressure as possible.
      2. On variable speed systems, the pump controls shall be adjusted by limiting the maximum speed of the pump.
      3. Exceptions: Impellers need not be trimmed:
        1. For pumps with pump motors 5 hp or less.
        2. When throttling results in no greater than 5% of the nameplate horsepower draw, or 3 hp, whichever is less, above that required if the impeller was trimmed.
      4. For testing, adjusting and balancing requirements, refer to 23 05 93 Testing, Adjusting, and Balancing for HVAC.
    14. For insulation requirements, refer to 23 07 00 HVAC INSULATION.
      1. Provide removable insulation sections to cover parts of equipment that must be accessed periodically for maintenance (i.e. – strainers, grease fittings, vent/drain plugs or valves, p/t ports)  without damaging insulation or compromising vapor barrier; include metal vessel covers, fasteners, flanges, frames and accessories.
      2. Ensure that the bearing assembly grease fittings remain accessible and visible. Any vent slots on the sides and bottom of the bearing assembly should remain uncovered and completely open.
      3. Insulation on pump systems operating below ambient dew point (such as chilled water) shall be insulated with closed cell foam with all joints and penetrations completely sealed to maintain vapor barrier.
    15. Provide mechanical identification per University Standards.
      1. 23 05 01.06 Mechanical Identification
    16. Refer to Detail [23 21 23 – D01] for typical end suction pump installation.  (Details are not yet available in WEB-based manual.)
    17. Refer to Detail [23 21 23 – D02] for typical in-line pump installation.  (Details are not yet available in WEB-based manual).

23 22 00 STEAM AND CONDENSATE PIPING AND PUMPS

.01 Steam Piping (In Building)
  1. All steam piping shall be graded in the direction of flow, 1" in 40 ft.  At all low points in the steam piping system a drip station shall be installed. 
  2. Provide offsets and bends wherever possible to allow for expansion and to control pipe movement.  Provide anchors and expansion joints as required.
  3. Steam piping shall be black steel Schedule 40 ASTM A-53, Grade B.  Use all steel valves for steam piping.
  4. Joints 2" and smaller, screwed; 2-1/2" and larger, welded or flanged.  All high pressure piping welded.
    1. All steam pipe strainers and traps shall be removed and cleaned prior to acceptance by the University.
  5. ALL CLEANING WORK IN THIS SECTION MUST BE WITNESSED BY THE DEPARTMENT OF GENERAL SERVICES (FOR DGS PROJECTS) AND UNIVERSITY INSPECTOR TO BE ACCEPTABLE.
  6. Drip legs shall be a minimum 1/2 the size of the steam main 18" in length with blow down valve at the bottom.  Trap line connection shall be located in the center of the drip leg.
  7. Refer to 23 07 00 for Insulation.    
.02 Steam Condensate Return Piping (In Building)
  1. All steam condensate shall drain completely by gravity or be pumped.  Steam pressure shall not be used to lift condensate after a trap.
  2. All gravity return condensate lines shall be pitched 1" in 30' in the direction of flow.
  3. All condensate return lines in buildings shall be Schedule 80 black steel, ASTM A-53, Grade B.  Use all steel valves for condensate piping.
  4. Joints 2" and smaller shall be screwed; 2-1/2" and larger shall be welded or flanged.
.03 Steam and Steam Condensate Specialties
  1. Traps and strainers shall be installed with isolation valves, check valves, and telltale drain to facilitate cleaning, maintenance and to check proper operation of trap.
  2. Provide all traps with a minimum condensate collection leg of 18".
  3. For low-pressure drips, use float and thermostatic.
  4. For high-pressure drips use thermodynamic traps.
  5. For modulating service use float and thermostatic.
  6. Pressure Reducing Valves
    1. The Main Steam Pressure Control Stations shall consist of an air-operated diaphragm control valve and a remotely-adjustable external air-operated pressure control pilot.  Direct spring-operated valves and valves with steam pilots will not be accepted.  Air lines shall be provided under BAS.
    2. The diaphragm control valve shall have a flanged cast bronze body having a 250 psi pressure rating.  It shall have hardened stainless steel trim with a stellited seat ring.  The valve shall be single seated, and suitable for dead end service with a 250 psi pressure drip.  It shall operate on a 0 to 22 psi air signal from the control pilot and be normally closed (air to open).
    3. The air-operated pressure control pilot shall be of the differential type suitable for readjustment from a remotely-located air loading panel.
    4. The pressure controller shall be capable of maintaining outlet pressure within plus or minus 1/2 psi when passing flow from zero to the maximum specified, regardless of gradual inlet pressure variations.
    5. The Steam Pressure Controller shall consist of a diaphragm control valve, type DDL or GPK, and a control pilot, Type UDDV, and a remote panel loader, Type PPF, all as manufactured by the Leslie Company or equal by Spence or Sarce.  Remote panel loader shall have integral filters or be proceeded by strainers.
    6. Consideration shall be given to two-stage reduction when required by pressure and two-stage parallel reduction when required by varying load conditions.
    7. All pressure-reducing valves shall have an ASME/National Board stamped safety valve set at the low pressure side maximum pressure, with sufficient relieving capacity for a fully open PRV and its bypass line, along with a pressure gauge on the low pressure side of the PRV.  The safety valve shall be piped full size minimum to a safe point of discharge outside the building.
    8. The safety relief vent for PRV's serving systems of different pressures shall be piped independently of each other to a safe point outside the building.
    9. Refer to Detail [23 xx xx .xx].  Details are not yet available in WEB-based manual. 
  7. Y-TYPE PIPELINE STRAINERS
    1. General:  Locate strainers to protect components from steam or condensate-born debris.  Install in entering line ahead of the following equipment, and elsewhere as indicated, if integral strainer is not included in equipment.
      1. Heat Transfer Equipment
      2. Pressure reducing or regulating valves.
      3. Steam traps.
      4. Temperature control valves.
    2. Product Requirements:  Provide strainers full line size of connecting piping, with ends matching piping system materials.  Select strainers for respective working pressure of piping system.  Provide type 304 stainless steel screens, with perforations ( or mesh for sizes under 2:) per schedule below.       
      SERVICE PIPE SIZE Coarse Straining
      (typically at central plant equipment)

       Medium Straining
      (typically at terminal equipment, i.e. with temperatures
      or pressure control valves)

      Steam

      1/4 to 2"

      1/16" (0.057)

       1/32" (0.033)
      (20 mesh)


      2 1/2" and up

      1/16" (0.057)

       3/64" (0.045)

      1. Threaded Ends, 2" and Smaller:  Carbon steel body screwed screen retainer with centered blowdown fitted with drain plug.
      2. Flanged Ends, 2 1/2" and Larger:  Steel body, bolted screen retainer with blowdown fitted with hose end drain valve.
      3. Acceptable Manufacturers:  Subject to compliance with requirements, provide Y-type strainers of one of the following:
        1. Apollo; Conbraco
        2. Armstrong International
        3. Hoffman Specialty ITT; Fluid Handling Div.
        4. Metraflex Co.
        5. Spirax Sarco
        6. Watts Regulator Co.
    3. Installation: Install Y-type strainers full size of pipeline, in accordance with manufacturer's installation instructions.
      1. IMPORTANT:  Y-type strainers in horizontal steam or gas lines shall be installed so that the pocket is in the horizontal plane.  This prevents water collecting in the pocket, in order to avoid risk of serious equipment damage and safety hazard from water hammer and related stresses and to prevent any water droplets being carried over, which can cause erosion and affect heat transfer processes.helping to prevent water droplets being carried over, which can cause erosion and affect heat transfer processes.
      2. On liquid systems the pocket should point vertically downwards.  This ensures that the removed debris is not drawn back into the upstream pipework during low flow conditions.Although it is advisable to install strainers in horizontal lines, this i snot always possible, and they can be installed in vertical pipelines if the flow is downwards, in which case the debris is naturally directed into the pocket.  Installation is prohibited with upward flow, as the strainer would have to be installed with the opening of the pocket pointing downwards and the debris would fall back down the pipe.
      3. Install pipe nipple and hose end drain valve in strainer blowdown connection, full size of connection, except for strainers 2" and smaller installed ahead of control valves feeding individual terminals.
      4. Where indicated, provide drain line from shutoff valve to plumbing drain, full size of blowdown connection.
      5. Be sure to remove any temporary fine mesh start up screens if used during initial cleaning and flushing of systems.
.04 Blowdown Piping (Boiler)
  1. For high pressure boilers (over 15 psig steam), specify a heat recover unit on the blowdown system.  Flash steam could be utilitzed at the deaerator or other low pressure applications and hot water could be used to pre-heat the boiler make-up water.
    1. Verify with the University, or with the local municipal authority, the permissible maximum temperature of waste water.
  2. Piping:  Schedule 80, black steel, welded.
  3. Pipe to funnel type floor drain or approved receptor.

23 23 00 REFRIGERANT PIPING

.01 Refrigeration (General)
  1. Where water cooled condensing units are specified, cooling towers or evaporative condensers shall be utilized.  Cooling water to waste systems are not permitted.
  2. Where defrost units are required, they shall be electrically operated with adequate space provided to replace defrost elements.  Defrost should not be limited to electrical units.  In larger installations hot gas defrost is preferred.
  3. Installations shall be provided with necessary protective devices including, but not limited to electric overload devices, low suction pressure cutouts (manual reset), high head pressure cutouts (manual reset), low lube oil pressure cutouts (manual reset), oil traps, crankcase heaters, and anti-recycling.
  4. Systems shall be designed for 95°F outdoor ambient summer conditions and where winter operation is desired, 0°F conditions.
  5. All installations shall be performed by qualified refrigeration mechanics.
  6. Maintain manufacturer's minimum recommended clearances, including distances to any plant material.
.02 Refrigerant Specialties
  1. Installations shall be complete with filters, dryers, sight glass, and thermostatically controlled solenoid valve for pump down operation.
  2. Provide isolation valves at all specialties.
.03  Refrigerant Piping
  1. Refrigerant liquid and suction piping shall be type "L", hard drawn.
  2. Joints shall be made by brazing at a temperature greater than 900 degrees Fahrenheit.  A nitrogen purge shall be maintained while brazing all joints.  Copper-to-copper joints and copper-to-brass joints shall be made with 15 percent silver brazing alloy.
  3. Main piping fittings for driers, sight glasses, expansion valves, and controls should be flare type fittings, when available.
  4. Refrigerant system should be evacuated to 500 microns held for at least 24 hours under this vacuum prior to charging the system with refrigerant.  The procedure must be witnessed by PSU representatives.
  5. Double suction risers shall be employed on systems with capacity reduction and where required by lift.
  6. Precharged lines are not acceptable for systems above 5 tons.
  7. All refrigeration piping to be anchored with Hydra Zorb type anchors.
  8. Refer to Details [23 xx xx .xx] and [23 xx xx .xx].  Details are not yet available in WEB-based manual.

23 25 00 HVAC WATER TREATMENT

.01 General Owner Requirements and Design Intent
  1. The Professional shall design each HVAC water treatment application with all the required equipment, materials and labor to achieve the functional intent of effective and safe operation, high reliability, and minimizing maintenance costs on those piping systems.
    1. Construction documents hall include all drawings and specifications necessary to clearly define the scope of work for the contractor to furnish and install all the components and materials required to meet the functional intent above.
      1. Ensure details comply with manufacturer's installation instructions.
      2. Locate in safe and convenient area and provide convenient means for frequently inspecting and cleaning.  Maintain manufacturer's recommended clearance.
      3. Coordinate requirements between Specifications and Drawings.
    2. Guide Specifications are included at the end of this section.
  2. At University Park Campus, OPP's Water Treatment Contractor or authorized Mechanical Water Treatment representative shall be given adequate advance notification (minimum 4 weeks) in order to supervise the introduction of the chemical treatment into the system.
  3. The Professional shall discuss provisions of the chemical treatment program at Commonwealth Campus projects with the University.
  4. All closed systems (hot water and chilled water) shall be provided with chemical treatment.
  5. All open recirculating systems (cooling towers) shall be provided with chemical treatment.
  6. All steam boilers shall be provided with chemical treatment.
  7. Guidelines for the use of glycol are also covered in this section.
  8. Minimum requirements for flushing and cleaning of new and existing systems are covered in the Guide Specifications.
.02 Closed Systems Water Treatment (Hot & Chilled Water)
  1. Equipment: All closed loops shall have a Bypass Feeder (Pot Feeder) piped into the circulation line, so that chemical treatment can be introduced into the system.  A flow indicator shall be installed to show indication of flow through the bypass feeder.
  2. Equipment Installation: Bypass feeder shall be installed across the re-circulation pump to allow for a minimum 5 psi pressure drop.  The discharge side of the pump shall be piped to the bottom of the feeder and the suction side piped to the top.  This will allow an upward flow of material in the feeder.  The shot feeder shall be located at least 12 inches off the floor, and manual ball valves shall be conveniently located near the bypass feeder to isolate and drain the bypass feeder. One ball valves shall include a memory stop set to keep a trickle flow through feeder to keep seals wetted.
  3. Pre-operational Cleaner: All systems shall be flushed with water prior to chemical cleaning.  Use water meter to fill, record, and tag (permanent tag) the system with the actual system volume.  Chemical cleaner shall be added to remove grease, mill oil, organic soil, flux, iron oxide etc.  All terminal control valves and valves at end of runs (“dead legs”) shall be opened so that cleaner is circulated through the whole system.  After cleaning, all strainers shall be flushed, and strainer screens cleaned or replaced.  Once closed loop is chemically cleaned, system shall be dumped and flushed with water so that all cleaning chemical is removed from the system.
  4. Chemical treatment: Shall be an alkaline, buffered, nitrite-based corrosion inhibitor, maintained at proper levels to prevent corrosion to the system. 
.03 Open Re-circulating Systems Water Treatment (Cooling Towers)
  1. Equipment:
    1. All towers (including Evaporative Condenser type Towers) shall be equipped with an automatic blowdown controller, LMI, model DC4000, or approved equivalent.  Controller shall have flame retardant, molded TPFE housing and clear polycarbonate cover that can be secured with a padlock.  Controller shall be capable of feeding chemicals 4 ways: Pulse, Percent of time, Limit timer, and Percent of bleed.  Controller shall have LED indicators for all functions and shall have a 4 to 20 mA output.  Controller shall be supplied with a flow assembly to include the conductivity probe as well as a flow switch.  The flow switch shall be capable of preventing the controller from operating the blow down valve or feeding chemical if no flow is indicated.  Flow assembly shall be able to be isolated by manual ball valves so that assembly can be repaired or replaced.
    2. The fresh water make-up line to the tower shall have an electrical contacting water meter, Carlon, model JSJ, or approved equivalent.  This water meter must be capable of sending an electronic pulse to the controller to allow the controller to feed chemical based on the volume of fresh water to the tower.   The water meter shall be installed with a by-pass that is capable of being valved off so that water can still feed the tower and meter can be taken out for repairs.
    3. Chemical feed pump shall be LMI, model P131-392SI, or approved equivalent capable of pumping 10 gal/day maximum.  Pump shall be supplied with an integral anti-siphon/priming valve.  All tubing shall be clear polyethylene.  Pump shall be capable of modulating its stroke and speed.  Pump shall have a liquid end construction of Polypropylene/Flourofilm/Polyprel.
    4. If the condenser water volume is greater than 800 gallons, a solid halogen feeder (brominator) shall be installed to provide a controlled distribution of tableted, approved bromine and chlorine donors.  The brominator shall have an integrally mounted flow meter for accurate feeding and manual valve with the capacity to adjust the flow from 0 to 5 gal/min.  A pressure relief valve shall be used on those applications where the brominator is used on a pressure discharge or if the unit will be used in with conjunction with a solenoid and timer.   For systems with less than 800 gallons, a simple water filter housing shall be provided for the feeding of the solid holagen.
  2. Equipment Installation:
    1. Blow down valve shall be installed so that the valve can be isolated by conveniently located ball valves so that blow down valve can be removed, repaired, and or replaced.  A Strainer shall be installed up stream of the blow down valve to catch any dirt or debris that may prevent the blow down valve from functionally properly.  Strainer shall be capable of easily being cleaned and replaced.
    2. The chemical inhibitor shall be injected into an area of high flow and shall use an injection nozzle that has a check valve to prevent the flow of condenser water into the chemical injection line.
    3. All new systems shall have a corrosion coupon rack installed, so that coupons can be used to help diagnose any potential corrosion problems.  The rack shall be located so that coupons can be easily removed and installed.
  3. Pre-operational Cleaner: All condenser water systems shall be flushed with water prior to chemical cleaning.  Use water meter to fill, record, and tag (permanent metal tag) the system with the actual system volume.  Chemical cleaner shall be added to remove grease, mill oil, organic soil, flux, iron oxide etc.  Once condenser water system is chemically cleaned, the system shall be dumped and flushed with water so that all cleaning chemical is removed from the system.  After cleaning, all strainers shall be flushed, and strainer screens cleaned or replaced.
  4. Chemical Treatment: Inhibitor shall be designed to control corrosion of all metals, as well as inhibit the formation of scale. The chemical inhibitor shall be a blend of organic inhibitors and dispersants that contain no molybate, zinc, or heavy metals.  The use of the chemical inhibitor shall be in compliance with all local discharge regulations.  The chemical treatment program shall maintain proper levels of chemical inhibitor to sustain a LSI of 2.5 to 3.0.   PH of the condenser water shall not be below 8.0 and not exceed 9.5.   Biocide program shall be limited to solid halogen feed chemicals. These chemicals shall be fed in a manor that prohibits the growth of bacteria, especially Legionella prevention. 
.04 Steam Boilers Water Treatment
  1. Equipment:
    1. The fresh water make-up to the feed water tank shall be softened to remove calcium and magnesium particles from the water.  The softeners shall be regenerated automatically based on a water meter. The unit shall be sized so that softener regenerates approximately twice per week.
    2. The feed water tank shall be sized to allow for a minimum of 10-20 minutes residence time of the feed water to allow sufficient time for pre-warming of the feed water.  The feed water tank shall be fitted with a stainless steel sparge line. The sparge shall be located on the bottom of the tank to allow for sufficient contact with the feed water.  Holes in the sparge line shall be positioned to the center of the tank away from the tank walls. The oxygen scavenger shall be fed directly into the feed water tank below the water line with a Stainless Steel injection nozzle.  The feed water tank shall have a factory-installed coating to help prevent corrosion on the tank walls.
    3. A conductivity controller, LMI, model DC-4000, or approved equivalent shall be used to maintain conductivity limits within the boiler.  Controller shall have flame retardant, molded TPFE housing and clear polycarbonate cover, which can be secured with a padlock. Controller shall have LED indicators for all functions and shall have a 4 to 20 mA output. The controller will actuate a motorized ball valve when conductivity reaches above the set point.  The controller shall then close the motorized ball valve when the conductivity goes below the deadband.  The controller must be easily calibrated and come with a high-pressure conductivity probe.  Controller shall be provided with a motorized ball valve and globe valve to prevent flashing.
    4. Two mixing tanks shall be provided: one for the dispersant and phosphate liquid chemical, another mix tank for the oxygen scavenger.  The mix tank pumps shall be relayed to the feed water pump so they are both activated when the feed water pumps are on.  Each mix tank shall have a mixer to allow suitable mixing of chemicals.  The water for the mix tanks shall be soft water, and if possible from either condensate or feed water tank.  Chemical pumps shall be sized to overcome the boiler pressure as well as pressure in the feed water line.  All connections from the chemical pump to the point of injection shall be hard piped, with check valves to prevent the feed/boiler water being pushed back into the chemical pump.
    5. Stainless Steel Injection nozzles should be used to feed chemicals into the feed water line (or feed water tank for the oxygen scavenger). The injection nozzle for the inhibitor shall be in the feed water line, and after the feed water pumps but as far as possible from the boiler.   Each injection nozzle shall be installed with an isolation valve in case any repairs are needed to chemical feed system.   Provide check valves on all chemical feed lines to prevent the feed water from pushing back into the chemical injection line.
  2. Pre-operational Cleaner:  (Boil out)  All steam boilers shall to be flushed with water prior to chemical cleaning.  Specially formulated, liquid boil-out solution containing inorganic and organic surfactant materials, iron sequestrates, and corrosion inhibitors shall be used.  The product shall be designed to remove oil, grease, and mill scale from new boiler surfaces and shall clean water-side surfaces that have become contaminated with oil or grease during service.
  3. Chemical Treatment:  The dispersant and inhibitor shall be liquid blend of polymeric dispersants, phosphate conditioning agents for control of deposit formation and improved iron and sludge dispersion.  Product shall be suitable for FDA/USDA regulated facilities. The dispersant shall be mixed and maintained in a poly mix tank with mixer and high-pressure pump.  This pump shall be activated whenever the feed water pumps are turned on.  These chemicals shall be injected into the feed water line down stream from the feed water pumps and as close to the boiler as possible.  Oxygen scavenger shall be a powdered sodium sulfite, used to protect the feed water tank, piping and boiler from dissolved oxygen attack.  The oxygen scavenger shall be mixed and maintained in a poly mix tank with mixer and pump.  The pump shall be activated whenever the feed water pump is turned on. A check valve must prevent any back flow to the pump from the feed water tank.
.05 Glycol Systems
  1. Equipment:  Glycol systems shall be equipped with a mix and fill tank with manual fill capabilities, hose bibb from domestic water for tank filling, and tank level alarm interconnected with the BAS.
  2. Equipment Installation:
    1. Do not direct-connect makeup lines to glycol systems.
    2. Glycol systems should be configured so that small sections of the system can be isolated with valves and drained to a local floor drain.  Alternatively, a tank should be installed at the glycol system fill point that is large enough to capture the entire system’s contents.
  3. Pre-Operational Cleaning
    1. All systems that are to be filled with a glycol solution shall be cleaned as outlined under “Closed Systems Water Treatment (Hot & Chilled Water)” above.
  4. Chemical Treatment
    1. Take reading of Glycol concentration in system.  Required concentration may vary depending on the specific application.  Refer to concentration and tolerances in the associated specification.
    2. Shutdown circulation pumps prior to adding additional glycol.
    3. Open air vents at top of system to allow air to escape as system fills.
    4. Use Glycol pump and add Glycol mixture until desired pressure is achieved.  (If correct pressure level is unknown, use 5 lb. Per floor as rule of thumb).
    5. Turn on pumps and circulate system mixture.
    6. Continue to bleed air until system is free of air.
    7. Close valves to air vents once all air is out of system.
    8. Recheck Glycol concentration and system pressure.  Add additional Glycol or water if needed to bring system to correct concentration level and correct pressure.
  5. If you are not sure of proper fill procedures or how to determine correct concentration of mixture, please contact Mike Kelleher or one of the Environmental System technicians.
.06 Side Stream Filters
  1. Closed Systems (Heating and Cooling)
    1. All new closed circulating systems shall have a side stream filter.  This shall include all heating hot water, chilled water, dual temperature, and glycol solution piping distribution systems.
  2. Open Re-circulating Systems (Cooling Towers)
    1. All new open circulating condenser water systems shall have a side stream filter.
    2. Equipment:  All open circulating systems shall have a side stream filter piped into the circulation line, so that suspended solids can be removed from the system.  All filters shall be bag filter type so that bags can be either taken out and cleaned and reused or replaced.  All bags shall be 100 micron size.  Filters shall be sized to handle a minimum of 10% of the system flow (gallons per minute) that the circulating pumps are capable of producing.
    3. Filter Vessel:  Material of construction shall be 304 Stainless Steel, with removable cap and swing-out bolts with eyenuts.  Units shall be capable of 150 psi working pressure.  Pressure gauges shall be mounted so that pressure can be read on both sides of the filter. Gauges shall be capable of showing pressures from 0-100 psi.
    4. Filter Bags:  Construction shall be polyester fiber, felt material.  Bags shall be capable of operating temperatures between 275 – 325 ?F.  Bags shall be a standard size to fit into the filter vessel.
    5. Equipment Installation:  Filter shall be installed across the circulation pump to allow for a minimum of a 5 psig pressure drop across the filter unit.  Manual valves shall be conveniently located near the filter to isolate, balance, and drain the filter.  A ball valve shall be installed in the inlet pipe to the filter.  A combination shut-off/balancing valve shall be installed in the discharge pipe from the filter, and set for 10% system flow at all times.  The drain line shall be piped to the sanitary sewer.
  3. Manufacturer (open loop only, refer to specification for closed loop)
    1. Filter Vessels:  Filter Specialists, Inc.
      1. BFN 11:
        1. 2” inlet and 2” outlet
        2. Uses one #1 bag
        3. Maximum 100 GPM water flow
      2. BFN 12:
        1. 2” inlet and 2” outlet
        2. Uses one #2 bag
        3. Minimum 4.4 square ft bag surface area
        4. Maximum 220 GPM water flow
      3. BFN 13:
        1. 1” inlet and 1” outlet
        2. Uses one #3 bag
        3. Minimum 0.5 square ft bag surface area
        4. Maximum 25 GPM water flow
      4. BFN 14:
        1. 1” inlet and 1” outlet
        2. Uses one #4 bag
        3. Minimum 1.0 square ft bag surface area
        4. Maximum 45 GPM water flow
    2. Filter Bags:  Filter Specialists, Inc.
      1. Bag Size #1:
        1. Minimum 2.0 square ft bag surface area
        2. Minimum 2.1 gallon bag volume
        3. 7” diameter x 16.5” long bag
      2. Bag Size #2:
        1. Minimum 4.4 square ft bag surface area
        2. Minimum 4.6 gallon bag volume
        3. 7” diameter x 32” long bag
      3. Bag Size #3:
        1. Minimum 0.5 square ft bag surface area
        2. Minimum 0.37 gallon bag volume
        3. 4” diameter x 8.25” long bag
      4. Bag Size #4:
        1. Minimum 1.0 square ft bag surface area
        2. Minimum 0.67 gallon bag volume
        3. 4” diameter x 14” long bag
.07 Water Analysis and Testing for Closed Loop Systems
  1. The purpose of this procedure is to outline the steps used to test any closed re-circulating loops on campus, (chilled water, hot water, glycol, etc.).  This procedure also outlines many implications of what might happen if a closed loop system is not properly chemically treated.
  2. The following tests will be run on each closed loop:
    1. Visual Inspection:
      1. After taking a sample of the water, the water analyst will visually inspect the water and see how clear the water is.  If the water is relatively clear the water analyst may continue with the remaining tests.
      2. If the water appears cloudy and dark brown in color, the analyst will check to see if any filtration system is on the closed loop.  If so, the filter may need to be changed or backwashed.
      3. The analyst may choose to take a water sample and let it set for a couple of hours.
        1. After the water sample had time to sit for a couple of hours, if the water starts to clear up and a deposit forms on the bottom of the container – this indicates the water contains high levels of suspended solids.
        2. If a filter is not already on the system the analyst may choose to recommend installation of some type of filter to help clear up the water.
        3. Suspended solid loading in a closed water circulating loop can lead to problems, the solids can settle out in low flow areas.  The resulting deposit can cause corrosion and provide conditions that promote bacteria growth.  Some bacteria can absorb the chemical inhibitors used to prevent corrosion, which will still leave the system untreated, even though chemical has been added.  Deposits can act as an insulator preventing good heat transfer.  Not maintaining good heat transfer will increase energy costs to any system.
    2. The analyst may choose to run an iron test using the Hach colorimeter based on the degree of water discoloration.
      1. The water analyst should record the readings so comparisons can be made to previous readings to help diagnose the system in the future.
      2. If the dissolved levels of iron are greater than 30 ppm, the analyst will recommend to have the system flushed and chemically cleaned.
      3. High levels of dissolved iron left in the system can lead to more corrosion problems, leaks, poor heat transfer efficiency, as well as bacteria problems.
    3. Conductivity:  Every system will have the conductivity measured.
      1. After reading the conductivity with the conductivity meter the analyst will record the current reading and review past readings.  A conductivity reading higher or lower than the previous reading generally indicates a number of situations.
        1. If the conductivity reading is higher than previous readings, this indicates that something has been added to the system, for example the water analyst may have added chemical to the system during the last service.  If chemical was not added and the conductivity has increased dramatically, the water analyst may need to check for potential areas of contamination.  If conductivity is above 5000 mmhos, it may be recommended that the system be drained and refilled with treated water.
        2. Extreme levels of high conductivity can lead to some types of corrosion problems.
        3. If the conductivity reading is lower than previously recorded, this indicates that some water was lost from the system.  (Most likely the chemical inhibitor levels will be low as well).  The water analyst may need to check with area maintenance to see if any work was done on the system to explain the water loss.  If the closed system inhibitor (NT403) has been added and conductivity levels have not risen from the last visit, this may indicate the system has a continuous leak.  If the conductivity levels remain low (approximately the same conductivity as the raw water), the analyst will need to check for leaks and report the problem to area maintenance.
        4. Running at low conductivity may cause a number of problems.  First, it is a huge waste of water, chemicals and energy.  Secondly, it may damage equipment.  Fresh water makeup brought into a leaking hot water boiler loop will deposit certain types of deposition on the  boiler tubes.  If the leak is not caught in time the tubes could fail and the boiler may need to be re-tubed.  Leaks in a chilled water system can lead to scale build up in heat exchangers and chillers, lowering the equipment efficiencies  and raising the Universities energy costs. It may also promote corrosion and may increase the chance of piping failures.
    4. Nitrite Test:  Each treated closed loop will be tested for Nitrite levels.
      1. The water analyst will check past history of the nitrite levels for each system being tested.  If nitrite levels are lower than what is required, the water analyst will add the appropriate amount of closed system inhibitor (GE Betz NT403) to the system.  The water analyst should record the approximate amount of closed system inhibitor added to the system.  Not maintaining the proper nitrite levels will lead to corrosion problems, which may require the system to be repaired or re-piped.  It may also lead to iron oxide deposition in piping causing low flows and reduced heat transfer efficiencies.
      2. If the nitrite levels remain low after adding the closed system inhibitor and conductivity has remained the same.  The analyst may choose to run a bacteria test on the system in question by using the GE Betz BioScan.
        1. If the readings for the closed system is above 25 RLU’s the water analyst may request that the system be flushed.
        2. If the water analyst discovers that the system does have a bacteria growth problem, he may choose to recommend the closed loop system be drained, refilled and treated with a closed system biocide as well as a bio-dispersant.  After the system has circulated for a couple of days the system should be dumped and refilled with fresh water retreated with closed system inhibitor (GE Betz NT403).
        3. Within 2 weeks of retreating, the water analyst should retest the closed loop system for bacteria levels again, to verify the bacteria growth problem is gone.  Some bacteria can feed off the nitrite in the closed system inhibitor and will in turn promote corrosion was well as increase the chance of slimes and biomasses growing within the system.  These bacteria could reduce the efficiencies of the equipment and could cause health and safety issues for employees and the general public.
      3. If the nitrite levels are high, it is not recommended to drain the system.  Rather, leave the system as is and record nitrite levels.  Additional chemical will not hurt the system.
      4. The analyst may choose to run a sulfate reducing bacteria test and may need to contact the GE Betz water treatment representative to do so.
    5. PH Measurement:  Every closed loop will have the pH tested and recorded.
      1. The water analyst will review the previous pH reading s and see if any big pH swing is evident.
        1. The pH of the closed loop should always be higher than the make up water pH.
        2. The pH of a closed loop should never be below 7.0.  If this ever arises, the closed loop should immediately be drained and retreated.  Any pH below 7.0  is considered to be a corrosive environment.
        3. It is important to have a properly calibrated pH meter.  If the meter is not functioning properly the results may not be helpful in any system diagnosis.
      2. If the pH reading has dropped dramatically from the previous service visit, it would indicate that there might be a bacteria growth problem.  Refer to the Nitrite Testing section of this procedure for testing and dealing with the potential of bacteria growth.
      3. If the pH reading is high (above a pH of 11) the system should be drained, refilled and retreated with closed system inhibitor.  Certain types of corrosion can occur at high pH levels.
    6. Glycol:  Each glycol system should have the glycol measured using a refractometer.
      1. This reading will indicate the level of freeze protection the closed loop is treated for.
      2. If lower than what is required for the system, the water analyst will contact Central Services for glycol addition.
.08 Water Treatment Test Control Limits
  1. Condenser Water
    1. 6 to 9 ppm of Phosphonate
    2. 0.5 to 1.0 ppm of Chlorine Residual
    3. 2.5 cycles of concentration
  2. Closed Loop Chilled Water System
    1. 300 to 600 ppm of Nitrite
  3. Closed Loop Hot Water System
    1. 600 to 900 ppm of Nitrite
  4. Glycol Systems
    1. Refer to concentration and tolerances in the guide specification.
  5. Hot Water Boilers
    1. 600 to 900 ppm of Nitrite
  6. Steam Boilers
    1. 30-60 ppm of Sulfite
    2. 30-60 ppm of phosphate
    3. 3000-4000 mmhos of neutralized conductivity
.09 Guide Specifications
  1. Design Professional shall carefully review and edit the guideline specifications below, adapting them as needed to achieve application-specific, fully developed specifications for each project.
  2. These shall be edited using the process described in the instructions contained at the beginning of the document.  Proposed modifications shall be reviewed with OPP staff.
  3. Finalized version shall be included in the project contract documents.  Use of other specifications is not acceptable.
    Document Version Date
    Description
    232500 HVAC WATER TREATMENT - CLOSED SYSTEMS - GUIDE SPECIFICATION
    September 19, 2014
    OPP minimum specification requirements for HVAC Water Treatment for Closed Systems

 

    23 30 00 HVAC AIR DISTRIBUTION

    23 31 00 HVAC DUCTS AND CASINGS

    .01 General
    1. Ducts and Plenums
      1. Design and construction of duct systems shall comply with the following standards and guidelines:
        1. ASHRAE Fundamentals Handbook - Duct Design
        2. ASHRAE Systems and Equipment Handbook - Duct Construction
        3. Duct design and construction, including selection of acceptable materials, sheet metal thicknesses, seam and joint construction, reinforcements, and hangers and supports, shall comply with SMACNA's HVAC Duct Construction Standards - Metal and Flexible".
          1. All metal rectangular ductwork shall be cross-broken to insure rigidity.
          2. Ductwork constructed of fiberglass ductboard is prohibited.
      2. The use of fibrous/ fiberglass duct liner is prohibited.
        1. The University’s Environmental Health and Safety (EH&S) department position is that fiberglass duct liner shall be prohibited because of indoor air quality problems that eventually occur over long periods of time, even with the anti-microbial coatings.  The surface of the material itself collects dust and dirt over time.  Once the coating is covered, the dirt on the surface simply becomes a feeding ground for microbial growth (mold and bacteria).  If and when duct cleaning services are required, that tends to erode the surfaces and edges.  Then the fiberglass starts peeling and flaking and eroding into the airstream.  The University has had to remove fiberglass duct lining later to solve IAQ problems.   
        2. Duct liner (non-fibrous) may be used, but limited to only where needed for acoustical purposes that cannot be achieved by other means and methods.   Review application with University.
        3. If internal duct liner is absolutely otherwise unavoidable, any insulation surfaces in contact with the airstream shall comply with requirements in ASHRAE 62.1, Airstream Surfaces for resistance to microbial growth and erosion.  Flexible Elastomeric Sheets or rolls specifically approved for use as Duct/Plenum Lining is recommended, subject to complying with the following.
          1. Armacell product data is the basis of these requirements and designate the type and quality of work intended. Other comparable products shall be reviewed and approved by the specifying engineer.
          2. Preformed, cellular, closed-cell, sheet materials complying with ASTM C 534, Type II, Grade 1; and with NFPA 90A or NFPA 90B and UL 181 Class 1 specification. 
          3. Indoor Air Quality Ratings:  Materials shall comply with ASTM C 1071 – Erosion Resistance; ASTM G 21 – Fungi Resistance; ASTM C 1338 – Fungi
            Resistance; ASTM G 22 – Bacterial Resistance; ASTM C 665 – Non Corrosiveness and no objectionable odors. 
            1. Note:  When specifying duct liner by referencing ASTM C 1071, specifiers are assured of product qualifications for corrosiveness, water-vapor sorption, fungi resistance, temperature resistance, erosion resistance, odor emission, surface-burning characteristics, apparent thermal conductivity, sound absorption coefficients, bacteria resistance, and combustion characteristics.
          4. NRC rating of 0.30 – Test method ASTM C 423 with ASTM E 795 Type A mounting.
          5. Insulation materials shall be manufactured without the use of CFC’s, HFC’s, or HCFC’s.  It shall also be formaldehyde-free, low VOC’s, fiber free, dust free
            and resist mold and mildew and non-particulating.
          6. Materials must be approved for air plenums.
          7. Materials shall have a maximum thermal conductivity of 0.27 Btu-in./h-ft2 - °F at a 75°F mean temperature when tested in accordance with ASTM C 177 or
            ASTM C 518, latest revisions.
          8. Materials shall have a maximum vapor transmission of 0.08 perm-inches when tested in accordance with ASTM C 177 or ASTM C518, latest revisions. 
            Materials shall have a maximum water absorption rate of 0.2% (% by volume), when tested in accordance with ASTM C 209.
          9. Surface-Burning Characteristics: Maximum flame-spread index of 25 and maximum smoke-developed index of 50 when tested according to UL 723.
          10. The material thermal properties, water vapor transmission and fire performance shall be certified by an independent Nationally Recognized Testing Laboratory (NRTL).
          11. Liner Adhesive: As recommended by insulation manufacturer and complying with NFPA 90A or NFPA 90B.
      3. Clearly indicate specific ductwork pressure classifications on the contract documents.
        1. The pressure classifications of various duct sections throughout each system shall be fully defined.
        2. All modes of operations must be considered, especially in systems used for smoke management and those with fire or smoke dampers that must close when the system is running.
      4. All duct systems shall be designed and constructed to minimize air leakage in order to achieve required air flows and pressure relationships with minimal heating, cooling and fan energy waste.  All ducts and plenums shall be sealed to Seal Level A to comply with requirements in High Performance Building Standard ASHRAE 189.1.
        1. All duct/terminal connections shall be sealed.
        2. The use of cloth-backed, rubber adhesive tape (commonly referred to as "duct tape") as a duct sealant is prohibited.
        3. Representative duct leakage tests shall be conducted in compliance with SMACNA’s HVAC Air Duct Leakage Test Manual to verify the intent of the designer and the workmanship of the installing contractor. Leakage tests used to confirm leakage class shall be conducted at the pressure class for which the duct is constructed. Minimum representative leakage testing is addressed in ASHRAE Standard 90.1 and the International Energy Conservation Code.  If a test indicates excess leakage, corrective measures shall be taken to ensure quality.  Final test results shall be reviewed and approved by the designer demonstrating that the required representative sections have been tested and that all tested sections meet the requirements.
        4. Test for leaks before applying external insulation.
        5. Lower pressure class ducts that do not require duct leakage tests, shall at a minimum be visually inspected for compliance prior to being insulated.
        6. Include specifications that contractor shall give adequate advance notice for Design Professional and Owner’s representative to observe testing.
      5. Air systems shall be designed to minimize pressure drops through each component, fitting, and the total system to minimize associated fan energy.  The total allowable fan power limitation for each system shall comply with ASHRAE Standard 189.1 (10% less than the limits set by ASHRAE 90.1).
        1. Minimize fan System Effects:
          1. Avoid poor fan inlet and outlet conditions that reduce fan performance and increase energy waste.  Always consult manufacturer’s installation guidelines.
          2. Rules of thumb: AMCA Publication 201 quantifies System Effect for a number of the more common causes, and offers recommendations for avoiding System Effect.
            1. On the fan’s inlet side, AMCA Publication 201 recommends that elbows near the fan’s inlet be located at least three duct diameters upstream of the fan, while acknowledging that elbows can cause System Effect when they are located up to five diameters upstream.
            2. On the fan’s outlet side, AMCA Publication 201 introduces the term “Effective Duct Length.”  Effective Duct Length is 2.5 duct diameters when duct velocities are 2500 fpm or less, with one duct diameter added for each additional 1000 fpm. A centrifugal fan needs 100% of an Effective Duct Length on its outlet to avoid System Effect, while a vaneaxial fan needs 50% Effective Duct Length.
        2. Design ductwork to minimize 90 degree elbows and sharp transitions.
        3. Select all air distribution fittings and components that offer the lowest pressure drop.  Use fittings with low pressure drop characteristics such as long radius elbows (radius of 1.5 times duct width), smooth radius elbow with minimum radius of 0.75 times duct width with splitter vane, 45° laterals or Wyes in direction of flow for branches, tapered transitions, and bell-mouth inlets.
        4. Where radius elbows do not fit, rectangular mitered elbows shall have turning vanes of type and spacing selected for the duct classification to minimize pressure drop.    Exceptions:  Elbows in dishwasher, kitchen grease-laden, and laundry exhaust or other dirty industrial or special process applications shall be unvaned, smooth radius construction with minimum radius equal to 1.5 times the width of the duct.
        5. Do not use fittings with abrupt changes that cause high pressure drops such as non-tapered transitions or inlets/discharges from plenums or headers, or bullhead tee connections (either two streams connected to each end of a tee with the discharge on the branch, or the main flow coming into the branch connection and discharging at each end).
      6. Follow the general duct layout and sizing requirements below.
        1. Show duct sizes as inside clear dimensions.
        2. Wherever space allows, conservatively upsize ducts to reduce pressure drop and allow future flexibility if increased airflow is required.
        3. Typically design ducts to be installed vertically and horizontally, and parallel and perpendicular to building lines.
        4. Route ducts to avoid passing through transformer vaults and electrical equipment rooms and enclosures.
        5. Change only one rectangular duct dimension at a time so transitions are easier to fabricate and install and therefore generally less expensive.
        6. Make sure bell-mouth branch takeoffs and associated mains have coordinated sizes so taps can be properly installed and fully sealed to the main duct.
        7. Ensure there are adequate lengths of straight runs of properly sized ductwork before and after airflow measuring devices per manufacturer’s installation instructions in order to get accurate readings.
        8. Every runout duct shall be provided with a low-loss rectangular 45° tap or round bell-mouth tap from the main duct.  A manual balancing damper shall be installed at the take-off and used for balancing rather than relying on damper at air distribution devices in the space.
        9. Comply with SMACNA's "HVAC Duct Construction Standards - Metal and Flexible" for branch, outlet and inlet, and terminal unit connections.
        10. Use round ducts wherever feasible.  Round ducts are inherently strong and rigid, and are generally the most efficient and economical ducts for air systems.  Round duct is also recommended for any horizontal exterior ductwork due to inherent strength and to minimize rain or snow collecting on upper surfaces.
      7. Include necessary specific materials and details for special exhaust duct systems.
        1. In ductwork carrying steam or high humidity (dishwasher, sterilizer, cagewashers, shower rooms, etc.), all seams shall be welded or sealed liquid-tight.  Indicate sloping of horizontal runs and any intermediate condensation drain requirements.
        2. Duct material for handling corrosive gases, vapors, or mists must be selected carefully.  For the application of metals and use of protective coatings in corrosive environments, consult SMACNA Rectangular and Round Industrial Duct Construction Standards.
      8. Provide protection from water entry and damage at exterior air intake and discharge openings and associated plenums.
        1. Give particular consideration to locate and design intake and discharge openings to minimize the penetration of wind driven rain and snow at all times.
        2. Include construction details inside such openings to contain and drain away any precipitation at points of entry so that rainwater or melted snow does not accumulate and leak into and damage surrounding building construction.
    2. Manual Volume Dampers
        1. Manual volume dampers shall be installed in all branch ducts for balancing and shall be indicated on the drawings.  All balancing shall be done with branch duct dampers and not with diffuser dampers.
        2. Dampers shall be opposed blade with adjustable quadrant and locking device with position indicator.
    3. Access Doors
        1. Hinged access door shall be installed at all automatic dampers, fire dampers, reheat coils and other apparatus requiring inspection and servicing.
        2. Doors shall be suitable for the pressure classification.
        3. Doors shall open against static pressure in duct.
        4. Doors shall be fully gasketed and insulated when installed in insulated ductwork.
    4. Flexible Connections
      1. Flex connections shall be provided at connections to all moving equipment.
    5. Flexible Ductwork
      1. Flexible ductwork shall not exceed 6' in extended length. 

    23 33 00 AIR DUCT ACCESSORIES

    .01 Fire Dampers
    1. Fire dampers shall be installed where required by the International Mechanical Code and NFPA.
    2. Temperature rating of fusible links shall be shown in the contract documents.
    3. Frames shall be large enough so that there will be no obstruction to air flow when the dampers are open.  Construction and arrangement of fire dampers shall be as approved in each case prior to installation.  Access shall be provided for replacement of links and so labeled.
    4. Fire dampers shall be approved by U.L. and so labeled and installed, shall comply with the requirements of NFPA 90A and the International Mechanical Code. 
    .02 Sound Attenuators
    1. Refer to 23 05 01.05 Sound Pressure Level Requirements
    2. An analysis is required for both supply and return ductwork systems.
    3. Drawings shall indicate velocity, S.P. loss, and db attenuation through all octave bands for each attenuator. 

    23 34 00 HVAC FANS

    .01 General Owner Requirements and Design Intent
    1. Design for High Energy-Efficiency Performance:  Professional shall design each fan application for optimal operating efficiency, and flexibility with the lowest life cycle cost.
      1. The total allowable fan power limitation for each system shall be 10% less than the limits set by ASHRAE 90.1 or the current International Energy Conservation Code (whichever is more stringent), or as otherwise modified by most current edition of ASHRAE Standard 189.1.
      2. Air systems shall be designed to minimize pressure drops through each component, fitting, and the total system.
        1. Design ductwork to minimize 90 degree elbows and sharp transitions.
        2. Select all air distribution fittings and components that offer the lowest pressure drop.
        3. Wherever space allows, design larger duct sizes to reduce pressure drop and allow future flexibility if increased airflow is required.
        4. Select any associated coils and filters with low air pressure drops.  Limit face velocity as follows:
          1. VAV systems: 400 (recommended) to 450 (max) feet per minute (fpm)
          2. Constant air volume systems:  300 (recommended) to 350 (max) fpm.
        5. Minimize fan System Effects:  Avoid poor fan inlet and outlet conditions that reduce fan performance and increase energy waste.  Always consult manufacturer’s installation guidelines.
          1. Rules of thumb - AMCA.
            1. AMCA Publication 201 quantifies System Effect for a number of the more common causes, and offers recommendations for avoiding System Effect.
            2. On the fan’s inlet side, AMCA Publication 201 recommends that elbows near the fan’s inlet be located at least three duct diameters upstream of the fan, while acknowledging that elbows can cause System Effect when they are located up to five diameters upstream.
            3. On the fan’s outlet side, AMCA Publication 201 introduces the term “Effective Duct Length".
            4. Effective Duct Length is 2.5 duct diameters when duct velocities are 2500 fpm or less, with one duct diameter added for each additional 1000 fpm. A centrifugal fan needs 100% of an Effective Duct Length on its outlet to avoid System Effect, while vaneaxial fan needs 50% Effective Duct Length.
      3. Design Professional shall carefully evaluate and properly select the most effective fan type and wheel to best suit the needs of the application with emphasis on stable and quiet operation and minimizing operating and life cycle cost, rather than minimizing size and first cost.
        1. Typically the backward oriented wheel designs (airfoil, backward curved, and backward inclined) offer greater peak efficiency, greater strength and non-overloading power characteristics and should be used whenever available as an option in lieu of forward curved wheels for central fans and air handling equipment.
        2. Fan selections at the actual operating point(s) shall be within 10 points of the peak total efficiency.
        3. In all cases, selections shall be made to avoid stall, surge and pulsating conditions throughout full range of operating range of fan system.
        4. Select for quiet operation.  The only valid basis for comparison are the actual sound power levels generated by the different types of fans when they are all producing the required volume airflow rate and total pressure. Sound power level data shall be obtained from the fan manufacturer for the specific fans being considered.  Low outlet velocity does not necessarily ensure quiet operation, so selections made on this basis alone are not appropriate. Also, noise comparisons of different types of fans, or fans offered by different manufacturers, made on the basis of rotational or tip speed are not valid.
      4. Part Load Capacity Controls shall be effectively applied to fullest extent practical for optimal energy efficiency over entire system operating range.
        1. Variable Frequency Drives for HVAC Motors: Designers shall use guide specification in 26 29 23 Variable-Frequency Motor Controllers. Guide specification shall be edited only as required to meet project specific requirements. Proposed modifications shall be reviewed with OPP Engineering Services.
    2. Reliability and Redundancy: Professional shall determine the consequences of system failure and provide for adequate system redundancy for each application.
      1. Confirm Owner requirements for redundancy are defined and met. 
      2. Install fully redundant (N+1) stand-by fans for extremely critical applications (such as critical research laboratories and computer centers) and/or as otherwise defined specifically in the Owner’s Project Requirements.
      3. For non-critical applications (such as general office spaces, general purpose classrooms, general commercial type spaces) full redundancy/complete standby is typically not required.
      4. Consider parallel fan configurations where effective and practical.
      5. Determine and specify applicable emergency power requirements. (Research, lab fume hood, process or other specific critical application).
    3. Flexibility: Consider potential future expansion. Extent of expansion will be determined on a case-by-case basis. Consult with the University Project Leader and Engineering Services.
    4. Space Planning:  Refer to 01 05 05 Space Planning, .01 Planning for Engineered Building Systems.
      1. Make sure that minimum clearances are maintained, as required by manufacturer.
      2. Allow at least three feet between all service sides of fans, and other large equipment and obstructions.
      3. Mechanical room locations and placement must take into account how fans and replacement parts can be moved into and out of the building during installation and future major repair/replacement.
      4. Plan for and clearly label any future equipment space needs on drawings.
      5. Controls must not be placed in public areas.
    5. Sound and Vibration Control:
      1. Determine sound attenuation requirements.
        1. Properly locate and specify to meet project needs.
        2. Comply with requirements for vibration isolation devices specified in Division 23 Section  23 05 01 Mechanical General Requirements, .04 Sound and Vibration Control.
      2. Minimize objectionable fan noise from intake or exhaust points to nearby buildings or sensitive neighboring areas.
      3. Determine and specify appropriate allowable vibration limits for each application of fan, motor and base combination according to level of criticality.
    6. Specialized exhaust systems - (Clothes Dryer, Kitchen Grease/Heat, Hazardous, Research Lab Fume Hood, Smoke Control, etc.):
      1. General:
        1. Apply variable air volume control wherever practical for optimal energy conservation – beyond code minimum prescriptive requirements.
        2. Comply with Chapter 5 Exhaust Systems of International Mechanical Code for special requirements.
        3. Select fan materials and construction most suited for the application.  Considerations in selecting materials include resistance to chemical attack and corrosion, reaction to condensation, flame and smoke ratings, ease of installation, ease of repair or replacement, and maintenance costs.  Appropriate materials shall be selected from standard references and by consulting with manufacturers.
      2. Lab Fume Hood systems:
        1. Comply with ANSI/AIHA Z9.5-(current) Laboratory Ventilation.
        2. Refer to the U.S. EPA and DOE sponsored Labs for the 21st Century (Labs21) Tool Kit, including the Best Practices Guides, and best-fit apply them to each specific project scope.
    7. Documentation:
      1. Schedules: Shall be complete with area served, location, total air quantity, static pressures, operating temperatures minimum fan efficiency (or maximum brake horsepower), motor hp, voltage, (including starter/speed drive type), and whether on normal/emergency standby power (where applicable), any maximum dimensions and weights, sound power level data, method of control, and if fans are interlocked, indicate the unit(s) the fan is interlocked with.
      2. For lab fume hood high plume exhaust fan systems, Engineer must provide all pertinent selection criteria including: minimum plume heights; laboratory fume exhaust air and total flow design rates; quantity, size and location of bypass dampers; special corrosion-resistant materials and finishes; spark-resistance class, and any other application-specific options and accessories on equipment schedules.
      3. Provide mechanical identification per University Standards, 23 05 01.05 Mechanical Identification.
      4. The configuration of all components of fans, including fan/motor arrangement, rotation, and required dimensions for all internal access sections and external access clearances, shall be clearly defined in sufficient detail in plan and elevation views on the design documents.
    8. Quality Assurance and Uniformity:
      1. Equipment manufacturer shall be ISO-9001 certified.
      2. Equipment shall be of U.S. manufacturer.
      3. Provide equipment of same type by same manufacturer.
      4. AMCA Compliance: 
        1. Airflow Performance Ratings:  Fans shall conform to AMCA 210 and bear the AMCA Certified Ratings Seal.
        2. Sound ratings:  Fans shall be sound rated in accordance with AMCA 301 and AMCA 300 "Test Code for Sound Rating Air Moving Devices" and bear the AMCA Certified sound ratings seal.
      5. UL Compliance:  Provide centrifugal fan electrical components which have been listed and labeled by UL.
    9. Submittals:  Documents shall require the following:
      1. Product Data:  Submit manufacturer's technical product data for fans, including:
        1. Selection characteristics and rated capacities.
        2. Fan performance curves with system operating conditions indicated.
        3. Sound power ratings, with an 8 octave band analysis for large, central system fans.
        4. General specifications:  Fan type description, material of construction, thicknesses and finishes.
        5. Motor type, ratings and electrical characteristics.
        6. Accessories furnished.
        7. Product data on special coatings and construction where applicable.
        8. For laboratory fume hood exhaust fan systems, provide nozzle velocity of exhaust fan, total exhaust flow, and results of the effective discharge plume height based on the specified wind velocity of [15 mph – Design Professional shall confirm and edit for project specific requirements].
      2. Shop Drawings:  Include the following:
        1. Plans, elevations, sections, and attachment details.
        2. Details of equipment assemblies.  Indicate dimensions, weights, loads, required clearances, method of field assembly, components, and location and size of each field connection.
        3. Vibration Isolation Base Details:  Detail fabrication, including anchorages and attachments to structure and to supported equipment.  Include auxiliary motor slides and rails, and base weights.
      3. Wiring Diagrams:  Submit manufacturer's electrical requirements for power supply wiring to fan units.  Submit manufacturer's ladder-type wiring diagrams for interlock and control wiring.  Clearly differentiate between portions of wiring that are factory-installed and portions to be field-installed.
      4. Coordination Drawings:  As required to meet project complexity, show fan room layout and relationships between components and adjacent structural and mechanical elements.  Show support locations, type of support, and weight on each support.  Indicate and certify field measurements.
      5. Maintenance Data:  Submit operation and maintenance instructions, including lubrication instructions, motor and drive replacement, and spare parts lists.  Include this data, product data, shop drawings, and wiring diagrams in maintenance manuals; in accordance with requirements of Section 23 01 00 OPERATION AND MAINTENANCE OF HVAC SYSTEMS.
      6. Field quality-control reports.
    .02 Product Requirements
    1. General:
      1. Fan ratings shall be AMCA certified.
      2. All fans shall be statically and dynamically balanced and run tested at the factory.
      3. Fan housings shall be aerodynamically designed and engineered to reduce incoming air turbulence and provide maximum efficiency. Housing shall be suitably braced to prevent vibration or pulsation.
      4. All fan and system components shall be corrosion resistant.  Materials and finishes shall be selected appropriately for each application.  Considerations in selecting materials include resistance to chemical attack and corrosion and protection from reaction to condensation where it can occur.
    2. Bearings:  Fans, except power roof ventilators, shall be provided with lubricating type bearings with extended fittings as required.
      1. Bearings:  on primary/central fan applications, provide heavy-duty, grease-lubricated, precision anti-friction, self-aligning, ball or roller or tapered double spherical roller, pillow block type bearings, selected for minimum life (AFBMA L10) of 200,000 hours.

        Designer Note:  Refer to Understanding Bearings for the Fan Industry (FA/103-00) http://www.greenheck.com/library/articles/6.
      2. Extend grease fittings to safe, accessible locations.
    3. Shafts: Designed for continuous operation at maximum-rated fan speed and motor horsepower, and with field-adjustable alignment.
    4. Motors:  Refer to other requirements in .01 Motors and Drives.
      1. Shall be NEMA Premium efficiency, 
      2. Motors on variable speed drives shall be inverter duty, with factory installed motor shaft grounding technology.  Designer Note: Indicate CLEARLY on contract documents, preferably noted on equipment schedules, so they are less likely to be missed by equipment vendors.  The objective is to most pro-actively and cost-effectively protect the motors to avoid expensive and disruptive corrective field installed work, which otherwise becomes necessary after unprotected motors have started failing prematurely.
      3. Do not select motor within the service factor range.
    5. Belt Drives, Refer to 23 05 01 - Motors and Drives:
      1. Drive assemblies: Factory mounted, with adjustable alignment and belt tensioning with 1.5 service factor based on rated nameplate HP of motor.
      2. For speed adjustments, the Contractor shall provide required sheaves and pulleys to meet specified CFM. 
      3. Belts: Oil-resistant, heat-resistant, non-sparking, and anti-static cogged v-belts; in matched sets for multiple-belt drives.
        1. Where option is available, shall have a minimum of 2 belts, each rated to carry full load in case one breaks.

          Designer Notes:

          Cogged belts have slots that run perpendicular to the belt’s length. The slots reduce the bending resistance of the belt. Cogged belts can be used with the same pulleys as equivalently rated V-belts. They run cooler, last longer, and have an efficiency that is about 2% higher than that of standard V-belts.

          Consider synchronous belt drive assemblies with soft start capabilities, where they can be applied appropriately and effectively to eliminate slip losses for best efficiency. However, cogged belts may be a better choice when vibration damping is needed or shock loads cause abrupt torque changes that could shear a synchronous belt’s teeth. Synchronous belts also make a whirring noise that might be objectionable in typical HVAC applications where fan/drive noise could be transmitted to noise-sensitive occupied areas.

          For more information, refer to US Department of Energy, Energy Efficiency and Renewable Energy (EERE), Motor Systems Tip Sheet #5, “Replace V-Belts with Cogged or Synchronous Belt Drives”:
          http://www1.eere.energy.gov/industry/bestpractices/pdfs/replace_vbelts_motor_systemts5.pdf.

          As an alternative to belt drives, on variable flow systems, consider application of direct drive fans with variable speed driven motors via VFDs or ECM motor-controllers.
    6. Accessories:  Select most appropriately for each application and clearly indicate on contract documents.
      1. Belt guards:  Where required, guards shall be fabricated to comply with OSHA and SMACNA requirements, constructed of expanded metal mesh to allow for quick visual inspection of belts and pulleys without removal.  Guards shall be attached to equipment with hinges and/or quick release fasteners that can be turned without tools to allow for ease of maintenance. Secure to fan or fan supports without short circuiting vibration isolation.
      2. Equip fans with lifting lugs.
      3. Access for Inspection, Cleaning, and Maintenance:  Comply with requirements in ASHRAE 62.1.
      4. Scroll Drain Connection:  NPS 1 steel pipe coupling welded to low point of fan scroll.
      5. Inlet Screens:  Provide where required to adequately protect maintenance staff.  Grid screen of same material as housing.
      6. Roof Exhaust fans:  Roof Curbs:  Provide manufacturers roof curb with outer finish to match fan.  Provide hinging kit to allow easy access to damper.  Curb shall be insulated with 2" thick sound and thermal insulation.  Exception:  Fans used for grease or dishwasher exhaust application shall not have exposed acoustic insulation. Provide vented curb extension and grease trap and drain for grease duct application.
      7. Shaft Cooler:  Metal disk between bearings and fan wheel, designed to dissipate heat from shaft on fans with operating temperatures higher than 250 degrees F.
      8. Shaft Seals:  Airtight seals installed around shaft on drive side of single-width fans.
      9. Weather Cover:  For exterior applications, provide removable protective cover with ventilation slots over motor and drive assembly.
      10. Isolation Damper:  For multiple fans on a common header, equip each fan with isolation damper on inlet or outlet (depending on application and arrangement) to prevent it from turning in reverse rotation when the fan is off.
      11. Vibration Cut-out Switch:  In applications subject to damage to equipment or facility or unacceptable effect on vibration-sensitive research equipment due to outside of normal operating tolerance levels of vibration, each fan shall be provided with vibration cut-out switch. The switch shall incorporate a manual reset button and SPDT contacts encased in a NEMA type enclosure suitable for the application. The switch shall be mounted on the motor support plate and also be accessible for manual adjustment and reset by the Owner.  A 2-conductor cable and cable clamps are to be supplied with each switch.
    .03 Execution
    1. INSPECTION
      1. Examine areas and conditions under which fans are to be installed.  Do not proceed with work until unsatisfactory conditions have been corrected in manner acceptable to Installer.
    2. INSTALLATION
      1. General:  Install fans where indicated, in accordance with manufacturer's installation instructions, and with recognized industry practices, to ensure that fans comply with requirements and serve intended purposes.
        1. Install fans level and plumb.
        2. Protect belts, sheaves, bearings, motors and other fan parts during installation.
        3. Protect units with protective covers during balance of construction.
      2. Access:  Provide adequate access and service clearance space around and over fans as indicated, but in no case less than that recommended by manufacturer.  Allow adequate and safe pathway for components and unit replacement.
      3. Isolation:  Comply with requirements for vibration isolation devices specified in Division 23 Section  23 05 01 Mechanical General Requirements, .04 Sound and Vibration Control.
      4. Duct Connections:
        1. Minimize fan System Effects:  Avoid poor fan inlet and outlet conditions. Comply with manufacturer’s installation guidelines.
        2. Make final duct connections with flexible connectors. 
        3. Install ducts adjacent to fans to allow service and maintenance.
        4. Provide access door in duct below power roof ventilators to service damper.
      5. Piping Connections:  Install piping from scroll drain connection, with trap with seal equal to 1.5 times specified static pressure, to nearest floor drain with pipe sizes matching the drain connection.
      6. Secure roof-mounted fans to roof curbs with cadmium-plated hardware.
      7. Electrical Connections:
        1. Ground equipment according to Division 26 Section "Grounding and Bonding for Electrical Systems".
        2. Connect control wiring according to Division 26 Section "Low-Voltage Electrical Power Conductors and Cables".
      8. Identification:  Label fans according to requirements specified in "Mechanical Identification".
    3. CLEANING AND TOUCH-UP
      1. After construction and painting is completed, clean exposed surfaces of units.
      2. Touch up marred or scratched factory-finished surfaces, using finish materials furnished by manufacturer.
    4. FIELD QUALITY CONTROL
      1. Upon completion of installation of fans, and after motor has been energized with normal power source, perform the following tests and inspections with the assistance of a factory-authorized service representative to demonstrate compliance with requirements:
        1. Verify that shipping, blocking, and bracing are removed.
        2. Verify that unit is secure on mountings and supporting devices and that connections to ducts and electrical components are complete.  Verify that proper thermal-overload protection is installed in motors, starters, and disconnect switches.
        3. Verify that cleaning and adjusting are complete.
        4. Disconnect fan drive from motor, verify proper motor rotation direction, and verify fan wheel free rotation and smooth bearing operation.  Reconnect fan drive system, make final alignments of pulleys and belt tension, and install belt guards.
        5. For vibration testing requirements, refer to Section 23 05 01 .04 Sound and Vibration Control.
          1. IMPORTANT: Incorrect alignment and belt tension causes energy losses and premature equipment failure. This work must be completed to the satisfaction of the University as part of the criteria determining Substantial Completion.
          2. The Contractor shall coordinate and contract the services of the University’s HVAC Vibration Analyst (At University Park, arranged through the Supervisor of Refrigeration and Mechanical Services) whenever available. Otherwise (and at Commonwealth Campus locations) the Contractor shall hire an independent, third party Vibration Analyst meeting the approval of the University.
          3. Measured results of vibration testing and final alignment and tensioning shall be recorded and coordinated to be entered into University’s Preventative Maintenance Software at time of start-up AND included in final report to be submitted as part of TAB/O&M submittals.
        6. Adjust damper linkages for proper damper operation.
        7. Verify lubrication for bearings and other moving parts.
        8. Verify that manual and automatic volume control and fire and smoke dampers in connected ductwork systems are in fully open position.
        9. See Division 23 Section "Testing, Adjusting, and Balancing for HVAC" for testing, adjusting, and balancing procedures.
        10. Test and adjust controls and safeties.  Controls and equipment will be considered defective if they do not pass tests and inspections.
        11. Prepare test and inspection reports.
      2. Remove and replace malfunctioning units that cannot be satisfactorily corrected and retest as specified above.


    23 36 00 AIR TERMINAL UNITS 

    .01 VAV Boxes
    1. Specify non-fibrous "IAQ" type internal insulation.
    2. Include optional low leakage, gasketed, factory installed access door between damper and heating coil for access and cleaning.
    3. VAV boxes shall be supplied without the manufacturer's controller.
      1. The controller/actuator and temperature sensors shall be by the BAS vendor.
      2. Include requirement for averaging velocity grid inlet airflow sensor.  Single point type not acceptable.
    4. VAV Box schedule shall include minimum and maximum cfm's, NC levels, and coil ratings.
      1. Selection of VAV terminal units:  Overhead heating shall limit supply air temperature to a maximum of 20 degrees above room heating setpoint to avoid room air stratification leading to complaints of cold feet and warm head.  Affect coil sizing and min-max heating cfm.  Define occupied and unoccupied heating and cooling min/max airflows, not just general min and max.  Needs to be fully defined to do programming setup of individual DDC controllers. Coordinate with control sequence.
    5. When multiple boxes are used to serve a single zone, all shall be controlled from a single thermostat.
    6. Location of all boxes shall be accessible for maintenance.

    23 37 00 AIR OUTLETS AND INLETS

    .01 Air Terminal Devices (Diffusers, Registers, Grilles)
    1. The Professional shall require as part of the shop drawing submission:
      1. The air terminal submittal shall include a complete tabulation of all devices identified by room number and listing the model, velocity, cfm, throw, pressure drop, sound level and flow factor and/or core area in square feet. 
      2. The submittal shall also include the manufacturer's recommendations for air balancing procedures for the devices submitted.
    2. Specify aluminum in damp or wet atmospheres.
    3. Panel diffusers are not permitted.
    4. Perforated supply diffusers are not permitted.
    5. Linear diffusers are preferred for VAV systems.

    23 38 00 VENTILATION HOODS

    23 38 16 Fume Hoods

    .01 Fume Hood Exhaust Systems
    1. All systems shall have an adequate supply of make-up air tempered to room temperature.  Auxiliary air hoods shall not be used.  Total make-up air quantity shall not exceed that required to maintain the specified pressure relationship for the space.
    2. Exhaust fans serving fume hoods shall be located at the discharge end of the system.  For additional information see Division 11 53 13 - Laboratory Fume Hoods.
    3. Exhaust fans shall discharge a sufficient height above the roof level to provide safe discharge and dilution of hazardous chemicals.  System design shall meet ANSI/AIHA Z9.5.
    4. Duct systems and fans serving hoods used with combustible materials shall be of spark-proof construction.
    5. Use Type 316 stainless steel (welded), FRP or PVC.  Suitability of duct material shall be verified with the University.
    6. Hoods, fans, and discharges shall be tagged for type of service and location of hood and fan.  Fume hoods shall be tagged to match serving fan tag.
    7. Exhaust fans and ductwork handling toxic fumes and/or radioisotopes shall have a self-adhering CAUTION sticker attached.
    8. Exhaust stacks shall be designed according to the latest edition of the ASHRAE Fundamentals Handbook, Airflow Around Buildings.

    23 40 00 HVAC AIR CLEANING DEVICES

    23 41 00 PARTICULATE AIR FILTRATION

    .01 Air Filters
    1. Filters for comfort systems serving offices, classrooms and other non-critical areas shall be minimum MERV 8* rated throwaway filters.  *Comply with Filtration and Air Cleaner Requirements in ASHRAE Standard 189.1, Chapter 8:  Indoor Environmental Quality.
    2. Filters for systems serving critical lab areas, animal rooms and special areas will be dictated by the project requirements.  The Engineer shall review specific requirements with the University.
    3. Filters shall have separate holding frame with side access and slide out frames properly sized in accordance with filter manufacturers' guidelines.  Frames shall be located to permit removal of entire frame for filter replacement.
    4. Select filters, frames and housings to maximize use of common idnustry standard filter sizes and avoid custom or odd sizes that require special orders.
    5. All filter frames, air cleaner racks, access doors, and air cleaner cartridges shall be sealed to prevent bypass pathways.
    6. Do not specify or use pre-filters with cardboard type frames in airstreams that can cause the filter assembly to prematurely collapse such as in applications subject to high moisture content that can weaken the cardboard and/or with high rates of fine/dense particles such as lint, sports chalk, animal dander, etc. that quickly overload the media and the air pressure differential causes the filter assembly to pull out of the rack.  In those cases, the recommendation is to use self-supporting panel/link filters with multi-ply, depth-loading, synthetic media constructed into a heavy-duty steel wire frame such as TRI-DEK series as manufactured by Tri-Dim Filter Corporation or approved equivalent.
    7. Other design and installation guidelines:
      1. Select filters with low air pressure drops and limit face velocities per recommendations in 23 73 00 AIR-HANDLING UNITS AND 23 34 00 HVAC FANS as applicable.
      2. When air volume is subject to future increase, a larger filter bank should be installed initially.
      3. Include gradual duct transitions to and from the filter shall to ensure even air distribution over the entire filter area.
      4. Provide sufficient access space, depending on its type, to make filters accessible for inspection and service.  A distance of 20 to 40 in. is required, depending on the filter chosen.
      5. Include lights in filter access sections of central, primary equipment for inspection and service of filters.
      6. Filters installed close to an outside air inlet shall be protected from the weather by suitable louvers or inlet hood.  In areas with extreme rainfall or where water can drip over or bounce up in front of the inlet, use drainable track moisture separator sections upstream of the first filter bank.  Include a large-mesh wire bird screen in front of the louvers or in the hood.
      7. Provide permanent indicators to give notice when the filter reaches its final pressure drop.

    23 50 00 CENTRAL HEATING EQUIPMENT

    .01 Combustion Safeguards
    1. All fuel burner combustion safeguards on gas-fired boilers over 100 HP and oil-fired boilers over 50 HP should be Factory Mutual approved equipment.
    2. Drawings, including section details of wiring and gas train, along with a Factory Mutual Application for acceptance form, shall be submitted to Factory Mutual for review and acceptance prior to installation.
    3. Final approval is based on a satisfactory field test of completed installation.
    4. Gas fired unit heaters up to 400,000 BTUs need AGA approval. 

    23 57 00 HEAT EXCHANGERS FOR HVAC

    .01 Owner General Requirements
    1. Summary:  Section includes requirements for shell-and-tube andplate type heat exchangers in HVAC applications.
    2. General Requirements:
      1. Professional shall design each heat exchanger application for optimal operating efficiency, reliability, flexibility, and ease of maintenance with the lowest life cycle cost.
        1. Design for efficient and stable system operation:  Professional shall determine the anticipated minimum and maximum loads for each system and evaluate most appropriate number, combination and arrangement of exchangers for optimal system efficiency and stable operation over entire operating range.
          1. In variable flow pumping systems, minimum velocities to avoid laminar conditions to maintain adequate heat exchange capacity shall be maintained with minimum anticipated hydronic system flows.
          2. Maximum velocities shall not be exceeded to avoid erosion of tube surfaces.
          3. Ensure only dry steam enters the control valve and heat exchanger inlet to avoid water hammer or damaging tubes due to wet steam impingement.
        2. Reliability/Redundancy:  Professional shall determine the consequences of system failure and provide for adequate system redundancy for each application. 
          1. Install fully redundant (N+1) stand-by units for extremely critical applications (such as critical research laboratories and computer centers) and/or as otherwise defined specifically in the Owner’s Project Requirements.
          2. For non-critical applications (such as general office spaces, general purpose classrooms, general commercial type spaces) full redundancy/complete standby is typically not required.  In such cases two (2) units in parallel, each sized for a minimum of approximately 75% of maximum load may be considered.  This arrangement offers greater flexibility and turndown and still provides majority of capacity when one of the units is out of operation for any reason.
          3. On applications with a single heat exchanger assembly, install a manual bypass assembly with globe valve around the temperature control valve(s) and strainer to allow emergency servicing of control valve(s) or strainer without complete shutdown.
        3. Flexibility: Consider potential future expansion. Extent of expansion will be determined on a case-by-case basis. Consult with the University Project Leader and Engineering Services.
        4. Controls:
          1. Select arrangement of control valve(s) for each heat exchanger for most appropriate turndown for anticipated operating range.
          2. Coordinate control devices and operational sequences with Section 25 00 00 INTEGRATED AUTOMATION and 25 90 00 GUIDE SEQUENCES OF OPERATION
        5. Maintenance: 
          1. Locate in safe and convenient area and provide convenient means for frequently inspecting and cleaning.
          2. Provide valves and bypasses in the piping so unit may be bypassed when required to permit isolation for inspection and repairs with interrupting main systems.
      2. Equipment Layout: 
        1. Comply with all Space Planning Requirements indicated in 01 05 05.02 Planning for Engineered Building Systems
        2. Maintain minimum recommended service clearances of 36” around service ends of heat exchangers and 24” in general.
        3. Maintain minimum clearances for tube pull and/or cleaning of tubes as recommended by the equipment manufacturer, typically no less than the length of the heat exchanger. 
        4. Coordinate structural reinforcements and other provisions for rigging of tube bundles for future removal and replacement.
        5. Dimensions, sizes, weights and locations of heat exchangers must take into account how they can be easily moved in and out of building both during and after initial construction for installation and/or replacement.
        6. For hot water applications, install pumps on the cooler return water side of the heat exchanger.  The lower operating temperature helps to extend mechanical seal life.
      3. Seismic Performance:  Coordinate project specific seismic restraint requirements with structural engineer. 
    3. Types, Applications and Selection Criteria:
      1. General:  Heat exchangers for HVAC applications shall be rated for minimum of 150 psig working pressure at 375ºF, or higher if otherwise required to provide rated working pressure of at least 1.5 times maximum operating pressure.
        1. A relief valve sized at not greater than 90% of the heat exchanger's maximum working pressure shall be installed on the water side of each steam/hot water heat exchanger and on both sides of water to water units.  The relief valves must be installed at the heat exchanger and prior to the isolation valves. 
        2. Since PA L&I currently considers chilled water heat exchangers to be unfired pressure vessels, provide relief valves on both the building chilled water side and campus chilled water side.
        3. The relief valves selection parameters shall be determined and scheduled by the design professional.
      2. Shell and Tube “Converter” type:
        1. Applications include:
          1. Steam to hot water HVAC systems.
          2. Water to water with design approaches typically greater than 15ºF.
          3. Special high temperature and/or pressure separation requirements of parts of a system or systems with large differences or fluctuations in temperature or pressures between fluid sides.
        2. Selection Criteria
          1. Converters shall have steam in the shell and water in the tubes.  For high temperature difference water to water systems, lower temperature water to heated shall be in the tubes.
          2. Converters shall typically be selected at 2 psig steam pressure operating in the shell for most efficient operation heating fluids up to 200 ºF.  Otherwise select a steam pressure that has a saturation temperature approximately 30 ºF higher than the required outlet temperature of the fluid being heated in the tubes.
          3. Do not oversize the control valve or else temperature overshooting and excessive control hunting will result in unstable operation and premature valve/actuator failure. 
            1. For University Park campus steam characteristics refer to 33 63 00 STEAM ENERGY DISTRIBUTION.
            2. For buildings served by campus low pressure steam, system pressures can vary seasonally between 5-12 psi, with 5 psi as the winter design condition.  Coordinate selection of control valve and heat exchanger accordingly.  Review with OPP Engineering Services.
          4. Maximum Velocity limits:  (confirm with manufacturer per application)
            1. Tubeside Nozzle Velocity:  8 fps
            2. Shellside Nozzle Velocity:  4 fps
            3. Shellside Condensate Velocity:  2.5 fps
            4. Maximum tube velocity shall not exceed the following, but may be less to keep water pressure drop low.
              Material
              Max. Tube Velocity
              Stainless Steel:
              10 ft/sec
              90-10 Cupronickel:
              10 ft/sec
              Copper: 6 ft/sec
          5. Minimize water pressure drop while maintaining effective heat transfer:  select to minimize pumping energy, typically 8 feet (3.5 psi) max.
          6. Fouling factor:  Shall be determined based on specific application and local water quality and Professional judgment.  Refer to manufacturer’s recommendations and/or Standards of Tubular Exchanger Manufacturers Association.  Typical listed value for low pressure steam heating medium (approximately 230-250ºF) to recirculated hot water application with “treated boiler feedwater” (temp. greater than 125ºF and velocity over 3 ft/sec) is 0.001 ft2 ºF/Btu. [Note:  This is higher than the previous value in the OPP standard of 0.0005 (the value for distilled water per table from TEMA).]
          7. Refer to Equipment Requirement Piping Connection options to avoid excessive velocity and impingement erosion on the tubes.
          8. Steam Traps:  Provide properly sized and installed steam traps for complete condensate drainage. Inadequate drainage of condensate can result in significant loss of capacity and even in mechanical failure.
            1. The trap should be sized based on a 0.5 psig differential pressure, assuming 2 psig inlet pressure, 0 psig outlet pressure and a minimum 18” fill leg from the shell outlet to the trap inlet.  \
            2. Allow a minimum 1.5 safety factor times the anticipated full load capacity for start-up conditions.
            3. A float and thermostatic trap is typically the best selection for heat exchanger with modulating temperature control.
          9. Mounting Height:  Always allow enough mounting height of heat exchanger to allow gravity drainage of the condensate from the steam trap to a vented gravity return line or a condensate return pump if gravity return is not feasible.  Avoid any lift in condensate return line above trap.
      3. Gasketed Plate and Frame type:
        1. Applications include:  
          1. Closed Water to water systems with design approaches typically less than 15ºF and small fluctuations of temperatures and pressures. (i.e. - Process Cooling Water, Segregated loops requiring anti-freeze solution).
          2. Fluid separation between open and closed systems. (Open cooling tower to closed loop condenser water or water-side economizer).
          3. Heat transfer between systems with fluids that require routine cleaning of heat exchanger surfaces due to fouling conditions.
          4. Special temperature and/or pressure separation requirements of parts of a system with relatively low pressure and temperature differences and fluctuations.
          5. Specialized industrial or food processes with steam (non-HVAC applications).
        1. Selection Criteria
          1. Minimize water pressure drop while maintaining effective heat transfer:  select to minimize pumping energy, typically 8 feet (3.5 psi) max.
          2. Fouling factor:  Shall be determined based on specific application and local water quality and Professional judgment.  
      4. BRAZED-PLATE HEAT EXCHANGERS
        1. Applications could include:
          1. Closed, very clean systems that would not require routine opening for cleaning of heat exchanger.
          2. Refrigeration.
          3. Review potential application with OPP.
        2. Other specialty heat exchangers for special applications:  Review with OPP.
          1. Spiral
          2. Helical tube
          3. Additional Resources:
            1. ASHRAE Systems and Equipment Handbook:  Heat Exchangers
            2. Standards of Tubular Exchanger Manufacturers Assciation
            3. Bell Gossett Article Steam Control and Condensate Drainage for Heat Exchangers, http://completewatersystems.com/2011/04/steam-control-and-condensate-drainage-for-heat-exchangers
        3. Related Standards Section
          1. 23 00 01 Owner General Requirements and Design Intent
          2. 23 00 10 Systems Selection and Application
          3. 23 01 00 OPERATION AND MAINTENANCE OF HVAC SYSTEMS
          4. 23 05 01 Mechanical General Requirements
          5. 23 05 19 Measuring Instruments for HVAC
          6. 23 05 93 Testing, Adjusting, and Balancing for HVAC
          7. 23 07 00 HVAC INSULATION
          8. 23 21 13 Hydronic Piping
          9. 23 22 00 STEAM AND CONDENSATE PIPING AND PUMPS
          10. 25 00 00 INTEGRATED AUTOMATION
          11. 25 90 00 GUIDE SEQUENCES OF OPERATION
        4. Documentation:  The Professional shall schedule all heat exchanger selection and performance data and project/application specific requirements on the drawings (not within project specifications).  Schedules shall indicate identification tag, system served, location, operation (Duty/Standby or Lead/Lag), type (i.e. end suction, double suction), service fluid (i.e percentage of glycol), entering and leaving temperatures, heat exchange capacity, fouling factor, minimum and maximum flow rates, maximum fluid velocities, minimum rated working pressure, inlet steam pressure, water pressure drops, number of passes, number of plates, manufacturer and model number (basis of design), maximum dimensions, operating weight, options/remarks.
          1.  It is imperative to define all parameters to optimize selection for efficient heat transfer, achieving low pressure drop, and keeping velocities in range to avoid failures due to erosion.
          2. Professional shall follow University Equipment Acronym List and Equipment numbering policy defined in Mechanical Identification in developing equipment tags and schedules.
          3. Professional shall carefully review and edit the guideline installation details below, adapting them as needed to achieve application-specific, fully developed details for each project.
            Document
            Version Date
            Description
            23 57 00 D01.dwg                                      
            23 57 00 D01.pdf
            November 9, 2011                       
            Guideline detail:  Typical low pressure steam to hot water shell and tube heat exchanger with extended shell and high performance v-ball control valve.

        5. Quality Assurance and Uniformity:
          1. All heat exchangers shall be constructed, installed, inspected and tested in accordance with requirements of all Authorities Having Jurisdiction:
            1. Current local Building Codes
            2. PA Dept. of Labor & Industry, Bureau of Occupational and Industrial Safety, Boilers & Unfired Pressure Vessels: Installation and Other Requirements
              1. Boiler and Unfired Pressure Vessel Law (Act 85 of 1998)
                1. Design and Construction
                2. Registration
                3. Inspections
              2. Boiler and Unfired Pressure Vessel Regulations                   
                1. 3a.36 Clearances.
                2. 3a.71 Compliance with ASME Code for installations of unfired pressure vessels.
                3. 3a.167 Hot water/steam heat exchangers.
          2. Construction:  Fabricate and label heat exchangers to comply with ASME Boiler and Pressure Vessel Code, Section VIII, "Pressure Vessels," Division 1.   Affix ASME label.\
          3. Heat exchangers shall be of U.S. manufacturer.
            1. Provide US steel certification if required by Project.  See Exhibit E: Trade Practices Act Contract Clause; and Exhibit F:  Steel Products Procurement ACT Contract Clause in  00 00 00 PROCUREMENT AND CONTRACTING REQUIREMENTS , DGS Exhibits A-H
          4. Provide heat exchangers of same type by same manufacturer.
          5. Source Quality Control
            1. For special high pressure applications above typical HVAC working pressure rating (150 psig) hydrostatically test heat exchangers to minimum of one and one-half times pressure rating before shipment.
              1. Heat exchangers will be considered defective if they do not pass tests and inspections.
              2. Prepare and submit test and inspection reports.
        6. Submittals:  Documents shall require the following:
          1. Product Data:  Include manufacturer's specifications, rated capacities, operating characteristics, gages and finishes of materials, accessories, and furnished specialties.
          2. Shop Drawings:  Detailed equipment assemblies including dimensions, weights, required clearances, components, and location and size of each field connection and installation instructions.
            1. Base Details:  Detail fabrication including anchorages and attachments to structure and to supported equipment.
            2. Delegated-Design Submittal:  If required for seismic retraints for heat exchangers.  Calculate requirements for selecting seismic restraints and for designing bases.  Signed and sealed by a qualified professional engineer.
          3. Coordination Drawings:  Where space constraints dictate careful planning for efficient installation of different components or if coordination is required for installation of products and materials by separate installers include detailed scaled drawings and/or 3-D CAD models, on which the following items are shown and coordinated with each other, using input from installers of the items involved:
            1. Tube-removal space.
            2. Structural members to which heat exchangers will be attached.
          4. Maintenance Data:  Include operating, maintenance and repair instructions and spare parts lists.
          5. Source quality-control reports.
          6. Seismic Qualification Certificates:  For projects with Seismic requirements, include from manufacturer for heat exchanger, accessories, and components.
          7. Field quality-control test reports.
          8. Sample warranty.
          9. Include all approved submittal data in maintenance manuals; in accordance with requirements of Section 23 01 00 OPERATION AND MAINTENANCE OF HVAC SYSTEMS.
        7. WARRANTY
          1. Include manufacturer's standard form in which manufacturer agrees to repair or replace components of heat exchangers that fail under normal use due to defective materials or workmanship within specified minimum warranty period.
            1. Within a period of six months from date of shipment as to those parts which contain perishable elastomers.
            2. Within one year from the date all other equipment or part thereof is first placed in use, or two years from the date of shipment, whichever shall be less.
        .02 Equipment Requirements
        1. SHELL-AND-TUBE HEAT EXCHANGERS
          1. General Description:  Packaged assembly of outer shell with pipe connections, removable tube bundle, piping connection header, support saddles and specialties.  Capacities as scheduled on drawings with permanently affixed nameplate information.
          2. Construction:  Fabricate and label heat exchangers to comply with ASME Boiler and Pressure Vessel Code, Section VIII, "Pressure Vessels," Division 1.
          3. Configuration:  U-tube with removable bundle.
          4. Shell Materials: 
            1. Typical HVAC applications.
              1. Steam to hot water: Steel
              2. Water to water (closed systems):  Steel 
            2. Consult manufacturer for special applications.
          5. Head:
            1. Select material for fluid and service conditions to be resistant to corrosion.  Do not use ferrous materials on open systems.  [Cast Iron, Fabricated Steel, Cast Bronze, Stainless Steel - consult with manufacturer for applications].
            2. Shall be flanged and bolted to shell.
          6. Tubes:  Shall be selected to withstand corrosive attack by both fluids in the heat exchanger and to be resistant to impingement erosion.  Diameter shall be determined by manufacturer based on service. 
            1. (Typical HVAC heating applications - ): 
              1. Steam to hot water:
                1. [Copper, 18 ga. Seamless:] to be used in combination with extended shell with steam inlet beyond end of u-bends so steam does not directly hit tubes.
                2. [Stainless steel (304), Electric Resistance Welded:] to be used if extended shell will not fit and steam inlet must be directly over tubes.
              2. Water to water (closed systems):  18 ga. Copper, seamless
            2. Special applications:  consult with manufacturer for recommended materials for application.  Do not use copper or stainless steel in applications with chlorine such as pool water heating.  Substitute 90/10 CuNi or as otherwise recommended by heat exchanger manufacturer.
          7. Tubesheet Materials:  The tubesheet, in addition to its mechanical requirements, must be selected to withstand corrosive attack by both fluids in the heat exchanger and must be electro-chemically compatible with the tube and all tube side materials.  Low carbon steel tube sheets can include a layer of a higher alloy metal bonded to the surface to provide more effective corrosion resistance with the expense of using the solid alloy.  Do not use ferrous materials on open or otherwise high oxygen content systems.
            1. Typical HVAC heating application
              1. Steam to water:  [steel, 90/10 CuNi, stainless steel]
              2. Water to water:  [steel, 90/10 CuNi, brass]
            2. Special applications:  consult with the manufacturer for recommended materials for application.
          8. Baffles:  Select for fluid application and tube material to avoid galvanic corrosion and rust.
            1. Typical HVAC heating application
              1. Steam to water:  [brass or stainless steel]
              2. Water to water:  brass
            2. Special applications:  consult with manufacturer for recommended materials for application
          9. Piping Connections:
            1. For steam applications, the shell inlet connection shall be adequately sized and located to avoid excessive velocity and impingement erosion on the tubes.
              1. Preferred method where space allows is extended shell with steam inlet beyond end of u-bends so steam does not directly hit tubes.
              2. Where confined due to existing space constraints, oversized inlet connection and shell with impingement baffles.
            2. NPS 2” and Smaller:  Threaded ends according to ASME B1.20.1.
            3. NPS 2-1/2” and Larger:  Flanged ends according to ASME B16.5 for steel and stainless-steel flanges and according to ASME B16.24 for copper and copper-alloy flanges.
          10. Support Saddles:
            1. Fabricated of material similar to shell.
            2. Fabricate foot mount with provision for anchoring to support.
            3. For project with seismic restraint requirements as determined by Structural Engineer:  Fabricate attachment of saddle supports to pressure vessel with reinforcement strong enough to resist heat-exchanger movement during seismic event when heat-exchanger saddles are anchored to building structure.
          11. Manufacturers:  Subject to compliance with requirements, [available manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following:
            1. API Heat Transfer Inc.; Basco
            2. Armstrong Pumps, Inc.
            3. Diversified Heat Transfer
            4. ITT Corporation; Bell & Gossett
            5. TACO Incorporated.
            6. Thrush Company, Inc.
        2. GASKETED-PLATE HEAT EXCHANGERS
          1. Configuration:  Freestanding assembly consisting of frame suport, top and bottom carrying and guide bars, fixed and movable end plates, tie rods, individually removable plates, and one-piece gaskets.
          2. Construction:  Fabricate and label heat exchangers to comply with ASME Boiler and Pressure Vessel Code, Section VIII, "Pressure Vessels,"  Division 1.
          3. Frame:
            1. Capacity to accommodate a minimum of 10 percent additional plates.
            2. Painted carbon steel with provisions for anchoring to support.
          4. Top and Bottom Carrying and Guide Bars:  stainless steel.
            1. For project with seismic restraint requirements as determind by Structural Engineer:  Fabricate attachment of heat-exchanger carrying and guide bars with reinforcement strong enough to resist heat-exchanger movement during seismic event when heat-exchanger carrying and guide bars are anchored to building structure.
          5. End-Plate Material: Epoxy painted carbon steel.
          6. Tie Rods and Nuts:  Steel or stainless steel.
          7. Plate Material:  Designer shall consult with heat exchanger manufacturer to select the most effective material and thickness for each application to achieve the lowest life cycle cost.
            1. Typically stainless steel [304 or 316] for most general HVAC applications.
          8. Gasket Materials:  Gaskets shall be clipped onto the plates.  Glued gaskets are not acceptable.
            1. Nitrile butyl rubber (NBR) gaskets:  for applications up to 2300F.
            2. Ethylene-Propylene Diene Monomer (EPDM) gaskets:  for applications up to 3200F.
          9. Piping Connections:
            1. NPS 2 and Smaller:  Threaded ends according to ASME B1.20.1.
            2. NPS 2-1/2 and Larger:  Flanged ends according to ASME B16.5 for steel and stainless-steel flanges and according to ASME B16.24 for copper and copper-alloy flanges.
          10. Accessories:
            1. Enclose plates in solid aluminum removable shroud.
            2. Drip Pans:  Provide Stainless steel pans under footprint of heat exchanger to contain leakage on start-up or shut down, gasket failure, or condensation.
          11. Manufacturers:  Subject to compliance with requirements, available manufacturers offering prodcuts that may be incorporated into the Work include, but are not limited to, the following:
            1. Alfa Laval Inc.
            2. API Heat Transfer Inc.
            3. APV; a brand of SPX Corporation
            4. Armstrong Pumps, Inc.
            5. Diversified Heat Transfer
            6. ITT Corporation; Bell & Gossett
            7. Mueller, Paul, Company
            8. TACO Incorporated
            9. Tranter, Inc.
        3. BRAZED-PLATE HEAT EXCHANGERS
          1. Configuration:  Brazed assembly consisting of embossed or pressed stainless-steel plates brazed together and two end plates, one with threaded nozzles and one with pattern-embossed plates.
          2. Construction:  Fabricate and label heat exchangers to comply with ASME Boiler and Pressure Vessel Code, Section VIII, "Pressure Vessels," Division 1.
          3. End-Plate Material:  Type 316 stainless steel.
          4. Nozzles:  Type 316 stainless steel.
          5. Brazing Material:  Copper.
          6. Manufacturers:  Subject to compliance with requirements, [available manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following:
            1. Alfa Laval Inc.
            2. API Heat Transfer Inc.
            3. APV; a brand of SPX Corporation
            4. Armstrong Pumps, Inc.
            5. Diversified Heat Transfer
            6. GEA PHE Systems North America, Inc.
            7. ITT Corporation; Bell & Gossett
            8. Mueller, Paul, Company
            9. Tanter, Inc.
        .03 Execution
        1. Installation
          1. General:  Install heat exchangers and accessories in strict accordance with the manufacturer's requirements for maintaining optimum performance and serviceability.
            1. Maintain manufacturer's and University recommended clearances for tube removal, service, and maintenance.
            2. Mount units at height that are serviceable without the need for ladders or scaffolding.
          2. Structural Mounting:  Structural support must be adequate so that exchangers will not settle and cause strains on piping connections.
            1. Mount shell and tube heat exchangers on elevated support legs, which in turn shall be anchored to housekeeping pad with anchor bolts.  In general, avoid suspending heat exchangers from piping or structure above.  Install shell-and-tube heat exchangers on saddle supports.  One end of the shell fasteners shall be left loose to allow proper expansion compensation of the shell.
            2. Mount frame of gasketed-plate heat exchangers on base anchored to housekeeping pad with anchor bolts.
            3. Install brazed-plate heat exchanger on custom-designed supports anchored to structure.
            4. In general, concrete housekeeping pads shall be at least 4 in. thick and 6 in. wider on each side than the heat exchanger support footprint.  Concrete work shall comply with requirements in Division 03 - Concrete.
          3. Hydronic Piping and Specialties:  Comply with requirements for piping specified in 23 21 13 Hydronic Piping.  Drawings shall be coordinated to indicate general arrangement of piping, fittings, and specialties.
            1. Install piping adjacent to heat exchangers to allow space for service and maintenance of heat exchangers.  Arrange piping for easy removal of heat exchangers.  Unions shall be installed at final connections at right angles to allow the least amount of pipe dismantling for ease of repair and replacement.
            2. The manufacturer's intended flow path of each fluid on both sides of a heat exchanger design shall be carefully followed.  Failure to connect to the correct inlet and outlet connections may reduce performance.
            3. All piping shall be independently supported so that not strain is imposed on the heat exchanger connections.
            4. Install flexible pipe connectors to isolate exchanger from any external vibrations that can cause fatigue failures within the heat exchanger.
            5. Install line-sized, low pressure drop shutoff valves (typically butterfly) in the entering and leaving piping of each exchanger to permit servicing without draining the system.
            6. Install long-tapered reducers and increasers to smoothly transition the pipe size and connection flanges with minimum pressure drop. Abrupt transitions, bushings and reducing flanges are not permissible.
            7. Install relief valves on heat exchanger heated-fluid connection and install drain piping from relief valves, full size of valve connection, to floor drain. Avoid creating tripping hazards.
            8. Piping shall be arranged so it can be easily vented. Provide an air vent at high points and a hose end drain valve at the low points of water piping connections. Install hose end drain valve to drain shell.
            9. Drip pans made of stainless steel shall be installed under plate heat exchangers to contain leakage on start-up or shut down, gasket failure, or condensation. Provide ¾” drain connection, piped to nearest floor drain.
          4. Steam Piping and Accessories:  Comply with requirements for steam and condensate piping specified in 23 22 00 STEAM AND CONDENSATE PIPING AND PUMPS.
            1. Steam Inlet:
              1. Install steam isolation valve to isolate assembly from main. Install pressure gauge assembly on main side of isolation valve.
              2. Install fine mesh steam strainer downstream of isolation valve and ahead of steam separator, with screen pocket installed horizontally to avoid forming condensate pocket.
              3. Ensure only dry steam enters the control valve and heat exchanger inlet to avoid water hammer or damaging tubes due to wet steam impingement.
                1. Install end of main drip trap assembly on bottom of steam supply pipe. Install top takeoff on steam supply pipe to control valve. Or
                2. Install a general purpose baffle type moisture separator (made of ductile/SG iron) with drip trap assembly at low point immediately ahead of control valve.
              4. Install properly sized temperature control valve assembly with unions.
                1. For steam applications use a high-performance, stainless steel, v-ball control valve with equal percentage control characteristic with minimum 100:1 rangeability.  Refer to BAS Guide Specification in 25 00 00 INTEGRATED AUTOMATION.
              5. Install pressure gauge assembly downstream of control valve prior to inlet connection.
            2. Condensate Outlet:
              1. The heat exchanger shall be pitched slightly (minimum 1/16” per foot) toward the condensate drain connection to ensure good drainage.
              2. For modulating steam supply, install vacuum breaker at heat-exchanger steam inlet connection or on shell. The vacuum breaker shall be mounted on a vertical pipe a minimum of 8” above the tapping to provide a cooling leg to protect vacuum breaker from dirt and extreme temperatures.
              3. Provide a minimum 18" fill leg to trap inlet, with flushable dirt leg, terminating with hose end drain valve below level of trap inlet.
              4. Install strainer with drain valve ahead of steam trap.
              5. Install a shut off valve between strainer and trap.
              6. Install properly sized steam traps according to manufacturer’s instructions for complete condensate drainage so condensate never backs up in heat exchanger. Include unions to allow trap service or replacement.
              7. Install a check valve and shut off valve to isolate runout assembly from condensate return main.
              8. Return line shall be pitched from trap discharge with no lift to gravity condensate return or to vented condensate return unit if gravity system is unavailable.
          5. Measuring Instruments:  Comply with requirements of 23 05 19 Measuring Instruments for HVAC.
            1. Install a single pressure gauge assembly with 1/4" ball valves and interconnecting piping from the entering and leaving sides of each hydronic system in order that each pressure and/or difference can be observed from a single gauge.
            2. Install pressure gauge assemblies at steam main and after control valve.
            3. Install thermowells and thermometers at each hydronic inlet and outlet, located as near to unit connections as possible.
          6. Install metal shroud over installed gasketed-plate heat exchangers according to manufacturer's written instructions.
          7. Insulation:  Insulate assembly to comply with insulation thickness and performance prescribed by University's High Performance Design Standard (ASHRAE 189.1) and other requirements in 23 07 00 HVAC INSULATION.
            1. Provide removable insulation sections to cover parts of equipment that must be accessed periodically for maintenance (i.e. – tube heads, strainers, vent/drain plugs or valves, p/t ports) without damaging insulation or compromising vapor barrier. Include covers, fasteners, flanges, frames and accessories.
            2. Insulation on systems operating below ambient dew point (such as chilled water) shall be insulated with closed cell foam with all joints and penetrations completely sealed to maintain vapor barrier.
            3. Keep nameplate information uncovered (heating systems) or easily accessible (cold systems).
          8. Identification:  Provide mechanical identification per University Standards, 23 05 01.05 Mechanical Identification
        2. Start-up/Commissioning
          1. Hydronic System Balancing:
            1. For general testing, adjusting and balancing requirements, refer to 23 05 93 Testing, Adjusting, and Balancing for HVAC.
            2. Heat Exchanger TAB data:
              1. Identification/Number, Service, Location
              2. Manufacturer, Model Number, Serial Number
              3. Primary Source fluid entering conditions (temperature/pressure), design and actual
              4. Primary source fluid leaving conditions (temperature/pressure), design and actual
              5. Primary flow rate, design and actual
              6. Primary pressure drop, design and actual
              7. Secondary entering and leaving conditions (temperature and pressure), design and actual
              8. Secondary flow, design and actual
              9. Total heat transferred:  at design flow conditions and at peak control valve output
              10. Secondary water pressure drop, design and actual
              11. Relief valve(s), size, rated capacity, pressure setting
        3. FIELD QUALITY CONTROL
          1. Perform the following tests and inspections [with the assistance of a factory-authorized service representative]:
            1. Leak Test:  After installation, charge system and test for leaks.  Repair leaks and retest until no leaks exist.
            2. Test and adjust controls and safeties.  Replace damaged and malfunctioning controls and equipment.
            3. Prepare and submit test and inspection reports.
            4. Heat exchanger will be considered defective if it does not pass tests and inspections.
        4. CLEANING:  After completing system installation, including outlet fitting and devices, inspect exposed finish.  Remove burrs, dirt, and construction debris and repair damaged finishes.

        23 60 00 CENTRAL COOLING EQUIPMENT

        23 64 00 PACKAGED WATER CHILLERS

        .01 General Owner Requirements and Design Intent
        1. General:  Professional shall design each chiller application for optimal operating efficiency, reliability, and flexibility with the lowest life cycle cost.  Coordinate and review chillers and chilled water systems with OPP Engineering Services, Chilled Water Services Supervisor (for projects at University Park), Maintenance Superviser at Commonwealth Campuses, and Building Automation System (BAS) Application Engineering Groups.
        2. Related Standards Sections:  General requirements related to chiller work, include, but are not necessarily limited to, the following:
          1. 23 00 01 Owner General Requirements and Design Intent
          2. 23 05 01.05 Mechanical Identification:  Coordinate mechanical identification nomenclature with University Standards.
        3. Chiller System Considerations:
          1. Chiller Selection:
            1. Refer to ASHRAE Systems and Equipment Handbook, Liquid Chilling Systems
            2. Discuss chiller selection at conceptual design stage with the University. 
            3. Evaluate centrifugal chillers within commonly available capacity ranges and use whenever that alternative is the lowest life cycle cost for the application. 
            4. Carefully evaluate operational full and part load profile and system turndown requirements. 
            5. Consider modular, multiple unit configurations where effective and practical for proper low part load operation and to help prevent complete system or building shutdown upon failure of a single chiller. Any applications with a single chiller shall have a minimum of 2 refrigeration circuits to provide redundancy.  Single chiller applications with single refrigerant circuit are not acceptable.
            6. Use energy-efficient modulating compressor control technologies that unload input power proportionally to match load.  Refer to .02 Product Requirements below.
            7. Try to avoid requiring a central chiller and pump system to operate to serve a relatively small continuous internal load during unoccupied periods or when the chiller system could otherwise be off.  But if absolutely unavoidable, be sure chiller has energy-efficient capacity reduction control so it does not excessively cycle during those periods.
            8. Wherever practical, apply water side economizer cooling to supply continuous cooling loads in winter.  Options include:
              1. Cooling tower water to chilled water heat exchangers for water cooled chillers
              2. Integral dry fluid cooler coil in condenser section with associated controls for new packaged air cooled chillers.
              3. Separate packaged dry fluid coolers for modifications to existing air cooled chiller systems.
            9. Determine any requirements for low ambient operation and specify control options accordingly.
            10. Design for low flow, high temperature differences and variable flow distribution systems to minimize pump energy.
              1. Maintain average overall system water temperature rise of at least 12°F.
              2. Selection of cooling coils in typical HVAC applications is recommended with a 14-16°F rise at peak conditions.
            11. Allow for distribution system heat gains (conduction through pipe insulation, pump heat) in determining the required chiller capacity.
            12. Select chillers for altitude in which installed to achieve minimum performance indicated.  Make adjustments to affected chiller components to account for site altitude.
            13. Consider combination chiller-heaters where they can be applied for net energy cost savings to satisfy simultaneous needs for chilled water and hot water.  
              1. Options might include:
                1. Water to water heat pumps
                2. Dedicated Heat Recovery Chillers 
                3. Air to Water Heat Pump
              2. Resources:  
                1. ASHRAE Systems and Equipment Volume, Applied Heat Pump and Heat Recovery Systems
                2. “Dedicated Heat Recovery”, ASHRAE Journal article, October 2003.
                3. Manufacturer’s Literature:  http://www.multistack.com/products/chiller_heaters.aspx
          2. Distribution Systems:
            1. Provide minimum system fluid volume in circulation to provide sufficient thermal mass in system as required to avoid excessive cycling of compressors, poor temperature control, and/or erratic system operation.  
              1. Chiller systems require adequate time to recognize a load change, respond to the change and stabilize to avoid undesirable short cycling of the compressors or loss of temperature control. In air conditioning systems, the potential for short cycling usually exists when the building load falls below the minimum chiller plant capacity or on close-coupled systems with very small water volumes. 
              2. To determine the minimum system fluid volume in circulation, the designer shall consider the type of application, the allowable system temperature control swing, the minimum cooling load, the minimum chiller plant capacity during the low load period and the desired cycle time for the compressors.  Consult with chiller manufacturers and comply with their application recommendations.  
              3. Volume calculations for fluid volume in circulation shall exclude any dead leg piping and equipment beyond any control valves.
              4. A "buffer” tank specifically designed for this application may have to be added to the system to reach the recommended system volume.  Refer to Product Requirements and Execution for additional details. 
            2. Typically design chilled water and condenser water systems to pump into the chiller.  Review exceptions with OPP.
              1. Exception:  On hi-rise applications in which the static pressure is great, installing the primary pump on the outlet of the chiller might be advantageous to reduce the total pressure on the evaporator.
            3. Ensure chillers are circuited and piping system is arranged to achieve maximum efficiency.
              1. Ensure the manufacturer’s required water flow through evaporator is maintained.
              2. Connect piping so that all return water and any water from a bypass are thoroughly mixed before any of the water enters a chiller.  After the tee, there should be at least 10 pipe diameters to the nearest chiller. This is to help avoid the possibility of having stratification in the primary return line, which can lead to unmixed water to the nearest chiller. This can lead to chiller cycling.
              3. Arrange piping such that all chillers obtain equal return water temperature.  
                1. Exception:  in systems where “backloading” or “preferential” loading of chillers is advantageous by design to maximize the operating performance of different types of chillers.
              4. For primary-secondary systems, the system must be piped and controlled so that water never flows in the reverse direction in the decoupler bypass during normal operation.
                1. The supply tee connecting the building supply distribution loop to the chiller loop shall be arranged such that the secondary loop is the side branch and the bypass is the straight through direction.  This directs the primary loop water’s energy into the decoupler bypass and requires the secondary loop to pull the water out of the tee.
                2. The return tee connecting the secondary return loop to the primary chiller return shall be arranged such that the bypass is the side branch and the secondary return to the primary chiller return loop is the straight through direction. 
                3. The secondary loop return must not be connected too closely to the supply pipe with a bullhead tee in which the velocity head rams into the decoupler bypass which can encourage migration. 
                4. Although in theory there should be no pressure drop in the decoupler, in order to avoid thermal contamination in actual systems the decoupler should be at least 10 pipe diameters in length (per 2008 ASHRAE Systems Handbook, p. 12.22). Longer decouplers tend to increase the pressure drop. 
                5. Size decouplers for the flow rate of the largest primary pump. This may be more than the design flow rate of the largest chiller if overpumping is being considered. The pressure drop should not exceed 1.5 ft. As the pressure drop through the decoupler increases, it tends to make the primary and secondary pumps behave like they are in series.
          3. Controls:
            1. Include reliable safety flow proving switches to protect chiller.
            2. Include accurate and reliable flow meter(s) to monitor system GPM flow through BAS and to ensure minimum flow is maintained through chiller evaporators whenever operating chiller(s) in variable primary flow applications.
            3. Apply energy saving control strategies, including:
              1. Enable chiller on actual cooling requests rather than just outside air temperature.
              2. Chilled water temperature reset optimization. Control to minimize combined chiller and pump energy that always just satisfies the control zone cooling and dehumidification demands. Optimization shall be based on the following: 
                1. Zone cooling/dehumidification requests
                2. Pump Speed
                3. Chiller efficiency operating curve
                4. Maintaining minimum flow requirements through chiller
                5. Limiting temperature reset range to a lower upper limit when OA enthalpy is higher to ensure better dehumidification is available when needed.
              3. Condenser water temperature reset based on constant approach with respect to ambient wet bulb.
            4. Controls must not be placed in public areas.
          4. Sound and Vibration Control:  Comply with requirements Section  23 05 01 Mechanical General Requirements, .04 Sound and Vibration Control
            1. Refer to ASHRAE Applications, Sound and Vibration Control and comply with guidelines and recommendations therein.
            2. Chiller systems produce significant and often objectionable amounts of sound power levels as both average noise level overall and as strong peaks within certain octave bands.  These specific characteristics are dependent on the chiller type and must be accounted for in the overall application and design.  
            3. Historically screw type chillers have been the source of many noise complaints.  Therefore they require extra careful attention regarding their relative location with respect to noise sensitive areas and subsequent noise and vibration control design. 
            4. Coordinate with Architect to locate chillers away from noise sensitive areas and to provide adequate general construction sound barrier assemblies as needed.  
            5. Minimize objectionable noise to nearby buildings or sensitive neighboring areas.
            6. Include sound performance criteria in equipment schedules.
          5. Coordination for indoor chillers:
            1. Mechanical rooms containing refrigeration machinery shall be designed to meet the requirements of Chapter 11, Refrigeration of the International Mechanical Code and ASHRAE Standard 15.
            2. Indicate location on drawings of all required refrigeration machine room safety equipment (refrigerant leak detection, self-contained breathing apparatus, emergency exhaust systems, refrigerant relief piping, etc.) as required by building code.
            3. Locate refrigerant pumpdown, pumpout and storage devices if they are required for application.
            4. Mechanical room locations and placement must take into account how equipment and largest replacement parts can be moved into and out of the building during installation and future major repair/replacement.
            5. Make sure that all clearances are maintained, including: 
              1. Minimum as required by manufacturer.  
              2. Allow at least three feet between all service sides of equipment and obstructions.
              3. Allow sufficient clear space equal to length and width of machine for tube pull clearance.  Show tube pull clearances and locations on drawings.
              4. Maintain minimum electrical clearances required by NEC.
            6. Coordinate height of chiller with overhead obstructions.  Provide beam with minimum 4' clearance above chiller or allow sufficient clear space above and around machine for utilizing gantry for compressor replacement.   
        4. Quality Assurance and Uniformity: 
          1. ARI Compliance:  Rate and certify chiller performance according to requirements in ARI. 
          2. ASHRAE Compliance:
            1. ASHRAE 15 for safety code for mechanical refrigeration.
            2. ASHRAE 147 for refrigerant leaks, recovery, and handling and storage requirements.
            3. ASHRAE/IESNA Compliance:  Applicable requirements in ASHRAE/IESNA 90.1 or ASHRAE 189.1 as required in 01 80 00 PERFORMANCE REQUIREMENTS
          3. ASME Compliance:  Fabricate and label chiller to comply with ASME Boiler and Pressure Vessel Code:  Section VIII, Division 1, and include an ASME U-stamp and nameplate certifying compliance.
          4. Comply with NFPA 70.
          5. Comply with requirements of UL and include label by a qualified testing agency showing compliance.
          6. Equipment manufacturer shall be ISO-9001 certified. 
          7. Equipment shall be of U.S. manufacturer. 
          8. Provide equipment of same type by same manufacturer.
          9. Perform functional run tests of chillers before shipping. (Note: Not all manufacturers "run test" chillers.  Consult manufacturers for availability.) 
        5. Submittals:  Documents shall require the following:
          1. Product Data:  Submit manufacturer's technical product data for chillers, including:
            1. Selection characteristics and rated capacities.
            2. Performance curves with system operating conditions indicated.
            3. Sound pressure levels per ARI Standard 575 for indoor chillers and ARI Standard 370 for outdoor chillers.
            4. General specifications:  type description, material of construction, thicknesses and finishes, 
            5. Motor type, ratings and electrical characteristics
            6. Accessories furnished
          2. Shop Drawings:  Include the following:
            1. Plans, elevations, sections, and attachment details.
            2. Details of equipment assemblies.  Indicate dimensions, weights, loads, required clearances, method of field assembly, components, and location and size of each field connection.
            3. Vibration Isolation Base Details:  Detail fabrication, including anchorages and attachments to structure and to supported equipment.  Include auxiliary motor slides and rails, and base weights.
          3. Wiring Diagrams:  Submit manufacturer's electrical requirements for power supply wiring to chiller units.  Submit manufacturer's ladder-type wiring diagrams for interlock and control wiring.  Clearly differentiate between portions of wiring that are factory-installed and portions to be field-installed.
          4. Coordination Drawings:  As required to meet project complexity, show chiller room layout and relationships between components and adjacent structural and mechanical elements.  Show support locations, type of support, and weight on each support.  Indicate and certify field measurements.
          5. Maintenance Data:  Submit operation and maintenance instructions, including lubrication instructions, motor and drive replacement, and spare parts lists.  Include this data, product data, shop drawings, and wiring diagrams in maintenance manuals; in accordance with requirements of Section 23 01 00 OPERATION AND MAINTENANCE OF HVAC SYSTEMS.
          6. Manufacturer’s functional run test report.
          7. Field quality-control reports.
        6. Warranty
          1. Standard Warranty:  Manufacturer's standard form in which manufacturer agrees to repair or replace components of chillers that fail in materials or workmanship within specified warranty period of minimum of 2 years from date of Substantial Completion.
          2. Special Warranty:  Manufacturer's standard form in which manufacturer agrees to repair or replace components of chillers that fail in materials or workmanship within specified warranty period.   Extended warranties include, but are not limited to, the following:
            1. Complete chiller including refrigerant and oil charge.  Warranty Period:  minimum of 2 years from date of Substantial Completion.
            2. Complete compressor and drive assembly including refrigerant and oil charge.  Extended Warranty Period:  minimum of 5 years from date of Substantial Completion.
        .02 Product Requirements
        1. General:
          1. Discuss refrigerant selection with the University prior to equipment selection.  
            1. Select with respect to current EPA regulations regarding phaseout of Ozone-Depleting Substances. http://www.epa.gov/ozone/title6/phaseout/index.html
            2. At University Park, chillers for central plants shall match existing refrigerant (R-134a).
            3. In general, OPP prefers not to use R-123, but may consider for special applications.
          2. Statically and dynamically balance rotating parts.
          3. Serviceability:  All components shall be easily accessible for inspection and service.
        2. Basis of design shall include models from a minimum of two reputable manufacturers.
        3. Capacity Control:  Chillers shall be configured to achieve most energy-efficient, reliable and stable operation throughout expected service conditions. Options shall include combination of:
          1. Multiple refrigerant circuits
          2. Multiple compressors
          3. Modulating, power unloading compressor technologies such as variable speed drives or time averaged pulsed loading and unloading with digital scroll type compressors in lieu of energy-wasteful hot gas bypass.
            1. Digital (Pulse Width Modulation) Scroll Compressors: http://www.digitalscroll.com/sb300/portal/home/normal/1
            2. VFD Driven Compressors: 
              1. Scroll: http://www.danfoss.com/NR/rdonlyres/ED489694-517C-4A3D-BE71-0586F73B20A3/0/Apexx_Brochure.pdf
              2. Screw
              3. Centrifugal
          4. If hot-gas bypass is only available option, use only on smallest stage(s). Review with OPP Engineering Services.
        4. Compressors:
          1. Shall be factory mounted, aligned, and balanced as part of compressor assembly before shipping.
          2. Vibration Balance:  Balance chiller compressor and drive assembly to provide a precision balance that is free of noticeable vibration over the entire operating range.
          3. Provide lifting lugs or eyebolts attached to casing.
        5. Refrigeration Circuits:  Shall include the following:
          1. Compatibility:  Chiller parts exposed to refrigerants shall be fully compatible with refrigerants, and pressure components shall be rated for refrigerant pressures.
          2. Full operating charge of refrigerant and oil.
          3. Refrigerant filter drier (replaceable core type) with isolation valves.
          4. Flow Control: Electronic or thermal expansion valve satisfying performance requirements and sized for maximum operating pressure.
          5. Pressure Relief Device:
            1. Comply with requirements in ASHRAE 15 and in applicable portions of ASME Boiler and Pressure Vessel Code:  Section VIII, Division 1.
            2. Pressure relief valve(s) shall be provided for each heat exchanger.  Condenser shall have dual valves with one being redundant and configured to allow either valve to be replaced without loss of refrigerant.
          6. Provide each evaporator with sight glass or other form of positive visual verification of liquid-refrigerant level.
          7. Provide each condenser with sight glass or other form of positive visual verification of refrigerant charge and condition.
          8. Charging valve.
          9. Refrigerant Isolation Valves:  Provide factory installed, positive shutoff, manual isolation valves to allow storage of full refrigerant charge inside the chiller condenser to reduce refrigerant loss and time-consuming transfer procedures during routine servicing.
          10. Refrigeration Transfer:  Provide service valves and other factory-installed accessories required to facilitate transfer of refrigerant from chiller to a remote refrigerant storage and recycling system.  Comply with requirements in ASHRAE 15 and ASHRAE 147. 
          11. Discharge and oil line check valves.
        6. Evaporators:
          1. The evaporator shall be designed, tested, and stamped in accordance with ASME code for refrigerant side working pressure and waterside working pressures suitable for each application.
          2. Shall be designed to prevent liquid refrigerant carryover from entering compressor.
          3. Provide water drain connection, vent and fittings for factory installed leaving water temperature control and low temperature cutout sensors.
          4. Evaporator shall have only one entering and one leaving connection.  If manufacturer provides 2 separate evaporators, contractor shall provide manifold and pressure gauges to ensure equal flow is provided to each evaporator. Such requirements shall be accounted for in manufacturer's chiller bid and submittal.
        7. Insulation:
          1. Apply insulation over all cold surfaces of chiller capable of forming condensation.  Components shall include, but not be limited to, evaporator shell and end tube sheets, evaporator water boxes including nozzles, refrigerant suction pipe from evaporator to compressor, cold surfaces of compressor, refrigerant-cooled motor, and auxiliary piping.
            1. Apply adhesive to 100 percent of insulation contact surface.
            2. Before insulating steel surfaces, prepare surfaces for paint, and prime and paint as indicated for other painted components.  Do not insulate unpainted steel surfaces.
            3. Seal seams and joints to provide a vapor barrier.
            4. After adhesive has fully cured, paint exposed surfaces of insulation to match other painted parts.
          2. Type:  Closed-cell, flexible elastomeric thermal insulation with Conductivity (k) of 0.22-0.28 Btu•in./(h•ft2•°F) complying with ASTM C 534, Type I for tube and Type II for sheet materials, meeting 25/50 flame spread/smoke developed ratings.  
          3. Minimum thickness: Shall meet the most stringent of the following.
            1. For condensation control:  Shall avoid surface condensation under all operating conditions of application.
            2. For High-Performance Energy Efficiency:  Shall meet minimum pipe insulation thickness for cooling systems listed in current High Performance Design Standard referenced in 01 80 00 PERFORMANCE REQUIREMENTS.     
            3. Review these requirements and availability of options with manufacturer.  It is preferable to have chillers factory insulated to meet requirements above.  However, if manufacturer’s available options for factory installed insulation are not able to satisfy the above, then coordinate to specify field-installed supplemental insulation as required.
        8. Electrical Power:  Factory-installed and -wired switches, motor controllers, transformers, and other electrical devices necessary shall provide a single-point field power connection to water chiller.
          1. Field power interface shall be to NEMA KS 1, heavy-duty, nonfused disconnect switch.
          2. House in a unit-mounted enclosure of the type rated for the application with hinged access door with lock and key or padlock and key.
          3. High Power Factor:  Equipment shall maintain minimum power factor of 0.95 lagging at all operating conditions. 
          4. Provide terminal blocks with numbered and color-coded wiring to match wiring diagram.  Spare wiring terminal block for connection to external controls or equipment.
          5. Factory-installed wiring outside of enclosures shall be in metal raceway except make connections to each motor and heater with not more than a 24-inch length of liquid-tight conduit.  [Designer Note: Review application specific requirements and retain to enclose wiring.  Chiller manufacturers do not normally enclose all wiring.  Verify availability with manufacturers].
          6. Provide branch power circuit to each motor, dedicated electrical load and  controls with NEMA AB 1, motor-circuit protector (circuit breaker) with field-adjustable, short-circuit trip coordinated with motor locked-rotor amperes.
          7. Motor Controllers: Select type for each application as required to meet electrical system requirements.  Refer to 23 05 01.01 for motor inrush current and voltage drop requirements.
          8. NEMA- and ICS 2-rated motor controller for auxiliary motors, hand-off-auto switch, and overcurrent protection for each motor.  
          9. Provide variable frequency controller for each variable-speed motor furnished. Furnish in accordance with University guide specifications, 26 29 23 Variable-Frequency Motor Controllers
          10. Control-circuit transformer: Unit-mounted transformer with primary and secondary fuses and sized with enough capacity to operate electrical load of unit mounted controls plus spare capacity.
          11. Overload Relay:  Shall be sized according to UL 1995 or shall be an integral component of chiller control microprocessor.
          12. Phase-Failure, Phase-Reversal, and Undervoltage Relays:  Solid-state sensing circuit with adjustable undervoltage setting and isolated output contacts for hardwired connection.
        9. Accessories:
          1. Flow Switches:  Chiller manufacturer shall furnish a dependable safety flow switch for each evaporator, and condenser when water cooled, and confirm field-mounting location before installation.
          2. Vibration Isolation:  Chillers shall include vibration isolation properly selected for each application both for supporting unit and for piping connections.
          3. Sound Control:  Designer shall determine if sound attenuation option is required and specify the following accordingly. 
            1. Sound-reduction package shall consist of removable acoustic enclosures around the compressors and drive assemblies that are designed to reduce sound levels without affecting performance.
            2. Noise Rating:  <Insert dBA> sound power level when measured according to ARI 575 (indoor chillers) or ARI 370 (outdoor chillers).  Provide factory-installed sound treatment if necessary to achieve the performance indicated.
        10. Controls:  Shall be standalone and microprocessor based with all memory stored in nonvolatile memory so that reprogramming is not required on loss of electrical power.
          1. General:  Coordinate with OPP Engineering Services and Building Automation System (BAS) Application Engineering Groups and Chilled Water Services Supervisor.
          2. Operator Interface:  Multiple-character digital or graphic display with dynamic update of information and with keypad or touch-sensitive display located on front of control enclosure.  In either imperial or metric units, display the following information:
            1. Date and time.
            2. Operating or alarm status.
            3. Pump status.
            4. Fault history with not less than last 10 faults displayed.
            5. Set points of controllable parameters.
            6. Trend data.
            7. Operating hours.
            8. Number of starts for each compressor.
            9. Antirecycling timer status.
            10. Outdoor-air temperature or space temperature if required for chilled-water reset.
            11. Temperature and pressure of operating set points.
            12. Entering- and leaving-fluid temperatures of evaporator and condenser.
            13. Difference in fluid temperatures of evaporator and condenser.
            14. Fluid flow of evaporator and condenser.
            15. Fluid pressure drop of evaporator and condenser.
            16. Refrigerant pressures in evaporator and condenser.
            17. Refrigerant saturation temperature in evaporator and condenser.
            18. Oil temperature.
            19. Oil discharge pressure.
            20. Percent of maximum motor amperage.
            21. Demand power (kilowatts).
            22. Energy use (kilowatt-hours).
            23. Current-limit set point.
            24. Phase current.
            25. Phase voltage.
            26. Power factor.
            27. Compressor bearing temperature.
            28. Motor bearing temperature.
            29. Motor winding temperature.
          3. Control Functions: 
            1. Manual or automatic startup and shutdown time schedule.
            2. Entering and leaving chilled-water temperatures, control set points, and motor load limits.  Evaporator fluid temperature shall be reset based on system cooling demand.  Coordinate with Division 25 – BAS Guidespec and Sequence of Operations.
            3. Current limit and demand limit.
            4. Condenser-fluid temperature.
            5. External chiller emergency stop.
            6. Antirecycling timer.
            7. Variable evaporator flow.
            8. Thermal storage.
            9. Heat reclaim.
            10. <Insert other control functions as required by specific application>.
              1. Designer Note:  Consider if the application would benefit from remote fault reset as an option – perhaps a transient over/under voltage spike from electrical storm on a chiller serving a critical research process.
          4. Manually Reset Safety Controls:  The following conditions shall shut down chiller and require manual reset:
            1. Low evaporator pressure or temperature; high condenser pressure.
            2. Low evaporator fluid temperature.
            3. Low oil differential pressure.
            4. High or low oil pressure.
            5. High oil temperature.
            6. High compressor-discharge temperature.
            7. Loss of condenser-fluid flow.
            8. Loss of evaporator-fluid flow.
            9. Motor overcurrent.
            10. Motor overvoltage.
            11. Motor undervoltage.
            12. Motor phase reversal.
            13. Motor phase failure.
            14. Sensor- or detection-circuit fault.
            15. Processor communication loss.
            16. Motor controller fault.
            17. Extended compressor surge.
          5. Trending:  Capability to trend analog data of up to five parameters simultaneously over an adjustable period and frequency of polling.
          6. Security Access:  Provide electronic security access to controls through identification and password with at least three levels of access:  view only; view and operate; and view, operate, and service.
          7. Control Authority:  At least four conditions:  Off, local manual control at chiller, local automatic control at chiller, and automatic control through a remote source.
          8. Communication Port:  RS-232 port or equivalent connection capable of connecting a portable computer and and/or a printer.
          9. BAS Interface:  Chiller manufacturer shall include factory-installed hardware and software to enable the BAS primarily to monitor and display chiller status, alarms and energy usage, and secondarily to allow but not be fully dependent on BAS control commands.  Each individual chiller shall have the protocol in the base controller.  
            1. Hardwired Points:  Essential functions shall be hardwired.
              1. Monitoring:  On-off status, common fault alarm, pump enable.
              2. Control:  On-off enable, pump status/proof of flow, [optional - chilled-water, discharge temperature set-point adjustment].
            2. ASHRAE 135 (BACnet) communication interface with the BAS shall enable the BAS operator to remotely control and monitor the chiller from an operator workstation.  Control features and monitoring points displayed locally at chiller control panel shall be available through the BAS.
              1. Designer Note:  Typically include the above in accordance with BAS subsystem integration requirements in Division 25 - Integrated Automation.  Requests for exceptions in certain applications (such as no existing BAS with little or no probability for having any BAS for the expected life of the drive) shall be submitted to OPP, Environmental Systems Manager for review and approval.Requests for exceptions to use MODBUS protocol in certain applications shall be submitted to OPP, Environmental Systems Manager for review and approval.
        11. Chilled Water Buffer Tank:
          1. The buffer tank shall be baffled to ensure optimal temperature difference and time lag between entering and leaving conditions.  
          2. The tank must be constructed as an ASME unfired pressure vessel in accordance with most recent addition of Section VIII of the ASME Boiler and Pressure Vessel Code.  
        12. Equipment Schedules: 
          1. Shall be shown on drawings, 
          2. Shall include at a minimum: tag designation, description/type, service, location, capacity (peak and minimum), operating conditions (flows (max design and minimum allowable), temperatures, pressure drops), minimum efficiency (at full and integrated part-load), number of compressors, electrical characteristics, KW, voltage, (including starter/speed drive type), and whether on normal/emergency standby power (where applicable), method of control, maximum dimensions and weights, and any application-specific options and remarks.
            1. Determine and clearly indicate in contract documents the maximum allowable equipment sound pressure levels per ARI Standard 575 for indoor chillers and ARI Standard 370 for outdoor chillers, Be sure to evaluate sound performance when listing or comparing acceptable manufacturers.
            2. Similarly clearly indicate all required sound attenuation performance requirements.
        .03 Execution
        1. Chiller Installation:  
          1. General:  Comply with manufacturer’s installation instructions.  Maintain manufacturer's recommended clearances.  Coordinate requirements on Drawings.
          2. Equipment Mounting:  Install chillers on supporting base.
            1. Indoor Mechanical Room:  concrete base
            2. Outdoor on grade:  concrete pad with turndown edges below frost line to prevent heaving.
            3. Roof:  Continuous equipment curb or raised structural steel frame with corrosion resistant finish.  Base details shall allow independent replacement of roofing and mechanical equipment.
            4. Concrete bases:
              1. Comply with requirements for concrete bases specified in Section 03 00 00 CONCRETE.
              2. Coordinate with Structural Engineer to detail the connection of concrete base to structural floor with dowel rods.
              3. Place and secure anchorage devices. Install epoxy-coated anchor bolts that extend through concrete base and anchor into structural concrete floor or as otherwise directed by Structural Engineer.  Install anchor bolts to elevations required for proper attachment to supported equipment.  Use setting drawings, templates, diagrams, instructions, and directions furnished with items to be embedded.
          3. Vibration isolation:  Comply with requirements for vibration isolation devices specified in Section 23 05 01 Mechanical General Requirements, .04 Sound and Vibration Control.
            1. Review application with a vibration consultant to verify suitability.
            2. Include isolator heights in clearance requirements.
            3. Coordinate piping connections to allow for deflection changes between full and drained chiller.
          4. Charge chiller with refrigerant and fill with oil if not factory installed.
          5. Install separate devices furnished by manufacturer and not factory installed.
        2. Connections:  
          1. General:  Coordinate piping installations and specialty arrangements with schematics on Drawings and with requirements specified in piping systems.  Drawings shall indicate general arrangement of piping, fittings, and specialties.  
            1. Comply with requirements for piping specified in the following Sections.
              1. 23 21 13 Hydronic Piping
              2. 23 23 00 REFRIGERANT PIPING
            2. Install piping adjacent to chiller to allow service and maintenance.  Arrange piping for easy dismantling to permit tube cleaning.
            3. Thoroughly flush all water piping to the unit before making final connections.  Construct a temporary bypass around the unit to prevent damage to internal components.
          2. Fluid Connections:
            1. Make easily detachable final piping connections to chiller with a flange or mechanical coupling and flexible pipe connectors.
            2. To prevent evaporator or condenser damage, pipe strainers must be installed in the water supplies to protect components from water born debris.
            3. To prevent damage, install pressure relief valves in both the evaporator and condenser water systems.
            4. Provide vents at high points in the piping to bleed air from the chilled water system. 
            5. Provide drain valve at low points.
            6. Comply with requirements of 23 05 19 Measuring Instruments for HVAC for all measuring instruments on chiller inlets and outlets.
            7. Connect to evaporator inlet with vibration isolator flexible connector, strainer, temperature and pressure measuring instruments and shutoff valve.
            8. Connect to evaporator outlet with vibration isolator flexible connector, flow switch (if shipped loose, not factory installed), temperature and pressure measuring instruments, balancing valve (if used), and shutoff valve.
            9. Connect to condenser inlet with vibration isolator flexible connector, strainer, temperature and pressure measuring instruments, and shutoff valve.
            10. Connect to condenser outlet with vibration isolator flexible connector, flow switch, (if shipped loose, not factory installed), plugged tee with shutoff valve, temperature and pressure measuring instruments, balancing valve (if used), shutoff valve.
          3. Refrigerant Pressure Relief Device Connections:  For chillers installed indoors, extend separate vent piping for each chiller to the outdoors without valves or restrictions.  Comply with ASHRAE 15.  Connect vent to chiller pressure relief device with flexible connector and dirt leg with drain valve.
          4. For chillers equipped with a purge system, extend separate purge vent piping for each chiller to the outdoors.  Comply with ASHRAE 15 and ASHRAE 147.
          5. Connect each chiller drain connection with a union and drain pipe, and extend pipe, full size of connection, to floor drain.  Provide a shutoff valve at each connection.
          6. Designer Note:  Refer to Detail [23 64 00 .xx] for typical piping connections.  Reserved for future.  Details are not yet available in WEB-based manual. 
        3. Chilled Water Buffer Tank Installation:
          1. Tank shall be fully insulated to prevent condensation and to meet insulation requirements in high performance building standard. 
            1. Closed-cell, flexible elastomeric thermal insulation with Conductivity (k) of 0.22-0.28 Btu•in./(h•ft2•°F) complying with ASTM C 534, Type I for tube and Type II for sheet materials.  
            2. Minimum thickness: Conform to current edition of ASHRAE 189.1
              1. 1.5 inch for fluids operating temperature range of 40-60°F.
              2. 2 inch for fluids operating temperature range less than 40°F.
            3. Seal seams and joints to provide a continuous vapor barrier.
            4. Provide protective embossed aluminum jacket covering where located in areas subject to harsh conditions, abuse or exposed to weather.
          2. Provide manual shut off valves at inlet and outlet to allow tank repair/replacement and a main bypass valve with automatic actuator interlocked with BAS to open for scheduled chemical treatment flush of normally closed leg.
        4. Control Wiring Installation and Coordination 
          1. The Control Systems Contractor shall install control wiring between chillers and remote devices and facility's central BAS per requirements in BAS specifications.
            1. Connect all hard-wired control inputs from BAS devices to chillers.
            2. Connect all hard-wired control outputs (normal/fault indication) from chillers to BAS.
            3. Connect network communication and coordinate with chiller start-up representative that correct parameter values are reading to BAS.
        5. Startup Service
          1. Engage a factory-authorized service representative to perform startup service that includes the following:
            1. Complete installation and startup checks according to manufacturer's written instructions.
            2. Verify that refrigerant charge is sufficient and chiller has been leak tested.
            3. Verify that pumps are installed and functional.
            4. Verify that thermometers and gages are installed.
            5. Operate chiller for run-in period.
            6. Check bearing lubrication and oil levels.
            7. For chillers installed indoors, verify that refrigerant pressure relief device is vented outdoors.
            8. Verify proper motor rotation.
            9. Verify static deflection of vibration isolators, including deflection during chiller startup and shutdown.
            10. Verify and record performance of fluid flow and low-temperature interlocks for evaporator and condenser.
            11. Verify and record performance of chiller protection devices.
            12. Test and adjust controls and safeties.  Replace damaged or malfunctioning controls and equipment.
          2. Inspect field-assembled components, equipment installation, and piping and electrical connections for proper assembly, installation, and connection.
          3. Prepare and submit test and inspection startup reports
        6. Testing, Adjusting and Balancing:
          1. For requirements, refer to 23 05 93 Testing, Adjusting, and Balancing for HVAC.
        7. Vibration Testing:
          1. Perform vibration testing per Section 23 05 01 Mechanical General Requirements, .04 Sound and Vibration Control.  
            1. The Contractor shall coordinate and contract the services of the University’s HVAC Vibration Analyst (At University Park, arranged through the Supervisor of Refrigeration and Mechanical Services) whenever available.  Otherwise (and at Commonwealth Campus locations) the Contractor shall hire an independent, third party Vibration Analyst meeting the approval of the University.
            2. Measured results of vibration testing and final alignment shall be recorded and coordinated to be entered into University’s Preventative Maintenance Software at time of start-up AND included in final report to be submitted as part of TAB/O&M submittals.
            3. IMPORTANT:  Excessive vibration contributes to noise problems, wastes energy and accelerates equipment failure and therefore must be corrected when found.  This work must be completed to the satisfaction of the University as part of the criteria determining Substantial Completion.

        23 65 00 COOLING TOWERS

        .01 Cooling Towers (General)
        1. In general, specify units of galvanized steel construction with PVC fill.  Cooling towers may be similar to the Baltimore Air Coil "V" line. 
        2. Indoor sumps should be considered where winter operation is required.  When towers are required to operate in the winter, sump heaters and heat tracing of piping shall be specified.
        3. The Professional shall consult the University during the design phase and seek approval of the location of all cooling towers.
        4. Select towers at 77°F W.B.
        5. Provide fan shaft pull space at ends of tower.
        6. See 23 25 00.03 for Cooling Tower water treatment.
        7. Maximum acceptable sound levels shall be included in the specification.  Sound levels shall be appropriate for the location and take into account any local noise ordinances.
        8. Condenser water temperature control shall be provided by a bypass valve unless an alternate control scheme is reviewed and approved by the University in advance.
          1. Review application and best practices of piping arrangement, valve selection and control sequence of tower bypass control valve.  OPP has experienced several misapplications related to this.  Bypass should only be used for maintaining minimum temperature on system startup during cold weather.  We have seen these misapplied for primary control condenser water temperature.  Use tower fan speed control to maintain constant approach condenser water control scheme for near optimal energy savings and chiller efficiency.
        9. Cooling tower fan speed control shall be specified unless the use of constant speed fan control is reviewed and approved by the University in advance.
        10. Belt guards:  Where required, guards shall be constructed of expanded metal mesh to allow for quick visual inspection of belts and pulleys without removal.  Guards shall be attached to equipment with hinges and/or quick release fasteners that can be turned without tools to allow for ease of maintenance 

        23 70 00 CENTRAL HVAC EQUIPMENT

        23 72 00 AIR-TO-AIR ENERGY RECOVERY EQUIPMENT

        .01 General
        1. Refer to 01 80 00 PERFORMANCE REQUIREMENTS.  In general, apply energy recovery equipment in accordance with current edition of ASHRAE Standard 189.1 Standard for the Design of High-Performance Green Buildings: Energy Efficiency - Prescriptive Option.
          1. The Standard 189.1 supersedes the minimum requirements in International Energy Conservation Code/ASHRAE 90.1.  It requires energy recovery equipment when the system’s supply airflow rate exceeds the associated tabular values based on the climate zone and percentage of outdoor air at design conditions.
          2. The energy recovery system effectiveness required by Standard 189.1 is also more stringent than the current minimum building code requirements.
          3. Provisions shall be made to bypass or control the energy recovery system to permit air economizer operation as required elsewhere in the Standard 189.1.
          4. Exceptions:
            1. Do not apply rotary energy recovery wheels to systems with risk of cross leakage from contaminated air streams such as chemical lab fume hood exhaust or animal facilities.  Use equipment with no potential for cross leakage.
        2. Submit cost analysis and control sequence for approval prior to submission of final review drawings.
        3. In general, any factory-assembled air handling units with energy recovery equipment shall comply with requirements in 23 73 00 AIR-HANDLING UNITS.
        4. Additional Design Resources: 
          1. ASHRAE Systems and Equipment Handbook (current edition); Air-to-Air Energy Recovery Equipment
          2. ASHRAE GreenGuide: The Design, Construction and Operation of Sustainable Buildings, current edition.
          3. National Institute of Building Sciences (NIBS) - Whole Building Design Guide; HVAC and Refrigerating Engineering; High-Performance HVAC.

        23 73 00 AIR-HANDLING UNITS

        .01 General Owner Requirements and Design Intent
        1. Professional shall design each application for optimal operating efficiency, reliability, and flexibility with the lowest life cycle cost.
          1. Evaluate and select basic fan configuration of each AHU system (whether relief damper, relief fan, or return fan) for best balance of energy optimization and reliable control function. Follow industry recommendations and review with OPP Engineering Services early in the design process. The following are general OPP application guidelines:
            1. Relief damper:  These are the simplest and least expensive but can be used only for air distribution systems with few individual spaces and little or no return ductwork (negligible return external static pressure requirements – less than approximately 0.10”).  Relief dampers (low-leakage type) shall be sized to limit pressure loss to 0.08-0.10”
            2. Relief Fan:  Recommended for systems that require forced relief beyond that provided by separate general exhaust for proper outdoor air/economizer and space pressurization control and that have low return duct static pressure requirements – between approximately 0.10-0.30”.
            3. Return fan: These configurations are the most expensive and most complicated to install, control and operate.  Therefore they should only be used to meet high pressure return requirements – greater than approximately 0.3 inches of water (per ASHRAE HVAC Systems and Equipment Handbook, Chapter 2, Air Handling Unit Components).
          2. High Performance Energy Efficiency:  Comply with requirements in ASHRAE Standard 189.1 for:
            1. Demand Controlled Ventilation
            2. Economizers
            3. Fan System Power Limitation
            4. Part Load Capacity Controls
            5. Energy Recovery
          3. Design for minimizing fan energy.
            1. The total allowable fan power limitation for each system shall be 10% less than the limits set by ASHRAE 90.1 or the current International Energy Conservation Code (whichever is more stringent), or as otherwise modified by most current edition of ASHRAE Standard 189.1.
            2. Minimize fan System Effects:  Avoid poor fan inlet and outlet conditions that reduce fan performance and increase energy waste.  Always consult manufacturer’s installation guidelines.
            3. Select any associated coils and filters with low air pressure drops.  Limit face velocity as follows:
              1. VAV systems: 400 (recommended) to 450 (max) feet per minute (fpm)
              2. Constant air volume systems:  300 (recommended) to 350 (max) fpm.
            4. Carefully evaluate and properly select the most effective fan type and wheel to best suit the needs of the application with emphasis on minimizing operating and life cycle cost, rather than minimizing size and first cost.
              1. Typically the backward oriented wheel designs (airfoil, backward curved, and backward inclined) offer greater peak efficiency, greater strength and non-overloading power characteristics and should be used whenever available as an option in lieu of forward curved wheels for central fans and air handling equipment.
              2. Fan selections at the actual operating point(s) shall be within 10 points of the peak total efficiency.
              3. Plenum fans not recommended for high static (>6”) applications.
              4. Plenum fans might not comply with ARI 430.  Verify.
              5. Direct drive fans:  May be considered but they need to be carefully selected to match motor rpm closely to max fan rpm.
          4. In cooling applications where there can be a net gain in energy performance, consider blow-through supply fan arrangement.  Primary potential energy benefit is to reduce latent subcooling required to account for fan heat.  Sensible heat of fan is added prior to coil and takes less energy to remove than to subcool air a few degrees below design supply air temperature (at saturated conditions) in typical draw-through arrangement.  However, care must be taken to achieve evenly distributed air across coils in blow-through arrangement with the least pressure drop penalty or reduction in fan efficiency.  Caution:  Evaluate leaving air conditions and do not apply on systems in which discharge air conditions can cycle and cause condensation on components and casing downstream of cooling coil due to air being at or very near saturation.
          5. Air Mixing/Blender Section:  Recirculation systems intended with mixing of air streams shall have a mixing section with necessary components specifically engineered to achieve evenly and thoroughly mixed conditions prior to entering heating or cooling coils.  This is critical in cold climates to avoid stratification and nuisance freezestat tripping.  Complete mixing is also important to achieve optimal coil performance, controllability and energy efficiency.  Professional shall include in the engineered design the application of air blenders, directional deflectors/baffles designed to force air streams into each other to mix, and/or blow-through supply fan arrangements in which air is mixed in fan section prior to coils.  Manufacturers “standard” mixing damper sections have repeatedly performed inadequately and are not acceptable.
            1. Actual performance shall be field verified as part of Functional Performance Testing.
            2. Design for adequate mixing between leaving face and bypass preheat coils and entering cooling coils.
            3. Complete mixing external to AHU is another alternative.
            4. Other resources for further reference: Functional Testing Guide,  Air Blenders and Baffle Plates
            5. Make sure blenders are designed for adequate mixing at lowest anticipated airflow.  Lower face velocities can affect blender performance.
          6. Coil Selection Criteria:
            1. Coils shall be “right-sized” for the application.  Carefully evaluate operational full and part load profile and system turndown requirements.  Do not substantially oversize and then rely on controls to effectively control at low load conditions.
            2. Design for low flow, high temperature differences, low water side pressure drop, and variable flow distribution systems to minimize pump energy.
            3. For buildings connected to campus utilities, coordinate requirements with 33 62 00 CAMPUS CHILLED WATER DISTRIBUTION and 33 63 00 STEAM ENERGY DISTRIBUTION as applicable.
            4. Selection of cooling coils in typical HVAC applications is recommended with a 14-16°F rise at peak conditions.
            5. For applications requiring cooling/dehumidification of high latent loads and reheat within the air handling unit such as Dedicated Outdoor Air Systems or high occupant assembly spaces, use technologies to avoid or minimize use of mechanical cooling and simultaneous addition of heating and cooling energy.  Options include:
              1. Wrap-around dehumidification heat pipe cooling coil assemblies.  http://heatpipe.com/abouthpt/heatpipes.htm
              2. Cross flow heat exchangers.
              3. Energy Wheels.
            6. Freeze Protection:  Reliable and effective means of freeze protection shall be provided on all applications in which coils are subject to freezing.
              1. Recirculating units shall have air blenders to ensure thorough mixing as described above.
              2. Steam coils shall be steam-distributing type for even temperature distribution across entire coil with modulating control.
              3. Multiple Staged Coils:  When high temperature rises are required (with high percentages of outside air and/or above typical preheat conditions of approximately 55°F), two or more single row staged steam heating coil assemblies, arranged in series in the airstream, controlled with individual control valves per stage provides some redundancy, protection against freezing, and better turndown control operation.  Review project specific application with AHU manufacturer and Engineering Services.
              4. Face and Bypass:  Some sources recommend that when entering air is near or below 32°F, the steam supply to the coil should not be modulated, but controlled to a reset minimum open or full open position to ensure continuous flow, which is less likely to freeze.  Temperature control is then achieved via face and bypass damper assembly.
                1. However, face and bypass sections inherently cause large leaving temperature variations and require extra considerations for adequate means of remixing to prevent nuisance freezestat trips if cooling coil is located downstream.
                2. Integral face and bypass coils are an option but still require sufficient distance downstream and/or mixing baffle option.
                3. Alternately an external face and bypass assembly can be used to bypass unheated air around the heating coil and the cooling coil to the discharge or fan section to be remixed there without risk to cooling coil or freezestat trips.
                4. Internal face and bypass sections have tended to be the most problematic for temperature stratification and therefore shall be avoided if cooling coil is downstream.
              5. Designers and installers must give particular care in the selection and installation of piping, controls, and insulation necessary to protect the coil from freeze-up caused by incomplete condensate drainage.
                1. Components shall include a vacuum breaker, thermostatic air vent, and a minimum 14" fill leg to trap inlet.
                2. Steam coil condensate drains shall be double trapped in parallel with fully redundant assemblies.  On coils subject to freezing conditions, provide a Thermoton liquid expansion steam trap (Spirax/Sarco Type C Thermoton or similar) and isolation valve at lowest point to drain coil if condensate fails to drain through primary trap assembly.  Trap shall be set to open and release subcooled condensate at 75°F.  Trap outlet shall be rotated down for full drainage.
              6. Review other heating mediums with University when steam is not available.
              7. Hot water coils with glycol antifreeze circulating system fluid are another alternative.
              8. In general, coil freeze protection pump arrangements are strongly discouraged.  Pumps themselves are prone to failure and would be required to be on emergency standby electrical power.  Any exceptions for extreme cases must be reviewed with Engineering Services.
              9. Consider application of freeze burst protection via removable pressure relief caps on all return bends and applicable headers and tube ends as required.  Similar to “Sentry-Guard” by USA Coil and Air.
          7. Additional Design Resources:
            1. ASHRAE Systems and Equipment Handbook (current edition).
        2. Reliability and Redundancy:  Professional shall determine the consequences of system failure and provide for adequate system redundancy for each application.
          1. Confirm Owner requirements for redundancy are defined and met.
          2. Install fully redundant (N+1) stand-by units for extremely critical applications (such as critical research laboratories and computer centers) and/or as otherwise defined specifically in the Owner’s Project Requirements.
          3. For non-critical applications (such as general office spaces, general purpose classrooms, general commercial type spaces) full redundancy/complete standby is not required.
          4. Consider parallel fan configurations where effective and practical for running a single fan at part load and for partial redundancy.
          5. Determine and specify applicable emergency power requirements. (research, lab fume hood, process or other specific critical application).
        3. Flexibility: Consider potential future expansion. Extent of expansion will be determined on a case-by-case basis. Consult with the University Project Leader and Engineering Services.
          1. Casings for heat and vent applications shall have space for installation of future cooling coil and associated access for inspection and cleaning.
          2. Consider potential for and make provisions for future heat recovery components whenever appropriate.
        4. Equipment Location, Layout and Design Team Coordination:
          1. Comply with all Space Planning Requirements indicated in Section 01 05 05.01 Planning for Engineered Building Systems.
            1. To the greatest extent possible, mechanical equipment shall be located indoors to maximize useful service life and for safety and ease of maintenance staff, particularly during adverse weather conditions.
          2. Maintain recommended minimum service clearances.  Units shall be installed to allow removal of all coils, filters, and fan shaft.  Provide full finned width of coil on one side of each coil section to facilitate removal.
          3. Units shall include a structural base rail and placed on a concrete housekeeping pad with sufficient combined height for adequate condensate drain trapping and steam fill leg and trap assembly.
          4. Provide at least 24” of access space upstream and between each coil with doors to facilitate installation of sensors and for inspection and cleaning.
        5. Related Standards Sections
          1. 23 00 01 Owner General Requirements and Design Intent
          2. 23 00 10 Systems Selection and Application
          3. 23 01 00 OPERATION AND MAINTENANCE OF HVAC SYSTEMS
          4. 23 05 01 Mechanical General Requirements
          5. 23 05 93 Testing, Adjusting, and Balancing for HVAC
          6. 23 21 00 HYDRONIC PIPING AND PUMPS
          7. 23 30 00 HVAC AIR DISTRIBUTION
          8. 23 40 00 HVAC AIR CLEANING DEVICES
          9. 25 00 00 INTEGRATED AUTOMATION
          10. 25 90 00 GUIDE SEQUENCES OF OPERATION
          11. 26 29 23 Variable-Frequency Motor Controllers
        6. Documentation:
          1. Schedules shall be complete with area served, location, total air quantity, outside air (min/max), external and internal static pressures, all coil selection parameters and performance characteristics, filter characteristics, fan rpm, minimum fan efficiency (or maximum brake horsepower), motor hp, voltage, (including starter/speed drive type), and whether on normal/emergency standby power (where applicable), allowable dimensions and weights, octave band sound level performance.
          2. The configuration of all components of modular and built-up air handling units, including required dimensions for all internal access sections and external access clearances, shall be clearly defined in sufficient detail in plan and elevation views on the design documents.
          3. Provide mechanical identification per University Standards, 23 05 01.05 Mechanical Identification.
        7. Quality Assurance and Uniformity:
          1. Equipment manufacturer shall be ISO-9001 certified.
          2. Equipment shall be of U.S. manufacturer.
          3. Provide equipment of same type by same manufacturer.
          4. Fan ratings shall be AMCA certified.
          5. ARI Certification:
            1. Air-handling units and their components shall be factory tested according to ARI 430, "Central-Station Air-Handling Units," and shall be listed and labeled by ARI.
            2. Coils shall be ARI 410 certified.
            3. Sound data shall be ARI 260.
          6. ASHRAE Compliance:  Applicable requirements in ASHRAE 62.1, Section 5 - "Systems and Equipment" and Section 7 - "Construction and Startup.".  Surfaces in contact with the airstream shall comply with requirements in ASHRAE 62.1.
          7. ASHRAE/IESNA 90.1 Compliance:  Applicable requirements in ASHRAE/IESNA 90.1, Section 6 - "Heating, Ventilating, and Air-Conditioning."
          8. NFPA 70 Compliance:  Electrical Components, Devices, and Accessories shall be listed and labeled as defined in NFPA 70, by a qualified testing agency, and marked for intended location and application.
          9. NFPA 90A Compliance:  Comply with NFPA 90A for design, fabrication, and installation of air-handling units and components.
          10. Air Leakage Testing:  Specify requirement for independent pressure test of unit isolated from system to determine total air leakage of cabinet for units 10,000 cfm and greater.
        .02 Product Requirements
        1. General:  Provide factory-fabricated and factory-tested air handling units as described herein.
          1. Unit layout and configuration of all components, including required dimensions for all internal access sections and external access clearances and shall be clearly defined in project plans and schedules.
          2. Unit shall be constructed of a complete structural frame with removable panels.  The removal of side panels shall not affect the structural integrity of the unit.
          3. Unit manufacturer shall construct and ship separate segments as required so unit can be broken down for ease of installation in tight spaces.
          4. Units shall be mounted on vibration isolators, unless fan and drive assemblies are internally isolated by the manufacturer.
        2. Unit Casings:
          1. General:  All unit casings shall be double wall, corrosion-resistant, sheet metal panel construction with thermal breaks at connections, including those serving heating and ventilation only applications.  Exposed insulation is not acceptable.
          2. Thermal Performance:
            1. Panel insulation shall provide a minimum thermal resistance (R) value of 12 ft²•h•ºF/Btu throughout the entire unit. Insulation shall completely fill the panel cavities in all directions so that no voids exist and settling of insulation is prevented. Panel insulation shall comply with NFPA 90A.
            2. Cabinet shall have additional insulation and vapor seals if required to prevent condensation on the interior and exterior of the cabinet.
            3. Portions of cabinet located downstream from the cooling coil shall have a thermal break at each thermal bridge between the exterior and interior casing to prevent condensation from occurring on the interior and exterior surfaces.  The thermal break shall not compromise the structural integrity of the cabinet.
          3. Leakage Performance:  All casings shall be constructed to minimize leakage and shall be in accordance with duct and plenum leakage class required by Energy Conservation Code or better.
            1. The casing air leakage shall not exceed duct leakage class 6 (CL = 6) per ASHRAE 111 at specified casing static pressure (P in inches w.g.), where maximum casing leakage (cfm/100 ft2 of casing surface area) = CL x P 0.65.
            2. Air leakage shall be determined at 1.25 times maximum casing static pressure up to +/-8 inches w.g. Specified air leakage shall be accomplished without the use of caulk. Total estimated air leakage shall be reported for each unit in CFM, as a percentage of supply air, and as an ASHRAE 111 Leakage Class.
          4. Use bellmouth transition fittings at discharge connections to reduce pressure losses.
          5. All components shall be accessible via access doors and removable panels.
            1. Formed and reinforced, single- or double-wall and insulated panels of same materials and thicknesses as casing.
            2. Hinges:  A minimum of two ball-bearing hinges or stainless-steel piano hinge and two wedge-lever-type latches, operable from inside and outside.  Arrange doors to be opened against air-pressure differential.
            3. Gasket:  Neoprene, applied around entire perimeters of panel frames.
            4. Include a viewing window in access section doors requiring inspection/troubleshooting of operation of components while unit is running (such as downstream of cooling coil to detect moisture carryover or humidifier section to check visual plume distance).  Fabricate of double-glazed, wire-reinforced safety glass with an air space between panes and sealed with interior and exterior rubber seals.
            5. Size:  At least 18 inches wide by full height of unit casing up to a maximum height of 72 inches.
          6. Sound Attenuation:  Provide fan or intake/discharge plenum sections with perforated liner and sound absorbing material to provide acoustical attenuation as required for each application.
            1. The liner shall be fabricated from stainless steel perforated material to prevent corrosion and designed to completely encapsulate acoustic insulation. The perforation spacing and hole size shall be such as to prevent insulation breakaway, flake off, or delamination when tested at 9000 fpm, in accordance with UL 181 or ASTM C1071.
            2. Insulation material must be resistant to fungi in accordance with ASTM C1338.
          7. Safety guards:  Provide as required for safe and convenient service access inside unit:  at open bottom connections, large plenum fan inlets and discharges.
          8. Provide marine lights in sections requiring routine service (fans, filters, full-sized access/inspection).  Marine light shall be UL listed for wet locations.  Light shall be complete with energy efficient, long-life fluorescent lamp and junction box.
        3. Fan and Drive Assemblies:
          1. Fans and motors on 5 tons and larger shall be on a common isolation base or rail unless internally isolated by the equipment manufacturer.
          2. Provide thrust restraints between AHU casing and fan housings on horizontal discharge fans >3” total s.p.
          3. Shall be statically and dynamically balanced and designed for continuous operation at maximum-rated fan speed and motor horsepower.
          4. Fan wheels shall be optimally designed and selected with sufficient strength and minimum inertia for the application.
            1. Evaluate 9 vs. 12 blades on airfoil fans.
            2. Consider aluminum vs. steel wheel construction for weight reduction to reduce inertia and bearing stresses, particularly on direct drive applications.
          5. Bearings: Shall be grease-lubricated, self-aligning type, minimum L10 life of 200,000 hours (preferred, but no less than L10 life of 100,000 hours - Note:  L50 life of 200,000 hours is NOT acceptable.)  Provide extended grease lines to safe and readily accessible location with 1/8" steel tubing and flush plugs with relief set at 5 psig.
          6. Shafts:  Designed for continuous operation at maximum-rated fan speed and motor horsepower, and with field-adjustable alignment.
            1. Turned, ground, and polished hot-rolled solid steel with keyway.  Ship with a protective coating of lubricating oil.
            2. Designed to operate at no more than 70 percent of first critical speed at top of fan's speed range.
            3. Adequate fan shaft pull space must be provided.
          7. Belt Drives, Refer to 23 05 01 - Motors and Drives:
            1. Drive assemblies: Factory mounted, with adjustable alignment and belt tensioning with 1.5 service factor based on rated nameplate HP of motor.
            2. Belts:  Oil-resistant, heat-resistant, non-sparking, and anti-static cogged v-belts; in matched sets for multiple-belt drives.  Shall have a minimum of 2 belts, each rated to carry full load in case one breaks.

              Designer Note:  Cogged belts have slots that run perpendicular to the belt’s length. The slots reduce the bending resistance of the belt. Cogged belts can be used with the same pulleys as equivalently rated V-belts. They run cooler, last longer, and have an efficiency that is about 2% higher than that of standard V-belts.

            3. Belt guards:  Where required, guards shall be constructed of expanded metal mesh to allow for quick visual inspection of belts and pulleys without removal.  Guards shall be attached to equipment with hinges and/or quick release fasteners that can be turned without tools to allow for ease of maintenance.
            4. Consider synchronous belt drive assemblies on large units where they can be applied cost effectively to eliminate slip losses.
              1. Typically not available on standard units.  Custom only.  Can be noisy.
              2. http://www1.eere.energy.gov/industry/bestpractices/pdfs/39157.pdf
              3. http://www1.eere.energy.gov/industry/bestpractices/pdfs/replace_vbelts_motor_systemts5.pdf
        4. Motors:  Refer to other requirements in .01 Motors and Drives
          1. Shall be NEMA Premium efficiency.
          2. Motors on variable speed drives shall be inverter duty, with factory installed motor shaft grounding.
          3. Do not select motor within the service factor range.
        5. Dampers:  High-performance, low resistance, airfoil type.
          1. Shall have edge seals, low leakage (2%) type.
          2. Provide separate min OA damper, economizer damper (when present), return damper with separate actuators for each.
          3. On economizer applications, apply dual OA dampers for better control and airflow measurement accuracy; (1) for minimum OA and (1) for economizer.
          4. Minimum Outdoor, Economizer, Return, and Relief damper types and sizes shall be selected per ASHRAE Guideline 16.
            1. OA and Relief air dampers shall be opposed blade.
            2. Return damper shall be parallel blade.
            3. Minimum OA damper must be sized for a minimum of 200 fpm at absolute minimum OA flow rate for proper control.
          5. Comply with airflow measuring device manufacturer’s recommendations and instructions regarding airflow measuring devices to avoid inaccuracies such as turbulence created by adjacent crossflows of return air streams.
        6. Coil Sections:
          1. Provide at least 24” of access space upstream and between each coil with doors to facilitate installation of sensors and for inspection and cleaning.
          2. On applications that will condense moisture, such as typical air conditioning cooling/dehumidification and exhaust air heat recovery, provide coil casings, tube sheets and intermediate supports of minimum 16 gauge (0.0625" thick) stainless steel.  Use 14 gauge on very large coils that need extra strength.  Also use stainless steel for associated independent structural supports of multiple coil banks as described below.
          3. Fabricate coil section to allow removal and replacement of each coil segment and to allow in-place access for service and maintenance of coil(s).  For units with banks of multiple coil segments, provide independent supports of coils to allow slide out removal and replacement of each coil segment.  Coils shall not act as structural component of unit or support other coils.

            Designer Note:  Independent coil supports for multiple stacked coils are typically only available on semi-custom or custom grade units, not standard units.  Verify.

          4. All coils shall be air vented and arranged for proper drainage.
          5. Primary Drain Pans:  All cooling coil sections and heat recovery coils subject to condensing conditions shall be provided with an insulated, double-wall, stainless steel drain pan.
            1. The drain pan shall be designed in accordance with ASHRAE 62.1 being of sufficient size to collect all condensation produced from the coil and sloped in two planes, pitched toward drain connections, promoting positive drainage to eliminate stagnant water conditions when unit is installed level and trapped per manufacturer's requirements. See below for specifications on intermediate drain pans between cooling coils.

            2. The outlet shall be located at the lowest point of the pan and shall be sufficient diameter to preclude drain pan overflow under any normally expected operating condition.

            3. All drain pan threaded connections shall be visible external to the unit. Threaded connections under the unit floor shall not be accepted.

            4. Drain connections shall be of the same material as the primary drain pan and shall extend beyond the base to ensure adequate room for field piping of condensate traps.

          6. Intermediate Drain Pans:  Units with stacked coils shall have an intermediate drains pan to collect condensate from each row of coils.

            1. The intermediate drain pan shall be designed being of sufficient size to collect all condensation produced from the coil and sloped to promote positive drainage to eliminate stagnant water conditions.

            2. The intermediate drain pan shall be constructed of the same material as the primary drain pan.

            3. The intermediate drain pan shall begin at the leading face of the water-producing device and be of sufficient length extending downstream to prevent condensate from passing through the air stream of the lower coil.

            4. Intermediate drain pans shall have drop tubes to guide condensate to the main drain pan, thus preventing flooding of lower coils that would result in moisture carryover.

          7. All coils shall be completely cleaned prior to installation into the air handling unit.  Complete fin bundle in direction of airflow shall be degreased and steam cleaned to remove any lubricants used in the manufacturing of the fins, or dirt that may have accumulated, in order to minimize the chance for water carryover.

          8. Water Coils:

            1. Factory tested to 300 psig according to ARI 410 and ASHRAE 33.

            2. Supply and return header connections shall be clearly labeled on outside of units such that direction of coil water-flow is counter to direction of unit air-flow.

          9. Refrigerant Coils:  Factory tested to 450 psig according to ARI 410 and ASHRAE 33.

          10. Steam coils:

            1. Coils shall be “non-freeze”, steam-distributing type specifically designed to evenly distribute steam along the entire coil.

            2. Tubes shall consist of nominal 1” O.D. outer tubes with 5/8” inner tubes.  Inner tubes shall have orifices that ensure even steam distribution throughout the length of the outer tube. Orifices shall direct steam toward return connections to ensure steam condensate is properly drained from coils to prevent flashing of condensate.

            3. Coils shall be pitched in units for proper drainage of steam condensate from coils.

            4. Coils shall be proof tested to 300 psig and leak tested to 200 psig air pressure under water.

            5. Steam supply, condensate return, and vacuum breaker connections shall be clearly labeled on unit exterior.

        7. Air Mixing/Blender Section:  Air mixers (blenders) shall be provided and located as indicated on the schedule and drawings to enhance the mixing of outside air with return air to a required mixing effectiveness to eliminate freeze stat trips, minimize sensor error and enhance outdoor air distribution. The air mixing device shall provide even airflow and temperature across filters, coils and control sensors to ensure accuracy of averaged temperature readings.

          Designer Note:  Manufacturer’s standard “mixing damper” sections have repeatedly performed inadequately and are not acceptable.

          1. Mixers shall incorporate fixed blades, with no moving parts.

          2. Mixer panels shall be sized and installed in the unit with adequate distances upstream and downstream, based on the manufacturer’s cataloged performance, to ensure a minimum mixing effectiveness.

          3. The performance requirements for each system should be as listed in the schedule of equipment shown on the plans. The required mixing effectiveness shall be stated in terms of % range mixing effectiveness at the appropriate outside air percentage at one mixer diameter downstream of the mixer.  Range mixing effectiveness is defined as follows: (Emixer= 1-(Range/(Tra-Toa))) Where: Tra= Return air temperature, Toa=Outside air temperature, Range=Tmax-Tmin at one mixer diameter downstream.

          4. Static air mixers shall be geometrically scaled to ensure consistent performance across full range of applications. Mixers that are not geometrically scaled are not acceptable.

          5. The mixing device shall maintain mixing performance across the anticipated airflow range of each application.

          6. Pressure Drop: The pressure drop rating for static air mixers shall include the pressure loss due to the mixer design and the mixer-to-plenum area ratio.

          7. Installation shall be in accordance with the manufacturer’s written installation instructions and SMACNA plenum construction guidelines. If necessary, provide reinforcement in plenum where the mixing device is installed to eliminate excess vibration or deflection of blank off plenum.

          8. Actual performance shall be field verified as part of Functional Performance Testing.

        8. Controls:

          1. General:  Coordinate and comply with Division 25 00 00 INTEGRATED AUTOMATION

          2. Sequences:  Refer to 25 90 00 GUIDE SEQUENCES OF OPERATION

          3. Air Flow Measuring Stations:    Refer to specific requirements in BAS Guidespec for “COMBINATION AIR FLOW /TEMPERATURE MEASUREMENT STATION (AFMS)”.  Coordinate locations and proper mounting details with manufacturer of air flow measuring stations for accurate sensing and control.

        .03 Execution
        1. INSTALLATION

          1. General:  Install air handling units where indicated, in accordance with equipment manufacturer's published installation instructions and with recognized industry practices, to ensure that units comply with requirements and serve intended purposes.

          2. Coordination:  Coordinate with other work, including ductwork, roof decking and piping, as necessary to interface installation of air handling units with other work.

          3. Access:  Provide access space around air handling units for service as indicated, but in no case less than that recommended by manufacturer.

          4. Support:

            1. Install indoor air handling units on a minimum 4” high concrete housekeeping pad.    Coordinate installation with General Contractor for final size of pad.

            2. For rooftop applications in which the unit is to be supported on a raised structural platform, refer to 07 70 00 ROOF AND WALL SPECIALTIES AND ACCESSORIES for minimum height requirements of legs to allow for future roofing replacement.

          5. Electrical Wiring:  Install electrical devices furnished by manufacturer but not specified to be factory-mounted.  Furnish copy of manufacturer's wiring diagram submittal to Electrical Installer.

            1. Verify that electrical wiring installation is in accordance with manufacturer's submittal and installation requirements of Division-16 sections.

            2. Grounding:  Provide positive equipment ground for air handling unit components.

            3. Do not proceed with equipment start-up until wiring installation is acceptable to equipment installer.

          6. Piping Connections:  Refer to related Division-23 HVAC sections.  Provide piping, valves, accessories, gauges, supports and flexible connectors as indicated.

            1. Steam coils:

              1. Shall be piped to ensure condensate can fully drain by gravity to trap or vented condensate receiver pump assembly to prevent freeze-ups.  This shall include a vacuum breaker, thermostatic air vent, and a minimum 14" fill leg to trap inlet, which may dictate that units be mounted on extended rail or frame above housekeeping pad.

              2. Shall be double trapped in parallel with fully redundant assemblies.

              3. On coils subject to freezing conditions, provide a Thermoton liquid expansion steam trap (Spirax/Sarco Type C Thermoton or similar) and isolation valve at lowest point to drain coil if condensate fails to drain through primary trap assembly.  Trap shall be set to open and release subcooled condensate at 75°F.  Trap outlet shall be rotated down for full drainage.

              4. Since they can become blocked and obstruct condensate, strainers in front of the traps in freeze prone applications shall require regularly scheduled screen removal and cleaning along with steam trap service.  Coordinate locations of these steam trap and strainer assemblies with Owner’s Preventative Maintenance Manager at time of project turnover.

          7. Duct Connections:  Refer to related Division-23 HVAC sections.  Provide ductwork, accessories and flexible connections as indicated.

        2. FIELD QUALITY CONTROL

          1. Upon completion of installation of units, and after motor has been energized with normal power source, perform the following tests and inspections with the assistance of a factory-authorized service representative to demonstrate compliance with requirements:

            1. Verify that shipping, blocking, and bracing are removed.

            2. Verify that unit is secure on mountings and supporting devices and that connections to ducts and electrical components are complete.  Verify that proper thermal-overload protection is installed in motors, starters, and disconnect switches.

            3. Verify that cleaning and adjusting are complete.

            4. Disconnect fan drive from motor, verify proper motor rotation direction, and verify fan wheel free rotation and smooth bearing operation.  Reconnect fan drive system, make final alignments of pulleys and belt tension, and install belt guards.

            5. For vibration testing requirements, refer to Section 23 05 01 .04 Sound and Vibration Control.

              1. IMPORTANT:  Incorrect alignment and belt tension causes energy losses and premature equipment failure.  This work must be completed to the satisfaction of the University as part of the criteria determining Substantial Completion.

              2. The Contractor shall coordinate and contract the services of the University’s HVAC Vibration Analyst (At University Park, arranged through the Supervisor of Refrigeration and Mechanical Services) whenever available.  Otherwise (and at Commonwealth Campus locations) the Contractor shall hire an independent, third party Vibration Analyst meeting the approval of the University.

              3. Measured results of vibration testing and final alignment and tensioning shall be recorded and coordinated to be entered into University’s Preventative Maintenance Software at time of start-up AND included in final report to be submitted as part of TAB/O&M submittals.

            6. Adjust damper linkages for proper damper operation.

            7. Verify lubrication for bearings and other moving parts.

            8. Verify that manual and automatic volume control and fire and smoke dampers in connected ductwork systems are in fully open position.

            9. See Division 23 Section "Testing, Adjusting, and Balancing For HVAC" for testing, adjusting, and balancing procedures.

            10. Air Leakage Test: Pressurize casing to positive and negative ratings and measure leakage.  If leakage exceeds specified performance, seal leakage points with a permanent solution. Repeat test. If the AHU still does not pass, contact the manufacturer to seal unit.  Submit a field test report with testing data recorded.  Include description of any corrective actions taken.

            11. Test and adjust controls and safeties.  Controls and equipment will be considered defective if they do not pass tests and inspections.

            12. Prepare test and inspection reports.

          2. Remove and replace malfunctioning units that cannot be satisfactorily corrected and retest as specified above.

        23 80 00 DECENTRALIZED HVAC EQUIPMENT

        23 81 00 DECENTRIALIZED UNITARY HVAC EQUIPMENT

        .01 Packaged Rooftop Equipment

        The Professional shall obtain permission from the University before designing packaged rooftop units for University projects.

        1. Air cooled packaged air-conditioning equipment shall be equipped with low ambient controls to permit operation to 0°F.
        2. Rooftop package air conditioners 5 tons and larger shall be mounted on structural steel channel curbs with curb isolation rails.  Smaller units may be mounted on manufacturers' prefabricated curbs.
        3. Submit details and catalog cuts of unit prior to design.  Units must be manufactured for that application. 
        .02 Packaged Heat Pumps
        1. Use of air cooled packaged heat pumps on University Park Campus are not permitted. 
        2. When considered for use on Commonwealth Campus, prior approval must be received and 100% auxiliary heat must be provided.
        .03 Water-Source Heat Pump Systems
        1. Evaluate and select systems and equipment for lowest 30 year life cycle cost.  Refer to Design Phase Submittal Requirements, “Design Phase” Section, paragraph B.1.  Also refer to Design and Construction Standards, Introduction, Paragraph K and 23 00 01.01 Owner General Requirements and Design Intent.
          1. Consider extra high efficiency units with 2 stage compressors and ECM fans whenever appropriate to achieve energy efficiency goals and improved part load performance, including reduced cycling of compressors.
          2. Select refrigerant type for least environmental impact and best long term economic benefit. 
          3. Where close dehumidification control is needed for the application, use technologies that avoid simultaneous heating and cooling mechanical energy.  Hot gas reheat or wrap around heat pipe may be viable options.
          4. Minimize pump energy use with variable flow pumping controls whenever justified by lowest life cycle cost.
            1. Systems shall be designed to include means to ensure proper flow to each unit within allowable ranges as overall system pressure and flow fluctuates without objectionable noise or maintenance nuisances.
        2. Large quantities of decentralized terminal units with DX refrigeration systems and filters are undesirable in large scale projects due to extensive, multiplied maintenance requirements.
        3. Dedicated outside air systems to supply preconditioned and dehumidified fresh air are required to adequately maintain zone relative humidity within acceptable ranges for indoor air quality and to minimize risk for mold growth.
          1. Experience has shown that areas served by terminal cooling units with constant volume and occupied continuous fan operation and supplied with untreated OA as a rule have problems with inadequate dehumidification.   When compressors cycle off when space temperature is satisfied, any moisture condensed on the coil during the on cycle is re-absorbed back into supply air.  This problem is worsened by short cycling due to cooling loads lower than design maximum, which is most of the time.  Very serious high humidity problems occur when space has low cooling load and outside air conditions are cool and humid. 
          2. Refer to economizer requirements elsewhere for spaces that will have year round cooling requirements.
        4. Mechanical equipment requiring routine access for inspection and maintenance such as fans, compressors and filters shall be located in mechanical spaces with sufficient working clearances maintained.  Refer to Coordination requirements in 23 00 01.06.
        5. Free delivery type units with compressors and fans located within areas served are prone to objectionable noise levels.  Therefore, they are not acceptable in noise sensitive areas such as classrooms, conference rooms, and sleeping areas.  Refer to Vibration and Sound Control requirements in 23 05 01.05.
        6. Maintain at least a minimum deadband of 20 degrees in the condenser water temperature control(per IECC) between minimum setpoint(enabling heat addition) and maximum setpoint (enabling heat rejection). 
        7. Be sure to insulate piping that will carry fluids below 55 degrees F or otherwise where condensation may occur due to transporting fluid at temperatures lower than ambient indoor dewpoint.
        8. With low temperature loop temperature, the use of high efficiency condensing boilers is a viable option.  However, special care must be taken to ensure acidic condensate will be neutralized and operating staff must be properly trained to keep it maintained in perpetuity in order to not harm plumbing systems. 
          1. Preferred method of heat rejection is open cooling tower (induced-draft type with VFD fan speed control), remote indoor sump, tower loop pump, plate and frame heat exchanger (or shell and tube with marine type headers that allow easy end removal for inspection and cleaning without disturbing the piping system) and a constant pressure, centrifugal solids separation system.
        9. The first cost of this combination is relatively close to the cost of the closed circuit fluid cooler with all required freeze protection methods.  In addition, operating costs are lower because no heat is lost from the loop in the winter, winterization/freeze protection is minimized and less power is required for cooling tower fans.
          1. Ground-Source Heat Pump systems shall, in addition to all of the above, meet the requirements listed below:
            1. Refer to associated ground coupled heat exchanger (well field) requirements in 23 21 13.08 and 33 20 00.
          2. Test wells:  In addition to the geological information required, the test well data shall include empirical thermal conductivity values that can be used to optimize the well field design.
            1. Design and installation of ground-source heat pump systems shall comply with industry best practices in accordance with the following publications:
            2. ASHRAE:  Ground Source Heat Pumps – Designing Geothermal Systems for Commercial and Institutional Buildings, current edition.
              1. International Ground Source Heat Pump Association (IGSHPA):
              2. Closed Loop Ground Coupled Installation Guide,
              3. Slinky™ Installation Guide,
              4. Design and Installation Standards,
              5. Grouting Procedures for GHP Systems,
              6. Soil and Rock Classification Field Manual,
              7. Grouting for Vertical Heat Pump Systems
          3. Antifreeze solution, if required, shall be non-toxic and have low environmental impact to minimize risk in the event of uncontrolled fluid loss through the well field to the ground/groundwater.  Ethanol formulated for commercial antifreeze solution and Propylene Glycol appear to be relatively non-hazardous and are presently the only options acceptable to the University.  Ethanol has slightly better heat transfer and lower pump energy characteristics and estimated lower solution costs of those two options.

        23 82 00 CONVECTION HEATING AND COOLING UNITS

        .01 Air Coils
        1. Separate drain pans for each cooling coil shall be provided.
        2. Access doors shall be provided on upstream side of all coils.
        3. Clearance shall be provided for the full finned width of coil for removal.
        4. Cooling coil face velocities shall not exceed 500 fpm.
        5. Air vents shall be provided at highest point.
        6. Hose end drain valves shall be provided with isolation valves.
        7. Vacuum breakers shall be provided on all steam heating coils.
        8. Water coils shall be piped in counter-flow configuration.
        9. When installing coils in a corrosive atmosphere, appropriate corrosion resistant coating shall be provided, i.e., fume hood run-around loops.
        10. Refer to Details [23 xx xx .xx], [23 xx xx .xx], and [23 xx xx .xx].  Details are not yet available in WEB-based manual. 
        .02 Heating Terminal Units (General)
        1. Provide isolation valves on each item.
        2. Design for average hot water temperature of 190°F or 1 psig steam supply.  Size steam control valve for 8 psig inlet pressure and 6 psi maximum drop through the valve.
        3. Design drawings shall indicate all selection criteria.
        4. Finish shall be submitted with color chip for approval.
        5. Refer to Details [23 xx xx .xx] and [23 xx xx .xx].  Details are not yet available in WEB-based manual. 
        .03 Finned Tube Radiation
        1. Use sloped top style enclosure.
        2. Use commercial grade enclosure.  Residential grade enclosure not permitted.
        3. Controls (See 23 09 00).
        .04 Unit Ventilators
        1. When installed in hydronic systems without glycol, units must have manual reset freezestat to (1) shutdown fan, (2) close outdoor air damper, and (3) open heating valve.
        2. Motors shall be three speed with unit-mounted selector switch. 

        23 82 19  FAN COIL UNITS

        .01 General
        1. Summary:   Section includes requirements for fan coil units and accessories.
        2. Related Standards Sections:  General requirements related to fan coil work include, but are not necessarily limited to, the following:
          1. 23 00 01 Owner General Requirements and Design Intent
          2. 23 00 10 Systems Selection and Application
          3. 25 00 00 INTEGRATED AUTOMATION
          4. 25 90 00 GUIDE SEQUENCES OF OPERATION
        3. General Requirements:
          1. Professional shall design each fan coil application for minimizing noise, optimal operating efficiency, and ease of maintenance with the lowest life cycle cost. 
          2. Mechanical identification nomenclature shall conform to University Standards per 23 05 01.05 Mechanical Identification
          3. FCU applications shall comply with: 
            1. University’s CLASSROOM & TECHNOLOGY DESIGN & CONSTRUCTION MINIMUM REQUIREMENTS.
            2. Section  23 05 01 Mechanical General Requirements, .04 Sound and Vibration Control, “Interior Sound Pressure Level Requirements”, which cites ASHRAE Handbook—HVAC Applications, Indoor Sound Criteria, Table of Design Guidelines for HVAC-Related Background Sound in Rooms.
            3. ASHRAE 189.1:  Water Use Efficiency; Energy Efficiency; Indoor Environmental Quality
          4. Designer shall provide an integrated mechanical system design and control sequence that will optimize dehumidification and avoid re-evaporation on cooling coil for each application.
            1. Common fan coil unit applications typically are poor at maintaining acceptable indoor humidity levels in spaces with latent loads, especially from unconditioned minimum ventilation air.
              1. At part load conditions (most of the time), constant speed fan operation has nearly zero net dehumidification efficiency and shall be strictly avoided where latent loads are present with partial sensible load.
              2. Modulating cooling coil control valve to maintain space temperature directly can allow DAT under low load conditions to rise above dew point and thus no dehumidification can occur.
            2. Therefore FCU’s should generally only be applied as sensible cooling/heating applications.  Options include:
              1. Dedicated Outdoor Air System (DOAS) to mechanically dehumidify the ventilation air; and 
              2. FCU’s with DAT limit control and high efficiency, variable-speed fans to maintain room temperature.
          5. Select high efficiency fan motors (ECM type) with variable speeds that can be automatically controlled to match load requirements in order to minimize fan noise, maximize fan energy and maximize potential for dehumidification during part load cooling operation.  Refer to 25 90 00 GUIDE SEQUENCES OF OPERATION.
          6. Use demand based ventilation strategies such as CO2 sensors and/or zone occupancy sensors for “standby” mode for high variation of occupant density applications such as classrooms, assembly or large conference rooms.  Coordinate with Electrical/Lighting design for dual use of occupancy sensors.
          7. Design for low flow, high temperature differences and variable flow distribution systems to minimize pump energy and optimize operation of central plant equipment.
            1. Selection of individual chilled water cooling coils in typical HVAC applications is recommended with a 14-16°F rise at peak conditions.
            2. Maintain average overall system chilled water temperature rise of at least 12°F.
            3. For systems connected to University Park campus chilled water, 
              1. Coordinate with 33 62 00 CAMPUS CHILLED WATER DISTRIBUTION
              2. Cooling season:  Design for campus chilled water at a supply temperature of 44°F.
              3. Winter Water Side Economizer:  Chilled water coils that are expected to provide cooling year-round to isolated zones that are not practical to serve via airside economizer (examples: telecom/data closets, elevator equipment rooms) must be selected to function at a supply chilled water temperature maximum of 48°F.
              4. Design to achieve a chilled water system return temperature to campus that is as warm as possible.  Refer to choke valve control sequence, which typically will not allow lower than 54°F return to campus.
        4. Quality Assurance and Uniformity: 
          1. ARI Compliance:  Test and rate fan-coil units in accordance with ARI Standard 440 "Room Fan-Coil Air Conditioners".
          2. ASHRAE Compliance:
            1. DX Units:  ASHRAE 15 for safety code for mechanical refrigeration. 
            2. Applicable requirements in ASHRAE 62.1, Section 5 - "Systems and Equipment" and Section 7 - "Construction and Startup."
              1. LEED Prerequisite IEQ 1 requires compliance with requirements in ASHRAE 62.1, including requirements for controls, surfaces in contact with the airstream, particulate and gaseous filtration, humidification and dehumidification, drain pan construction and connection, finned-tube coil selection and cleaning, and equipment access.  Verify, with manufacturers, availability of units with components and features that comply with these requirements.
            3. Applicable requirements in ASHRAE/IESNA 90.1 or ASHRAE 189.1 as required in 01 80 00 PERFORMANCE REQUIREMENTS
          3. Electrical Components, Devices, and Accessories:  Listed and labeled as defined in NFPA 70, by a testing agency acceptable to authorities having jurisdiction, and marked for intended use.
          4. Equipment manufacturer shall be ISO-9001 certified.
          5. Provide equipment of same type by same manufacturer.
        5. Submittals:  Documents shall require the following:
          1. Product Data:  Include manufacturer’s specifications, rated capacities, operating characteristics, gages and finishes of materials, accessories, and furnished specialties.
            1. Submit color samples for selection by Architect with equipment to be installed in aesthetic areas.
            2. LEED Submittals (as applicable to project):
              1. Product Data for Credit EA 4:  Documentation indicating that equipment and refrigerants comply.
              2. Product Data for Prerequisite IEQ 1:  Documentation indicating that units comply with ASHRAE 62.1, Section 5 - "Systems and Equipment."
          2. Shop Drawings:  Detailed equipment assemblies including dimensions, weights, required clearances, components, and location and size of each field connection and installation instructions.
            1. Wiring Diagrams:  Include requirements for power supply wiring and ladder-type wiring diagrams for interlock and control wiring.  Clearly differentiate between portions of wiring that are factory-installed and portions to be field-installed.
          3. Maintenance Data:  Include lubrication instructions, filter replacement, motor and drive replacement, and spare parts lists.  
          4. Field quality-control test reports.
          5. Include all approved submittal data in maintenance manuals; in accordance with requirements of Section 23 01 00 OPERATION AND MAINTENANCE OF HVAC SYSTEMS.
        .02 Product Requirements
        1. General:  Provide fan-coil units having cabinet sizes, and in locations indicated, and of capacities, style, and having accessories as scheduled.  Include in basic unit chassis, insulated cabinets, fans, motor, coils, drain pan, and filter.
          1. Provide factory-packaged and -tested units rated according to ARI 440, ASHRAE 33, and UL 1995.
          2. Include all features for fan-coil units that are required for Project, and identify additional features for specific units in the Fan-Coil-Unit Schedule on Drawings.
        2. Chassis:  Galvanized steel where exposed to moisture, with baked-enamel finish and removable access panels.  
          1. Floor-mounted units shall have leveling screws.
        3. Cabinets:  Construct of minimum 18-ga steel removable panels. 
          1. Exposed cabinet units:  
            1. Units shall have published sound power level data tested in accordance with ARI Standard 350.
            2. Baked-enamel finish in manufacturer's [standard or custom] paint color as selected by Architect.
            3. Vertical Unit Front Panels:  Removable, 16-ga front steel, with double-deflection adjustable pattern discharge grille and channel-formed edges, cam fasteners, and insulation on back of panel. Provide optional minimum 8” valve compartment extensions with opposite end coil connections on units with dual coils.
            4. Horizontal Unit Bottom Panels:  Fastened to unit with cam fasteners and hinge and attached with safety chain; with discharge grille appropriately selected for the application.
            5. Steel recessing flanges for recessing fan-coil units into ceiling or wall.
          2. Concealed ducted units:  
            1. Units shall have published sound power level data tested in accordance with ARI Standard 260-01.
            2. Steel with baked-enamel finish in manufacturer's standard paint color.
            3. Supply-Air Plenum:  Sheet metal plenum finished and insulated to match the chassis with minimum 1” duct collar.
            4. Return-Air Plenum:  Sheet metal plenum finished to match the chassis.
            5. Damper Plenum:  Sheet metal plenum finished and insulated to match the chassis with outdoor- and return-air, formed-steel dampers.
            6. Dampers:  Galvanized steel with extruded-vinyl blade seals, flexible-metal jamb seals, and interlocking linkage.
        4. Coil Section Insulation: 
          1. Surfaces in contact with the airstream shall comply with requirements in ASHRAE 62.1, Airstream Surfaces for resistance to microbial growth and erosion.
          2. Provide Elastomeric Closed Cell Foam Insulation, conforming to:
            1. Antimicrobial Performance Rating of 0, no observed growth, per ASTM G-21.
            2. UL 181 for erosion 
            3. NFPA 90A for fire, smoke and melting, and comply with a 25/50 Flame Spread and Smoke Developed Index per ASTM E-84 or UL 723. 
            4. Polyethylene insulation is not acceptable.
            5. ASTM C 1071 and attached with adhesive complying with ASTM C 916.
            6. Thickness:  
              1. Minimum: 1/2” for surface condensation control.
              2. Supplemental for energy efficiency as required per application:  Provide Minimum Duct Insulation R-Value, Combined Heating and Cooling Supply Ducts and Return Ducts per ASHRAE 189.1 High Performance Building Standard. 
        5. Fan Section:
          1. Direct-Driven Fans:  Double width, forward curved, centrifugal; with permanently lubricated, multispeed motor resiliently mounted in the fan inlet.  Aluminum or painted-steel wheels, and painted-steel or galvanized-steel fan scrolls.  Plastic fans are prohibited.  
            1. Fan and Motor Board:  Removable 
            2. Wiring Termination:  Connect motor to chassis wiring with plug connection.
            3. Motors shall be ECM, variable-speed, DC, brushless motors specifically designed for use with single phase, 277 volt (or 120 volt), 60 hertz electrical input. 
              1. Motor shall be complete with and operated by a single phase integrated controller/inverter that operates the wound stator and senses rotor position to electronically commutate the stator. All motors shall be designed for synchronous rotation. Motor rotor shall be permanent magnet type with near zero rotor losses. Motor shall be able to be mounted with shaft in horizontal or vertical orientation. Motor shall be permanently lubricated with ball bearings. Motor shall be direct coupled to the blower. Motor shall include integral thermal overload protection.
              2. Motor shall maintain a minimum of 70% efficiency over its entire operating range. 
              3. Provide isolation between fan motor assembly and unit casing to eliminate any vibration from the fan to the terminal unit casing. Provide anti-back rotation system or provide a motor that is designed to overcome reverse rotation and not affect life expectancy.
              4. Inductors shall be provided to minimize harmonic distortion and line noise. http://www.krueger-hvac.com/lit/pdf/white_powerquality.pdf
              5. Motor control module shall have built-in soft start and soft speed change ramps.  Provide robust electronics and built-in surge pro-tectors to protect the solid state controls from line transients. The motor control module shall include a variable speed mode to receive a variable control voltage signal to control the unit airflow directly from the DDC system in response to zone heating and cooling PID outputs. 
              6. Additional information:  
                1. http://www.krueger-hvac.com/lit/pdf/whiteecm.pdf
                2. http://www.columbiaheating.com/page_images/file/GET-8068.pdf
                3. http://www.gotoevo.com/GEMotors.htm
          2. Belt-Driven Fans:  Double width, forward curved, centrifugal; with permanently lubricated, single-speed motor installed on an adjustable fan base resiliently mounted in the cabinet.  Aluminum or painted-steel wheels, and painted-steel or galvanized-steel fan scrolls.
            1. Provide premium efficiency motor.
            2. Include inverter duty rated motor and VFD when required by High Performance Building Standard ASHRAE 189.1.
        6. Hydronic Coils:  All cooling and heating coils shall optimize rows to meet the specified capacity and minimize air pressure drop.  
          1. Seamless Copper tube, minimum 0.025” thick, with mechanically bonded aluminum fins, rated for a minimum working pressure of 250 psig at a maximum entering-water temperature of 200 deg F.  
          2. Coil Casings shall be fabricated from galvanized steel.
          3. All water coils shall include manual air vent at high point and drain valve at low point in piping on coil side of isolation valve.
        7. Electric-Resistance Heating Coils:  Avoid using to fullest extent possible.  Where project conditions allow no better option, comply with the following.  
          1. All heating elements on floor mounted units shall be finned tubular type.
          2. Nickel-chromium heating wire, free of expansion noise and hum, mounted in ceramic inserts in a galvanized-steel housing; with fuses in terminal box for overcurrent protection and limit controls for high-temperature protection.  Terminate elements in stainless-steel machine-staked terminals secured with stainless-steel hardware.
          3. Silent solid state relays shall be supplied in exposed cabinet applications.
          4. Door interlocking disconnect switch.
        8. Main and Auxiliary Drain Pans:  Fabricate pans and drain connections to comply with ASHRAE 62.1.
          1. Provide a primary drain pan extended under the entire coil section, constructed entirely of heavy gauge stainless steel for superior corrosion resistance.  Drain pans shall be of one piece construction and be positively sloped for condensate removal.  Drain pans shall be accessible and removable without requiring removal of coils.
          2. The primary drain pan shall be externally insulated with a fire retardant, elastomeric closed cell foam insulation. The insulation shall carry no more than a 25/50 Flame Spread and Smoke Developed Rating per ASTM E-84 and UL 723 and an Antimicrobial Performance Rating of 0, no observed growth, per ASTM G-21.
          3. Non-corrosive, insulated auxiliary drain pan shall be used for condensate from primary drain pan and piping accessories.
          4. Condensate Overflow Switch:  A water level detection device conforming to UL 508 shall be provided that will send an alarm and disable all mechanical cooling in the event that the condensate drain is blocked.  
            1. The device shall typically be installed in the equipment-supplied drain pan, located at a point higher than the primary drain line connection and below the overflow rim of such pan.
            2. Refer to International Mechanical Code, Condensate Disposal, “Auxiliary and secondary drain systems” for optional methods.
        9. Filters:  Synthetic, Multi-density, Depth Loading Media, minimum arrestance according to ASHRAE 52.1, and a minimum efficiency reporting value (MERV) below according to ASHRAE 52.2.  
          1. ASHRAE 189.1 requires a minimum MERV rating of 8.  Use in ducted units with higher fan static pressure capability.
          2. LEED Prerequisite IEQ 1 requires compliance with ASHRAE 62.1, which requires a MERV rating of 6 or higher.  Acceptable alternative to MERV 8 in units with minimal fan static pressure capability to ensure adequate airflow.
          3. Manufacturer:  Tri-Dim, “Tri_Dek” Panel http://www.tridim.com/DesktopDefault.aspx?Product=Panel%20Filters&tabindex=1
        10. Piping Accessories:
          1. Runout piping to coils:  Copper tube with wrought copper fittings and sweat joints.  Piping system longevity is important so flexible hose kits are not recommended due to concerns with rubber deteriorating over time.
          2. Isolation valves:  Two-Piece Ball Valves:  Bronze body with full-port, chrome-plated bronze ball; PTFE or TFE seats; and 600-psig minimum CWP rating and blowout-proof stem.
          3. P/T Ports on inlet and outlet of each coil per 23 05 19 Measuring Instruments for HVAC.
          4. Balancing device:  typically not required for small units on variable flow systems.  Refer to further details in 23 05 01 Mechanical General Requirements, .02 Valves, “Balancing Valves”.
          5. Bronze/Copper Unions:  ASME B16.22.  Include to provide a mechanical connection between the coil and valve package that can be connected, disconnected, and re-connected without the need to cut tubing or unsolder a joint. Dielectric unions are prohibited.
          6. Y-Pattern Hydronic Strainers:  Cast Bronze; minimum 400-psig  working pressure, 250 F working temperature; with threaded connections, bolted cover, stainless-steel screen, and bottom drain connection.  Include nominal ¼” ball-type blowdown valve with minimum ½” hose-end connection on blowdown leg to allow backflushing the strainer screen without removing the plug.
        11. Miscellaneous Accessories:
          1. Locks:  Provide tamperproof fasteners on access doors and front panel for exposed cabinet units.
        12. Electrical:  Units shall operate on electrical power as specified on the equipment schedule. All wiring shall be in flexible metal conduit.  
        13. Controls:
          1. Coordinate control devices and operational sequences with Section 25 00 00 INTEGRATED AUTOMATION and 25 90 00 GUIDE SEQUENCES OF OPERATION
          2. Coordinate and complete wiring from unit mounted control devices to BAS equipment controller.
          3. Typically provide two-way, modulating, characterized control valves for hydronic coils.  Refer to BAS Guidespec, “Control Valves”.
          4. DAT sensors shall be quality averaging type and/or located sufficiently down-stream of coils to achieve accurate reading and DAT limit control.
        .03 Execution
        1. Installation 
          1. General:  Install fan coil units and accessories in strict accordance with the manufacturer's installation instructions for maintaining optimum performance and serviceability.
            1. Maintain manufacturer's and University recommended clearances for service. 
            2. Coordinate with other trades to assure correct recess size for recessed units.
          2. Suspend horizontal concealed fan-coil units from structure with properly selected vibration isolation hangers.  
          3. Verify locations of thermostats and other exposed control sensors with Drawings and room details before installation.
          4. Install new filters in each fan-coil unit within two weeks after Substantial Completion.
          5. Piping installation requirements are specified in other Sections.  Drawings indicate general arrangement of piping, fittings, and specialties.  Specific connection requirements are as follows:
            1. Install piping adjacent to equipment to allow service and maintenance.
            2. Connect piping to fan-coil-unit factory hydronic piping package.  Install piping package if shipped loose.
            3. Connect condensate drain to indirect waste.
            4. For concealed and ducted fan-coil units, install condensate trap of adequate depth to seal against the pressure of fan.  Install cleanouts in piping at changes of direction.
          6. Connect supply and return ducts to fan-coil units with flexible duct connectors.
          7. Protect exposed cabinet units with protective covers during balance of construction.
        2. FIELD QUALITY CONTROL
          1. Perform the following field tests and inspections and prepare test reports:
            1. Operational Test:  After electrical circuitry has been energized, start units to confirm proper motor rotation and unit operation.
            2. Operate electric heating elements through each stage to verify proper operation and electrical connections.
            3. Test and adjust controls and safety devices.  Replace damaged and malfunctioning controls and equipment.
          2. Remove and replace malfunctioning units and retest as specified above.

        23 83 00 RADIANT HEATING UNITS

        .01 Radiant Heaters
        1. Consider only for areas with high ceiling and low ventilation areas.
        2. Do not use in office areas. 

        23 84 00 HUMIDITY CONTROL EQUIPMENT

        .01  Humidifiers
        1. The steam source must be from building steam whenever possible.
          1. Electronic steam generators to be used only when building steam is not available.
          2. Water softening equipment shall be provided when electronic steam generators are used.
          3. Provide two changes of canisters.
        2. Follow manufacturers' guidelines for location.
        3. Provide access panel with a glass vision panel on downstream side of manifold.
        4. Controls (See 23 09 00).
        5. Refer to Detail [23 xx xx .xx].  Details are not yet available in WEB-based manual. 
        .02 Dehumidifiers
        1. Small packaged dehumidifiers shall be arranged so condensate is piped to sanitary system.