MDACC Project No. XX-XXXX / MDACC PROJECT NAME
A/E Name / Issue Description
A/E Project No. / Month, 00, 0000

SECTION 238126 –DX SPLITSYSTEM AIRCONDITIONERS

PART 1 - GENERAL

1.01RELATED DOCUMENTS

  1. Drawings and general provisions of the Contract, including General Conditions and Division01 Specification Sections, apply to this Section.
  2. Specifications throughout all Divisions of the Project Manual are directly applicable to this Section, and this Section is directly applicable to them.

1.02SUMMARY

  1. Providesplitsystem airconditioningsystem consistingofindoorair handling/fancoilunit(s),outdoorcondensingunit(s),refrigerantpiping, fittings, valves andaccessories,andcontrols.
  2. Perform all Work required to provide and install the factory assembled split-system air-conditioning and / or heat-pump systemrefrigerant piping, valves, filters driers, and any refrigerant specialties equipmentsuch as suction accumulators, site glass, receivers, strainers, etc. as specified in this specification,indicated, or notedon the Owner’s Contract Documents with supplementary items necessary for proper installation and testing and operation of the unit(s).

1.03REFERENCE STANDARDS

  1. The latest published edition of a reference shall be applicable to this Project unless identified by a specific edition date.
  2. All reference amendments adopted prior to the effective date of this Contract shall be applicable to this Project.
  3. All materials, installation and workmanship shall comply with the applicable requirements and standards addressed within the following references:
  4. ANSI/AMCA Standard 205-12 - Energy Efficiency Classification for Fans.
  5. ANSI/ARI 410 - Forced Circulation Air-Cooling and Air-Heating Coils.
  6. ANSI/ARI 460 - Remote Mechanical-Draft Air Cooled Refrigerant Condensers.
  7. ANSI/ARI 210/240 - Unitary Air-Conditioning and Air-Source Heat Pump Equipment.
  8. ANSI/ARI 340-360 - Commercial and Industrial Unitary Air-Conditioning and Heat Pump Equipment.
  9. ANSI/ARI 270 -Sound Rating of Outdoor Unitary Equipment.
  10. ANSI/ARI 365 - Commercial and Industrial Unitary Air-Conditioning Condensing Unit(s)..
  11. ANSI/ARI 500-2000 Variable Capacity Positive Displacement Refrigerant Compressors and Compressor Unit(s). for Air Conditioners and Heat Pump Applications.
  12. ANSI/ASHRAE 90.1 - Energy Standard for Buildings Except Low-Rise Residential. Buildings.
  13. ASHRAE 15 - Safety Code for Mechanical Refrigeration.
  14. NEMA MG 1 - Motors and Generators.
  15. NFPA 70 National Electrical Code
  16. ASTM B280 - Seamless Copper Tube for Air Conditioning and Refrigeration Field Service.
  17. ASTM B117 - Standard Practice for Operating Salt Spray (Fog) Apparatus.
  18. NFPA 90A - Standard for the Installation of Air Conditioning and Ventilating Systems.
  19. AWS A5.8 - Specification for Brazing Filler Metal.
  20. ASME B31.5 - Refrigeration Piping.
  21. SMACNA HVAC Duct Construction Standards Metal and Flexible.

1.04QUALITY ASSURANCE

  1. Manufacturer Qualifications: Company specializing in manufacturing the products specified in this Section with minimum three (3) years documented experience, who issues complete catalog data on total product.
  2. Provide capacity ratings with ARI certification.Energy Efficiency Rating (EER) and Coefficient of Performance (COP) not less than prescribed by ASHRAE 90.1 when used in combination with compressors and evaporator coils when tested in accordance with ARI Standards.
  3. Insulation shall be a flexible, closed-cell elastomeric pipe insulation AP Armaflex, AC Accoflex. Adhesive shall be Armaflex 520, 520 Black or 520 BLV Adhesive. Theinsulation must conform to ASTM C534 Grade 1, Type, and shall have a maximum thermal conductivity of 0.27 Btu-in./h-ft2-°F at a 75°F mean temperature as tested in accordance with ASTM C 177 or ASTM C 518.
  4. Insulation materials shall have a flame-spread index of less than 25 and a smoke-developed index of less than 50 as tested in accordance with ASTM E 84. In addition, the products, when tested, shall not melt or drip flaming particles, and the flame shall not be progressive.

1.05SUBMITTALS

  1. Product Data:
  2. Provide literature that indicates dimensions, weights, and supply air fan performance such as capacity, brake horsepower, wheel type and finishes of materials.Submit electrical load characteristics, voltage, amperage,and rough-in connection requirements for electrical and refrigerant tubing.
  3. Submit electrical requirements for power supply wiring including wiring diagrams for signal interlocks and control wiring, clearly indicating factoryinstalled and fieldinstalled wiring.
  4. Record Documents:
  5. Electrical and refrigerant tubing drawings with noted seal procedures and sealant material products and product material data sheets.
  6. Includemanufacturer'sinstall installationinstructions.
  7. Provideoperationandmaintenance manual.
  8. Submit manufacturer’s certificate that coils are tested in accordance with and rated in accordance with ARI 410.
  9. Manufacturer's warranty form in which manufacturer agrees to repair or replace failed components, materials or workmanship within specified warranty period.
  10. Operation and Maintenance Data
  11. The contractor shall provide closeout documents for the unit(s) which includes emergency operation (if applicable), normal operating and maintenance (O&M) manuals, in addition to any field change documents that affect the operation or maintenance of the unit(s).
  12. Permanently mount condensate trapping calculation instructions within the unit O&M Manual that illustrates the unit casing at the condensate drain connection.
  13. Per the Manufacturer's Instructions: Provide Start-up information and maintenance required prior to Start-up of the unit(s).

1.06DELIVERY, STORAGE and HANDLING

  1. Deliver, store, protect and handle products to the Project Site under provisions of Division 01 and Division 20.
  2. Accept products on site in factory-fabricated protective containers, with factory-installed shipping skids and lifting lugs. Inspect for damage and make any necessary replacement. If the damage can be repaired notify Owner for acceptance prior to preforming work. Any replacement or repair due to damage to a product will be at no expense to the Owner.
  3. Store in clean dry place and protect from weather and construction traffic. Handle carefully to avoid damage to components, enclosures, and finish.
  4. Protect openings in casing and seal them with plywood and plastic sheeting to keep dirt,debris moisture from entering the air handler and, also protect coils connections from entry of dirt and moisture with pipe caps or plugs.
  5. Protect all coils to avoid damage; if the coils are damage they shall be replaced.

1.07WARRANTY

  1. A minimum 5 year compressor warranty, 10 year warranty on condenser coil, and evaporator coil, 1 year parts and labor warranty on the rest of the system controls and components.

PART 2 - PRODUCTS

2.01GENERAL

  1. All materials shall meet or exceed all applicable referenced standards, federal, state and local requirements, and conform to codes and ordinances of authorities having jurisdiction.
  2. Provideonerefrigerantlinefilterdrierandoutsidepressuretapsineach refrigerantcircuit on brazed tubing refrigerant piping systems.

2.02manufacturers

  1. American Standard
  2. Trane
  3. York
  4. Daikin / McQuay
  5. Mitsubishi

2.03AIR HANDLING / FAN COIL UNIT

  1. Fabricatedexteriorunitcasingshall be constructed with minimum of18gaugegalvanizedsteel, paintedwithepoxybasedenamelpaint. Providecolorchartfor colorselectionbyArchitect.
  2. All are to be double wall withaminimum 2inch microbialresistantandcleanablefoam insulation linerwith an R value of 12 or greater.Unit access panelsmustberemovable.
  3. Fabricatefandeckofgalvanizedsteel.
  4. Primary Drain Pan:
  5. Unit(s) shall have afire retardant,closedcell foaminsulated, rust-inhibiting IAQ stainless steel drain pan across the full width of the unit, extending from the cooling coil to the end of the unit.
  6. Drain connection shall be minimum 7/8-inch outside diameter, copper construction.
  7. Arrange coil and drain pan connections on the side of the unit as shown on the Drawings.
  8. Each unit shall be provided with integral mounting brackets adequate to support the unit’s weight.
  9. Each unit shall be provided with a one (1) inch discharge and inlet duct collar.
  10. Furnish access doors as required to service all elements of the unit from each side of the unit, not from the bottom.
  11. Fan(s) shall be direct drive with centrifugal, single width wheel mounted on vibration isolators.
  12. Fan wheel design must meet Fan Efficiency Grade requirements and tested and certified in accordance with the requirements of ANSI/AMCA Standard 205-12.
  13. Fan motors that are 1 hp or less shall be Electronically Commutated Motor (ECM) motor with an Electronic Speed Control (ESC) module. Fan motors greater than 1 hp shall be three-phase, suitable for Variable Speed Drive (VFD) service intotalcompliancewithSection20 0513.

2.04cOILS

  1. Coils shall be comprised of aluminum fins mechanically bonded to copper tubes. If the cooling coils are used to cool mixed air (outside air and return air) the coil shall be comprised of copper fins mechanicallybonded to copper tubes.
  2. Test all coils for maximum system design working pressure and or static pressure based on the type of refrigerant being used.
  3. Heating and cooling coils shall be sized as required to meet or exceed industry standards, capacities, and notes, on theDrawings.

2.05air cooled condensing units

  1. Provideaircooledcondensingunitsasscheduled. Units shall beself-contained, packaged,factoryassembledandpre-wiredsuitableforoutdooruse consistingofcabinet,compressors,condensingcoilandfans,integral sub-coolingcoil,controls,liquidreceiverandscreens.
  2. Providecorrosionresistantmaterialsforunitpartswhichcomeincontact withrefrigerant.
  3. Providetimerconduitstopreventrapidcyclingofcompressor.
  4. Fabricatecabinetfrom galvanizedsteel,equipped with removableaccessdoorsorpanelswithquickfasteners.The cabinet and framing shall be protected from environmental elements using a powder coat or epoxy paintfinishcapable of withstanding 500-hour salt spray exposure per ASTM B117.
  5. Compressor: [Hermeticallysealedscroll with capacitymodulation] or [semi-hermetic]type withpositivelubrication,crankcaseheater,un-loaderforcapacitymodulation,motoroverloadprotection,service valves,filterdrier,suctionanddischargevalves,withgaugeports,and highandlow pressuresafetycontrols.
  6. Condenser:
  7. Coils shall be made from seamless copper tubing with mechanically bonded aluminum fins and capable of withstanding 500-hour salt spray exposure per ASTM B117.
  8. Provide condenser fans which discharge, vertically and that have direct drive fans resiliently mounted with guard and motor.
  9. Provide unit with high and low pressure cutouts for compressor, non-recycling pump down, reset relay and oil pressure safety control (7 1/2 ton units and larger).
  10. Provide anti-short cycle timer for loss of power conditions to protect the compressor.
  11. Low suction pressure cut out switch to reduce probability of pulling non condensable gases into the refrigerant system.

Note to A/E add this sentence if the application and ASHRAE zone minimum temperatures is appropriate for this requirement; “Provide with controls to permit operation down to 0 degree F ambient temperature at minimum compressor load.”

2.06PipinG

  1. Copper Tube and Fittings:
  2. Drawn-Temper Copper Tube per ASTM B 280, Type ACR, clean, dry and capped.
  3. Annealed-Temper Copper Tube per ASTM B 280, Type ACR, clean, dry and capped. Annealed copper tubing shall not be used for piping larger than 0.625 O.D.
  4. Wrought-Copper Fittings: ASME B16.22.
  5. Bronze Filler Metals: AWS A5.8, Classification BAg-7 (50% silver), BCuP5 (15% Silver).

2.07Filter Section:

  1. Refer to Section 23 40 00 – Filters, and Drawings for additional requirements.
  2. Filters shall have a maximum width of 24 inches.
  3. The air handling unit manufacturer shall provide one (1) set of scheduled filters for each air handling unit as shown on the Drawings. The filters shall be boxed and placed within the air handling unit during shipment. The box shall identify the type of filter and be labeled with the corresponding air handling unit identification tag number.

PART 3 - EXECUTION

3.01PREPARATION

  1. Coordinate layout and installation of refrigerant piping and piping suspension and support system components with other construction trades, including light fixtures, HVAC ducts and equipment, fire-suppression-system piping, equipment components, and fire and/or smoke partition assemblies.
  2. Coordinatepipe sleeve installations through wall or foundation penetrations.
  3. Coordinate and verify core bores for conduit and pipe sleeve installations on existing facilities to preclude cutting rebar in the concrete floor or conduit supported directly on the bottom of the concrete floor.
  4. Verify the proper sleeve penetration detail is being applied prior to core boring or drilling for fire and or smoke wall partitions and floors.
  5. Assure refrigerant piping, valves and specialty items are stamped or certified to meet refrigerant design pressures for the following refrigerants.
  6. Select pipe, fittings, and components that have design pressure ratings per ASHRAE 15 but not less than the following system design pressures:

Refrigerant Type / Low Side (psig) / High Side (psig)
R-134a(Air Cooled) / 115 / 225
R-410a (Air Cooled) / 260 / 510

3.02INSTALLATION

  1. Installation shall meet or exceed all applicable federal, state and local requirements, referenced standards and conform to codes and ordinances of authorities having jurisdiction.
  2. All installations shall be in accordance with manufacturer’s recommendations:
  3. Air cooled condensing units shall have the proper clearance requirements that not only meet space requirements to permit proper air flow and for maintenance or removal needs.
  4. Air handling or fan-coil units should be located to allow full access to perform preventative and replacement maintenance which also includes space for coil removal. Units shall not be located above or near electrical panels or electronic control panels.
  5. Provide sufficient access space and install refrigerant valves, strainers, and driers at aheight that is easily accessible for maintenance.
  6. Contractor shall furnish and maintain and replace clean pre-filter media in each air handling unit as listed in the equipment schedule on the Drawings during start-up and construction. The Contractor shall install the tagged set of new filter products provided by the air handling unit manufacturer for each unit after it has been tested, commissioned and receives final acceptance by the Owner.
  7. Condensate P-traps shall be properly sized for air handling unit design negative or positive static pressure based on relevant location of fan being upstream or downstream of the coil.
  8. Installation of refrigerant pipinghangers and supports:
  9. Purging with 99.9% nitrogen gas must be used when brazing copper tubing, fittings, and valves. The brazing filler material is specified in piping section of this specification.
  10. Manufacturer’s requirements must be followed when brazing specialty items and valves.
  11. All piping shall be rigidly supported from the building structure by means of adjustable ring-type hangers. Unistrut® type trapeze hangers shall be used where pipes run side by side. Hanger spacing shall be as follows:
  12. Horizontal:

Copper Piping / Maximum Spacing
3/8-inch and under / 4 feet
1/2-inch through 3/4-inch / 6 feet
1 – inch through 1-1/2-inch / 8’ feet
2 – inch through 1-1/2-inch / 10’ feet
  1. Vertical copper piping shall be supported at 10 feet intervals maximum.
  2. Round rods supporting the pipe hangers shall be of the following dimensions:

Piping Diameter / Rod Diameter
2-inch and under / 3/8-inch
2-1/2 to 3-inch / 1/2-inch
  1. Rods for trapeze hangers shall be minimum of 3/8 - inch and shall have the equivalent cross section listed above per pipe supported. The use of pipe hooks, chains, perforated iron strapping or wire for pipe supports isnot permitted.
  2. Insulated pipes shall be protected using galvanized steel shields similar to Grinnel Figure 167 or 360 or equal, galvanized steel shield by Pipe Shields Incorporated.
  3. Place a hanger within 1'-0" of each side for each horizontal elbow.
  4. Use hangers which are vertically adjustable 1-1/2" minimum after piping is erected.
  5. Use plastic coated straps on copper pipe.
  6. Where permitted by the A/E or Ownersoft copper tubing shall be fastened to the building structure with Unistrut® type supports, Unistrut® type clamps and cushion inserts. Clamps shall not be spaced greater than 4'-0" apart.

3.03TESTING

  1. Leak Testing Requirements:
  2. If the copper tubing is charged with refrigerant to connect the air cooled condensing unit with the air handler or fan coil unit use proper leak detection instruments to assure no refrigerant is leaking from the mechanical tube connections between thecooling coil andthe condensing unit.
  3. Brazedrefrigerant copper tubing shallbe evacuated using the deep vacuum method the system is thoroughly dry to ensure the system is thoroughly dry and free of non-condensibles and leaks.
  4. A micron gauge with a range from 50 to 9,000 micron shall be used to read the vacuum reading.
  5. Evacuation is considered to be complete when a system holds an absolute vacuum at 500 microns for 20 minutes.
  6. Performance Testing:
  7. Performance test shall be in accordance with manufacturer’s pressure and temperature charts for entering air temperatures of the outside coiland inside coil including amperage and voltage readings, to assure the unit is operating properly.

END OF SECTION 2381 26

The University of Texas / DX SPLITSYSTEM AIRCONDITIONERS
MD AndersonCancerCenter / 238126
MS102115 / 1 of 8