Attachment 04- 238123.pdf

PART 1 - VA Pittsburgh Healthcare System (VAPHS) H.J. Heinz III Campus | EHRM Infrastructure Upgrades Project Number: 646A-22-700 | Issue Date: 07.24.2026

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SECTION 23 81 23

COMPUTER-ROOM AIR-CONDITIONERS

PART 1 - GENERAL

DESCRIPTION

A. This section specifies process cooling split systems air conditioning unit.

B. A complete listing of common acronyms and abbreviations are included in

Section 23 05 11, COMMON WORK RESULTS FOR HVAC.

C. Definitions:

Energy Efficiency Ratio (EER): A ratio calculated by dividing the cooling capacity in Btu per hour by the power input in watts at any given set of rating conditions, expressed in Watts (Btu/h) per watt.

Integrated Energy Efficiency Ratio (IEER): Calculated by weighting the EER values at different load capacities and adding them together. The formula is based in the approximate number of hours a unit spends at each load point throughout its life. A minimum of four loads points are used for the calculation.

Coefficient of Performance (COP): A ratio calculated by dividing the change in heating or cooling capacity (Btu/h) to the energy consumed by the system (kW), expressed in Btu/kWh.

Unitary (AHRI): Consists of one or more factory-made assemblies, which normally include an evaporator or cooling coil, a compressor and condenser combination, and may include a heating function.

CRAC Units: Computer Room Air Conditioning Units.

RELATED WORK

A. Section 01 00 00, GENERAL REQUIREMENTS.

B. Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, and SAMPLES.

C. Section 01 81 13, SUSTAINABLE CONSTRUCTION REQUIREMENTS.

D. Section 23 05 11, COMMON WORK RESULTS FOR HVAC.

E. Section 23 05 93: TESTING, ADJUSTING, and BALANCING FOR HVAC.

F. Section 23 07 11, HVAC, and BOILER PLANT INSULATION.

G. Section 23 08 00, COMMISSIONING OF HVAC SYSTEMS.

H. Section 23 09 23, DIRECT-DIGITAL CONTROL SYSTEM FOR HVAC.

I. Section 23 21 13, HYDRONIC PIPING.

J. Section 23 23 00, REFRIGERANT PIPING.

K. Section 23 31 00, HVAC DUCTS and CASINGS.

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SUBMITTALS

A. Submit in accordance with specification Section 01 33 23, SHOP

DRAWINGS, PRODUCT DATA, and SAMPLES.

B. Information and material submitted under this section shall be marked

“SUBMITTED UNDER SECTION 23 81 23, COMPUTER-ROOM-AIR-CONDITIONERS”,

with applicable paragraph identification.

C. Manufacturer’s Literature and Data Including: Rated capacities (at design indoor and outdoor conditions), EER/COP, operating characteristics, required specialties and accessories. Submit published catalog selection data showing equipment ratings and compliance with required sensible ratio.

Indoor Air Conditioning Unit

Air Cooled Condensing Unit

D. Submit detailed equipment assemblies with dimensions, operating weights, required clearances.

E. Submit wiring diagrams for power, alarm and controls.

F. Certification: Submit, simultaneously with shop drawings, a proof of certification:

G. Completed System Readiness Checklists provided by the CxA and completed by the contractor, signed by a qualified technician and dated on the date of completion, in accordance with the requirements of Section 23

08 00 COMMISSIONING OF HVAC SYSTEMS.

H. Submit training plans and instructor qualifications in accordance with the requirements of Section 23 08 00, COMMISSIONING OF HVAC SYSTEMS.

QUALITY ASSURANCE

A. Refer to specification Section 23 05 11, COMMON WORK RESULTS FOR HVAC.

GUARANTEE

A. The unit shall be guaranteed against all mechanical defects in material, parts or workmanship and shall be repaired or replaced at the

Contractor's expense within the period of one year from final acceptance. Contractor shall adhere to a four-hour service response time to troubles during the guarantee period.

APPLICABLE PUBLICATIONS

A. The publications listed below form a part of this specification to the extent referenced. The publications are referenced in the text by the basic designation only. Where conflicts occur these specifications and the VHA standards will govern.

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B. Air-Conditioning, Heating and Refrigeration Institute (AHRI) Standards:

210/240-2023 (2020).....Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment

340/360-(I-P 2019)......Performance Rating of Commercial and Industrial

Unitary Air Conditioning and Heat Pump

Equipment

410-2001................Forced-Circulation Air-Cooling and Air-Heating

Coils

460-2005................Performance Rating of Remote Mechanical-Draft

Air-Cooled Refrigerant Condensers

520-2004................Performance Rating of Positive Displacement

Condensing Units

DCPP (Web-based)........Directory of Certified Product Performance -

Applied Directory of Certified Products

C. Air Movement and Control Association (AMCA):

210-2016................Laboratory Methods of Testing Fans for

Certified Aerodynamic Performance Rating (ANSI)

410-1996................Recommended Safety Practices for Users and

Installers of Industrial and Commercial Fans

D. American Society of Heating, Refrigerating, and Air-Conditioning

Engineers Inc. (ASHRAE):

15-2019.................Safety Standard for Refrigeration Systems and

Designation and Classification of Refrigerants

(ANSI)

52.1-1992(withdrawn)....Gravimetric and Dust-Spot Procedures for

Testing Air-Cleaning Devices used in General

Ventilation for Removing Particulate Matter

62-1-2019...............Ventilation for Acceptable Indoor Air Quality

(ANSI)

90.1-2019 (I-P).........Energy Standard for Buildings except Low-Rise

Residential Buildings (ANSI Approved; IES Co-sponsored)

2020 ...................HVAC Systems and Equipment Handbook

2018 ...................Refrigeration Handbook

E. American Society of Testing and Materials (ASTM):

B117-2017...............Standard Practice for Operating Salt Spray

(Fog) Apparatus

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F. National Electrical Manufacturer's Association (NEMA):

MG 1-2016 (R2019).......Motors and Generators (ANSI)

G. National Fire Protection Association (NFPA) Publications:

70-2020.................National Electrical Code

90A-2021................Standard for the Installation of Air-

Conditioning and Ventilating Systems

AS-BUILT DOCUMENTATION

A. Comply with requirements in Paragraph AS-BUILT DOCUMENTATION of Section

23 05 11, COMMON WORK RESULTS FOR HVAC.

PART 2 - PRODUCTS

FLOOR-MOUNTED UNITS 28 KW (8 TONS) AND LARGER

A. Description: Packaged, factory assembled, prewired, and pre-piped;

consisting of cabinet, fans, filters, and controls.

B. Cabinet and Frame: Welded steel, braced for rigidity, and supporting compressors and other mechanical equipment and fittings.

C. Doors and Access Panels: Galvanized steel with polyurethane gaskets, hinges, and concealed fastening devices.

D. Insulation: Thermally and acoustically insulate cabinet interior with -

25-mm (1-inch) thick 24 kilogram/cubic meter (1.5 pound/cubic foot) high-density mineral fiber duct liner coated on airstream side.

E. Finish of Interior Surfaces: Surfaces in contact with the airstream shall comply with requirements in ASHRAE 62.1.

F. Finish of Exterior Surfaces: Baked-on, textured vinyl enamel; color as selected from manufacturer's standard colors.

G. Supply-Air Fan(s): Double-inlet, forward-curved centrifugal or plenum fans(s), statically and dynamically balanced.

H. Drive:

Plenum Fans: Direct-drive, Arrangement 4, variable-speed drive fan(s) with aluminum wheels; with multiple fans, the number of fans shall not exceed four.

I. Compressors: Digital scroll with resilient suspension system, crankcase heater, manual-reset high-pressure switch, and pump-down low-pressure switch.

J. Refrigeration Circuits: Two; each with hot-gas mufflers, thermal-expansion valve with external equalizer, liquid-line solenoid valve, 23 81 23 - 5 liquid-line filter-dryer, sight glass with moisture indicator, service shutoff valves, charging valves, and charge of refrigerant.

K. Use refrigerant type R-454B or R-32. EPA approved refrigerants are listed at https://www.epa.gov/snap/. Submit proposed refrigerant for government approval.

L. Refrigerant Evaporator Coil: Alternate-row or split-face-circuit, direct-expansion coil of seamless copper tubes expanded into aluminum fins.

Coil assembly shall be mounted over stainless-steel drain pan complying with ASHRAE 62.1 and having a condensate pump unit with integral float switch, pump-motor assembly, and condensate reservoir.

M. Remote Air-Cooled Refrigerant Condenser: Corrosion-resistant cabinet, copper-tube, aluminum-fins, coils arranged for two circuits, multiple direct-drive propeller fans with permanently lubricated ball bearings, and single-phase motors with internal overload protection and integral electric control panel and disconnect switch. Control capacity by modulating fan speeds.

N. Hydronic Cooling Coil: Seamless copper tubes expanded into aluminum fins with modulating two-way control valve.

O. Control Valve: Class 125 body, with a maximum pressure drop of 21 kPa

(3 psig) at design flow rate.

P. Close-Off (Differential) Pressure Rating: 100 percent of pressure differential across valve or 100 percent of total system (pump) head.

Q. Mount coil assembly over stainless-steel drain pan complying with

ASHRAE 62.1-2010 and having a condensate pump unit with integral float switch, pump-motor assembly, and condensate reservoir.

R. Filter:

Extended-Surface, Disposable, Panel type: Pleated, lofted, nonwoven, reinforced cotton fabric; supported and bonded to welded wire grid;

enclosed in cardboard frame.

a. Thickness: 100 mm (4 inches).

b. Arrestance: 90 percent according to ASHRAE 52.1.

c. MERV Rating: 8, according to ASHRAE 52.2.

S. Controls:

Integral Electrical Controls: Unit-mounted electrical enclosure with piano-hinged door, grounding lug, combination magnetic starters with

23 81 23 - 6 overload relays, circuit breakers and cover interlock, and fusible control-circuit transformer.

a. Disconnect Switch: Nonautomatic, molded-case circuit breaker with handle accessible when panel is closed and capable of preventing access until switched to off position.

Electronic-Control System: Solid state, with start button, stop button, temporary loss of power indicator, manual-reset circuit breakers, temperature control, humidity control, and monitor panel.

T. Microprocessor-Control System: Continuously monitors operation of process cooling system; continuously displays room temperature and room relative humidity; sounds alarm on system malfunction and simultaneously displays problem. If more than one malfunction occurs, system displays fault in sequence with room temperature and continues to display fault when malfunction is cleared until system is reset.

U. Malfunctions:

Power loss, loss of airflow, clogged air filter, high room temperature, and low room temperature.

High humidity.

Low humidity.

Smoke/fire, water under floor supply fan overload, compressor No. 1, overload compressor No. 1 low pressure.

Digital Display:

a. Control power on.

b. Compressor No. 1 operating.

c. Compressor No. 2 operating.

Push buttons shall stop and start process cooling system, silence audible alarm, test indicators, and display room's relative humidity.

V. BAS Interface: Factory-installed hardware and software to enable the

BAS to monitor, control, and display unit status and alarms via an open protocol BACnet data interface.

W. Hardwired Points:

Monitoring: On-off status, common trouble alarm, space temperature, space relative humidity.

Control: On-off operation, space temperature set-point adjustment, space relative humidity set-point adjustment.

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X. Compatible with ASHRAE 135 (BACnet) Industry-accepted, open-protocol for communication interface with the BAS shall enable the DDC or the

BAS operator to remotely control and monitor the unit from an operator workstation. Control features and monitoring points displayed locally at unit control panel shall be available through the DDC or the BAS.

FAN MOTORS

A. Default motor characteristics are specified in Section 23 05 12, GENERAL MOTOR REQUIREMENTS FOR HVAC and STEAM GENERATION EQUIPMENT.

B. Comply with NEMA designation, temperature rating, service factor, enclosure type, and efficiency requirements for motors specified in

Section 23 05 12, GENERAL MOTOR REQUIREMENTS FOR HVAC and STEAM

GENERATION EQUIPMENT.

C. Motor Sizes: Minimum size as indicated. If not indicated, large enough so driven load will not require motor to operate in service factor range above 1.0. Provide high static fan motors for ducted applications.

D. Controllers, Electrical Devices, and Wiring: Comply with requirements for electrical devices and connections specified in Division 26

Sections.

SPECIAL TOOLS

A. If any part of equipment furnished under these specifications requires a special tool for assembly, adjustment, setting, or maintenance and the tool is not readily available from the commercial tool market, furnish the necessary tools with equipment as a standard accessory.

PART 3 - EXECUTION

INSTALLATION

A. Handle and install refrigeration units and accessories in accordance with the instructions and recommendations of the manufacturer.

B. Coordinate installation of Computer room Air Conditioning Units with

Computer room access flooring installer.

C. Field Refrigerant Piping: As specified in specification Section

23 23 00, REFRIGERANT PIPING.

D. Electrical System Connections and Equipment Ground: As specified in

Division 26 Sections.

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CONNECTIONS

A. Coordinate piping installations and specialty arrangements with schematics on Drawings and with requirements specified in piping systems. If Drawings are explicit enough, these requirements may be reduced or omitted.

B. Piping installation requirements are specified in other Division 23

Sections. Drawings indicate general arrangement of piping, fittings, and specialties.

C. Install piping adjacent to machine to allow service and maintenance.

D. Field Piping: Chilled water Piping as specified in specification

Section 23 21 13, HYDRONIC PIPING.

E. Drainage Connections: Comply with applicable requirements in Section

23 21 13, HYDRONIC PIPING.

F. Refrigerant Piping: Comply with applicable requirements in Section

23 23 00, REFRIGERANT PIPING. Provide shutoff valves and piping.

FIELD QUALITY CONTROL

A. Tests and Inspections:

Inspect for and remove shipping bolts, blocks, and tie-down straps.

After installing computer-room air conditioners and after electrical circuitry has been energized, test for compliance with requirements.

Operational Test: After electrical circuitry has been energized, start units to confirm proper motor rotation and unit operation.

Test and adjust controls and safeties. Replace damaged and malfunctioning controls and equipment.

B. After startup service and performance test, change filters and flush humidifier.

STARTUP AND TESTING

A. The CxA will observe startup and contractor testing of selected equipment. Coordinate the startup and contractor testing schedules with the COR and CxA. Provide a minimum of 7 days prior notice.

B. Provide services of manufacturer’s technical representative for four hours to instruct VA personnel in operation and maintenance of computer room air conditioning equipment.

COMMISSIONING

A. Provide commissioning documentation in accordance with the requirements of Section 23 08 00, COMMISSIONING OF HVAC SYSTEMS for all inspection, 23 81 23 - 9 start up, and contractor testing required above and required by the

System Readiness Checklist provided by the CxA.

B. Components provided under this section of the specification will be tested as part of a larger system. Refer to Section 23 08 00, COMMISSIONING OF HVAC SYSTEMS and related sections for contractor responsibilities for system commissioning.

DEMONSTRATION AND TRAINING

A. Provide services of manufacturer’s technical representative for 4 hours to instruct VA personnel in operation and maintenance of units.

B. Submit training plans and instructor qualifications in accordance with the requirements of Section 23 08 00, COMMISSIONING OF HVAC SYSTEMS.

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