ATTACHMENT 20 Addendum 1 Section 238123 ComputerRoom AirConditioners.pdf

ADDENDUM NO. 1

May 31, 2024

CONSTRUCT A NEW BOILER BUILDING AND

CONTROLS IN THE OLD INCENERATOR AREA

EXPAND/MOVE GRAPHIC CONTROL

VAMC MIAMI, FLORIDA

546-22-110 23 81 23-1

SECTION 23 81 23

COMPUTER-ROOM AIR-CONDITIONERS

PART 1 - GENERAL

1.1 DESCRIPTION

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

B. Definitions:

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

2. 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.

3. 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.

4. CRAC Units: Computer Room Air Conditioning Units.

1.2 RELATED WORK

A. Section 01 00 00, GENERAL REQUIREMENTS.

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

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

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

GENERATION EQUIPMENT.

E. Section 23 05 41, NOISE and VIBRATION CONTROL FOR HVAC PIPING and EQUIPMENT.

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

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

H. Section 23 08 00 – COMMISSIONING OF HVAC SYSTEMS.

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

J. Section 23 21 13, HYDRONIC PIPING

K. Section 23 21 23, HYDRONIC PUMPS and Section 23 22 23, STEAM CONDENSATE PUMPS.

L. Section 23 22 13, STEAM and CONDENSATE HEATING PIPING.

M. Section 23 23 00, REFRIGERANT PIPING.

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

O. Section 23 40 00, HVAC AIR CLEANING DEVICES.

1.3 QUALITY ASSURANCE

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

1.4 SUBMITTALS

A. Submit in accordance with specification Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, and SAMPLES.

B. Manufacturer’s Literature and Data 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.

1. Indoor Air Conditioning Unit

CONSTRUCT A NEW BOILER BUILDING AND

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2. Air Cooled Condensing Unit

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

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

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

F. Completed System Readiness Checklists provided by the Commissioning Agent 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.

1.5 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.

1.6 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.

B. Federal Specifications (Fed Spec):

00-A-374C-1999

Air-Conditioners with Remote Condensing

Units or Remote Air-cooled and Water-Cooled

Condenser Units, Unitary

TT-C-490D-1993

Cleaning Methods for Ferrous Surfaces and

Pretreatments for Organic Coatings

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

210/240-2017 Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment

340/360-2015

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 -2008

Directory of Certified Product Performance -

Applied Directory of Certified Products

D. 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

E. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Inc. (ASHRAE):

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15-2019 Safety Standard for Refrigeration Systems

(ANSI)

Handbook 2020 HVAC Systems and Equipment

Handbook 2018 Refrigeration

52.1-1992

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

Energy Standard for Buildings except Low-Rise

Residential Buildings (ANSI Approved; IESNA

Co-sponsored)

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

B117-2019 Standard Practice for Operating Salt Spray

(Fog) Apparatus

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

MG 1-2019

Motors and Generators (ANSI)

H. National Fire Protection Association (NFPA) Publications:

70-2020 National Electrical Code

90A-2021 Standard for the Installation of Air-Conditioning and Ventilating Systems

PART 2 - PRODUCTS

2.1 WALL-MOUNTED UNITS

A. Description: Self-contained, factory assembled, prewired, and prepiped; consisting of cabinet, fan, filters, and controls; for wall mounting..

B. Cabinet: Galvanized steel with baked-enamel finish, insulated with 13-mm (1/2-inch) thick duct liner.

C. Integral factory-supplied supply and return grille to fit ceiling grid kit of 610 by 1220 mm (24 by 48 inches), with filter.

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

E. Supply-Air Fan:

1. Forward-Curved, Centrifugal Fan: Provide with directly-driven fan with two-speed motor.

F. Compressor: Hermetic scroll, (VA: Type) with oil strainer, internal motor overload protection, resilient suspension system, and crankcase heater.

G. Refrigeration Circuit: Low-pressure switch, manual-reset high-pressure switch, thermal-expansion valve with external equalizer, sight glass with moisture indicator, service shutoff valves, charging valves, and charge of refrigerant.

H. Refrigerant: Manufacturers standard unless otherwise indicated.

I. Refrigerant Evaporator Coil: Direct-expansion coil of seamless copper tubes expanded into aluminum fins.

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1. Mount coil assembly 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.

J. Remote Air-Cooled Refrigerant Condenser: Integral, copper-tube E-coated aluminum-fin coil with propeller fan, direct driven.

K. Split system shall have suction- and liquid-line compatible fittings and refrigerant piping for field interconnection.

L. Filter: 25-mm (1 inch) thick, disposable, glass-fiber media.

1. MERV Rating: 7 according to ASHRAE 52.2.

M. Plumbing Components and Valve Bodies: Plastic, linked by flexible rubber hosing, with water fill with air gap and solenoid valve incorporating built-in strainer, pressure-reducing and flow-regulating orifice, and drain with integral air gap.

N. Control: Fully modulating to provide gradual 0 to 100 percent capacity with field-adjustable maximum capacity; with high-water probe.

O. Drain Cycle: Field-adjustable drain duration and drain interval.

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

Q. Control System: Unit-mounted panel with main fan contactor, compressor contactor, compressor start capacitor, control transformer with circuit breaker, solid-state temperature- control modules , time-delay relay, and high-temperature thermostat. Wall-mounted control panel shall be solid-state, with start-stop switch dirty set point, and adjustable temperature set point.

R. DDC or BAS Interface: Provide connection to the BAS system.

2.2 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.

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

2.3 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

2.4 CORROSION CONTROL

A. Remote Outdoor Condenser Coils:

1. Epoxy Immersion Coating – Electrically Deposited: The multi-stage corrosion-resistant coating application comprises of cleaning (heated alkaline immersion bath) and reverse-osmosis immersion rinse prior to the start of the coating process. The coating thickness shall be maintained between 0.6-mil and 1.2-mil. Before the coils are subjected to high-temperature oven cure, they are treated to permeate immersion rinse and spray. Where the coils are subject to UV exposure, UV protection spray treatment comprising of UV-resistant urethane mastic topcoat shall be applied. Provide complete coating process

CONSTRUCT A NEW BOILER BUILDING AND

546-22-110 23 81 23-5 traceability for each coil and minimum five years of limited warranty. The coating process shall be such that uniform coating thickness is maintained at the fin edges. The quality control shall be maintained by ensuring compliance to the applicable ASTM Standards for the following:

a. Salt Spray Resistance (Minimum 6,000 Hours)

b. Humidity Resistance (Minimum 1,000 Hours)

c. Water Immersion (Minimum 260 Hours)

d. Cross-Hatch Adhesion (Minimum 4B-5B Rating)

e. Impact Resistance (Up to 160 Inch/Pound)

PART 3 - EXECUTION

3.1 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.

E. Install outdoor equipment to withstand wind rating specified on Structural drawings.

3.2 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. Water and Drainage Connections: Comply with applicable requirements in Section 22 05 23, GENERAL-DUTY VALVES FOR PLUMBING PIPING and Section 22 11 00, FACILITY WATER DISTRIBUTION. Provide adequate connections for water-cooled units, condensate drain, and humidifier flushing system.

E. Refrigerant Piping: Comply with applicable requirements in Section 23 23 00, REFRIGERANT PIPING. Provide shutoff valves and piping.

3.3 FIELD QUALITY CONTROL

A. Tests and Inspections:

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

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

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

4. 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.

3.4 STARTUP AND TESTING

A. The Commissioning Agent will observe startup and contractor testing of selected equipment.

Coordinate the startup and contractor testing schedules with the COR and Commissioning Agent. Provide a minimum of 7 days prior notice.

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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.

3.5 COMMISSIONING

A. Provide commissioning documentation in accordance with the requirements of Section 23 08 00 – COMMISSIONING OF HVAC SYSTEMS for all inspection, start up, and contractor testing required above and required by the System Readiness Checklist provided by the Commissioning Agent.

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.

3.6 DEMONSTRATION AND TRAINING

A. Provide services of manufacturer’s technical representative for four 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.

END OF SECTION