SECTION 15786

COMPUTER ROOM AIR CONDITIONING UNITS - UNITARY CEILING

PART 1 GENERAL

SECTION INCLUDES

Air Conditioning Units.

Controls.

RELATED SECTIONS

Section [_____-_________]: Controls and instrumentation.

Section 16180 - Equipment Wiring Systems: Electrical supply to units.

REFERENCES

ANSI/ASME - Boiler and Pressure Vessels Code.

ANSI/NEMA 250 - Enclosures for Electrical Equipment (100 Volts Maximum).

ASHRAE 52 - Air-Cleaning Devices Used in General Ventilation for Removing Particulate Matter.

UL - Underwriters Laboratories.

SUBMITTALS

Submit under provisions of Section [01300] [_____].

Product Data: Provide manufacturers literature and data indicating [water,] drain, and electrical rough-in connections.

Manufacturer's Installation Instructions: Indicate procedures required for rigging and making service connections.

OPERATION AND MAINTENANCE DATA

Submit under provisions of Section [01700] [_____].

Include manufacturer's descriptive literature, operating instructions, installation instructions, maintenance and repair data.

WARRANTY

Provide [five] [_____] year warranty under provisions of Section [01700] [_______].

Warranty: Include coverage of [refrigeration compressor] [entire unit] [___________].

PART 2 PRODUCTS

MANUFACTURERS

[___________________________________] Model [__________]

[___________________________________] Model [__________]

[___________________________________] Model [__________]

Substitutions: Under provisions of Section [01600.] [01630.]

AIR CONDITIONING UNITS

Description:	Self contained [water] [air] cooled, factory assembled, pre-wired and pre-piped unit, consisting of cabinet, fan, filters, [humidifier,] controls.

Assembly: For horizontal ceiling mounting to fit 24 x 48 inches (610 x 1220 mm) T-bar ceiling opening.

Cabinet:	[10] [14] [_____] gage ([3.3] [1.8] [_____] mm) welded steel with baked enamel finish, and lined with 1/2 inch (15 mm) thick acoustic duct liner.

Evaporator Fan: Forward curved centrifugal, directly driven by two speed motor.

Compressor: Hermetic with resilient suspension system, oil strainer, internal motor overload protection, low pressure switch, manual reset high pressure switch.

Evaporator Coil:	Direct expansion cooling coil of seamless copper tubes expanded into aluminum fins, with thermal expansion valve with external equalizer, liquid line filter-drier, service shutoff valves and charging valves. Mount coil assembly in stainless steel drain pan.

Water Cooled Condenser: Coaxial counterflow tube-in-tube type with liquid line stop valve and head pressure actuated water regulating valve, sized for rated capacity with [_____] gpm ([_____] L/s) water entering at [_____] degrees F ([_____] degrees C).

****** [OR] ******

Air Cooled Condenser: Integral copper tube aluminum fin coil sized for rated capacity at [95] [_____] degrees F ([35] [_____] degrees C) with [fan driven by double shafted evaporator fan motor] [remote fan package].

Filter: One inch 925 mm) thick disposable glass fiber

media.

Heating Coils: Nichrome wire electric elements with contactor, dehumidification relay, and high temperature limit switch.

Atomizing Humidifier: Centrifugal atomizer with stainless steel pan, demister pad, and solenoid valve.

****** [OR] ******

Evaporative Pad Humidifier: Evaporative, self-flushing type with disposable evaporation pad medium, stainless steel drain pan, solenoid valve control.

****** [OR] ******

Evaporative Pan Type: Stainless steel pan and cover, with stainless steel or brass float valve mechanism, electric heating coil with low water cut-off switch, flush cycle timer and solenoid drain valve.

REMOTE GLYCOL COOLER

Cooler: Corrosion resistant cabinet with copper tube aluminum fin coil, direct drive propeller fan with fan guards and [permanently lubricated ball bearing] single phase [_____] hp fan motors with internal overload protection.

Pump: In-line type centrifugal pump with mechanical seal, [_____] hp motor, [_____] volt, [single] [three] phase, 60 Hz.

Controls: Electrical control cabinet with starters, relays, and disconnects.

Piping: Interconnecting piping, from suction to discharge with shut-off valves, flow switch, check valve in pump discharge and unions.

Glycol: Inhibited [ethylene] [propylene] glycol and water solution mixed [50-50] [______] suitable for operation temperature of [-40] [_______] degrees F ([-40] [____] degrees C).

Expansion Tank: [Diaphragm] [Open] expansion tank and vent fitting with air separator, [automatic air vent,] and system charging connection.

CONTROL SYSTEM

Unit Mounted: Main fan contactor, compressor [and condenser fan] contactor, compressor start capacitor, controls transformer with circuit breaker, solid state temperature [and humidity] control modules, [humidity contactor, time delay relay, reheat contactor, and high temperature thermostat].

Controls: Solid state [wall] [unit] mounted with start/stop switch, adjustable temperature setpoint [, adjustable humidity setpoint].

PERFORMANCE

Cooling Capacity: [_____] Btu/hr ([_____ W) with [_____] cfm ([_____] L/sec) of air entering evaporator at [_____] degrees F ([_____] degrees C) DB and [_____] degrees F ([_____] degrees C) WB, leaving evaporator at [_____] degrees F ([_______] degrees C) DB and [_____] degrees F ([_____] degrees C) WB, with evaporator fan motor at [_____] hp ([_____] W).

[Water] [Glycol] Cooled:	[_____] gpm ([_____] L/sec condenser water entering at [_____] degrees F ([_____] degrees C), condenser fan motor at [_____] hp ([_____] W).

Air Cooled: Air entering air cooled condensing unit at [_____] degrees F ([_____] degrees C), condenser fan motors at [_____] hp ([_____] W).

Reheat Capacity: [_____] Btu/hr ([_____] W).

Humidifier: Total capacity of [_____] lb/hr ([_____] kg/hr) with [______] W input.

Power Connection: [_____] volt, [single] [three] phase, 60 Hz.

PART 3 EXECUTION

EXAMINATION

Verify that ceiling system is ready to receive work and opening dimensions are as [indicated on shop drawings.] [instructed by the manufacturer.]

Verify that proper power supply is available.

INSTALLATION

Install units in accordance with manufacturer's instructions.

Coordinate installation of air conditioning unit with computer room ceiling installer.

Provide adequate drainage connections for [water cooled units] [condensate] and humidifier flushing system.

Provide shut-off valves in condenser water inlet and outlet piping on [water] [glycol] cooled units.

SCHEDULE

Drawing_Code	CAC-1	CAC-2	CAC-3

Location

Manufacturer

Model Number

Cooling Capacity

Total

Sensible

Room DB Temp

Room WB Temp

Air Flow

Fan Motor Size

Condenser

[Water] [Glycol] Flow

[Water] [Glycol] Temp

Ambient Air Temp

Fan Motor Size

Glycol Pump Motor Size

Reheat

Capacity

Humidifier

Capacity

Power Input

Power Volt/Phase/Cycle

END OF SECTION