Specifications

GUIDE SPECIFICATIONS 7-46 kW DX units

Computer Room Air Conditioning Units

(Floor Mounted, Direct Expansion, 7 to 46 kW)

1.01 GENERAL

A. The environmental control units shall be provided with a high sensible cooling system, factory assembled, piped, wired,

and run tested prior to shipment and designed for either upﬂ ow or downﬂ ow air delivery as detailed on the project plans and

schedule.

B. The system shall be designed for draw through air arrangement to insure even air distribution to the entire face of the

coil.

C. Units shall be ETL or UL listed.

1.02 CABINET and FRAME

A. The frame shall be constructed of 14 gauge welded tubular steel and coated with a heavy corrosion inhibiting ﬁ nish for

long life. The unit shall have complete front and side access by means of steel doors with heavy-duty hinges. All doors shall be

easily removable via lift-off hinges for easier service access. Doors shall be manufactured of minimum 18-gauge steel for superior

sound attenuation and shall be lined with one-inch thick, 1-1/2-pound density, ﬁ berglass insulation. Each door shall be provided

with sure close latches and a polyurethane gasket to prevent air leakage.

B. The unit shall be painted the color selected from the manufacturer’s standard color chart.

1.03 REFRIGERATION CIRCUIT

A. Air Cooled with Remote Outdoor Condenser - The refrigeration system shall be split type with an indoor evaporator section

and remote outdoor condenser.

The indoor evaporator section shall include the cooling coil, compressors, humidiﬁ er, reheat, ﬁ lters, and controls. The cooling

coil shall be in a cross circuited or interlaced “A” frame arrangement to allow maximum coil surface in a small cabinet. The large

faced coil area shall be constructed with 1/2” O.D. riﬂ ed copper tube with 12 ﬁ ns per inch of corrugated aluminum for maximum

heat transfer. Maximum face velocity shall be less than 500 feet per minute. The expansion valve shall be of the adjustable

thermostatic type with external equalization. The compressor shall be of the hermetic scroll with complete overload protection on

all three power lines, internal thermostat for winding protection, crankcase heater, sight-glass, and low pressure override timer for

positive starting at low temperatures. The circuit shall contain high and low pressure safety switches. The high and low pressure

safety switches shall be installed with Shraeder type ﬁ ttings with valve core.

The doors shall be painted to match or contrast with other room equipment.

Each system shall include a low proﬁ le, slow speed, direct drive propeller fan type air cooled condenser. The air discharge

shall be vertical to minimize the effects of wind blowing through the coil at low ambient temperatures. The condenser shall be

constructed of stainless steel. The condenser shall contain a 1/2” O.D. riﬂ ed copper tube coil with corrugated aluminum ﬁ ns for

maximum heat transfer. The condenser shall have fan speed control with transducers to modulate the speed of the ﬁ rst condenser

fan motor and provide positive start-up and operation at ambient temperatures to -20° F. Condensers with more than one fan shall

utilize a pressure control on the second fan. Condensers with additional condenser fan motors are to be controlled by ambient

thermostats. All controls including the fan speed controller shall be factory mounted in the air cooled condenser in an integral

factory wired and tested control panel. The air cooled condenser shall be manufactured by the manufacturer of the indoor unit.

B. Air Cooled with Floor Mounted Indoor Condenser - The refrigeration system shall be split type with an indoor evaporator sec-

tion and ﬂ oor mounted indoor condenser section.

The indoor evaporator section shall include the cooling coil, compressors, humidiﬁ er, reheat, ﬁ lters, and controls. The cooling