General:
Heating and Ventilating unit shall be as
manufactured by Greenheck or approved equal provided
all specifications are met. Greenheck Model IGX-HV is
used as the basis of design. Performance shall be as
scheduled on plans.
Furnace:
Indirect gas fired furnace shall be 80% efficient,
ETL Listed and have a blow through fan design. Furnace
shall be capable of operation with Natural or LP gas and
have a power venting system with post purge cycle. The
heat exchanger shall be constructed of aluminized steel
or stainless steel. Standard furnace features shall include
main gas pressure regulator, main gas valve, electronic
staged controls, direct spark ignition system, high limit and
a 24 volt control transformer. Furnace shall be insulated
and have double wall construction.
Temperature Control:
Heating and cooling output shall
be controlled by a room thermostat to maintain desired
room temperature. Economizer control shall provide the
first stage of cooling, where specified. Furnaces shall
provide one or two stages of heat output control.
Unit Casing and Frames:
All frames and panels shall
be G90 galvanized steel. Where top panels are joined
there shall be a standing seam to insure positive weather
protection. All metal-to-metal surfaces exposed to the
weather shall be sealed, requiring no caulking at job
site. All components shall be easily accessible through
removable doors.
Insulation:
Models provided with a mixing box shall be
insulated from the return section through to the supply
discharge. Insulation shall be in accordance with NFPA
90A and tested to meet UL 181 erosion requirements.
Double wall shall be provided if specified.
Fan Section:
Centrifugal fans shall be double width,
double inlet. Fan and motor shall be mounted on a
common base and shall be internally isolated. All blower
wheels shall be statically and dynamically balanced.
Ground and polished steel fan shafts shall be mounted in
permanently lubricated ball bearings (up to size 118) or
ball bearing pillow blocks (size 120 and larger). Bearings
shall be selected for a minimum (L10) life in excess of
100,000 hours at maximum cataloged speeds.
Motors and Drives:
Motors shall be energy efficient,
complying with EPACT standards, for single speed
ODP and TE enclosures. Motors shall be permanently
lubricated, heavy duty type, matched to the fan load and
furnished at the specified voltage, phase and enclosure.
Drives shall be sized for a minimum of 150% of driven
horsepower. Pulleys shall be cast and have machined
surfaces, 10 horsepower and less shall be supplied with
an adjustable drive pulley.
Electrical:
All internal electrical
components shall be prewired for
single point power connection. All
electrical components shall be UL
listed, recognized or classified where
applicable and wired in compliance
with the National Electrical Code.
Control center shall include motor
starter, control circuit fusing, control
transformer for 24 VAC circuit,
integral disconnect switch with
separate motor fusing and terminal
strip. Contactors, Class 20 adjustable
overload protection and single phase
protection shall be standard.
Filter Section:
Filters shall be
mounted in a V-bank arrangement
such that velocities across the filters
do not exceed 550 feet per minute. Filters shall be easily
accessible through a removable access panel.
Weatherhood:
Weatherhood shall be mist eliminating
type, constructed of G90 galvanized steel. The
weatherhood shall contain drainable blade louvers, backed
by mist eliminating filters to prevent moisture intake.
Mixing Box:
Mixing box shall contain outside air and
return air dampers with low leak, pressure activated,
extruded vinyl blade seals, aluminum jamb seals, Belimo
actuator and 30% efficient pleated filters in a V-bank
arrangement. The mixing box shall modulate the amount
of outdoor and return air by use of dampers. Input signal
for return damper shall be from potentiometer, 2-10 volt
signal, 4-20 mA signal or manual quadrant controller.
Evaporative Cooling Section:
Evaporative cooling
section shall include a galvanized steel housing with
louvered intake, two inch aluminum mesh filters and a
stainless steel evaporative cooling module all provided
by the make-up air unit manufacturer. The louver shall
be stationary type with drainable blades, designed to
withstand wind loads of 25 PSF and bear the AMCA seal.
Evaporative cooling media shall be Munters CELdek with
a depth of 12 inches for a cooling effectiveness of 90%.
Drain and overflow connections shall be piped through the
side of the evaporative cooling section.
Cooling Coil:
Direct expansion (DX) or chilled water
coil shall be factory tested and rated in accordance with
ARI 410. Coils shall have copper tubes with permanently
expanded aluminum fins, 12 fpi or less. DX coils shall be
equipped with distributors to receive expansion valves at
the liquid connections. Drain pans shall extend at least
12 inches downstream of coil and be sloped to drain
connection.
Copyright © 2008 Greenheck Fan Corp. • IGX-HV Rev. 2 October 2008 SN
Specifications
