Low Temp Industries CFM Installation Manual
Direct Gas-Fired Heating
Model DG
• 800 to 15,000 cfm • Up to 1,600,000 BTU/hr
Optional Evaporative Cooling
January
2005
2
PRODUCT FEATURES
Durable Construction
Designed for maximum weather resistance, DG
housings are constructed of heavy gauge G90
galvanized steel. Lifting lugs are standard.
Model DG
Direct Gas-Fired
Make-Up Air Unit
The Greenheck model DG is a 100%
efficient direct gas-fired make-up air unit.
Evaporative cooling is also available for
combination heating and cooling
requirements.
The DG is designed to provide make-up air to
commercial and industrial facilities with process
exhaust. Air flow volumes range from 800 to 15,000
cfm with heating capacities up to 1,600,000 BTU/hr.
Direct Gas-Fired System
Greenheck’s direct gas-fired make-up air units
feature:
• High quality cast aluminum
burners with stainless steel
mixing plates
• Maxitrol burner
modulation control
• Flame safeguard with
digital fault indicator
capability (over 400,000 BTU/Hr)
• 25:1 turn down ratio
Control Center
The control center
includes the following
standard components:
• Magnetic motor
starter with solid
state overload
protection
• Control transformer with fusing
• Integral door interlocking disconnect switch
• Distribution terminal strip
Premium grade control components are selected for
reliable operation. All electrical components are UL
Listed, recognized or classified and factory prewired
for single point power connection.
Vibration Isolators
The entire fan and motor assembly is
mounted on vibration isolators to minimize
noise transmission into the building.
Reliable Fan
Performance
Air performance ratings
from Greenheck’s
AMCA registered test
chamber ensure
accurate data.
Double width, double
inlet, forward curved wheels for high efficiency and
low sound levels are constructed of heavy gauge
steel. Wheels are statically and dynamically balanced
to ensure vibration free operation.
Access Panels
Large access panels are provided for easy
inspection and maintenance of motors, drives, fan
wheels, filters, and heater controls.
Factory
Wired and
Tested
All units are
tested prior to
shipment. Units
are checked for
proper operation
of the gas train,
electrical
components and
airflow.
Direct Gas-Fired
Heat
®
3
Stand Alone Arrangements
The model DG is available for stand alone installations with a downblast (Arrangement DB) or horizontal
(Arrangement HZ) discharge.
Downblast Discharge - Arrangement DB Horizontal Discharge - Arrangement HZ
Combination Package - Arrangement DBC
The combination curb extension is the
component that pulls the Combination
Package together, providing a factory
engineered interface between the roof curb
and the fans.
With a standard 12 inch roof curb, louvered
weatherhood, and Greenheck Model CUBE
exhaust fan, the combination curb extension
will ensure compliance to the above NFPA 96
requirements.
Note: Consult local codes and the authority having
jurisdiction if there are questions concerning the use of
this product.
Roof Curb
Combination Curb Extension
INSTALLATION
®
Combination Packages
The Greenheck combination package
simplifies installation and reduces field
labor costs. The pre-engineered
design ensures that the supply fan,
exhaust fan, curb, and combination
extension components interface
properly for kitchen ventilation
applications.
Equally important, Greenheck
combination packages are specifically designed to
comply with NFPA 96.
NFPA 96 states:
• Exhaust duct must terminate at least 24 inches
above the roof deck
• Fan discharge must be at least 40 inches
above the roof deck
• Air intake shall have a horizontal separation of
10 feet from the exhaust discharge