33
CL3
Series
3.0
Installation
•
Combustion Air Requirements
Combustion Air Requirements
Combustion air may be supplied to the heater by indoor or outdoor means. Follow these guidelines and
all applicable codes for all models prior to installing the combustion air duct work. Local codes may
vary. In the absence of local codes, refer and comply with the National Fuel Code ANSI Z223.1 (NFPA 54)
latest edition or the National Standards of Canada.
Note:
When installed in a CNG maintenance facility, CL3 series heaters
must
utilize outside air for
combustion.
This unit comes standard equipped for connection of supplied outdoor air for combustion. It is
designed for outside air to be brought into the appliance from combustion intake ducts, and is referred
to as a “separated combustion” appliance.
This heater must operate as a separated combustion system if any of the following criteria
apply:
• Chemicals such as chlorinated or fluorinated hydrocarbons (typical sources are refrigerants,
solvents, adhesives, degreasers, paints, paint removers, lubricants, pesticides, etc.) are present in
the atmosphere.
• High humidity.
• Contaminants such as sawdust, welding smoke, etc.
• Negative building pressure.
• Unusually tight construction where the air infiltration rate is less than 0.40 air changes per hour.
If your application does not meet any of these criteria, then room air may be used as supplying
combustion air to the heater. Refer to ‘Combustion Air Supply - Room Air’ on page 35 for details on how
to utilize room air for combustion.
Sufficient combustion air must be supplied to the appliance at all times.
Lack of combustion air may result in property damage, serious injury, or death.
WARNING
!
Roof
Roof Intake Cap
18 in.
minimum
6” pipe
Air Inlet Connection
(Flexible boot and band
clamps are recommended)
Air Inlet Connection
Burner
Control Box
Burner
Control Box
4” intake pipe
4” intake pipe
Figure 3.24
•
Vertical Outside Air Supply for Common Intake
- Side View
NOTE:
Common intake
heaters must share the
same thermostat.
