29
Non-contaminated outside air for combustion must be ducted to the heater if any of the following apply:
• Chemicals such as chlorinated or fluorinated hydrocarbons (typical sources are refrigerants, solvents,
adhesives, degreasers, paints, paint removers, lubricants, pesticides, etc.).
• High humidity.
• Contaminants such as sawdust, welding smoke, etc.
• Negative building pressure.
• Unusually tight construction where there is an air infiltration rate of less the 0.40 air changes per hour.
3.0
Installation
• Combustion Air Requirements
Figure 3.27
Vertical Outside Air Supply for
Single Heater Intake
•
Side View
Figure 3.28
Horizontal Outside Air Supply
for Single Heater Intake
•
Side View
Figure 3.29
Vertical Outside Air Supply
for Common Intake
•
Side View
Roof Intake Cap
Roof
18 in.
minimum
Wall
Air Intake Cap
Roof
Burner
Control Box
Air Inlet Connection
4” pipe
4” pipe
Roof Intake Cap
18 in.
minimum
6” pipe
NOTE:
Common
intake heaters must
share the same
thermostat.
Combustion air intake may be located on either the sidewall or roof (see figure 3.27 - 3.29).
Burner
Control Box
(Flexible boot and band
clamps are recommended)
Air Inlet Connection
(Flexible boot and band
clamps are recommended)
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
