Page 28
Modulating Unitary Range
VA-LT206_11292016al
VENTING AND COMBUSTION AIR DUCTING
Figure 28: Installation of Outside Air as Supply for Combustion
Combustion Air Supply (Optional)
•
An outside combustion air supply is strongly recommended if the building space encloses a negative
pressure due to exhaust etc. or if the building contains materials which would expose the heater to
halogenated hydrocarbon atmospheres.
•
The outside air terminal must be of an approved type, and should be located at an elevation equal to or
below the vent terminal elevation to prevent back-venting of flue gases into the burner compartment.
•
Install single wall pipe or PVC pipe and fittings with a 12-inch linear section of flexible duct to allow
movement of the heater. Do not use flexible duct throughout the entire length of fresh air duct. This
may cause nuisance air switch tripping.
TO OUTSIDE AIR:
DIRECTLY TO OUTSIDE
OR TO COMMON
DUCTWORK
FROM BLOWER
MUST BE FLEXIBLE DUCT
NOTE:
DO NOT USE FLEX DUCT TO FORM AN ELBOW!
12"
MAX.
FOR ALL FLEX
DUCT
AIR FLOW DIRECTION
NOTE:
CLOSE ALL CHAIN LINKS, QUICK LINKS AND ANY OPEN CONNECTIONS
