Easy Radiant Works ED-40U, Operating Instructions Manual

Page: 23 / 44

23
COMBUSTION AIR INTAKE VENTING REQUIREMENTS
This appliance can draw combustion air from indoors, or utilize the factory installed air
intake duct collar located on the blower assembly to duct combustion air in from outside.
CAUTION:
When the appliance is located in a building with a negative air condition, or
in a dusty or dirty atmosphere such as a welding shop, wood working shop, poultry barn
or foundry, it is mandatory to duct combustion air from outdoors or from an area free of
the negative pressure conditions / contaminated air.
Air intake duct must be a minimum of 4” (10 cm) in diameter, gas tight, and constructed
of a suitable rigid material that will be able to withstand general environmental
conditions.
Any 90 degree bends in the combustion air intake venting reduces the total allowable
combined intake/exhaust venting by 5’ (1.5 m)
The air intake duct must not be directly connected to the appliance.
It is mandatory
that a heavy duty metal flexible duct be installed between the appliance air intake duct
collar and the intake air ducting to allow for free expansion/contraction of the appliance.
(See accessory AC1220 – Air Intake Flex Duct/Cap Kit)
Combustion air intake may be drawn either horizontally or vertically, and must be
protected with a suitable screened cap to prevent pest/debris infiltration of the duct. Do
not use termination caps that utilize a damper or flapper system. (See accessory
AC1220 – Side wall air Intake Flex Duct/Cap Kit. Roof caps are field supplied.)
Air intake terminations shall not be located less than 3 ft (90 cm) above grade, and must
be adequately protected from potential blockages due to snow/ice/debris accumulation.
Ensure adequate clearance around the air intake to allow sufficient combustion air
supply to the heater. It is recommended that any single wall pipe containing cold air be
insulated to prevent or reduce nuisance condensation on the duct surface.
Appliances may not share common air intake ducting except in cases where those
appliances are jointly controlled.
In situation where indoor air is especially humid (e.g., carwash applications, food
processing, etc.) it is recommended that combustion air be drawn from an alternate
source. Ensure that all venting materials used are suitable to withstand high moisture
conditions (e.g., stainless steel, ABS, PVC, etc.).
WARNING
Never use a flexible duct as the only means of combustion air intake duct. Flexible
ducts are meant to be used as a flexible transition from the burner assembly to a
rigid duct only.
Plastic flexible duct and light duty residential “dryer vent” type ducts are not suitable
for this purpose.