Water vapor is a by-product of gas combustion.
An unvented room heater produces approxi-
mately one (1) ounce (30 mL) of water for every
1,000 BTUs (0.3 KWs) of gas input per hour.
Unvented room heaters are recommended
as supplemental heat (a room) rather than a
primary heat source (an entire house). In most
supplemental heat applications, the water vapor
does not create a problem. In most applications,
the water vapor enhances the low humidity
atmosphere experienced during cold weather.
AIR FOR COMBUSTION AND VENTILATION
WARNING: This heater shall
not be installed in a confined
space or unusually tight construc-
tion unless provisions are provid-
ed for adequate combustion and
ventilation air. Read the following
instructions to insure proper fresh
air for this and other fuel-burning
appliances in your home.
Today's homes are built more energy efficient
than ever. New materials, increased insulation
and new construction methods help reduce
heat loss in homes. Home owners weather
strip and caulk around windows and doors
to keep the cold air out and the warm air in.
During heating months, home owners want
their homes as airtight as possible.
While it is good to make your home energy
efficient, your home needs to breathe. Fresh
air must enter your home. All fuel-burning ap-
pliances need fresh air for proper combustion
and ventilation.
Exhaust fans, fireplaces, clothes dryers and
fuel burning appliances draw air from the house
to operate. You must provide adequate fresh
air for these appliances. This will insure proper
venting of vented fuel-burning appliances.
8
WATER VAPOR: A BY-PRODUCT OF
UNVENTED ROOM HEATERS
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The following steps will help ensure that water
vapor does not become a problem.
1. Be sure the heater is sized properly for the
application, including ample combustion
air and circulation air.
2. If high humidity is experienced, a dehu-
midifier may be used to help lower the
water vapor content of the air.
3. Do not use an unvented room heater as
the primary heat source.
WARNING: This heater
shall not be installed in a room
or space unless the required
volume of indoor combustion
air is provided by the method
described in the National Fuel
Gas Code, ANSI Z223.1/NFPA
54, the International Fuel Gas
Code, or applicable local codes.
WARNING: If the area in which
the heater may be operated is
smaller than that defined as
an unconfined space or if the
building is of unusually tight
construction, provide adequate
combustion and ventilation air
by one of the methods described
in the National Fuel Gas Code,
ANSI Z223.1/NFPA 54, the In-
ternational Fuel Gas Code, or
applicable local codes.
200317-01E