Combustion & Ventilation Air - Williams 2001622A Owner's Manual

Installing Your Heater
FIGURE 3
IMPORTANT: All piping must comply with local codes and ordinances or with the National Fuel Gas Code (ANSI Z223.1 NFPA No. 54),
whichever applies. (In Canada: CAN/CGA B149).
FIGURE 4 Enclosed Model
Combustion & Ventilation Air
WARNING: Danger of property damage, bodily
injury or loss of life. The furnace and any other fuel-
burning appliances must be provided with enough
fresh air for proper combustion and ventilation of
flue gases. Most homes will require that outside air
be supplied into the heated area.
The high cost of energy for home heating has brought about new
materials and methods used to construct or remodel most current
homes. The improved construction and additional insulation has
reduced the heat loss and made these homes much tighter
around windows and doors so that infiltrated air is minimal. This
creates a problem to supply combustion and ventilation air for
gas-fired or other fuel burning appliances. Any use of appliances
that pull air out of the house (clothes dryers, exhaust fans,
fireplaces, etc.) increases this problem and appliances could be
starving for air.
In addition, these energy measures mean that your home will
retain more water vapor or a higher relative humidity.
8
Proper Piping Practice
FIGURE 5 Gas Pipe Sizes
PIPE CAPACITY - Btu/hr.
PIPE CAPACITY - Btu/hr.
High humidity, especially during cold weather, may be damaging
to buildings because condensation forms on windows and inside
walls.
The combination of a tight energy efficient home with the use of
exhaust fans, fireplaces, clothes dryers, and gas appliances result
in more and more air being drawn from the house until fresh air
may be sucked back into the house down a furnace flue or
fireplace chimney. Carbon monoxide can be the result. Carbon
monoxide (CO) is a colorless, odorless gas produced when fuel is
not burned completely or when the flame does not receive
sufficient oxygen. Automobiles, charcoal, wood fires and
improperly vented or air-starved coal, oil and gas furnaces or
other appliances can produce carbon monoxide.
Be aware of these air-starvation signals:
1. Headaches, nausea, dizziness.
2. Excessive humidity shown by heavily frosted windows or a
moist "clammy" sensation.
3. Fireplace smoke fills the room or will not draw.
4. Furnace flue backs up.