Bard Bayrd Furnace 403293A - Manual (Page 12)

WARNINO: Combustion and vsntllatlon air that contains
chlorine, fluorine, bromine and Iodine could cause heat
exchanger or vent system failure, resulting In damage,
Injury or death,
WARNINO: When installing a furnace In an attic or other
insulated space, keep furnace free and clear of all lnsu>
lating materials. Make surs all Insulation Is at least 12"
away from burner combustion air openings and well away
from openings into furnace space that supply air for
combustion and ventilation. Failure to do this could causa
nausea, asphyxiation or fire, resulting In damage, injury
or death.
WARNINGS When Installing furnace in an alcove, attic,
basement, closet, garage, or utility room do not store
items in front of furnace or In front of closet or utility
door which would block combustion air openings to fur*
nace. Failure to do this could cause nausea, asphyxia­
tion or fire, resulting In damags, Injury or death.
DO NOT install furnace where any combustion or ventilation
air openings will allow outside air to blow directly against
furnace.
WARNINGS Drafts blowing directly against furnace could
cause improper combustion which could cause heat ex­
changer failure or fire, resulting In damage, Injury or
death.
Sufficient air MUST be provided to insure there wilt not be a
negative pressure in furnace room or space. In addition, there
MUST be a positive seal between furnace and return air duct
to avoid pulling air from burner area.
Provide adequate combustion and ventilation air by consider'
ing volume of furnace installation space. Use these instruc­
tions and current National Fuel Gas Code ANSI Z223.1/NFPA
54 to determine whether furnace is in an unoonfined or con­
fined space.
A. Determining If your space Is confined or unconflned.
Two factors determine whether a furnace installation
space is confined or unconfined:
— Volume of installation space;
—
Total gas input of appliances to be installed in that
space.
To determine which your space is:
1. First calculate furnace installation space volume in
cubic feet.
2. Determine combined input rating (BTUH) of all gas
appliances in furnace installation space, including
furnace input. This is the total combined input rating.
3. Divide total combined input rating by 1,000. Then
divide this number into installation space volume.
Here's the formula:
If ratio is less than 50, installation space is a con­
fined space. If ratio is 50 or greater, installation space
is an unconfined space.
B. Installing furnace In confined space.
WARNING: You must provide permanent air open­
ings to a conflned furnace installation space from
another area as described below. Failure to do ao
could result In Inadéquat# combustion and vsntllatlon
air. Thsae could cause nausea, asphyxiation or fire,
resulting In damage, injury or death.
1. Combustion and ventilation air openings.
a. All combustion and ventilation air from inside the
structure.
1. The furnace space must be provided with
two permanent openings to an additional
room(s) of sufficient volume so that the
combined volume of all spaces meet the cri­
teria above for an unconfined space.
The total input of all gas appliances within
the combined space must be considered in
making this determination. See Figure 12.
2. a. Each opening must have minimum free
area of one square Inch per 1,000 Btuh
per hour of the total combined input rat­
ing of all gas appliances within the con­
fined furnace space, but not less than
100 square inches. One opening must
be within 12 inches of the top and an­
other opening within 12 inches of the
bottom of the furnace space. See Fig­
ure 12.
Space Volume
Total lnput/1,000
Ratio
10