Installation manual

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123502-01E8
AIR FOR COMBUSTION AND VENTILATION
Continued
The space in the previous example is a conned
space because the actual Btu/Hr used is more
than the maximum Btu/Hr the space can sup-
port. You must provide additional fresh air. Your
options are as follows:
A. Rework worksheet, adding the space of an
adjoining room. If the extra space provides
an unconned space, remove door to adjoin-
ing room or add ventilation grills between
rooms. See Ventilation Air From Inside
Building.
B. Vent room directly to the outdoors. See
Ventilation Air From Outdoors.
C. Install a lower Btu/Hr replace, if lower Btu/
Hr size makes room unconned.
If the actual Btu/Hr used is less than the maxi-
mum Btu/Hr the space can support, the space is
an unconned space. You will need no additional
fresh air ventilation.
WARNING: If the area in which
the heater may be operated does
not meet the required volume for
indoor combustion air, combus-
tion and ventilation air shall be
provided by one of the methods
described in the National Fuel
Gas Code, ANSI Z223.1/NFPA 54,
the International Fuel Gas Code,



This fresh air would come from an adjoining
unconned space. When ventilating to an
adjoining unconned space, you must provide
two permanent openings: one within 12" of the
ceiling and one within 12" of the oor on the
wall connecting the two spaces (see options
1 and 2, Figure 4). You can also remove door
into adjoining room (see option 3, Figure 4).
Follow the National Fuel Gas Code, ANSI
Z223.1/NFPA 54, Air for Combustion and
Ventilation for required size of ventilation
grills or ducts.

Provide extra fresh air by using ventilation
grills or ducts. You must provide two perma-
nent openings: one within 12" of the ceiling
and one within 12" of the oor. Connect these
items directly to the outdoors or spaces open
to the outdoors. These spaces include attics
and crawl spaces. Follow the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, Air for
Combustion and Ventilation for required size
of ventilation grills or ducts.
IMPORTANT: Do not provide openings for
inlet or outlet air into attic if attic has a thermo-
stat-controlled power vent. Heated air entering
the attic will activate the power vent.
Figure 5 - Ventilation Air from Outdoors
Outlet
Air
V e ntilated
Attic
Outlet
A
ir
Inlet
Air
Inlet Air
V e ntilated
Crawl Space
T o
Crawl
Space
T o Attic
Figure 4 - Ventilation Air from Inside
Building
Or
Remove
Door into
Adjoining
Room,
Option
3
V e ntilation Grills
Into Adjoining Room,
Option 2
V e ntilation
Grills Into
Adjoining
Room,
Option 1
12"
12"