AIR FOR COMBUSTION AND VENTILATION
Ventilation Air From Inside Building
This fresh air would come from an adjoining
unconfined space. When ventilating to an
adjoining unconfined space, you must provide
two permanent openings: one within 12" of the
ceiling and one within 12" of the floor on the
wall connecting the two spaces (see options
1 and 2, Figure 2). You can also remove door
into adjoining room (see option 3, Figure 2).
Follow the National Fuel Gas Code, ANSI
Z223.1/NFPA 54, Air for Combustion and
Ventilation for required size of ventilation
grills or ducts.
Ventilation
Grills
Or
into Adjoining
Remove
Room,
Door into
Option 1
Adjoining
Room,
Option 3
Figure 2 - Ventilation Air from Inside
Building
8
VENTILATION AIR
12"
Ventilation Grills
Into Adjoining Room,
Option 2
12"
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Ventilation Air From Outdoors
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 floor. 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
thermostat-controlled power vent. Heated air
entering the attic will activate the power vent.
Rework worksheet, adding the space of the
adjoining unconfined space. The combined
spaces must have enough fresh air to supply
all appliances in both spaces.
Outlet
Air
Outlet
Air
Inlet
Air
Inlet Air
Figure 3 - Ventilation Air from Outdoors
Ventilated
Attic
To Attic
To
Crawl
Space
Ventilated
Crawl Space
200299-01A