Local Codes - Desa HDFB32CA Safety Information And Installation Manual

AIR FOR COMBUSTION
AND VENTILATION
Continued
The space in the previous example is a confined
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 unconfined space, remove door to adjoin-
ing room or add ventilation grills between
rooms. See Ventilation Air From Inside
Building below.
B. Vent room directly to the outdoors. See
Ventilation Air From Outdoors below.
C. Install a lower Btu/Hr heater, if lower
Btu/Hr size makes room unconfined.
If the actual Btu/Hr used is less than the
maximum Btu/Hr the space can support, the
space is an unconfined space. You will need
no additional fresh air ventilation.
WARNING: If the area in
which the firebox and gas log
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 Section 5.3
or applicable local codes.
veNtIlAtIoN AIR
Ventilation air from inside Building
This fresh air would come from an adjoin-
ing unconfined space. When ventilating to
an adjoining unconfined space, you must
provide two permanent openings: one within
1" of the ceiling and one within 1" of the
floor on the wall connecting the two spaces
(see options 1 and , 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, Section 5.3, Air
for Combustion and Ventilation for required
size of ventilation grills or ducts.
6
Ventilation
Grills
Into Adjoining
Room,
Option 1
Figure 4 - Ventilation Air from Inside
ventilation Air From outdoors
Provide extra fresh air by using ventilation
grills or ducts. You must provide two perma-
nent openings: one within 1" 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, Section 5.3,
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.
Outlet
A ir
Inlet
Air
Figure 5 - Ventilation Air from Outdoors
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12"
Ventilation Grills
Into Adjoining Room,
Or
Option 2
Remove
Door into
Adjoining
Room,
Option
3
12"
Building
Ventilated
Outlet
Attic
Air
Ventilated
Inlet Air
Crawl Space
To Attic
To
Crawl
Space
116533-01D