TriangleTube 399 Solo - Manual (Page 13)

7
Combustion Air Venting
Methods of Accessing Combustion Air Into A
Space - Category IV
Indoor Combustion Air
The methods listed in this section for
accessing Indoor Combustion Air
assume that the infiltration rate is ade-
quate and not less than .40 ACH. For
infiltration rates less than .40 ACH, ref-
erence the NFPA 54 National Fuel Gas
Code for additional guidance.
Opening Size and Location
Openings used to connect indoor spaces shall
be sized and located in accordance with the
following see Fig. 1:
- Combining spaces on the same story.
Each opening shall have a minimum
free area of 1 sq. in./1000 Btu/hr of the
total input rating of all gas utilization
equipment in the space, but not less than
100 sq. inches. One opening shall com-
mence within 12 inches of the top, and
one opening shall commence within 12
inches of the bottom of the enclosure.
The minimum dimension of air open-
ings shall be not less than 3 inches.
- Combining spaces in different stories.
The volumes of spaces in different sto-
ries shall be considered as communicat-
ing spaces where such spaces are con-
nected by one or more openings in
doors or floors having a total minimum
free area of 2 sq. in./1000 Btu/hr of
total input rating of all gas utilization
equipment.
Outdoor Combustion Air
Isolating the combustion appliance room
from the rest of the building and bring-
ing in uncontaminated outside air for
combustion and ventilation is always
preferred.
Opening Size and Location
The minimum dimension of air openings shall
be not less than 3 inches
Openings used to supply combustion and ven-
tilation air shall be sized and located in accor-
dance with the following:
One Permanent Opening Method. See Fig. 2
One permanent opening, commencing within 12
in. of the top of the enclosure, shall be provided.
The equipment shall have clearances of at least 1
inch from the sides and 6 in. from the front of the
appliance. The opening shall directly communi-
cate with the outdoors or shall communicate
through a vertical or horizontal duct to the out-
doors or spaces that freely communicate with the
outdoors and shall have a minimum free area of
the following:
- 1sq. in./3000 Btu/hr of the total input
rating of all equipment located in the
enclosures, and
NOTICE
BEST PRACTICE
All Combustion Air from Adjacent
Indoor Spaces Through Indoor
Combustion Openings Fig. 1: