Instruction manual

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methods described in 5.3.3-b or 5.3.4.
Space, Unconfined.
For purposes of this Code, a space whose volume is not less than 50
cubic feet per 1,000 BTU per hour of the aggregate input rating of
all appliances installed in that space. Rooms communicating di-
rectly with the space in which the appliances are installed through
openings not furnished with doors, are considered a part of the
unconfined space.
5.3.3 Equipment Located in Confined Spaces:
(a) All Air from Inside the Building: The confined space shall be
provided with two permanent openings communicating directly
with an additional room(s) of sufficient volume so that the
combined volume of all spaces meets the criteria for an uncon-
fined space. The total input of all gas utilization equipment
installed in the combined space shall be considered in making
this determination. Each opening shall have a minimum free
area of 1 square inch per 1,000 BTU per hour of the total input
rating of all gas utilization equipment in the confined space, but
not less than 100 square inches. One opening shall be within 12
inches of the top and one within 12 inches of the bottom of the
enclosure.
Equipment Located in Confined Spaces; All
Air from Inside Building. See 5.3.3-a.
(b) All Air from Outdoors: The confined space shall be provided
with two permanent openings, one commencing within 12
inches of the top and one commencing within 12 inches of the
bottom of the enclosure. The openings shall communicate
directly, or by ducts, with the outdoors or spaces (crawl or attic)
that freely communicate with the outdoors.
1. When directly communicating with the outdoors, each open-
ing shall have a minimum free area of 1 square inch per
4,000 BTU per hour of total input rating of all equipment in
the enclosure.
Equipment Located in Confined Spaces; All
Air from Outdoors—Inlet Air from Ventilated
Crawl Space and Outlet Air to Ventilated
Attic. See 5.3.3-b
2. When communicating with the outdoors through vertical
ducts, each opening shall have a minimum free area of 1
square inch per 4,000 BTU per hour of total input rating of
all equipment in the enclosure.
Equipment Located in Confined Spaces; All
Air from Outdoors Through Ventilated Attic.
See 5.3.3-b.
3. When communicating with the outdoors through horizontal
ducts, each opening shall have a minimum free area of 1
square inch per 2,000 BTU per hour of total input rating of
all equipment in the enclosure.