Combustion Air And Ventilation For Appliances In Confined Spaces - Maytag HN41240P User Manual

Instructions for Installation (cont'd)
Combustion Air and Ventilation
1. W hen directly communicating with t he outdoors, each
for
opening shall have a minimum free area of 1 square inch
Located
in
per 4,000 BTU per hour of total input rating of all equip
Confined
Spaces(cont'd)
merit in the enclosure. (See Figure 7.)
Confined Space is a space whose volume is less than 50 cubic 2. When communicating with the outdoors through vertical
feet per 1,000 Btu per hour of the aggregate input rating of all ducts, each opening shall have a minimum free area of 1
appliances installed in that space, square inch per 4,000 BTU per hour of total input rating of
a. ALL AIR FROM INSIDE BUILDINGS: all equipment in the enclosure. (See Figure 8.)
(See Page 11 Figure 1, and Figure 6 below)
(each
endofattic)
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
, VENT TO
of all spaces meets the criteria for an unconfined space.
The total input of all gas utilization equipment installed in
the combined space shall be considered in making this
r 3
determination. Each
opening shall have a minimum free [ Figure 8 ]
area of one square inch per 1,000 BTU per hour of the
total input rating of all gas utilization equipment in the 3. When communicating with the outdoors through horizon-
confined space, but not less than 100 square inches. One tal ducts, each opening shall have a minimum free area of 1
opening shall commence within 12 inches of the top and square inch per 2,000 BTU per hour of total input rating of
one commencing within 12 inches of the bottom of the all equipment in the enclosure. (See Figure 9.)
enclosure.
_ ROOF
VENT THROUGH j
_ ROOF
m
i 1 o oooRs I I
OPENINGS WATER
Figure
9
- HEATER
[igu,e ] "H
4. When ducts are used, they shall be of the same cross-sec-
tional area as the free area of the openings to which they
connect. The minimum short side dimension of rectangular
b. ALL AIR FROM OUTDOORS: (see Figures 7-9)
air ducts shall not be less than 3 inches. (See Figure 9.)
The confined space shall be provided with two permanent 5. Louvers and Grilles: In calculating free area, consideration
openings, one commencing within 12 inches of the top shall be given to the blocking effect of louvers, grilles or
and one commencing within 12 inches from the bottom of screens protecting openings. Screens used shall not be
the enclosure. The openings shall communicate directly, or smaller than 1/4inch mesh. If the free area through a design
by ducts, with the outdoors or spaces (crawl or attic) that
of louver or grille is known, it should be used in calculating
freely communicate with the outdoors, the size opening required to provide the free area specified.
If the design and free area is not known, it maybe assumed
(each endofattic)
that wood louvers will be 20-25 percent free area and metal
louvers and grilles will have 60-75 percent free area.
Louvers and grilles shall be fixed in the open position or
interlocked with the equipment so that they are opened
automatically during equipment operation.
6. Special Conditions Created by Mechanical Exhausting or
Fireplaces: Operation of exhaust fans, ventilation systems,
E
clothes dryers or fireplaces may create conditions requiring
Figure I special attention to avoid unsatisfactory operation of
7
VENTiLATiON LOUVERS installed gas utilization equipment.
13