Kenmore POWER MISER 153.336261 User Manual
Page 11
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Combustion Air and Ventilation for
Appliances Located in Confined Spaces
CONFINED SPACE
is
a
space
whose
volume
is less
than
50 cubic feet per 1,000 Btu per hour (4.8 m® per kW) of the
aggregate input rating of all appliances installed in that space.
A ALL AIR FROM INSIDE BUILDINGS:
(See Figure 9 on page 9 and Figure 10 below)
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 unconfined 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 one square inch
per 1,000 Btu per hour (22 cm^/kW) of the total input rating of all
gas utilization equipment in the confined space, but not less
than
100
square
inches
(645
cm^).
One
opening
shall
commence within 12 inches (30 cm) of the top and one
commencing within 12 inches (30 cm) of the bottom of the
enclosures.
FIGURE 10.
B. ALL AIR FROM OUTDOORS:
(See Figures 9, 11,12 and 13)
The confined space shall be provided with two permanent
openings, one commencing within 12 inches (30 cm) of the
top and one commencing within 12 inches (30 cm) from 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.
When directly communicating with the outdoors, each opening
shall have a minimum free area of 1 square inch per 4,CKX) Btu
per hour (5.5 cm7kW) of total input rating of all equipment in the
enclosure, see Figure 12.
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 (5.5 cm%W) of total
input
rating
of
all
equipment
in
the
enclosure,
see
Figure 12.
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 (11 cm7kW) of total
input
rating
of
all
equipment
in
the
enclosure,
see
Figure 13.
When ducts are used, they shall be of the same cross
sectional area as the free area of the openings to which
they
connect.
The
minimum
short
side
dimension
of
rectangular air ducts shall not be less than 3 inches
(76.2 mm), see Figure 13.
RGURE11.
Louvers and Grilles: in calculating free area, consideration
shall be given to the blocking effect of louvers, grilles or
screens
protecting
openings.
Screens
used
shall
not
be
smallerthan 1/4 inch (6.4mm)mesh. If the free area through
a design of louver or grille is known, it should be used in
calculating the size opening required to provide the free
area specified. If the design and free area is not known, it
may be assumed 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.
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