Loading ...
Loading ...
Loading ...
2, Onepermanentopeningcommencingwith 12
inches of the top of the enclosure, shall be
permitted where the equipment has clearance
of at least 1 inch from the sides and back and
6 inches form the front of the appliance. The
opening shell directly communicate with the
outdoorsor shallcommunicate through avertical
or horizontal duct to the outdoors or spaces
(crawl or attic) that freely communicate with
the outdoors, and shall have a minimum free
area of:
a) 1 sq. inch per3000 Btu per hour ofthe total
inputofallequipment locatedinthe enclosure
(See Fig. 4), and the front of the appliance
b) Not less than the sum of the areas of all
vent connectors in the confined space.
1 Square Inch
100% Free
Area
Fresh Air 1/4, Wire
Duct Size Mesh
3" x 12" 72,000
8" x 8" 128 000
8"x 12" 192,000
81/2"x 16" 256,000
)er 2,000 Btuh
75% Free 25% Free
Area Area
Metal Wood
Louvers Louvers
54,000 18,000
96,000 32,000
144,000 48,000
192,000 64,000
1 Square Inch )er 4,000 Btuh
100% Free 75% Free 25% Free
Area Area Area
Fresh Air 1/4" Wire Metal Wood
Duct Size Mesh Louvers Louvers
3"x 12" 144,000 108,000 36,000
8" x 8" 256,000 192,000 64,000
8" x 12" 384,000 288 000 96,000
81/2" x 16" 512,000 384,000 128,000
1 Square Inch
100% Free
Area
Fresh Air 1/4" Wire
Duct Size Mesh
3" x 12" 108,000
8" x 8" 192,000
8" x 12" 288,000
81/2"x 16" 384,000
oer 3,000 Btuh
75% Free 25% Free
Area Area
Metal Wood
Louvers Louvers
81,000 27,000
144,000 48,000
216,000 72,000
288,000 96,000
8
Loading ...
Loading ...
Loading ...