31
Ve
ntin
g
of the enclosure, shall be permitted where the equipment
has clearances of at least 1 inch from the sides and back
and 6 inches from the front of the appliance. The opening
shall directly communicate with the outdoors or communi-
cate through a vertical or horizontal duct to the outdoors or
spaces (crawl or attic) that freely communicate with the out-
doors, and shall have a minimum of:
A. 1 Square inch for each 3,000 BTUH of the total input rat-
ing of all equipment located in the enclosure
and
NON-DIRECT VENT (cont.)
GENERAL VENTING REQUIREMENTS AND
GUIDELINES
O
P
T
IO
N
A
L
IN
LE
T
A
IR
1
S
Q
. I
N
.
(6
.5
S
Q
. C
M
.)
P
ER
4
0
0
0
B
T
U
H
ST-A1194-19
FIG D
ST-A1194-82-00
OUTLET AIR 1 SQ. IN.
(6.5 SQ. CM.) PER 2000 BTUH
INLET AIR 1 SQ. IN.
(6.5 SQ. CM.) PER 2000 BTUH
ST-A1194-19
FIG E
FIGURE 14
COMBUSTION AIR FITTING
FIGURE 12
NON-DIRECT VENT AIR FROM
ATTIC OR CRAWL SPACE
FIGURE 13
NON-DIRECT VENT
OUTSIDE AIR USING A
HORIZONTAL DUCT