Rheem 96v series Installation Instructions Manual page 53

GENERAL VENTING REQUIREMENTS AND
NON-DIRECT VENT (cont.)
B. USING OUTDOOR AIR FOR COMBUSTION:
IMPORTANT: Do not take air from an attic space that is
equipped with power ventilation.
The confined space must communicate with the outdoors in
accordance with Methods 1 or 2 below. The minimum dimen-
sion of air openings shall not be less than 3 inches. Where
ducts are used, they shall be of the same cross-sectional
area as the free area of the openings to which they connect.
METHOD 1:
Two permanent openings, one located within 12 inches of the
top and one located within 12 inches of the bottom of the
enclosure, shall be provided. The openings shall communicate
directly, or by ducts, with the outdoors or spaces (crawl or
attic) that freely communicate with the outdoors.
 #%   $
TABLE 9: MINIMUM FREE AREA REQUIRED
$  
FOR EACH OPENING (WHEN TWO OPENINGS
 ' ) $  %
ARE USED) WITH A FURNACE:
    $
1. LOCATED IN A CONFINED SPACE
    $  
2. USING OUTDOOR AIR FOR COMBUSTION
3. COMMUNICATING DIRECTLY TO THE   
3. OUTSIDE THROUGH AN OPENING OR
    
3. THROUGH A VERTICAL DUCT.
   
$433 431 G;4
;216 <:B2 G;4 189 :3<5<=
17 H93< 3:14123
::651<837 :3<5<=7 143
&  ' B73D &7A 5<8937'
9. :::
%@ :::
>: :::
?9 :::
=? :::
//. :::
 (%   $
TABLE 10: MINIMUM FREE AREA REQUIRED
$  
FOR EACH OPENING (WHEN TWO OPENINGS
 ' ) $  %
ARE USED) WITH A FURNACE:
    $
1. LOCATED IN A CONFINED SPACE
    $  
2. USING OUTDOOR AIR FOR COMBUSTION
3. COMMUNICATING DIRECTLY TO THE   
3.    OUTSIDE THROUGH A HORIZONTAL DUCT.   
$433 431 G;4
;216 <:B2 G;4 189 :3<5<=
17 H93< 3:14123
::651<837 :3<5<=7 143
&  ' B73D &7A 5<8937'
9. :::
%@ :::
>: :::
?9 :::
=? :::
//. :::
 
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;B<D 5:3 B82
51>3234 & 3425816
B82 <6@' &5<8937'
/: 9
/% %
.: %
.% %
.% %
&: @

 
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  " 
 
;B<D 5:3 B82
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& ;45E;<216 B82
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9. ?
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GUIDELINES
A. Where directly communicating with the outdoors through
an opening or where communicating to the outdoors through
vertical ducts as shown in Figure 14, each opening shall have
a minimum free area of 1 square inch for each 4,000 BTUH of
total appliance input rating of all equipment in the enclosure.
Table 9 below specifies the minimum area for
the 2 combustion air openings and minimum round duct diam-
eter for direct openings and vertical ducting only.
B. Where communicating with the outdoors through horizontal
ducts, each opening shall have a minimum free area of 1
square inch for each 2,000 BTUH of total appliance input rat-
ing of all equipment in the enclosure (see Figure 15). Table
10 specifies the minimum area for each of the 2 combustion
air openings and minimum round duct diameter for horizontal
ducting only.
METHOD 2:
One permanent opening located within 12 inches of the top
 %   $
TABLE 11: MINIMUM FREE AREA REQUIRED
$  &)
FOR AN OPENING (WHEN ONE OPENING IS
 ' ) $  %
USED) WITH A FURNACE:
    $
1. LOCATED IN A CONFINED SPACE
    $  
2. USING OUTDOOR AIR FOR COMBUSTION
  
3. COMMUNICATING DIRECTLY TO THE
   
3. OUTSIDE.
;216 <:B2 G;4 $433 431 G;4 1<
17 :3<5<= H93<
::651<837 :3<5<= 57 B73D
&  ' &7A 5<8937'
9. ::: ./
%@ ::: .?
>: ::: &%
?9 ::: 9.
=? ::: 9=
//. ::: %@
FIGURE 13
NON-DIRECT VENT
AIR FROM
HEATED
SPACE
each of
 
  
  
  " 
;B<D 5:3 B82
51>3234 &5<8937'
@
@
>
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=
ST-A1194-19
FIG C
53