Rheem 801T Series Installation Instructions Manual page 16

COMBUSTION AND VENTILATION AIR (cont .)
TABLE 9 : MINIMUM FREE AREA REQUIRED
FOR EACH OPENING (WHEN TWO OPENINGS
COMBUSTION AIR REQUIREMENTS: CONFINED AND
ARE USED) WITH A FURNACE:
UNCONFINED SPACES
1. LOCATED IN A CONFINED SPACE
2. USING OUTDOOR AIR FOR COMBUSTION
TABLE 9 : MINIMUM FREE AREA REQUIRED
3. COMMUNICATING DIRECTLY TO THE
TABLE 3: MINIMUM FREE AREA REQUIRED
FOR EACH OPENING (WHEN TWO OPENINGS
OUTSIDE THROUGH AN OPENING OR
FOR EACH OPENING (WHEN TWO OPENINGS
ARE USED) WITH A FURNACE:
THROUGH A VERTICAL VENT DUCT.*
ARE USED) WITH A FURNACE:
1. LOCATED IN A CONFINED SPACE
1. LOCATED IN A CONFINED SPACE
Free Area for
2. USING OUTDOOR AIR FOR COMBUSTION
2. USING OUTDOOR AIR FOR COMBUSTION
Total Input for Each Opening
TABLE 9 : MINIMUM FREE AREA REQUIRED
3. COMMUNICATING DIRECTLY TO THE ALL Gas when 2 Separate
3. COMMUNICATING DIRECTLY TO THE
FOR EACH OPENING (WHEN TWO OPENINGS
Appliances Openings are
3. OUTSIDE THROUGH AN OPENING OR
OUTSIDE THROUGH AN OPENING OR
(BTUH) used (sq inches)
ARE USED) WITH A FURNACE:
3. THROUGH A VERTICAL DUCT.
THROUGH A VERTICAL VENT DUCT.*
50,000
1. LOCATED IN A CONFINED SPACE
75,000
Free Area for
2. USING OUTDOOR AIR FOR COMBUSTION
100,000
Total Input for Each Opening
125,000
3. COMMUNICATING DIRECTLY TO THE
ALL Gas when 2 Separate
150,000
OUTSIDE THROUGH AN OPENING OR
Appliances Openings are
(BTUH) used (sq inches)
THROUGH A VERTICAL VENT DUCT.*
50,000
Free Area for
75,000
Total Input for Each Opening
100,000
ALL Gas when 2 Separate
125,000
Appliances Openings are
150,000
(BTUH) used (sq inches)
TABLE 1 0: MINIMUM FREE AREA REQUIRED
50,000
A . Where directly communicating with the outdoors through an
FOR EACH OPENING (WHEN TWO OPENINGS
75,000
opening or where communicating to the outdoors through
vertical ducts as shown in Figure 11, each opening shall
100,000
ARE USED) WITH A FURNACE:
have a minimum free area of 1 square inch for each 4,000
125,000
1. LOCATED IN A CONFINED SPACE
BTUH of total appliance input rating of all equipment in the
150,000
enclosure . Table 3 specifies the minimum area for
2. USING OUTDOOR AIR FOR COMBUSTION
each of the 2 combustion air openings and minimum round
TABLE 1 0: MINIMUM FREE AREA REQUIRED
duct diameter for direct openings and vertical ducting only . 3. COMMUNICATING DIRECTLY TO THE
B . Where communicating with the outdoors through hori-
FOR EACH OPENING (WHEN TWO OPENINGS
OUTSIDE THROUGH A H ORIZONTAL DUCT.
zontal ducts, each opening shall have a minimum free area
ARE USED) WITH A FURNACE:
Free Area for
of 1 square inch for each 2,000 BTUH of total appliance
input rating of all equipment in the enclosure (see Figure
Total Input for Each Opening
1. LOCATED IN A CONFINED SPACE
ALL Gas when 2 Separate
2. USING OUTDOOR AIR FOR COMBUSTION
Appliances Openings are
TABLE 4: MINIMUM FREE AREA REQUIRED
TABLE 1 0: MINIMUM FREE AREA REQUIRED
3. COMMUNICATING DIRECTLY TO THE
(BTUH) used (sq inches)
FOR EACH OPENING (WHEN TWO OPENINGS
FOR EACH OPENING (WHEN TWO OPENINGS
OUTSIDE THROUGH A H ORIZONTAL DUCT.
50,000
ARE USED) WITH A FURNACE:
ARE USED) WITH A FURNACE:
75,000
Free Area for
1. LOCATED IN A CONFINED SPACE
1. LOCATED IN A CONFINED SPACE
100,000
Each Opening
Total Input for
125,000
2. USING OUTDOOR AIR FOR COMBUSTION
2. USING OUTDOOR AIR FOR COMBUSTION
ALL Gas when 2 Separate
150,000
3. COMMUNICATING DIRECTLY TO THE Appliances Openings are
3. COMMUNICATING DIRECTLY TO THE
(BTUH)
used (sq inches)
3. OUTSIDE THROUGH A HORIZONTAL DUCT.
OUTSIDE THROUGH A H ORIZONTAL DUCT.
50,000
Free Area for
75,000
Total Input for Each Opening
100,000
ALL Gas when 2 Separate
125,000
Appliances 150,000 Openings are
(BTUH) used (sq inches)
50,000
75,000
100,000
125,000
150,000
16
Round Pipe Duct
Diameter ( Ver cal
Duct Only) (inches)
13 5
19 5
25 6
32 8
Round Pipe Duct
38 8
Diameter ( Ver cal
Duct Only) (inches)
13 5
19 5
25 6
Round Pipe Duct
32 8
Diameter ( Ver cal
38 8
Duct Only) (inches)
13 5
19 5
25 6
32 8
38 8
Round Pipe Duct
Diameter
(Horizontal Duct
Only) (inches)
25 6
38 8
50 8
Round Pipe Duct
63 10
Diameter
75 10
(Horizontal Duct
Only) (inches)
25 6
38 8
Round Pipe Duct
50 8
Diameter
63 10
75 (Horizontal Duct 10
Only) (inches)
25 6
38 8
50 8
63 10
75 10
TABLE 5: MINIMUM FREE AREA REQUIRED
TABLE 1 1: MINIMUM FREE AREA REQUIRED
FOR AN OPENING (WHEN ONE OPENING IS
FOR AN OPENING (WHEN O N E OPENING IS
USED) WITH A FURNACE:
USED) WITH A FURNACE:
1. LOCATED IN A CONFINED SPACE
1. LOCATED IN A CONFINED SPACE
2. USING OUTDOOR AIR FOR COMBUSTION
2. USING OUTDOOR AIR FOR COMBUSTION
3. COMMUNICATING DIRECTLY TO THE
TABLE 1 1: MINIMUM FREE AREA REQUIRED
3. COMMUNICATING DIRECTLY TO THE
3. OUTSIDE.
FOR AN OPENING (WHEN O N E OPENING IS OUTSIDE. *
USED) WITH A FURNACE:
Total Input for Free Area for an
1. LOCATED IN A CONFINED SPACE
ALL Gas Opening when 1
2. USING OUTDOOR AIR FOR COMBUSTION
Appliances Opening is used
TABLE 1 1: MINIMUM FREE AREA REQUIRED
3. COMMUNICATING DIRECTLY TO THE
(BTUH) (sq inches)
FOR AN OPENING (WHEN O N E OPENING IS
50,000
OUTSIDE. *
USED) WITH A FURNACE:
75,000
100,000
1. LOCATED IN A CONFINED SPACE Total Input for Free Area for an
125,000
ALL Gas Opening when 1
2. USING OUTDOOR AIR FOR COMBUSTION
150,000
Appliances Opening is used
3. COMMUNICATING DIRECTLY TO THE
(BTUH) (sq inches)
12) . Table 4 specifies the minimum area for each of the 2
OUTSIDE. *
combustion air openings and minimum round duct diameter 50,000 25
for horizontal ducting only .
75,000 38
Total Input for Free Area for an
100,000 50
METHOD 2:
ALL Gas Opening when 1
One permanent opening located within 12 inches of the top 125,000 63
of the enclosure, shall be permitted where the equipment
Appliances Opening is used
150,000 75
has clearances of at least 1 inch from the sides and back
(BTUH) (sq inches)
and 6 inches from the front of the appliance . The opening
50,000 25
shall directly communicate with the outdoors or communi-
cate through a vertical or horizontal duct to the outdoors or 75,000 38
spaces (crawl or attic) that freely communicate with the out-
100,000 50
doors, and shall have a minimum of:
125,000 63
150,000 75
FIGURE 10
NON-DIRECT VENT
AIR FROM
HEATED
SPACE
Round Pipe Duct
Diameter (inches)
25 6
38 8
50 8
63 10
75 10
Round Pipe Duct
Diameter (inches)
6
8
8
10
Round Pipe Duct
10
Diameter (inches)
6
8
8
10
10
VENT PENETRATIONS
for non direct vent furnaces
air from heated space
ST-A1227-01