13
COMBUSTION--AIR AND VENT PIPING FOR DIRECT VENT/2--PIPE (ALL SIZES) AND
NON--DIRECT VENT/1--PIPE (SIZES 040 THROUGH 120 ONLY) APPLICATIONS
ALTITUDE
FT (M)
UNIT SIZE
(BTUH)
DIRECT VENT (2-PIPE) ONLY
NON-DIRECT
VENT (1-PIPE)
ONLY
NUMBER OF 90
°
ELBOWS
TERMINATION
TYPE
PIPE DIA
IN. (mm)*
PIPE DIA
IN. (mm)*
1
2
3
4
5
6
0 to 2000
(0 to 610)
40,000
2 Pipe or 2-in
Concentric
1 (25)
1 (25)
5
(1.5)
NA
NA
NA
NA
NA
1-1/2 (38)
1-1/2 (38)
70
(21.3)
70
(21.3)
65
(19.8)
60
(18.3)
60
(18.3)
55
(16.8)
2 (51)
2 (51)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
60,000
2 Pipe or 2-in
Concentric
1-1/2 (38)
1-1/2 (38)
20
(6.1)
15
(4.6)
10
(3.0)
5
(1.5)
NA
NA
2 (51)
2 (51)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
80,000
2 Pipe or 2-in
Concentric
1-1/2 (38)
1-1/2 (38)
10
(3.0)
NA
NA
NA
NA
NA
2 (51)
2 (51)
55
(16.8)
50
(15.2)
35
(10.7)
30
(9.1)
30
(9.1)
20
(6.1)
2-1/2 (64)
2-1/2 (64)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
100,000
2 Pipe or 3-in
Concentric
2 (51)
2 (51)
5
(1.5)
NA
NA
NA
NA
NA
2-1/2 (64)
2-1/2 (64)
40
(12.2)
30
(9.1)
20
(6.1)
20
(6.1)
10
(3.0)
NA
3 (76)
3 (76)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
120,000
2 Pipe or 3-in.
Concentric
2-1/2 (64)
one disk
2-1/2 (64)
10
(3.0)
NA
NA
NA
NA
NA
3 (76)†
NA
45
(13.7)
40
(12.2)
35
(10.7)
30
(9.1)
25
(7.6)
20
(6.1)
3 (76) † no disk
3 (76)†
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
ALTITUDE
FT (M)
UNIT SIZE
(BTUH)
DIRECT VENT (2-PIPE) ONLY
NON-DIRECT
VENT (1-PIPE)
ONLY
NUMBER OF 90
°
ELBOWS
TERMINATION
TYPE
PIPE DIA
IN. (mm)*
PIPE DIA
IN. (mm)*
1
2
3
4
5
6
2001 to 3000
(610 to 914)
40,000
2 Pipe or 2-in
Concentric
1-1/2 (38)
1-1/2 (38)
67
(20.4)
62
(18.9)
57
(17.4)
52
(15.8)
52
(15.8)
47
(14.3)
2 (51)
2 (51)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
60,000
2 Pipe or 2-in
Concentric
1-1/2 (38)
1-1/2 (38)
17
(5.2)
12
(3.7)
7
(2.1)
NA
NA
NA
2 (51)
2 (51)
70
(21.3)
67
(20.4)
66
(20.1)
61
(18.6)
61
(18.6)
61
(18.6)
80,000
2 Pipe or 2-in
Concentric
2 (51)
2 (51)
49
(14.9)
44
(13.4)
30
(9.1)
25
(7.6)
25
(7.6)
15
(4.6)
2-1/2 (64)
2-1/2 (64)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
100,000
2 Pipe or 3-in
Concentric
2-1/2 (64)
2-1/2 (64)
35
(10.7)
26
(7.9)
16
(4.9)
16
(4.9)
6
(1.8)
NA
3 (76)
3 (76)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
66
(20.1)
61
(18.6)
120,000
2 Pipe or 3-in.
Concentric
3 (76)
NA
14
(4.3)
9
(2.7)
NA
NA
NA
NA
NA
3 (76)†
63
(19.2)
62
(18.9)
62
(18.9)
61
(18.6)
61
(18.6)
61
(18.6)
3 (76)† no disk
NA
70
(21.3)
70
(21.3)
63
(19.2)
56
(17.1)
50
(15.2)
43
(13.1)
4 (102)† no
disk
4 (102)† no disk
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
70
(21.3)
See notes at end of table.
353AA
V
