41
Table 7 – Maximum Allowable Pipe Length -- Ft (M)
ALTITUDE
UNIT SIZE
(BTUH)
Direct Vent (2---Pipe Only)
NUMBER OF 90
_
ELBOWS
Termination
Type
Pipe Dia
In. (mm)*
1
2
3
4
5
6
0 to 2000
(0 to 610)
60,000
2 Pipe or 2---In. (51)
Concentric
1---1/2 (38)
50 (15.2)
45 (13.7)
40 (12.9)
35 (10.7)
30 (9.1)
25 (7.6)
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. (51)
Concentric
1---1/2 (38)
30 (9.14)
25 (7.6)
20 (6.1)
15 (4.6)
10 (3.0)
5 (1.5)
2 (51)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
100,000
2 Pipe or 2---In. (51)
Concentric
2 (51)
45 (13.7)
40 (12.9)
35 (10.7)
30 (9.1)
25 (7.6)
20 (6.1)
2---1/2 (64)
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. (76)
Concentric
2---1/2 one disk
10 (3.0)
NA
NA
NA
NA
NA
3 (76) one disk
35 (10.7)
30 (9.1)
15 (4.8)
NA
NA
NA
3 (76) one disk†
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Pipe Dia
In. (mm)*
NUMBER OF 90
_
ELBOWS
1
2
3
4
5
6
2001 to 3000
(610 to 914)
60,000
2 Pipe or 2---In. (51)
Concentric
1---1/2 (38)
45 (13.7)
40 (12.9)
35 (10.7)
30 (9.14)
25 (7.6)
20 (6.1)
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. (51)
Concentric
1---1/2 (38)
26 (7.9)
21 (6.4)
16 (4.9)
11 (3.4)
6 (1.8)
NA
2 (51)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
100,000
2 Pipe or 2---In. (51)
Concentric
2 (51)
40 (12.2)
35 (10.7)
30 (9.1)
25 (7.6)
20 (6.1)
15 (4.6)
2---1/2 (64)
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. (76)
Concentric
3 (76) one disk
31 (9.4)
26 (7.9)
12 (3.7)
NA
NA
NA
3 (76) one
disk†
63 (19.2)
62 (18.9)
62 (18.9)
61 (18.6)
61 (18.6)
61 (18.6)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Pipe Dia
In. (mm)*
NUMBER OF 90
_
ELBOWS
1
2
3
4
5
6
3001 to 4000
(914 to 1219)
60,000
2 Pipe or 2---In. (51)
Concentric
1---1/2 (38)
42 (12.8)
37 (11.2)
32 (9.8)
27 (8.2)
22 (6.7)
17 (5.2)
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. (51)
Concentric
1---1/2 (38)
25 (7.6)
20 (6.1)
15 (4.6)
10 (3.0)
5 (1.5)
NA
2 (51)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
100,000
2 Pipe or 2---In. (51)
Concentric
2 (51)
38 (11.6)
33 (10.1)
28 (8.5)
23 (7.0)
18 (5.5)
13 (4.0)
2---1/2 (64)
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
3 (76) one disk
29 (8.8)
24 (7.3)
10 (3.0)
NA
NA
NA
3 (76) one
disk†
59 (18.0)
59 (18.0)
58 (17.8)
57 (17.4)
57 (17.4)
56 (17.0)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Pipe Dia
In. (mm)*
NUMBER OF 90
_
ELBOWS
1
2
3
4
5
6
4001 to 5000
(1219 to 1524)‡
60,000
2 Pipe or 2---In. (51)
Concentric
1---1/2 (38)
40 (12.2)
35 (10.7)
30 (9.1)
25 (7.6)
20 (6.1)
15 (9.6)
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. (51)
Concentric
1---1/2 (38)
23 (7.0)
18 (5.5)
13 (4.0)
8 (2.4)
NA
NA
2 (51)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
68 (20.7)
100,000
2 Pipe or 2---In. (51)
Concentric
2 (51)
36 (11.0)
31 (9.4)
26 (7.9)
21 (6.4)
16 (4.8)
11 (3.4)
2---1/2 (64)
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. (76)
Concentric
3 (76) one
disk†
56 (17.1)
55 (16.8)
54 (16.5)
53 (6.2)
52 (15.8)
52 (15.8)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Pipe Dia
In. (mm)*
NUMBER OF 90
_
ELBOWS
1
2
3
4
5
6
5001 to 6000
(1524 to 1829)‡
60,000
2 Pipe or 2---In. (51)
Concentric
1---1/2 (38)
37 (11.3)
32 (9.8)
27 (8.2)
22 (6.7)
17 (5.2)
12 (3.7)
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. (51)
Concentric
1---1/2 (38)
22 (6.7)
17 (5.2)
12 (3.7)
7 (2.1)
NA
NA
2 (51)
70 (21.3)
70 (21.3)
70 (21.3)
70 (21.3)
68 (20.7)
63 (19.2)
100,000
2 Pipe or 2---In. (51)
Concentric
2 (51)
33 (10)
28 (8.5)
23 (7.0)
18 (5.5)
13 (4.0)
8 (2.4)
2---1/2 (64)
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. (76)
Concentric
3 (76) one
disk†
53 (16.2)
52 (15.8)
50 (15.2)
49 (14.9)
48 (14.6)
47 (14.3)
*See notes on next page.
58MV
C