Page 26
TABLE 14
Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or
Basement Using Ventilated Attic or Crawl Space For Intake Air in Feet
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total
vent length calculation.
Standard Termination at Elevation 0 - 2000 ft
Number
Of 90°
Elbows
1-1/2” Pipe
2” Pipe
2-1/2” Pipe
3” Pipe
Model
Model
Model
Model
045 070
090 110 045
070
090 110
045
070
090
110
045 070 090 110
1
10
10
N/A
N/A
51
36
14
N/A
85
65
28
n/a
107
107
88
88
2
N/A
N/A
46
31
9
80
60
23
102
102
83
83
3
41
26
n/a
75
55
18
97
97
78
78
4
36
21
70
50
13
92
92
73
73
5
31
16
65
45
8
87
87
68
68
6
26
11
60
40
n/a
82
82
63
63
7
21
n/a
55
35
77
77
58
58
8
16
50
30
72
72
53
53
9
11
45
25
67
67
48
48
10
n/a
40
20
62
62
43
43
Standard Termination at Elevation 2001 - 10,000 ft
Number
Of 90°
Elbows
1-1/2” Pipe
2” Pipe
2-1/2” Pipe
3” Pipe
Model
Model
Model
Model
045 070
090 110 045
070
090 110
045
070
090
110
045 070 090 110
1
N/A
N/A
N/A
N/A
30
20
10
N/A
80
53
28
n/a
107
107
88
88
2
25
15
n/a
75
48
23
102
102
83
83
3
20
10
70
43
18
97
97
78
78
4
15
n/a
65
38
13
92
92
73
73
5
10
60
33
n/a
87
87
68
68
6
n/a
55
28
82
82
63
63
7
50
23
77
77
58
58
8
45
18
72
72
53
53
9
40
13
67
67
48
48
10
35
n/a
62
62
43
43