Page 20
TABLE 7 Continued
Maximum Allowable Intake or Exhaust Vent Length
Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Intake and Exhaust must be same size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.
Concentric Termination at Elevation 0 - 4500 ft
Number
Of 90°
Elbows
Used
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
15
10
n/a
n/a
63
48
32
12
95
95
79
44
111
111
104
104
2
10
n/a
58
43
27
7
90
90
74
39
106
106
99
99
3
n/a
53
38
22
2
85
85
69
34
101
101
94
94
4
48
33
17
n/a
80
80
64
29
96
96
89
89
5
43
28
12
75
75
59
24
91
91
84
84
6
38
23
7
70
70
54
19
86
86
79
79
7
33
18
2
65
65
49
14
81
81
74
74
8
28
13
n/a
60
60
44
9
76
76
69
69
9
23
8
55
55
39
4
71
71
64
64
10
18
3
50
50
34
n/a
66
66
59
59
Concentric Termination Elevation 4501 - 10,000 ft
Number
Of 90°
Elbows
Used
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
15
10
n/a
n/a
63
48
32
n/a
95
95
79
44
111
111
104
94
2
10
n/a
58
43
27
90
90
74
39
106
106
99
99
3
n/a
53
38
22
85
85
69
34
101
101
94
94
4
48
33
17
80
80
64
29
96
96
89
89
5
43
28
12
75
75
59
24
91
91
84
84
6
38
23
7
70
70
54
19
86
86
79
79
7
33
18
2
65
65
49
14
81
81
74
74
8
28
13
n/a
60
60
44
9
76
76
69
69
9
23
8
55
55
39
4
71
71
64
64
10
18
3
50
50
34
n/a
66
66
59
59
TABLE 8
Maximum Allowable Exhaust Vent Length 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 - 10,000 ft
Number
Of 90°
Elbows
Used
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
15
10
n/a
n/a
61
46
24
n/a
90
90
68
33
108
107
88
88
2
10
n/a
56
41
19
85
85
63
28
103
102
83
83
3
n/a
51
36
14
80
80
58
23
98
97
78
78
4
46
31
9
75
75
53
18
93
92
73
73
5
41
26
4
70
70
48
13
88
87
68
68
6
36
21
n/a
65
65
43
8
81
82
63
63
7
31
16
60
60
38
3
78
77
58
58
8
26
11
55
55
33
n/a
73
72
53
53
9
21
6
50
50
28
68
67
48
48
10
16
1
45
45
23
63
62
43
43