507715-01
Page 20 of 61
Issue 1716
Table 5B.
GUH92A Maximum Allowable Exhaust Vent Length with Furnace Installed in a Closet or Basement Using
Ventilated Attic or Crawl Space for Intake in Feet
Standard Termination at Elevation 0 - 10,000 ft
Number of
90° Elbows
Used
2" Pipe
2-1/2" Pipe
3" Pipe
Capacity
Capacity
Capacity
045
070
090
110
135
045
070
090
110
135
045
070
090
110
135
1
66
51
29
9
n/a
95
80
48
23
n/a
112
112
93
93
89
2
61
46
24
4
90
75
43
18
107
107
88
88
84
3
56
41
19
n/a
85
70
38
13
102
102
83
83
79
4
51
36
14
80
65
33
8
97
97
78
78
74
5
46
31
9
75
60
28
3
92
92
73
73
69
6
41
26
4
70
55
23
n/a
87
87
68
68
64
7
36
21
n/a
65
50
18
82
82
63
63
59
8
31
16
60
45
13
77
77
58
58
54
9
26
11
55
40
8
72
72
53
53
49
NOTE
: Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
