Page 20
TABLE 6
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 - 4500 ft
Number Of
90° Elbows
2” Pipe
3” Pipe
Model
Model
040
060
080
100
040
060
080
100
1
71
56
34
14
118
117
98
98
2
66
51
29
9
113
112
93
93
3
61
46
24
4
108
107
88
88
4
56
41
19
n/a
103
102
83
83
5
51
36
14
98
97
78
78
6
46
31
9
93
92
73
73
7
41
26
4
88
87
68
68
8
36
21
n/a
83
82
63
63
9
31
16
78
77
58
58
10
26
11
73
72
53
53
