NOTE − Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake and Exhaust must be same pipe
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.
Number Of
90° Elbows
Used
045
070
1
81
66
2
76
61
3
71
56
4
66
51
5
61
46
6
56
41
7
51
36
8
46
31
9
41
26
10
36
21
Number Of
90° Elbows
Used
045
070
1
81
66
2
76
61
3
71
56
4
66
51
5
61
46
6
56
41
7
51
36
8
46
31
9
41
26
10
36
21
Maximum Allowable Intake or Exhaust Vent Length in Feet