Page 19
TABLE 7
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.
Standard Termination at Elevation 0 - 4500 ft
Number
Of 90°
Elbows
Used
2” Pipe 2-1/2” Pipe 3” Pipe
Model Model Model
045 070 090 110 045 070 090 110 045 070 090 110
1 71 56 34 14 105 105 83 48 128 127 108 108
2 66 51 29 9 100 100 78 43 123 122 103 103
3 61 46 24 4 95 95 73 38 118 117 98 98
4 56 41 19
n/a
90 90 68 33 113 112 93 93
5 51 36 14 85 85 63 28 108 107 88 88
6 46 31 9 80 80 58 23 101 102 83 83
7 41 26 4 75 75 53 18 98 97 78 78
8 36 21
n/a
70 70 48 13 93 92 73 73
9 31 16 65 65 43 8 88 87 68 68
10 26 11 60 60 38 3 83 82 63 63
Standard Termination Elevation 4501 - 10,000 ft
Number
Of 90°
Elbows
Used
2” Pipe 2-1/2” Pipe 3” Pipe
Model Model Model
045 070 090 110 045 070 090 110 045 070 090 110
1 71 56 34
n/a
105 105 83 48 128 127 108 108
2 66 51 29 100 100 78 43 123 122 103 103
3 61 46 24 95 95 73 38 118 117 98 98
4 56 41 19 90 90 68 33 113 112 93 93
5 51 36 14 85 85 63 28 108 107 88 88
6 46 31 9 80 80 58 23 103 102 83 83
7 41 26 4 75 75 53 18 98 97 78 78
8 36 21
n/a
70 70 48 13 93 92 73 73
9 31 16 65 65 43 8 87 87 68 68
10 26 11 60 60 38 5 83 82 63 63