Page 15
TABLE 5
Maximum Allowable Intake or Exhaust Vent Length in Feet
*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.
Standard Termination at Elevation 0 - 7500’
Number
Of 90
Elbows
Used
2” Pipe 2-1/2” Pipe 3” Pipe
Model Model Model
070 090 110 135 070 090 110 135 070 090 110 135
1 91 69 14
N/A
140 93 43
N/A
162 143 118 114
2 86 64 9 135 88 38 157 138 113 109
3 81 59
N/A
130 83 33 152 133 108 104
4 76 54 125 78 28 147 128 103 99
5 71 49 120 73 23 142 123 98 94
6 66 44 115 68 18 137 118 93 89
7 61 39 110 63 13 132 113 88 84
8 56 34 105 58
N/A
127 108 83 79
9 51 29 100 53 122 103 78 74
10 46 24 95 48 117 98 73 69
Standard Termination at Elevation 7501’ - 10,000’
Number
of 90
Elbows
Used
2” Pipe 2-1/2” Pipe 3” Pipe
Model Model Model
070 090 110 135 070 090 110 135 070 090 110 135
1 66 44
N/A N/A
115 68
N/A N/A
137 118 93 89
2 61 39 110 63 132 113 88 84
3 56 34 105 58 127 108 83 79
4 51 29 100 53 122 103 78 74
5 46 24 95 48 117 96 73 69
6 41 19 90 43 112 93 68 64
7 36 14 85 38 107 88 63 59
8 31
N/A
80 33 102 83 58 54
9 26 75 28 97 78 53 49
10 21 70 23 92 73 48 44
Concentric Termination 0 - 7501”
Number
of 90
Elbows
Used
2” Pipe 2-1/2” Pipe 3” Pipe
Model Model Model
070 090 110 135 070 090 110 135 070 090 110 135
1 83 67 12
N/A
130 89 39
N/A
146 139 114 105
2 78 62 7 125 84 34 141 134 109 100
3 73 57
N/A
120 79 29 136 129 104 95
4 68 52 115 74 24 131 124 99 90
5 63 47 110 69 19 126 119 94 85
6 58 42 105 64 14 121 114 89 80
7 53 37 100 59
N/A
116 109 84 75
8 48 32 95 54 111 104 79 70
9 43 27 90 49 106 99 74 65
10 38 22 85 44 101 94 69 60
Concentric Termination 7501” - 10,000”
Number
of 90
Elbows
Used
2” pipe 2-1/2” Pipe 3” Pipe
Model Model Model
070 090 110 135 070 090 110 135 070 090 110 135
1 58 42
N/A N/A
105 64
N/A N/A
121 114 89 80
2 53 37 100 59 116 109 84 75
3 48 32 95 54 111 104 79 70
4 43 27 90 49 106 99 74 65
5 38 22 85 44 101 94 69 60
6 33 17 80 39 96 89 64 55
7 28 12 75 34 91 84 59 50
8 23
N/A
70 29 86 79 54 45
9 18 65 24 81 74 49 40
10 13 60 19 76 69 44 35