Lennox ELITE Series Installation Instructions Manual page 19

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