Lennox ELITE Series Installation Instructions Manual page 20

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 63 48
2 58 43
3 53 38
4 48 33
5 43 28
6 38 23
7 33 18
8 28 13
9 23 8
10 18 3
Number
Of 90°
Elbows
045 070
Used
1 63 48
2 58 43
3 53 38
4 48 33
5 43 28
6 38 23
7 33 18
8 28 13
9 23 8
10 18 3
Maximum Allowable Exhaust Vent Length 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.
Number
Of 90°
Elbows
045 070
Used
1 61 46
2 56 41
3 51 36
4 46 31
5 41 26
6 36 21
7 31 16
8 26 11
9 21 6
10 16 1
TABLE 7 Continued
Maximum Allowable Intake or Exhaust Vent Length
Concentric Termination at Elevation 0 - 4500 ft
2" Pipe
Model
090 110
32 12
27 7
22 2
17
12
7
2 n/a
n/a
Concentric Termination Elevation 4501 - 10,000 ft
2" Pipe
Model
090 110
32
27
22
17
12
n/a
7
2
n/a
Standard Termination at Elevation 0 - 10,000 ft
2" Pipe
Model
090 110
24
19
14
9
4
n/a
n/a
2-1/2" Pipe
Model
045 070 090
95 95 79
90 90 74
85 85 69
80 80 64
75 75 59
70 70 54
65 65 49
60 60 44
55 55 39
50 50 34
2-1/2" Pipe
Model
045 070 090
95 95 79
90 90 74
85 85 69
80 80 64
75 75 59
70 70 54
65 65 49
60 60 44
55 55 39
50 50 34
TABLE 8
2-1/2" Pipe
Model
045 070 090
90 90 68
85 85 63
80 80 58
75 75 53
70 70 48
65 65 43
60 60 38
55 55 33
50 50 28
45 45 23
Page 20
3" Pipe
Model
110 045 070
44 111 111
39 106 106
34 101 101
29 96 96
24 91 91
19 86 86
14 81 81
9 76 76
4 71 71
n/a 66 66
3" Pipe
Model
110 045 070
44 111 111
39 106 106
34 101 101
29 96 96
24 91 91
19 86 86
14 81 81
9 76 76
4 71 71
n/a 66 66
3" Pipe
Model
110 045 070
33 108 107
28 103 102
23 98 97
18 93 92
13 88 87
8 81 82
3 78 77
73 72
n/a 68 67
63 62
090 110
104 104
99 99
94 94
89 89
84 84
79 79
74 74
69 69
64 64
59 59
090 110
104 94
99 99
94 94
89 89
84 84
79 79
74 74
69 69
64 64
59 59
090 110
88 88
83 83
78 78
73 73
68 68
63 63
58 58
53 53
48 48
43 43