Lennox ELITE Series Installation Instructions Manual page 20

Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement Using Ventilated
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
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
Usedl
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
Attic or Crawl Space For Intake Air in Feet
Standard Termination at Elevation 0 - 4500 ft
2" Pipe
Model
090 110 135 045
34 14 100
29 9
24 4
19
14
n/a
9
4 n/a
n/a
Standard Termination Elevation 4500 - 10,000 ft
2" Pipe
Model
090 110 135 045
34 100
29
24
19
14
n/a n/a
9
4
n/a
TABLE 6
2-1/2" Pipe
Model
070 090 110
100 78 43
95 95 73 38
90 90 68 33
85 85 63 28
80 80 58 23
75 75 53 18
70 70 48 13
65 65 43 8
60 60 38 3
55 55 33 n/a
2-1/2" Pipe
Model
070 090 110
100 78 43
95 95 73 38
90 90 68 33
85 85 63 28
80 80 58 23
75 75 53 18
70 70 48 13
65 65 43 8
60 60 38 3
55 55 33 n/a
Page 20
3" Pipe
Model
135 045 070 090
118 117 98
113 112 93
108 107 88
103 102 83
98 97 78
n/a
93 92 73
88 87 68
83 82 63
78 77 58
73 72 53
3" Pipe
Model
135 045 070 090
118 117 98
113 112 93
108 107 88
103 102 83
98 97 78
n/a
93 92 73
88 87 68
83 82 63
78 77 58
73 72 53
110 135
98 94
93 89
88 84
83 79
78 74
73 69
68 64
63 59
58 54
53 49
110 135
98 94
93 89
88 84
83 79
78 74
73 69
68 64
63 59
58 54
53 49