Lennox ML196DF045XE36B Manual page 24

Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement Using Ventilated
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.
1-1/2" Pipe
Number Of
Model
90° Elbows
Used
045 070
1 10 10
2
3
4
5
6
N/A N/A
7
8
9
10
Attic or Crawl Space For Intake Air in Feet
Standard Termination at Elevation 0 - 10,000 ft
2" Pipe
Model
090 110 045 070
71 56
66 51
61 46
56 41
51 36
N/A N/A
46 41
41 26
36 21
31 16
26 11
TABLE 13
2-1/2" Pipe
Model
090 110 045 070
34 115 100
29 110 95
24 105 90
19 100 85
14 95 80
N/A
9 90 75
4 85 70
n/a 80 65
n/a 75 60
n/a 70 55
Page 24
3" Pipe
Model
090 110 045 070
78 33 118 117
73 28 113 112
68 23 108 107
63 18 103 102
58 13 98 97
53 8 93 92
48 88 87
43 83 82
N/A
38 78 77
33 73 72
090 110
98 88
93 83
88 78
83 73
78 68
73 63
68 58
63 53
58 48
53 43