Lennox ML193DFE Series Unit Information page 25

*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 1-1/2" Pipe
Of 90°
Model
Elbows
045 070
Used
20 15
1
15 10
2
10
3
4
5
6
n/a
n/a
7
8
9
10
Number 1-1/2" Pipe
Of 90°
Model
Elbows
045 070
Used
15 10
1
10
2
3
4
5
n/a
6
n/a
7
8
9
10
Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement
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
90° Elbows
Model
Used
045 070
1 15 10
2 10
3
4
5
6 n/a
n/a
7
8
9
10
Maximum Allowable Intake or Exhaust Vent Length in Feet
Standard Termination at Elevation 0 - 10,000 ft.
2" Pipe
Model
090 045 070
61 46
56 41
51 36
46 31
41 26
n/a
36 21
31 16
26 11
21
n/a
16
Concentric Termination Elevation 0 - 10,000 ft.
2" Pipe
Model
090 045 070
53 38
48 33
43 28
38 23
33 18
n/a
28 13
23
18
n/a
13
n/a
Using Ventilated Attic or Crawl Space For Intake Air in Feet
Standard Termination at Elevation 0 - 10,000 ft.
2" Pipe
Model
090 045 070
51 36
46 31
41 26
36 21
31 16
n/a
26 11
21 6
16 1
11
n/a
6
TABLE 13
2-1/2" Pipe
Model
090 045 070
24 100 80
19 95 75
14 90 70
85 65
80 60
75 55
n/a 70 50
65 45
60 40
55 35
2-1/2" Pipe
Model
090 045 070
22 90 70
17 85 65
12 80 60
75 55
70 50
65 45
n/a 60 40
55 35
50 30
45 25
TABLE 14
2-1/2" Pipe
Model
090 045 070
14 85 65
9 80 60
4 75 55
70 50
65 45
60 40
55 35
50 30
45 25
40 20
Page 25
3" Pipe
Model
090 045 070
43 127 127
38 122 122
33 117 117
28 112 112
23 107 107
18 102 102
13 97 97
92 92
n/a
87 87
82 82
3" Pipe
Model
090 045 070
39 111 111
34 106 106
29 101 101
19 96 96
14 91 91
86 86
81 81
76 76
n/a
71 71
66 66
3" Pipe
Model
090 045 070
28 107 107
23 102 102
18 97 97
8 92 92
3 87 87
82 82
77 77
n/a 72 72
67 67
62 62
090
108
103
98
93
88
83
78
73
68
63
090
104
99
94
89
84
79
74
69
64
59
090
88
83
78
73
68
63
58
53
48
43