Lennox ML193UH045P36B Unit Information page 23

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
Used
045 070
1 81 66
2 76 61
3 71 56
4 66 51
5 61 46
6 56 41
7 51 36
8 46 31
9 41 26
10 36 21
Number Of
90° Elbows
Usedl
045 070
1 73 58
2 68 53
3 63 48
4 58 43
5 53 38
6 48 33
7 43 28
8 38 23
9 33 18
10 28 13
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.
Number Of
90° Elbows
Used
045 070
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
Maximum Allowable Intake or Exhaust Vent Length in Feet
Standard Termination at Elevation 0 - 10,000
2" Pipe
Model
090 110 135 045
44 24 115
39 19 110
34 14 105
29 100
24 95
n/a
19 90
14 85
n/a
80
75
n/a
70
Concentric Termination Elevation 0 - 10,000
2" Pipe
Model
090 110 135 045
42 22 105
37 17 100
32 12 95
27 90
22 85
n/a
17 80
12 75
n/a
70
65
n/a
60
Attic or Crawl Space For Intake Air in Feet
Standard Termination at Elevation 0 - 10,000
2" Pipe
Model
090 110 135 045
34 14 100
29 9 95
24 4 90
19 85
14 80
n/a
9 75
n/a
4 70
65
n/a
60
TABLE 14
2-1/2" Pipe
Model
070 090 110 135
100 68 43
95 63 38
90 58 33
85 53 28
80 48 23
n/a
75 43 18
70 38 13
65 33
60 28
n/a
55 23
2-1/2" Pipe
Model
070 090 110 135
90 64 39
85 59 34
80 54 29
75 49 24
70 44 19
n/a
65 39 14
60 34
55 29
n/a
50 24
45 19
TABLE 15
2-1/2" Pipe
Model
070 090 110 135
95 53 28
80 48 23
75 43 18
70 38 13
65 33 8
n/a
60 28 3
55 23
60 18
n/a
45 13
Page 23
3" Pipe
Model
045 070 090 110
137 137 118 118
132 132 113 113
127 127 108 108
122 122 103 103
117 117 98 98
112 112 93 93
107 107 88 88
102 102 83 83
97 97 78 78
92 92 73 73
3" Pipe
Model
045 070 090 110
121 121 114 114
116 116 109 109
111 111 104 104
106 106 99 99
101 101 94 94
96 96 89 89
91 91 84 84
86 86 79 79
81 81 74 74
76 76 69 69
3" Pipe
Model
045 070 090 110
117 117 98 98
112 112 93 93
107 107 88 88
102 102 83 83
97 97 78 78
92 92 73 73
87 87 68 68
82 82 63 63
77 77 58 58
135
114
109
104
99
94
89
84
79
74
69
135
105
100
95
90
85
80
75
70
65
60
135
94
89
84
79
74
69
64
59
54