Lennox ML193UH Installation Instructions Manual page 18

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 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
045 070
Usedl
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 Attic or Crawl Space
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
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 n/a 85
80
n/a 75
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 n/a 75
70
n/a 65
60
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
9 75
4 70
65
60
TABLE 5
2-1/2" Pipe
Model
070 090 110
100 68 43
95 63 38
90 58 33
85 53 28
80 48 23
75 43 18
70 38 13
65 33
60 28 n/a
55 23
2-1/2" Pipe
Model
070 090 110
90 64 39
85 59 34
80 54 29
75 49 24
70 44 19
65 39 14
60 34
55 29
n/a
50 24
45 19
TABLE 6
For Intake Air in Feet
2-1/2" Pipe
Model
070 090 110
95 53 28
80 48 23
75 43 18
70 38 13
65 33 8
60 28 3
55 23
60 18
45 13
Page 18
3" Pipe
Model
135 045 070 090
137 137 118
132 132 113
127 127 108
122 122 103
117 117 98
n/a
112 112 93
107 107 88
102 102 83
97 97 78
92 92 73
3" Pipe
Model
135 045 070 090
121 121 114
116 116 109
111 111 104
106 106 99
101 101 94
n/a
96 96 89
91 91 84
86 86 79
81 81 74
76 76 69
3" Pipe
Model
135 045 070 090
117 117 98
112 112 93
107 107 88
102 102 83
97 97 78
92 92 73
87 87 68
82 82 63
77 77 58
110 135
118 114
113 109
108 104
103 99
98 94
93 89
88 84
83 79
78 74
73 69
110 135
114 105
109 100
104 95
99 90
94 85
89 80
84 75
79 70
74 65
69 60
110 135
98 94
93 89
88 84
83 79
78 74
73 69
68 64
63 59
58 54