Lennox MERIT ML195UH 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.
2" Pipe
Number
Model
Of 90°
Elbows
045 070 090
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
2" Pipe
Number
Model
Of 90°
Elbows
045 070 090
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
Maximum Allowable Vent Length in Feet
Standard Termination at Elevation 0 - 4500 ft
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
Standard Termination Elevation 4500 - 10,000 f
110 135 045
44 115
39 110
34 105
29 100
24 95
n/a n/a
19 90
14 85
80
n/a 75
70
TABLE 5
2-1/2" Pipe
Model
070 090 110 135
115 93 58
110 88 53
105 83 48
100 78 43
95 73 38
n/a
90 68 33
85 63 28
80 58 23
75 53 18
70 48 13
2-1/2" Pipe
Model
070 090 110 135
115 93 58
110 88 53
105 83 48
100 78 43
95 73 38
n/a
90 68 33
85 63 28
80 58 23
75 53 18
70 48 13
Page 18
3" Pipe
Model
045 070 090 110
138 137 118 118
133 132 113 113
128 127 108 108
123 122 103 103
118 117 98 98
113 112 93 93
108 107 88 88
103 102 83 83
98 97 78 78
93 92 73 73
t
3" Pipe
Model
045 070 090 110
138 137 118 118
133 132 113 113
128 127 108 108
123 122 103 103
118 117 98 98
113 112 93 93
108 107 88 88
103 102 83 83
98 97 78 78
93 92 73 73
135
114
109
104
99
94
89
84
79
74
69
135
114
109
104
99
94
89
84
79
74
69