Lennox SL297UH040NV36B, Unit Information

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TABLE 21
Maximum Allowable Intake or Exhaust Vent Length in Feet
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.
Standard Termination at Elevation 0 - 4500 ft
Number Of 90° El­
bows Used
2” Pipe 2-1/2” Pipe 3” Pipe
Model Model Model
040 060 080 040 060 080 040 060 080
1 81 66 44 115 115 93 138 137 118
2 76 61 39 110 110 88 133 132 113
3 71 56 34 105 105 83 128 127 108
4 66 51 29 100 100 78 123 122 103
5 61 46 24 95 95 73 118 117 98
6 56 41 19 90 90 68 113 112 93
7 51 36 14 85 85 63 108 107 88
8 46 31
n/a
80 80 58 103 102 83
9 41 26 75 75 53 98 97 78
10 36 21 70 70 48 93 92 73
TABLE 21 Continued
Maximum Allowable Intake or Exhaust Vent Length in Feet
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.
Concentric Termination at Elevation 0 - 4500 ft
Number Of 90° El­
bows Used
2” Pipe 2-1/2” Pipe 3” Pipe
Model Model Model
040 060 080 040 060 080 040 060 080
1 73 58 42 105 105 89 121 121 114
2 68 53 37 100 100 84 116 116 109
3 63 48 32 95 95 79 111 111 104
4 58 43 27 90 90 74 106 106 99
5 53 38 22 85 85 69 101 101 94
6 48 33 17 80 80 64 96 96 89
7 43 28 12 75 75 59 91 91 84
8 38 23
n/a
70 70 54 86 86 79
9 33 18 65 65 49 81 81 74
10 28 13 60 60 44 76 76 69