Allied A93UH1E - Page 29

508107-01 Issue 2041 Page 29 of 58
A93UH1E & 92G1UHE Maximum Allowable Exhaust Vent Length with Furnace Installed in a Closet or Basement
Using Ventilated Attic or Crawl Space for Intake in Feet
Standard Termination at Elevation 0 - 10,000 ft
Number of
90° Elbows
Used
1-1/2" Pipe 2" Pipe 2-1/2" Pipe 3" Pipe
Capacity Capacity Capacity Capacity
030 /
045
070 090 110
030 /
045
070 090 110
030 /
045
070 090 110
030 /
045
070 090 110
1 20 15
n/a n/a
66 51 29 9 95 80 48 23 112 112 93 93
2 15 10 61 46 24 4 90 75 43 18 107 107 88 88
3 10
n/a
56 41 19
n/a
85 70 38 13 102 102 83 83
4
n/a
51 36 14 80 65 33 8 97 97 78 78
5 46 31 9 75 60 28 3 92 92 73 73
6 41 26 4 70 55 23
n/a
87 87 68 68
7 36 21
n/a
65 50 18 82 82 63 63
8 31 16 60 45 13 77 77 58 58
9 26 11 55 40 8 72 72 53 53
NOTE: Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
Table 12.