7
MAXIMUM ALLOWABLE EXPOSED VENT LENGTHS INSULATION TABLE -- FT. / M
Two Sta g e
Furnace High
Heat Input
Winter Design
Te m p ° F ( ° C )
Pipe
Length in
Ft. & M
No Insulation 3/8-in. (9.5 mm) 1/2-in. (12.7 mm)
Pipe Diameter-inches (mm) Pipe Diameter-inches (mm) Pipe Diameter-inches (mm)
1.5 2.0 2.5 3.0 4.0 1.5 2.0 2.5 3.0 4.0 1.5 2.0 2.5 3.0 4.0
(38) (51) (64) (76) (102) (38) (51) (64) (76) (102) (38) (51) (64) (76) (102)
40000*
20 (-10)
Ft. 40.0 35.0 35.0 N/A N/A 50.0 104.0 94.0 N/A N/A 50.0 122.0 110.0 N/A N/A
M 12.2 10.7 10.7 N/A N/A 15.2 31.7 28.7 N/A N/A 15.2 37.2 33.5 N/A N/A
0 (-20)
Ft. 19.0 14.0 12.0 N/A N/A 50.0 61.0 54.0 N/A N/A 50.0 74.0 65.0 N/A N/A
M 5.8 4.3 3.7 N/A N/A 15.2 18.6 16.5 N/A N/A 15.2 22.6 19.8 N/A N/A
-20 (-30)
Ft. 9.0 3.0 1.0 N/A N/A 50.0 41.0 35.0 N/A N/A 50.0 51.0 43.0 N/A N/A
M 2.7 0.9 0.3 N/A N/A 15.2 12.5 10.7 N/A N/A 15.2 15.5 13.1 N/A N/A
-40 (-40)
Ft. 3.0 0.0 0.0 N/A N/A 39.0 29.0 23.0 N/A N/A 48.0 37.0 30.0 N/A N/A
M 0.9 0.0 0.0 N/A N/A 11.9 8.8 7.0 N/A N/A 14.6 11.3 9.1 N/A N/A
60000
20 (-10)
Ft. 30.0 51.0 51.0 45.0 N/A 30.0 135.0 138.0 120.0 N/ A 30.0 135.0 162.0 141.0 N/A
M 9.1 15.5 15.5 13.7 N/A 9.1 41.1 42.1 36.6 N/A 9.1 41.1 49.4 43.0 N/A
0 (-20)
Ft. 30.0 24.0 23.0 16.0 N/A 30.0 93.0 82.0 69.0 N/A 30.0 111.0 98.0 83.0 N/A
M 9.1 7.3 7.0 4.9 N/ A 9.1 28.3 25.0 21.0 N/A 9.1 33.8 29.9 25.3 N/A
-20 (-30)
Ft. 18.0 11.0 9.0 1.0 N/A 30.0 65.0 56.0 44.0 N/A 30.0 79.0 68.0 55.0 N/A
M 5.5 3.4 2.7 0.3 N/ A 9.1 19.8 17.1 13.4 N/A 9.1 24.1 20.7 16.8 N/A
-40 (-40)
Ft. 10.0 3.0 0.0 0.0 N/A 30.0 48.0 40.0 29.0 N/A 30.0 59.0 50.0 38.0 N/A
M 3.0 0.9 0.0 0.0 N/ A 9.1 14.6 12.2 8.8 N/A 9.1 18.0 15.2 11.6 N/A
80000
20 (-10)
Ft. 20.0 64.0 64.0 56.0 47.0 20.0 70.0 173.0 150.0 125.0 20.0 70.0 175.0 177.0 147.0
M 6.1 19.5 19.5 17.1 14.3 6.1 21.3 52.7 45.7 38.1 6.1 21.3 53.3 53.9 44.8
0 (-20)
Ft. 20.0 32.0 30.0 22.0 11.0 20.0 70.0 104.0 87.0 67.0 20.0 70.0 124.0 104.0 82.0
M 6.1 9.8 9.1 6.7 3.4 6.1 21.3 31.7 26.5 20.4 6.1 21.3 37.8 31.7 25.0
-20 (-30)
Ft. 20.0 17.0 14.0 6.0 0.0 20.0 70.0 71.0 57.0 40.0 20.0 70.0 86.0 71.0 52.0
M 6.1 5.2 4.3 1.8 0.0 6.1 21.3 21.6 17.4 12.2 6.1 21.3 26.2 21.6 15.8
-40 (-40)
Ft. 15.0 7.0 5.0 0.0 0.0 20.0 61.0 52.0 40.0 24.0 20.0 70.0 64.0 50.0 33.0
M 4.6 2.1 1.5 0.0 0.0 6.1 18.6 15.8 12.2 7.3 6.1 21.3 19.5 15.2 10.1
100000
20 (-10)
Ft. N/ A 25.0 79.0 70.0 59.0 N/ A 25.0 110.0 186.0 155.0 N/A 25.0 110.0 219.0 182.0
M N/A 7.6 24.1 21.3 18.0 N/A 7.6 33.5 56.7 47.2 N/A 7.6 33.5 66.8 55.5
0 (-20)
Ft. N/ A 25.0 40.0 31.0 19.0 N/ A 25.0 110.0 109.0 86.0 N/A 25.0 110.0 131.0 104.0
M N/A 7.6 12.2 9.4 5.8 N/A 7.6 33.5 33.2 26.2 N/A 7.6 33.5 39.9 31.7
-20 (-30)
Ft. N/ A 23.0 21.0 13.0 0.0 N/A 25.0 91.0 74.0 54.0 N/A 25.0 110.0 90.0 68.0
M N/A 7.0 6.4 4.0 0.0 N/A 7.6 27.7 22.6 16.5 N/A 7.6 33.5 27.4 20.7
-40 (-40)
Ft. N/ A 13.0 10.0 1.0 0.0 N/A 25.0 68.0 53.0 35.0 N/ A 25.0 83.0 66.0 46.0
M N/A 4.0 3.0 0.3 0.0 N/A 7.6 20.7 16.2 10.7 N/A 7.6 25.3 20.1 14.0
120000
20 (-10)
Ft. N/ A N/A 15.0 85.0 73.0 N/A N/A 15.0 100.0 190.0 N/A N/A 15.0 100.0 224.0
M N/A N/A 4.6 25.9 22.3 N/A N/A 4.6 30.5 57.9 N/A N/A 4.6 30.5 68.3
0 (-20)
Ft. N/ A N/A 15.0 41.0 29.0 N/A N/A 15.0 100.0 109.0 N/A N/A 15.0 100.0 131.0
M N/A N/A 4.6 12.5 8.8 N/A N/A 4.6 30.5 33.2 N/A N/A 4.6 30.5 39.9
-20 (-30)
Ft. N/ A N/A 15.0 20.0 7.0 N/A N/A 15.0 94.0 71.0 N/A N/A 15.0 114.0 88.0
M N/A N/A 4.6 6.1 2.1 N/ A N/A 4.6 28.7 21.6 N/A N/A 4.6 34.7 26.8
-40 (-40)
Ft. N/ A N/A 15.0 7.0 0.0 N/A N/A 15.0 69.0 48.0 N/A N/A 15.0 85.0 62.0
M N/A N/A 4.6 2.1 0.0 N/ A N/A 4.6 21.0 14.6 N/A N/A 4.6 25.9 18.9
* Not all families have these models.
* Pipe len gth (f t) specified for maximum pipe lengths located in u n conditioned spaces. Pipes located in unconditioned space cannot exceed total allowable pi p e
length calculated from Table 1 or 3.
† Insulation thickness based on R value of 3.5 per in.
59TP5A