Filter
Top Products
40
Table 6 – Maximum Allowable Exposed Vent Pipe Length with Insulation in
Winter Design Temperature Ambient*
UNIT SIZE
WINTER DE SIGN
TEMPERATURE
MAXIMUM PIPE
DIAMETER IN.
(MM)
INSULATION THICKNESS†
0 3/8 1/2 3/4 1
060
20° F / ---7°C 2 ( 51) 28 (8.5) 50 (15.2) 56 (17.1) 66 (20.1) 70 (21.3)
0° F / ---18°C 2 ( 51) 11 (3.4) 25 (7.6) 29 (8.8) 35 (10.7) 41 (12.5)
--- 20° F / --- 29° C 2 ( 51) 4 (1.2) 15 (4.6) 18 (5.5) 23 (7.0) 27 (8.2)
080
20° F / ---7°C 2 ( 51) 36 (11.0) 65 (19.8) 70 (21.3) 70 (21.3) 70 (21.3)
0° F / ---18°C 2 ( 51) 16 (4.9) 34 (10.4) 39 (11.9) 47 (14.3) 55 (16.8)
--- 20° F / --- 29° C 2 ( 51) 8 (2.4) 21 (6.4) 25 (7.6) 31 (9.4) 37 (11.3)
100
20° F / ---7°C 2---1/2 ( 64) 42 (12.8) 70 (21.3) 70 (21.3) 70 (21.3) 70 (21.3)
0° F / ---18°C 2---1/2 ( 64) 18 (5.5) 38 (11.6) 43 (13.1) 53 (16.2) 61 (18.6)
--- 20° F / --- 29° C 2---1/2 (64) 9 (2.7) 23 (7.0) 27 (8.2) 34 (10.4) 41 (12.5)
120
20° F / ---7°C 3 ( 76) 44 (13.4) 70 (21.3) 70 (21.3) 70 (21.3) 70 (21.3)
0° F / ---18°C 3 ( 76) 18 (5.5) 38 (11.6) 44 (13.4) 54 (16.5) 63 (19.2)
--- 20° F / --- 29° C 3 ( 76) 8 (2.4) 23 (7.0) 27 (8.2) 35 (10.7) 41 (12.5)
* Pipe length (ft/m) specified for maximum pipe lengths located in unconditioned spaces. Pipes located in unconditioned space cannot exceed total allowable
pipe length as specified in Table 7.
†Insulation thickness based on R value of 3.5 per in.
355CAV