Carrier 58MXA Nstallation, Start-Up, And Operating Instructions page 32

Table 8—Maximum Allowable Exposed Vent Pipe Length (ft) With and Without Insulation in Winter Design
WINTER DESIGN
UNIT
TEMPERATURE
SIZE
040
060
080
100
120
140
* Pipe length (ft) 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 (ft_ • °F• hr)/(Btu•in.)
Fig. 42—Concentric Vent and Combustion-Air Roof
Termination (Dimension "A" is Touching or
2-in. Maximum Separation)
Temperature Ambient*
MAX PIPE
DIAMETER
(°F) (IN.)
20 1.5
0 1.5
-20 1.5
20 2
0 2
-20 2
20 2
0 2
-20 2
20 2
0 2
-20 2
20 2.5
0 2.5
-20 2.5
20 2.5
0 2.5
-20 2.5
20 3
0 3
-20 3
20 3
0 3
-20 3
20 4
0 4
-20 4
20 3
0 3
-20 3
20 4
0 4
-20 4
VENT
VENT
A
COMBUSTION
AIR
A93056
WITHOUT
INSULATION
51
28
16
45
22
10
65
35
20
55
48
30
70
47
28
40
40
38
70
50
28
70
61
37
70
48
23
60
60
44
70
57
30
COMBUSTION AIR
Fig. 43—Concentric Vent and Combustion-Air Side
Termination (Dimension "A" is Touching or
2-in. Maximum Separation)
32
WITH 3/8–IN. OR
THICKER INSULATION†
70
70
70
70
70
58
70
70
70
55
55
55
70
70
70
40
40
40
70
70
70
70
70
70
70
70
70
60
60
60
70
70
70
1" MAXIMUM
(TYP)
VENT
A
VENT
A93057