508146-01
Issue 2051
Page 3
6
of 7
0
Use the following steps to correctly size vent pipe diameter.
Figure 25.
070, 090,
110 or 135
btuh
Standard or
Concentric?
See Table 20
Intake or
Exhaust?
1-1/2”, 2”,
2-1/2”
or 3”
Furnace capacity?
1
Which termination?
2
Which needs most
elbows?
3
How many?
4
Desired pipe size?
5
What is the altitude?
6
Use Table 22 to find
max pipe length.
7