507768-04P
Page 18 of 56
Issue 1933
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
IMPORTANT
Table 4. Minimum Vent Pipe Lengths
Capacity
Min. Vent Length*
045, 070, 090, 110
15 ft or 5 ft plus 2 elbows or
10 ft plus 1 elbow
*Any approved termination may be added to the minimum
length listed.
045, 070,
090, 110
Standard or
Concentric?
See Table 3
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 5 to find
max pipe length.
7
Figure 24.