Lennox EL195UHE Installation Instructions Manual page 18

Use the following steps to correctly size vent pipe diam-
eter.
Pipe Size Process
What is the
furnace capacity?
1
030, 045, 070,
090, 110 or 135?
Which style termination
2
being used?
Standard or concentric?
See table 3..
Which needs
3 most elbows?
Intake or
exhaust?
How many elbows?
4
Count all elbows inside
and outside house.
Desired pipe size?
5
2", 2-1/2", 3"
What is the altitude of
6
the furnace installation?
Use table 5 or 6 to find
max intake or exhaust pipe
7
length. Includes all vent
pipe and elbows inside and
outside the house.
FIGURE 23
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
Page 18
IMPORTANT