Page 25
Horizontal Installation Offset Requirements
NOTE - Exhaust pipe MUST be glued to furnace exhaust fitting,
unless the optional glueless vent adapter kit 17H92 is used..
NOTE -
ward unit. A minimum of 1/4” (6mm) drop for each 12” (305mm)
of horizontal run is mandatory for drainage.
NOTE - Exhaust piping should be checked carefully to make
sure there are no sags or low spots.
Exhaust Pipe
Horizontal
Gas Furnace
12” Min.
12” Max.
FIGURE 18
NOTE - Lennox oers a glueless vent adapter kit 17H92
as an option for exhaust exiting at the furnace top cap
coupling. If the kit is not used the exhaust pipe MUST be
glued to furnace exhaust tting.
TABLE 13
MINIMUM VENT PIPE LENGTHS
ML296UHV MODEL 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. Two 45 degree elbows are the equivalent to one 90 de-
gree elbow.
IMPORTANT
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
Use the following steps to correctly size vent pipe diam-
eter.
1
2
3
4
5
6
Which style termination
being used?
Standard or
concentric?.
Which needs
most elbows?
Intake or
exhaust?
How many elbows?
Count all elbows inside
and outside house.
Desired pipe size?
Find max intake or
exhaust pipe length.
Includes all vent pipe and
elbows inside and outside
What is the altitude of
the furnace installation?
7
What is the
furnace capacity?
FIGURE 19
To Next Page
Loading...
Need help?
General