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31-5000727 Rev. 0
Regardless of the diameter of pipe used, the standard roof
and wall terminations described in section Exhaust Piping
Terminations should be used. Exhaust vent termination
pipe is sized to optimize the velocity of the exhaust gas as
it exits the termination. Refer to Table 12.
In some applications which permit the use of several
different sizes of vent pipe, a combination vent pipe may
be used. Contact GE Appliances Technical Services
department for assistance in sizing vent pipe in these
applications.
NOTE:
It is acceptable to use any pipe size which fits
within the guidelines allowed in table 12.
NOTE:
All horizontal runs of exhaust pipe must slope back
toward unit. A minimum of 1/4” (6mm) drop for each 12”
(305mm) of horizontal run is mandatory for drainage.
NOTE:
Exhaust pipe MUST be glued to furnace exhaust
fittings.
NOTE:
Exhaust piping should be checked carefully to
make sure there are no sags or low spots.
NOTE:
If right side venting option is used, you must include
the elbow at the furnace in the elbow count. If transitioning
to 3” dia pipe, this elbow equates to 20’ of equivalent vent
length for all models.
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
IMPORTANT
Model
Min. Vent Length
All
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.
Table 9. Minimum Vent Pipe Lengths
Use the following steps to correctly size vent pipe diameter.
070, 090,
or 110 btuh
Standard or
Concentric?
See Table 8
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 10A
through 10C to find
max pipe length.
7
Figure 20.
Summary of Contents for GE NF96DV
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