Vent Piping Guidelines - Haier GE APPLIANCES NF96US Service Manual

Vent Piping Guidelines

NOTE: GE Appliances has approved the use of DuraVent
and Centrotherm manufactured vent pipe and terminations
as an option to PVC. When using the PolyPro
or InnoFlue by Centrotherm venting system the vent pipe
®
requirements stated in the unit installation instruction
– minimum & maximum vent lengths, termination
clearances, etc. – apply and must be followed. Follow
the instructions provided with PoyPro by DuraVent and
InnoFlue by Centrotherm venting system for assembly
or if requirements are more restrictive. The PolyPro by
Duravent and InnoFlue by Centrotherm venting system
must also follow the uninsulated and unconditioned space
criteria listed in Table 11.
The NF96US can be installed as either a Non-Direct
Vent or a Direct Vent gas central furnace.
NOTE: In Non-Direct Vent installations, combustion air is
taken from indoors and flue gases are discharged outdoors.
In Direct Vent installations, combustion air is taken from
outdoors and flue gases are discharged outdoors.
Intake and exhaust pipe sizing -- Size pipe according to
Table 9 and Table 10A through Table 10F. Count all elbows
in side and outside the home. Table 9 lists the minimum
vent pipe lengths permitted. Table 10A through Table 10F
lists the maximum pipe lengths permitted.
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: The exhaust collar on all models is sized to
accommodate 2" Schedule 40 vent pipe. In horizontal
applications, any transition to exhaust pipe larger than 2"
must be made in vertical runs of the pipe. Therefore a 2"
elbow must be added before the pipe is transitioned to
any size larger than 2". This elbow must be added to the
elbow count used to determine acceptable vent lengths.
Contact the Application Department for more information
concerning sizing of vent systems which include multiple
pipe sizes.
®
by DuraVent
®
NOTE: All horizontal runs of exhaust pipe must slope back toward
ward 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.
*Any approved termination may be added to the minimum
length listed.
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
Page 24
Exhaust Pipe
12" Max.
Horizontal
Gas Furnace
Figure 21.
Capacity
045, 070, 090, 110
Table 9. Minimum Vent Pipe Lengths
IMPORTANT
12" Min.
Min. Vent Length*
15 ft or 5 ft plus 2 elbows or
10 ft plus 1 elbow
31-5000728 Rev. 0