Haier GE APPLIANCES NF96US Service Manual page 30

Intake Piping
The NF96US furnace may be installed in either direct
vent or non-direct vent applications. In non-direct vent
applications, when intake air will be drawn into the furnace
from the surrounding space, the indoor air quality must be
considered and guidelines listed in Combustion, Dilution
and Ventilation Air section must be followed.
Follow the next two steps when installing the unit in Direct
Vent applications, where combustion air is taken from
outdoors and flue gases are discharged outdoors. The
provided air intake screen must not be used in direct
vent applications (outdoors).
1. Use transition solvent cement or a sheet metal screw
to secure the intake pipe to the inlet air connector.
2. Route piping to outside of structure. Continue with
installation following instructions given in general
guidelines for piping terminations and intake and
exhaust piping terminations for direct vent sections.
Refer to Table 10A through Table 10F for pipe sizes.
INTAKE
TYPICAL INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT OR
NON-DIRECT VENT APPLICATIONS
2"
or
3"
AIR
TRANSITION
*2"
* When transitioning up in pipe size, use the shortest length of 2" PVC pipe possible.
NOTE: Exhaust pipe and intake pipe must be the same diameter.
Follow the next two steps when installing the unit in Non-
Direct Vent applications where combustion air is taken
from indoors and flue gases are discharged outdoors.
1. Use field-provided materials and the factory-provided
air intake screen to route the intake piping as shown in
Figure 27 or Figure 28. Maintain a minimum clearance
of 3" (76 mm) around the air intake opening. The air
intake opening (with the protective screen) should
always be directed forward or to either side in the
upflow position, and either straight out or downward in
the horizontal position.
The air intake piping must not terminate too close
to the flooring or a platform. Ensure that the intake
air inlet will not be obstructed by loose insulation
or other items that may clog the debris screen.
2. If intake air is drawn from a ventilated attic (Figure
29) or ventilated crawlspace (Figure 30) the exhaust
vent length must not exceed those listed in Table
10E through Table 10F. If 3" diameter pipe is used,
reduce to 2" diameter pipe at the termination point to
accommodate the debris screen.
3. Use a sheet metal screw to secure the intake pipe to
the connector, if desired.
Pipe size determined in Table 5
2"
2"
2"
2"
or
Figure 25.
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