International comfort products N92ESN Installation Instructions Manual page 26

Supply Air Connections
For a furnace not equipped with a cooling coil, the outlet duct shall
be provided with a removable access panel. This opening shall be
accessible when the furnace is installed and shall be of such a size
that the heat exchanger can be viewed for possible openings using
light assistance or a probe can be inserted for sampling the air
stream. The cover attachment shall prevent leaks.
Connect supply- -air duct to flanges on furnace supply- -air outlet.
Bend flange upward to 90_ with wide duct pliers. See Fig. 19. The
supply- -air duct must be connected to ONLY the furnace
supply- -outlet- -air duct flanges or air conditioning coil casing
(when used). DO NOT cut main furnace casing side to attach
supply air duct, humidifier, or other accessories. All supply- -side
accessories MUST be connected to duct external to furnace main
casing.
Return Air Connections
CAUTION
!
FURNACE RELIABILITY HAZARD
Failure to follow this caution may result in unit component
damage.
Return air connections to either side of the furnace in the
horizontal position can result in nuisance limit switch tripping.
Use only the factory bottom opening of the furnace for the
return air connection.
The return- -air duct can only
furnace. The sides of casing cannot be used for return air
connection. See Fig. 24.
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return- -air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel, see Fig.
27 and 28.
Side Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return- -air opening. This panel MUST be in place when
side return air inlet(s) are used without a bottom return air inlet.
Not all horizontal furnaces are approved for side return air
connections See Fig. 24. Where required by code, seal bottom
closure to furnace with tape, mastic, or other durable sealing
method.
SCREWS (2)
Representative drawing only,
some models may vary in appearance.
1 Lay furnace on the back or side
2 Remove the two (2) screws that secure the bottom
closure panel to the furnace casing and remove the
panel
Fig. 27 - - Removing Bottom Closure Panel (2 Screws)
26
be connected to bottom of the
BOTTOM
CLOSURE
A170123
Specifications subject to change without notice.
SCREWS (4)
BOTTOM
PLATE
Representative drawing only,
some models may vary in appearance.
1 Lay furnace on the back or side
2 Remove the four (4) screws that secure the bottom
plate to the furnace casing
3 Remove the bottom closure from the casing
4 Re--install the bottom plate to the furnace casing and
re--install the four (4) screws
Fig. 28 - - Removing Bottom Closure Panel (4 Screws)
Filter Arrangement
WARNING
!
FIRE, CARBON MONOXIDE AND POISONING
HAZARD
Failure to follow this warning could result in fire, personal
injury or death.
Never operate a furnace without a filter or filtration device
installed. Never operate a furnace with filter or filtration
device access doors removed.
There are no provisions for an internal filter in these furnaces. An
external filter rack is required and is purchased separately. A field
supplied accessory air cleaner may also be used in place of the filter
rack.
For upflow applications, the filter can be installed on either side of
the furnace, the bottom of the furnace or any combination of side
and bottom of the furnace. (See Fig. 22)
For downflow applications, the filter rack (or field supplied
accessory air cleaner) must only be connected to the bottom
opening on the furnace (See Fig. 23).
For horizontal applications, the filter rack (or field supplied
accessory air cleaner) can be connected to the bottom opening on
the furnace. For side return use in the horizontal position, refer to
Fig. 24. If both side and bottom openings are used in Fig. 24, each
opening used will require a filter.
A filter rack or any field supplied accessory air cleaner can also be
installed in the common return duct prior to entering the return air
opening in any orientation.
Refer to the instructions supplied with the Filter Rack or accessory
air filter for assembly and other details.
Due to the relatively high pressure drops of 1- -in (25 mm) thick
after- -market filter media, it is recommended that the filtration
system be designed for at least 2- -in (51 mm) thick media.
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