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F97CMN and G97CMN: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
17
A10491
Fig. 24 – Installation on Combustible Flooring
Connect supply-air duct to supply-air outlet on furnace. Bend flange
inward past 90° with wide duct pliers, see
. The supply-air duct
must be connected to ONLY the furnace supply outlet or air conditioning
coil casing (when used). When installed on combustible material,
supply-air duct must be connected to ONLY the factory-approved
accessory subbase, or a factory-approved air conditioning coil casing.
DO NOT cut main furnace casing to attach supply side air duct,
humidifier, or other accessories. All supply-side accessories MUST be
connected to duct external to furnace casing.
Return Air Connections
The furnace can be installed horizontally in an attic or crawlspace on
either the left-hand (LH) or right-hand (RH) side. The furnace can be
hung from floor joists, rafters or trusses or installed on a
non-combustible platform, blocks, bricks or pad.
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
. 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 accessories MUST be connected to duct external to
furnace main casing.
Return Air Connections
The return-air duct may be connected to bottom of the furnace. The side
of casing that faces downward may also be used for return air
connection. A combination of the bottom and downward facing side may
also be used. The upward facing side of the casing cannot be used as a
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in bottom
return-air opening. Remove this panel when bottom return air is used.
This panel may be used as a roll-out shield or discard. To remove bottom
.
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,
. Where required by code, seal bottom closure to furnace with
tape, mastic or other durable sealing method.
Filter Arrangement
Filter and Return Duct Sizing
Pressure drop must be taken into account when sizing filters, filter racks,
IAQ devices, and associated system ductwork. See
for a
comparison of Pressure Drop (initial/clean resistance to airflow) versus
Airflow for a variety of filter media types and sizes. These are
representative numbers. Consult the filter or IAQ device manufacturers’
specification sheet for performance data for a particular filter media or
IAQ device.
PLENUM
OPENING
C
A
B
D
FLOOR
OPENING
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
APPROVED
COIL ASSEMBLY
OR
COIL BOX
FURNACE
SHEET METAL
PLENUM
FLOOR
OPENING
COMBUSTIBLE
FLOORING
CAUTION
!
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and wear
appropriate protective clothing, safety glasses and gloves when
handling parts, and servicing furnaces.
WARNING
!
FIRE HAZARD
A failure to follow this warning could cause personal injury, death
and/or property damage.
Never connect return-air ducts to the back of the furnace. Follow
instructions below.
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.
FURNACE
CASING
WIDTH
FILTER SIZE
FILTER TYPE
SIDE
RETURN
BOTTOM
RETURN
17-1/2 (445)
16 x 25 x 3/4
(406 x 635 x 19)
16 x 25 x 3/4
(406 x 635 x 19)
Washable
*
*. Recommended to maintain air filter face velocity. See Specification Sheet
for part number.
21 (533)
16 x 25 x 3/4
(406 x 635 x 19)
20 x 25 x 3/4
(508 x 635 x 19)
Washable
24-1/2 (622)
16 x 25 x 3/4
(406 x 635 x 19)
24 x 25 x 3/4
(610 x 635 x 19)
Washable