Installation Manual

5
Clearances to Combustible Materials
This furnace is Design Certified in the U.S. and Canada
for the minimum clearances to combustible materials.
NOTE: The furnace is listed for installation on combustible
or non-combustible flooring. However, wood is the only
combustible flooring allowed for installation. To obtain
furnace base model number and specific clearance
information, refer to the furnace rating plate, located inside
of the furnace cabinet.
Access for positioning and servicing the unit must be
considered when locating the unit. The need to provide
clearance for access to panels or doors may require
clearance distances over and above the requirements.
Allow 18 inches minimum clearance from the front of
the unit. However 36 inches is strongly recommended.
See Table 1 for minimum clearance requirements.
The ductwork should be appropriately sized to the capacity
of the furnace to ensure its proper airflow rating. For
installations above 2,000 ft., the furnace should have a
sea level input rating large enough that it will meet the
heating load after deration for altitude.
Combustion Air Quality
CAUTION:
Combustion air must not be drawn from a
corrosive atmosphere.
To maximize heat exchanger life, the combustion air
must be free of chemicals that can form corrosive acidic
compounds in the combustion gases. The required source
of combustion air is to use outdoor air.
If outside air is used as return air to the furnace for
ventilation or to improve indoor air quality, the system must
be designed so that the return air is not less than 60° F
(15° C) during operation. If a combination of indoor and
outdoor air is used, the ducts and damper system must
be designed so that the return air supply to the furnace is
equal to the return air supply under normal, indoor return
air applications.
Exposure to the following substances in the combustion
air supply will result in safety and performance related
problems. The list below contains examples of chemical
containments found in a wide variety of common
commercial household products:
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine based swimming pool chemicals
Water softening chemicals
De-icing salts or chemicals
Carbon Tetrachloride
Halogen type refrigerants
Cleaning solvents (perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric Acid
Cements and glues
Antistatic fabric softeners
Masonry acid washing materials
Heating Load
This furnace should be sized to provide the design heating
load requirement. Heating load estimates can be made
using approved methods available from Air Conditioning
Contractors of America (Manual J); American Society of
Heating, Refrigerating, and Air Conditioning Engineers;
or other approved engineering methods. Excessive
oversizing of the furnace could cause the furnace
and/or vent to fail prematurely.
Condensate Disposal
The method for disposing of condensate varies according
to local codes. Consult your local code or authority having
jurisdiction. Neutralizer kit P/N 902377 is available for
use with this furnace. Please follow the instructions
provided with the kit.
INSTALLATION CLEARANCES
CLOSET ALCOVE
Front * 1" 1"
Rear 0" 0"
Sides 0" 0"
Top 6" 6"
Duct w/in 3ft of furnace 1/4" 1/4"
Vent 0” 0”
Plenum Without Coil Box 1" 1"
Plenum With Coil Box 0” 0”
NOTES:
Alcove Installations - Allow 18 in. minimum clearance from front of unit
to nearest wall or partition for servicing.
Closet installations - Require a return air grill installed in the door or a
partially louvered door across the opening for proper air circulation. For
clearances 6” or greater, the closet must have an open free area of 235
in
2
minimum. For special clearances between 1” & 6”, requirements are
a louvered door with a minimum of 250 in
2
(1613 cm
2
) free area. For 1”
clearance from furnace, use a fully louvered door with at least 400 in
2
of
free airflow area. A fully louvered closet door is strongly recommended
for all installation types.
LEFT
SIDE
FRONT
RIGHT
SIDE
REAR
RIGHT
SIDE
MODELS WITH FRONT AIR RETURN MODELS WITH TOP AIR RETURN
REAR
LEFT
SIDE
FRONT
VENT
VENT
Table 1. Minimum Clearances