Installation Manual

14
Specifications are subject to change without notice.
441 01 3500 00
Upflow and Horizontal
Furnaces
Connect supply-- air duct to flanges on furnace supply--air outlet.
Bend flange upward to 90_ with wide duct pliers. (See Fig. 14.)
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.
NOTE: For horizontal applications, the top most flange may be
bent past 90_ to allow the evaporator coil to hang on the flange
temporarily while the remaining attachment and sealing of the
coil are performed.
Downflow Furnaces
Connect supply-- air duct to supply-- air outlet on furnace. Bend
flange inward past 90_ with wide duct p liers (See Fig. 14.) 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 accessories MUST be connected to duct external
to furnace casing.
UPFLOW DOWNFLOW HORIZONTAL
YES
NO
NO
YES
YES
YES
NO
120
MIN
YES
120
MIN
YES
120
MIN
90
90
A02020
Fig. 14 -- Duct Flanges
Return Air
Connections
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
Downflow Furnaces
The return--air duct must be connected to return --air opening
(bottom inlet) as shown in Fig. 3. DO NOT cut into casing sides
(left or right). Side opening is permitted for only upflow and
certain horizontal furnaces. Bypass humidifier connections
should be made at ductwork or coil casing sides exterior to
furnace. (See Fig. 19.)
Upflow and Horizontal
Furnaces
The return--air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing as shown in Fig. 3. Bypass humidifier may be attached
into unused return air side of the furnace casing. (See Fig. 18 and
20.) Not all horizontal furnace models are approved for side
return air connections. (See Fig. 20.)