
-- 24 --
NOTES:
ANGLE
IRON OR
EQUIVALENT
(B)
(A) ROD LOCATION
USING DIMPLE
LOCATORS
(SEE DIMENSIONAL
DWG FOR
LOCATIONS)
13
/
16
-IN. (21 mm) MAX
ALTERNATE SUPPORT
LOCATION FROM BACK
ALTERNATE SUPPORT
LOCATION 4-IN. (102 mm) MIN
8-IN. (203 mm) MAX
3
/
8-IN. (10 mm) ROD
(A)
(B)
(A)
(B)
(B)
(A)
1. A 1-in. (25.4 mm) clearance minimum
between top of furnace and combustible
material.
2. The entire length of furnace must be
supported when furnace is used in horizontal
position to ensure proper drainage.
3. For non-direct vent/1-pipe application,
bottom side combustion-air entry cannot be
used when furnace is installed with hangers
as shown.
(A) PREFERRED ROD LOCATION
(B) ALTERNATE ROD LOCATION
DRAIN
5
3
/
4
″
3
/
8
-IN. HEX NUT
& WASHER (4)
REQD PER ROD
VENT
COMBUSTION-AIR PIPE
(DIRECT VENT/2-PIPE
APPLICATION,ALL SIZES)
COMBUSTION-AIR INTAKE
(NON-DIRECT VENT/1-PIPE
APPLICATION)
3-IN. (76 mm) MINIMUM CLEARANCE TO
COMBUSTION-AIR INTAKE IS REQUIRED
(NON-DIRECT VENT/1-PIPE
APPLICATION,)
(146 mm)
A05054
Fig. 25 --
Crawlspace Horizontal Application for Direct Vent/2-Pipe Installation and for
Non-Direct Vent/1-Pipe Installation
Downflow Furnaces
Connect supply-air duct to supply-air opening on furnace. The
supply-air duct attachment must be connected to ONLY furnace
supply/outlet or air conditioning coil casing (when used), when
installed on non-combustible material. When installed on
combustible material, supply-air duct attachment must be
connected to ONLY an accessory subbase or 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 external to furnace main casing.
Supply air opening duct flanges must be modified per Fig. 24.
Horizontal Furnaces
Connect supply-air duct to supply air opening on furnace. The
supply-air duct attachment must be connected to ONLY furnace
supply/outlet or air conditioning coil casing (when used). DO
NOT cut main furnace casing to attach supply side air duct,
humidifier, or other accessories. All accessories MUST be
connected external to furnace main casing.
RETURN AIR CONNECTIONS
The furnace and its return air system shall be designed and
installed so that negative pressure created by the air circulating
fan cannot affect another appliance’s combustion air supply or act
to mix products of combustion with circulating air. The air
circulating fan of the furnace, if installed in an enclosure
communicating with another fuel-burning appliance not of the
direct-vent type, shall be operable only when any door or panel
covering an opening in the furnace fan compartment or in a return
air plenum on ducts is in the closed position.
Upflow 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. 2. Bypass humidifier may be attached
into unused side return air portion of the furnace casing. DO NOT
connect any portion of return-air duct to back of furnace casing.
FIRE HAZARD
A failure to follow this warning could result in personal injury,
death, or property damage.
Never connect return-air ducts to the back of the furnace.
Return-air duct connections on furnace side(s) permitted in
upflow applications only.
!
WARNING
Downflow and Horizontal Furnaces
The return-air duct must be connected to end inlet opening
provided as shown in Fig. 2. DO NOT cut into casing sides or