10
18-CD29D1-11
Installer’s Guide
FILTER
REMOVE FILTER FROM UPFLOW
FURNACE WHEN RETURN DUCT IS
ATTACHED TO FURNACE TOP SIDE
(HORIZONTAL APPLICATIONS) AS
SHOWN.
Close coupled (less than 36")
return (filter directly beneath bottom
side return) not recommended due to
noise considerations. If used, securely
attach 1/2" mesh metal hardware cloth
protective screen to the inside bottom
of filter grill.
0
*
SEE OUTLINE DRAWING
q
LOCATING
NOTCHES
PROVIDED
FOR SIDE
RETURN
CUTOUT
*
*
*
*
CUT OUT
FOR
SIDE
FILTER
FRONT
of Furnace
TABLE 4 - MINIMUM CLEARANCE FROM COMBUSTIBLE MATERIALS FOR
UPFLOW/HORIZONTAL LEFT AND DOWNFLOW/HORIZONTAL RIGHT FURNACES
UNIT LOCATION
FURNACE SURFACE
VERTICAL
CLOSET
HORIZONTAL
CLOSET
HORIZONTAL
ALCOVE / ATTIC
SIDES
0"
1"
0"
BACK
0"
3"
6"
TOP
1"
1"
1"
FRONT
3"
3"
18"
VENT
0"
0"
0"
NOTE: CLEARANCE REQUIRED AT TOP OF PLENUM IS 1"
When the upflow furnace is installed in the horizontal
application and a close coupled (less than 36") return
duct is attached to the bottom side of the furnace as
shown in Figure 10, securely attach a 1/2" mesh metal
hardware cloth protective screen to the inside bottom
of the filter grill
to prevent personal injury from
contacting moving parts when reaching into the
return opening to replace the filter.
Close coupled (less than 36") return (filter directly
beneath bottom side return) is not recommended due to
noise considerations.
Downflow Furnaces: Brackets are factory supplied
to mount filters in the return air duct work.
RETURN AIR FILTERS
(Filter and filter rack are not supplied with unit)
TYPICAL UPFLOW RETURN AIR FILTER INSTALLATIONS
These furnaces require high velocity type air filters. The
optional filters may be located within the furnace blower
compartment for UPFLOW furnaces in either a BOTTOM
or SIDE (left side or right side) return air inlet. Some
optional filters may need to be trimmed for side or bottom
filter use.
The furnace and the blower filter rack installation can be
seen in Figure 12.
The optional furnace filter in the bottom or side configura-
tion can be removed by simply turning the two latches on
the blower door and tilting the door forward.
The filter rails are spring loaded for automatic adjustment
to allow standard size, locally obtainable replacement
filters. The filter rack itself slides to adjust to the required
width needed for bottom or side return.
▲
WARNING
!
FIRE OR EXPLOSION HAZARD
Do not install the filter in the return duct directly above
the furnace in horizontal applications. Install the filter re-
motely. Failure to follow the safety warnings exactly could
result in serious injury, death or property damage.
▲
WARNING
!
SAFETY HAZARD
To prevent injury or death due to contact with moving
parts, turn the power to the furnace off before servicing
filters
Failure to follow the safety warnings exactly could result
in serious injury, death or property damage.
7. Connect the duct work to the furnace. See Outline
Drawing (pages 5-6) for supply and return duct size
and location. Flexible duct connectors are recommend-
ed to connect both supply and return air ducts to the
furnace.
If only the front of the furnace is accessible, it is recom-
mended that both supply and return air plenums are
removable.
8. When replacing a furnace, old duct work should be
cleaned out. Thin cloths should be placed over the
registers and the furnace fan should be run for 10 min-
utes. Don’t forget to remove the cloths before you start
the furnace.
