Return Air Filters - Trane UD1A040A9241A Series Installer's Manual

3. The side panels on upflow furnaces include locating
notches which may be used as guides for cutting an
opening for return air. Refer to Figure 12 and the
outline drawing on page 4 for duct connection dimen-
sions for various furnaces.
4. If a 3/4" flange is to be used for attaching the air inlet
duct, add to cut where indicated by dashed lines in
Figure 12. Cut corners diagonally and bend outward to
form flange.
5. If flanges are not required, and a filter frame is in-
stalled, cut along knockout guidelines.
6. Upflow Furnaces: Use the optional filter rack on
either side or on the bottom if the filter is to be used
within the furnace cabinet.
When the upflow furnace is installed in the horizontal
right or left application and a return duct is attached to
the top side as shown in Figure 11, install the filter in a
remote location.
▲
WARNING
!
Do not install the filter in the return duct directly above the
furnace in horizontal applications. Install the filter remotely.
Installing the filter directly above the furnace in horizontal
applications may cause property damage, serious injury or
death.
▲
WARNING
!
TO PREVENT INJURY OR DEATH DUE TO CONTACT
WITH MOVING PARTS, TURN THE POWER TO THE
FURNACE OFF BEFORE SERVICING FILTERS.
Do not install the filter in the return duct directly above
the furnace in horizontal applications.
When the upflow furnace is installed in the horizontal
right or left application and a close coupled (less than
36") return duct is attached to the bottom side of the
furnace as shown in Figure 11, 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 reach-
ing into the return opening to replace the filter.
REMOVE FILTER FROM UPFLOW
FURNACE WHEN RETURN DUCT IS
ATTACHED TO FURNACE TOP SIDE
(HORIZONTAL LEFT OR RIGHT
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.
18-CD19D7-22
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.
7. Connect the duct work to the furnace. See Outline
Drawing (pages 4&5) for supply and return duct size and
location. Flexible duct connectors are recommended to
connect both supply and return air ducts to the furnace.
If only the front of the furnace is accessible, it is
recommended that both supply and return air ple-
nums 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.

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.
NOTE:
On upflow 5 or 6 ton airflow models where the airflow
requirement exceeds 1800 CFM - Models will require
return air openings and filters on: (1) both sides; or (2)
one side and the bottom; or (3) just the bottom.
w
LOCATING
NOTCHES
PROVIDED
FOR SIDE
RETURN
CUTOUT
q
SEE OUTLINE DRAWING
*
The furnace and the blower filter rack installation can be seen
in Figure 13.
FILTER
The optional furnace filter in the bottom or side configuration
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.
Installer's Guide
* CUT OUT
FOR
SIDE
FILTER
*
*
*
of Furnace
FRONT
9