36
FIGURE 31
BOTTOM RETURN
DISCONNECT MAIN ELECTRICAL
POWER TO THE UNIT BEFORE
ATTEMPTING ANY MAINTENANCE.
FAILURE TO DO SO CAN CAUSE
ELECTRICAL SHOCK RESULTING
IN SEVERE PERSONAL INJURY OR
DEATH.
FILTERS
Filter application and placement are
critical to airflow, which may affect the
heating and cooling system
performance. Reduced airflow can
shorten the life of the system’s major
components, such as motor, limits,
elements, heat exchanger, evaporator
coil or compressor. Consequently, we
recommend that the return air duct
system have only one filter location.
The most common location will be
inside the furnace or air handler or a
filter base. For systems with a return air
filter grill or multiple filter grills, can have
a filter installed at each of the return air
openings. DO NOT DOUBLE FILTER
THE RETURN AIR DUCT SYSTEM.
DO NOT FILTER THE SUPPLY AIR
DUCT SYSTEM.
If high efficiency filters or electronic air
cleaners are used in the system, it is
important that the airflow is not reduced
to maximize system performance and
life. Always verify that the system’s
airflow is not impaired by the filtering
system that has been installed, by
performing a temperature rise and
temperature drop test.
NOTE: Airflow external static pressure
measurements do not include filter or
coil.
TABLE 17 FILTER SIZES
MAINTENANCE
WARNING
!
FIGURE 30
RESIZING FILTERS & FRAME
*NOTE: Some filters must be
resized to fit certain units and
applications.
SOLID BOTTOM MAY BE ORDERED AS AN OPTION FROM THE FACTORY.
UPFLOW FILTER SIZES
FURNACE INPUT BOTTOM SIDE
QUANTITY
WIDTH BTUH SIZE SIZE
17-1/2" 50 & 100 15
3
⁄4" X 25" 15
3
⁄4" X 25" 1
21" 75 & 100 19
1
⁄4" X 25" 15
3
⁄4" X 25" 1
24-1/2" 125 22
3
⁄4" X 25" 15
3
⁄4" X 25" 1
DOWNFLOW FILTER SIZES
FURNACE INPUT
SIZE QUANTITY
WIDTH BTUH
14" 50 14" X 20" 1
17
1
/2" 75 & 100 12" X 20" 2
21" 100 12" X 20" 2
24
1
/2" 125 & 150 14" X 20" 2
Unit Unit Filter Rod Filter Rod Bottom Side
Size Width 20
3
/4"24
1
/4"
AE-61659-02 AE-61659-03
50,000 17-1/2" 1 Cut Off 3
1
/2" As is
75,000 21" 1 Cut Off 3
1
/2" As is
100,000 21" 1 Cut Off 3
1
/2" As is
125,000 24
1
/2" 1 As is Cut Off 3
1
/2"
To Next Page
