User Guide

9
PRODUCT DESIGN
Thermostats:
NOTE: Complete lineup of thermostats can be found in the Thermostat Specification Sheets.
Filters:
Filters are required with this furnace and must be provided by the installer. The filters used must comply with UL900 or
CAN/ULCS111 standards. Installing this furnace without filters will void the unit warranty.
This furnace has provisions for the installation of return air filters at the side and/or bottom return. The furnace will
accommodate the following filter sizes depending on cabinet size:
Refer to Minimum Filter Area tables to determine filter area requirement. NOTE: Filters can also be installed elsewhere in
the duct system such as a central return.
Upflow Filters
Cabinet
Width
(in.)
Nominal
Filter Size
(in.)
Approx.
Flow Area
(in
2
)
Cabinet
Width
(in.)
Nominal
Filter Size
(in.)
Approx.
Flow Area
(in
2
)
All 16 x 25 x 1 400 17-1/2 14 x 25 x 1 350
21 16 x 25 x 1 400
Side Return(s) Bottom Return
FURNACE INPUT FILTER SIZE TYPE
45M
160 in
2
permanent
70M
241 in
2
permanent
90M
320 in
2
permanent
115M
400 in
2
permanent
140M
370 in
2
permanent
45M
320 in
2
disposable
70M
483 in
2
disposable
90M
640 in
2
disposable
115M
800 in
2
disposable
140M
738 in
2
disposable
PERMANENT NOMINAL 600 F.M. FACE VELOCITY
DISPOSABLE NOMINAL 300 F.M. FACE VELOCITY
MINIMUM FILTER SIZES