INSTALLATION CONSIDERATIONS
30
system and a single stage heating/single stage cooling
system. Refer to the following figures for proper connec-
tions to the integrated control module.
CIRCULATING AIR AND FILTERS
DUCTWORK - AIR FLOW
Duct systems and register sizes must be properly designed
for the C.F.M. and external static pressure rating of the
furnace. Ductwork should be designed in accordance with
the recommended methods of "Air Conditioning Contrac-
tors of America" manual D.
A duct system should be installed in accordance with Stan-
dards of the National Board of Fire Underwriters for the In-
stallation of Air Conditioning, Warm Air Heating and Venti-
lating Systems, Pamphlets No. 90A and 90B.
A return air filter is not supplied with the furnace. The in-
staller must supply a means of filtering all of the return air.
Filter(s) shall comply with UL900 or CAN/ULC-S111 Stan-
dards.
Upflow furnaces with air delivery of less than 1800 CFM:
Use one side return or one bottom return ductwork connec-
tion.
Upflow furnaces with air delivery of 1800 CFM or higher:
Use two side returns or one side return and one bottom
return connection.
Guide dimples locate the side and bottom return cutout
locations. Use a straight edge to scribe lines connecting
the dimples. Cut out the opening on these lines. An under-
sized opening will cause reduced airflow. For bottom return
connection, remove the bottom of the cabinet before set-
ting the furnace on the raised platform or return air duct.
A closed return duct system must be used, with the return
duct connected to the furnace.
NOTE:
Ductwork must never
be attached to the back of the furnace.
Supply and return
connections to the furnace may be made with flexible joints
to reduce noise transmission, if desired. If a central return
is used, a connecting duct must be installed between the
unit and the utility room wall so the blower will not interfere
with combustion air or draft. The room, closet, or alcove
must not be used as a return air chamber.
When the furnace is used in connection with a cooling unit,
the furnace should be installed in parallel with or on the
upstream side of the cooling unit to avoid condensation in
the heating element. With a parallel flow arrangement, the
dampers or other means used to control the flow of air must
be adequate to prevent chilled air from entering the furnace
and, if manually operated, must be equipped with means
to prevent operation of either unit unless the damper is in
the full heat or cool position.
When the furnace is heating, the temperature of the return
air entering the furnace must be between
55°F
and
100°F
.
UPRIGHT FILTER INSTALLATIONS
Depending on the installation and/or customer preference,
differing filter arrangements can be applied. Filters can be
installed in the central return register and a side panel ex-
ternal filter rack kit (upflow filter kit # EFR02). As an alter-
native a media air filter or electronic air cleaner can be used
as the requested filter. Refer to the following minimum filter
requirement charts for determination of the minimum filter
area to ensure proper unit performance.
The following
figures
show possible filter locations.
NOTE:
A ductwork
access door must be used in counterflow applications to
allow filter removal. If the filter rack is used, the side of the
plenum must be at least as tall as dimension "A" shown in
the following illustration. For dimension of "A" refer to the
following chart.
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.
Horizontal Installations
Filter(s) must be installed external to the furnace casing for
horizontal installations. For most installations it is prefer-
able to use a central return with filters installed in the duct
behind the return air grill. In this way filter replacement is
relatively simple by merely removing the grille, rather than
going into the attic or crawl space.
ADDITIONAL FILTERING ACCESSORIES
External Filter Rack Kit (EFR02)
The external filter rack kit is intended to provide a location
external to the furnace casing, for installation of a perma-
nent filter on upflow model furnaces. The rack is designed
to mount over the indoor blower compartment area of either
side panel, and provide filter retention as well as a location
for attaching return air ductwork.
Electronic Air Cleaner (ASAS and GSAS) or Media
Air Cleaner (AMU and GMU)
The electronic air cleaner and media air cleaner are multi-
positional high efficiency air filtration devices that can be
installed in any position, except with the access door fac-
ing down. The best location for the air cleaner is in the
