Nordyne E3 Series - Manual (Page 7)

7
Return Air Codes and Requirements
Unducted return air systems may be used for
closet or alcove installations.
NOTE: Applicable installation codes may limit the
furnace to installation in a single-story residence
only. Furnace installations other than closet or
alcove installations require ducted return air
systems.
Air return to the furnace must have a minimum
free area opening (see Table 1).
Acceptable fl oor or ceiling return air systems
for closet installations with return air entering
through an opening in the closet fl oor or ceiling
must meet all of the following requirements:
• Return air opening into closet, regardless of
its location, must not be smaller than size
specifi ed on unit data label.
• If located in fl oor of closet, return air opening
must be provided with means of preventing
its inadvertent closure by a fl at object placed
over opening.
• Materials located in return air duct system
must have a fl ame-spread classifi cation of
200 or less.
• Noncombustible pans having 1” upturned
fl anges must be located beneath openings
in a fl oor-return duct system.
• Wiring materials located in return duct system
must conform to NEC Article 300-22(c).
• Gas piping must not run in or through return
air duct system.
• If return air opening is located below top
of furnace, a minimum clearance must be
provided between opening and furnace (see
“Accessibility for servicing” in Table 1).
Closed-Off Space Requirements
Living space not served by, and closed off from,
the return air ducts to the furnace by doors, sliding
partitions, and other means must be provided
with permanent, uncloseable openings in the
doors or partitions to allow air to return to the
furnace from all parts of the home. Return air
grilles, with a minimum open area of one square
inch for every fi ve square feet of living space
closed off from the furnace, must be provided
in the door or room partition.
OPTIONAL EQUIPMENT
Contact your nearest NORDYNE distributor for a
complete list of electric furnace accessories.
Return Air Grille
A return air grille and frame assembly (see Figure
2) is available for use in unducted return air instal-
lations. In downfl ow alcove installations, the grille
and frame assembly may be mounted directly
to the top of the furnace. In closet installations,
a wall mount grille is available for attachment
to a door or wall.
Optional Automatic Furnace
Damper #901083 -
Furnace may (not required) be equipped with
the optional automatic damper when a packaged
air conditioner is installed and connected to the
warm air duct system. This damper prevents
cooled air from discharging through the furnace
cabinet, causing excessive cooling of the immedi-
ate area. Refer to instructions supplied with the
damper for details.
Multi-Speed Blower Conversion
Package (4 or 5 ton):
Upgrade blower packages are available for
adding air conditioning or heat pump systems.
See furnace “Options and Compatibility” label
for systems available.
TYPICAL INSTALLATION OF
DOWNFLOW SYSTEMS OR
PLATINUM SYSTEM
The following steps describe installation instruc-
tions for an under-the-fl oor supply duct system
with a return air system that can be either
unducted or ducted. Duct connectors (Table 4)
are recommended for this application.
NOTE: Before installing this furnace, consider all
clearances for the installation and future servicing
of the furnace. Refer to Table 1.
Return Air and Filtering Systems
Furnaces may be installed with unducted or
ducted return air. For unducted return air
systems, either the optional grille and frame
assembly or the optional wall mount grille is rec-
ommended. For ducted return air systems with
air conditioners or heat pumps, either providing
an access panel in the duct or using the optional
coil cabinet is recommended. The duct system
must be properly sized so as to account for any
additional external static pressure produced from
the chosen fi ltering method.