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
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
•Noncombustible pans having 1” upturned fl anges must be located beneath openings in a fl
•Wiring materials located in return duct system must conform to NEC Article
•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 downflow 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
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.
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