DOWNFLOW DUCT CONNECTORS
ATTIC INSTALLATION
All downflow installations must use a suitable duct connector approved by the furnace manufacturer for use with this furnace. The duct connec- tors are designed to be connected to the rectangular duct under the floor and sealed. Refer to the instructions supplied with the duct con- nector for proper installation. Refer to the separate accessory parts list at the end of these instructions for the approved accessory duct con- nectors.
FURNACE
Line contact only permissible between lines formed by the intersection of furnace top and two sides and building joists, studs or framing
Filter rack |
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must be a minimum |
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distance | Gas Piping |
of 18” (45.7 cm) |
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from the |
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furnace |
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Supply
Air
Vent (Maintain required clearances to combustibles)
Sheet metal in
front of furnace
combustion air
12”Openings is Recommended
12” 
30” MIN. Work Area
WARM AIR PLENUM
WITH 1” FLANGES
FIBERGLASS
INSULATION
FIBERGLASS TAPE
UNDER FLANGE
COMBUSTIBLE FLOOR
BASE ACCESSORY
FIGURE 8: Combustible Floor Base Accessory
RESIDENTIAL AND MODULAR HOME UPFLOW RETURN PLENUM CONNECTION
Return air may enter the furnace through the side(s) or bottom depend- ing on the type of application. Return air may not be connected into the rear panel of the unit.
BOTTOM RETURN AND ATTIC INSTALLATIONS
Bottom return applications normally pull return air through a base plat- form or return air plenum. Be sure the return platform structure or return air plenum is suitable to support the weight of the furnace.
The internal bottom panel must be removed for this application.
Attic installations must meet all minimum clearances to combustibles and have floor support with required service accessibility.
HORIZONTAL APPLICATION
FIGURE 9: Horizontal Application
This furnace may be installed in a horizontal position on either side as shown above. It must not be installed on its back.
Return
AirSediment
Trap
FIGURE 10: Typical Attic Installation
This appliance is certified for line contact when the furnace is installed in the horizontal left or right position. The line contact is only permissible between lines that are formed by the intersection of the top and two sides of the furnace and the building joists, studs or framing. This line may be in contact with combustible material. Refer to Figure 10, "Typi- cal Attic Installation".
When a furnace is installed in an attic or other insulated space, keep all insulating materials at least 12 inches (30.5 cm) away from furnace and burner combustion air openings.
SUSPENDED FURNACE / CRAWL SPACE INSTALLATION
The furnace can be hung from floor joists or installed on suitable blocks or pad. Blocks or pad installations shall provide adequate height to ensure the unit will not be subject to water damage. Units may also be suspended from rafters or floor joists using rods, pipe angle supports or straps. Angle supports should be placed at the supply air end and near the blower deck. Do not support at return air end of unit. All four sus- pension points must be level to ensure quite furnace operation. When suspending the furnace use a secure platform constructed of plywood or other building material secured to the floor joists. Refer to for typical crawl space installation.
Support
Angle IronBracket
Bracket
6” Min. Between
Rod & Front of Furnace1” Max. Between
Rod & Back of Furnace
FIGURE 11: Typical Suspended Furnace / Crawl Space Installation
Johnson Controls Unitary Products | 7 |
