9
A
B
19”
(483 mm)
19"
(483 mm)
TOP VIEW
X
Reducer
*Felt Seal
Corner
Spacers
C
*OPENING TO DUCT
A= 13-1/4" (337 mm)
B= 10-3/4" (274 mm)
WITH PLATE (C) REMOVED
OPENING BECOMES
13-1/4” x 13-1/4”
*Indicates only applicable for Finger Tab Duct Connector
x
SUPPLY AIR DUCT
FLOOR CAVITY
TYPICAL INSTALLATION OF
DOWNFLOW SYSTEMS OR
PLATINUM SYSTEM
The following steps describe installation in-
structions for an under-the-floor supply duct
system with a return air system that can be
either non-ducted 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 non-ducted or
ducted return air. For non-ducted return air
systems, either the optional grille and frame
assembly or the optional wall mount grille is
recommended. 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 pres-
sure produced from the chosen filtering method.
NOTE: Refer to the instructions supplied with
any additional accessories for further installa-
tion details.
Filtering Methods - Non-Ducted Return Air
1.
Without A/C or H/P uncased coil:
- use the filter supplied with the furnace;
ensure that the filter is installed mat side
down between the filter retainer and fur-
nace top (see Figure 4).
2.
With A/C or H/P uncased coil:
- use the optional coil filters; the filter sup-
plied with the furnace is not used; REMOVE
AND DISCARD THIS FILTER.
3.
With optional coil housing:
- see coil cabinet instructions for specific
filtering methods.
Filtering Methods - Ducted Return Air
1.
Without optional coil housing:
- install a filter with a minimum unrestricted
medium area of 324 square inches in the
duct above the coil that is accessible for
monthly cleaning or replacement by home-
owner.
2.
With optional coil housing:
-install a filter with a minimum unrestricted
medium area of 324 square inches in the
duct above the coil that is accessible for
monthly cleaning or replacement by home-
owner.
Optional Duct Connectors for
Downflow Systems
Duct connectors are recommended for heated
air distribution in under-the-floor duct systems.
With this system, furnaces may be installed on
Figure 5. Duct Connector Selection (Non-Platinum)
Frame
Top of
Furnace
Fasteners (4)
Grille
Fur nace Filter
(not used with
A/C or H/P)
Figure 4. Grille Support Frame and Grille
Assembly
