Attachment To Structure; Combustible Floor Base Accessory - York MM9E Series Installation Manual

5715184-BIM-A-0519
DUCTWORK INSTALLATION AND SUPPLY PLENUM
CONNECTION - UPFLOW
Attach the supply plenum to the furnace outlet. The use of
an approved flexible duct connector is recommended on all
installations. This connection must be sealed to prevent air
leakage. The sheet metal must be crosshatched to elimi-
nate any popping of the sheet metal when the indoor fan is
energized.

Attachment to Structure

A furnace for installation in a manufactured (mobile) home must be
securely attached to the building structure. The perforated strap sup-
plied with the furnace may be used for that purpose. Refer to Figure 2.
FIGURE 2: Attachment to Structure
FLOOR BASE AND DUCTWORK INSTALLATION -
DOWNFLOW
Installations on combustible material or directly on any
floors must use a combustible floor base as shown in Fig-
ure 3. Follow the instructions supplied with the combustible
floor base accessory. This combustible floor base can be
replaced with a matching indoor coil, properly sealed to pre-
vent leaks. Follow the instructions supplied with the indoor
coil cabinet for installing the cabinet to the duct connector.
Plug intake and vent pipe holes in bottom panel and move
grommet to required vent side exit.
Downflow Air - Indoor Coil Cabinet
The furnace must be installed with coil cabinet part number specifically
intended for downflow application. If a matching indoor coil is used, it
may be placed directly on the furnace outlet and sealed to prevent leak-
age. For details of the coil cabinet dimensions and installation require-
ments, refer to the installation instructions supplied with the coil cabinet.
Attach the indoor coil cabinet to the duct connector, and then position
the furnace on top of the coil cabinet. The connection to the furnace,
indoor coil cabinet, duct connector, and supply air duct must be sealed
to prevent air leakage.
6
DOWNFLOW DUCT CONNECTORS
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.
FIGURE 3: 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.
SIDE RETURN APPLICATION
Side return applications pull return air through an opening cut in the
side of the furnace casing. This furnace is supplied with a bottom block-
off panel that must be left in place if a side return is used. If the furnace
is installed on a flat, solid surface, this bottom panel provides an ade-
quate seal to prevent air leakage through the unused bottom opening.
However, if the furnace is installed on a surface that is uneven, or if it is
installed on blocks or otherwise raised off the floor, it is necessary to
seal the edges of the bottom panel to the casing using tape or
other appropriate gasket material to prevent air leakage.
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.
Johnson Controls Ducted Systems