Duct Work And Air Conditioning; Air Filter Mounting - Thermo Pride OD6FA072D48 Installation, Operation And Service Manual

Duct Work and Air Conditioning

Design and installation of the duct system should follow the current guidelines of
the Air Conditioning Contractors of America (ACCA) or the American Society of
Heating, Refrigeration and Air Conditioning Engineers, Inc. (ASHRAE). Refer to
the Residential Duct Systems, Manual D, from the ACCA, and the ASHRAE
Handbook Fundamentals volume, from ASHRAE, for recommended practices in
duct system design and installation.
All furnaces are tested over a range of external static pressure that simulates the
airflow resistance of the ductwork, fittings, and diffusers connected to the furnace
for a typical (average) duct system. The furnace blower and blower motor have
been selected to work successfully against the following range of duct system
resistance.
Recommended range of the duct system external static pressure for all
models: 0.2 to 0.5 in. W.G...
Due to the need to maintain an adequate supply of combustion and ventilation
air, the furnace shall not be installed in small room without return air duct system.
A return air duct shall be connected to the furnace return air opening and extend
to a location outside the furnace room.
If the furnace is used in connection with a cooling coil, the coil must be installed
in parallel with, or on the supply side of the furnace to avoid water vapor
condensation in the furnace heat exchanger. If the cooling unit is installed in a
parallel flow arrangement, dampers (or other means used to control airflow)
should be provided to prevent chilled air from entering the furnace. If such a
damper is manually operated, it must be equipped with a means to prevent
operation of either unit, unless the damper is placed in either the full heat or full
cool position.
NOTICE: Return air grilles and supply registers in the air distribution
system should never be obstructed.

Air Filter Mounting

The OD6 comes with (2) two 19" x 13" reusable filters. A "W" style filter rack is
shipped with the furnace for placement of the filters inside the return air plenum
on counterflow installations. Access to the filters is through the removable blower
door. For horizontal installations, it is recommended that return air grill filters be
installed for homeowner access. See Fig. 2.
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