Whirlpool WAHM, Installation Instructions Manual, Page: 6 / 16

6
Ductwork Requirements
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Install the conditioned air plenum, ducts and air filters (not
provided) in accordance with NFPA 90B Standard for the
Installation of Warm Air Heating and Air-Conditioning
Systems (latest edition).
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The air handler is provided with flanges for the connection of
the plenum and ducts.
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The air handler is equipped with flanges that can form a filter
rack for the installation of the air filter, or the filter may be
installed as part of the return air duct system.
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Air filters must be listed as Class 2 furnace air filters.
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Supply and return ductwork must be adequately sized to
meet the system’s air requirements and static pressure
capabilities. Ductwork should be insulated with a minimum of
1" thick insulation with a vapor barrier in conditioned areas or
2" minimum in unconditioned areas.
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Supply plenum should be the same size as the flanged
opening provided around the blower outlet and should
extend ideally at least 3 ft from the air handler before turning
or branching off plenum into duct runs.The plenum forms an
extension of the blower housing and minimizes air expansion
losses from the blower.
INSTALLATION INSTRUCTIONS
Inspect Shipment
These air handlers are completely factory assembled, and all
components are performance tested. Each unit consists of a
blower assembly, refrigerant coil, and controls, in an insulated
galvanized steel factory finished enclosure. Knockouts are
provided for electrical wiring entrance.
1. Check the unit rating plate to confirm specifications are as
ordered.
2. Upon receipt of equipment, thoroughly inspect it for possible
shipping damage. Closely examine the unit inside the carton
if the carton is damaged.
If damage is found, it should be noted on the carrier’s freight bill.
Damage claims should be filed with the carrier immediately.
Claims of shortages should be filed with the seller within 5 days.
NOTE: If any damages are discovered and reported to the carrier,
do not install the unit because your claim may be denied.
If a filter is to be installed at the air handler, a filter rack must be
formed using factory-supplied flanges.
1. Lay air handler on its back.
2. Pry filter rack tabs out.
Excessive Weight Hazard
Use two or more people to move and install air handler.
WARNING
Failure to do so can result in back or other injury.