Horizontal
installation
Duct system installation
Proper duct sizing and design
is critical to the performance of
the unit. The duct system should
be designed to allow adequate
and even airflow through the unit
during operation. Air flow through
the unit
must
be at or above
the minimum stated airflow for
the unit to avoid equipment
damage and/or nuisance system
error codes. Duct systems
should be designed for quiet
operation. A flexible connector
is recommended for both
discharge and return air duct
connections on metal duct
systems to eliminate the transfer
of vibration to the duct system.
To maximize sound attenuation
of the unit blower, the supply
and return plenums should
include internal duct liner or be
constructed from ductboard for
the first few feet. Application of
the unit to uninsulated ductwork
in an unconditioned space is
not recommended, as the unit’s
performance may be adversely
affected.
At least one 90° elbow should
be included in the supply duct to
reduce air noise.
If the unit is connected to
existing ductwork, a previous
check should have been made
to ensure that the ductwork has
the capacity to handle the airflow
required for the unit. If ducting is
too small, as in the replacement
of a heating only system, larger
ductwork should be installed.
All existing ductwork should be
checked for leaks and repaired
as necessary.
Note
n
n
Refer to Figure 3 on page 8 for horizontal
duct system details.
Horizontal Installation
Flex hose
Return air
Return air
Supply air
Locate unit over hallways
where possible
Insulated return
(optional)
Flexible duct collar
90° elbow
Flexible duct
connection
Insulated
supply
Figure 8: Typical duct system
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