DUCTWORK
Ductwork should be designed and sized according to the
methods in Manual Q of the Air Conditioning Contractors of
America (ACCA).
A closed return duct system shall be used. This shall not
preclude use of economizers or outdoor fresh air intake. The
supply and return air duct connections at the unit should be
made with flexible joints to minimize noise.
The supply and return air duct systems should be designed for
the CFM and static requirements of the job. They should NOT
be sized to match the dimensions of the duct connections on
the unit.
CAUTION: When fastening ductwork to side duct flanges on
unit, insert screws through duct flanges only. DO
NOT insert screws through casing.
Outdoor ductwor k must be insulated and
waterproofed.
Refer to Dimensions and Clearances Figure for information
concerning side and bottom supply and return air duct openings.
FIXED OUTDOOR AIR INTAKE DAMPER
This damper is shipped inside the return air compartment. It is
completely assembled and ready for installation. A damper
baffle inside of the hood is adjustable to provide variable
amounts of outdoor air intake on units that are not provided
with an economizer or a motorized damper option. Refer to the
Fixed Outdoor Damper figure.
Gasketing and mounting screws are provided in a parts bag
attached to the hood assembly. Apply gasketing to the three
flange surfaces on the hood prior to installing the hood. Extend
gasketing 1/4 inch beyond the top and bottom of the two side
flanges to insure adequate sealing.
Adjusting the damper to the desired air flow may be done before
mounting the hood into position or (after installation) by
removing the front hood panel or the screen on the bottom of
the hood. Damper baffle in position 1 will allow approximately
10% recirculated air flow, position 2 approximately 15% and, to
allow approximately 25%, remove the damper baffle.
On units with bottom return air applications, install the damper
assembly over the opening in the side return air access panel.
Remove and discard the opening cover and the covering over
the hood mounting holes (used for shipping) before installing.
Secure with the screws provided.
On units with side return air applications, install the damper
assembly on the return air ductwork as close to the unit as
possible. Cut an opening 16 inches high by 18 inches wide in
the ductwork to accommodate the damper. Using the holes in
the hood flanges as a template, drill 9/64 inch dia. (#26 drill)
holes into the ductwork and secure with the screws provided.
CAUTION: If outdoor air intake will not be required on units
with bottom return air applications, the damper
assembly should still be mounted on the side return
air access panel, per the instructions above, to
insure moisture is not drawn into the unit during
operation. The covering over the mounting holes
only need be removed. Do not remove the opening
cover.
CONDENSATE DRAIN
Plumbing must conform to local codes. Use a sealing
compound on male pipe threads. Install a condensate drain line
from the one-inch NPT female connection on the unit to an open
drain.
An alternate drain connection (one-inch NPT female coupling)
is provided inboard on the same centerline as the exterior
location.
NOTE: The condensate drain operates in a negative pressure
in the cabinet. The condensate drain line MUST be
trapped to provide proper drainage. See figure below.
COMPRESSORS
Units are shipped with compressor mountings factory-adjusted
and ready for operation.
CAUTION: Do Not loosen compressor mounting bolts.
FILTERS
Two-inch filters are supplied with each unit. Filters must always
be installed ahead of the evaporator coil and must be kept clean
or replaced with same size and type. Dirty filters will reduce the
capacity of the unit and will result in frosted coils or safety
shutdown. Minimum filter area and required sizes are shown in
Physical Data Table.
SERVICE ACCESS
Access to all serviceable components is provided by the
following removable panels:
•
Compressor compartment
•
Gas Heat compartment (Two panels)
•
Side Supply & Return Air compartments (Two panels)
•
Blower compartment (Three panels)
•
Main control box
•
Filter compartment
•
Outdoor Air compartment (Two panels)
Refer to the Dimensions and Clearances Figure for location of
these access panels.
CAUTION: Make sure that all screws and panel latches are
replaced and properly positioned on the unit to
maintain an air-tight seal.
FIG. 3 - FIXED OUTDOOR AIR DAMPER
FIG. 4 - RECOMMENDED DRAIN PIPING
It is recommended that, in Canada, the outlet duct be provided with
a removable access panel. It is recommended that this opening be
accessible when the unit is installed in service, and of a size such
that smoke or reflected light may be observed inside the casing to
indicate the presence of leaks in the heat exchanger. The cover
should be attached in a manner adequate to prevent leakage.
530.18-N6Y
4
Unitary Products Group
