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 ductwork must be insulated and waterproofed.
Refer to the Dimensions and Clearances figure for information concerning side and bottom supply and return air duct openings.
It is recommended that, in Canada, the outlet duct on gas heating units 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.
FIXED OUTDOOR AIR INTAKE DAMPER
This damper is shipped inside the return air compartment on units that are not provided with an economizer or a motorized damper option. 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.
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" 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" high by 18" wide in the ductwork to accommodate the damper. Using the holes in the hood flanges as a template, drill 9/64" 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.
FIG. 3 - FIXED OUTDOOR AIR DAMPER
CONDENSATE DRAIN
Plumbing must conform to local codes. Use a sealing compound on male pipe threads. Install a condensate drain line from the 1" NPT female connection on the unit to an open drain.
FIG. 4 - RECOMMENDED DRAIN PIPING
NOTE: The condensate drain line MUST be trapped to provide proper drainage.
COMPRESSORS
Units are shipped with compressor mountings
CAUTION: Do Not loosen compressor mounting bolts.
FILTERS
2" 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 the Physical Data Table.
SERVICE ACCESS
Access to all serviceable components is provided by the following removable panels:
•Compressor compartment
•Electric Heat compartment - DCE models
•Gas Heat compartment (Two panels) - DCG models
•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
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