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Installation
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Duct and Condensate Drain Connections
Condensate Drain Connection
All condensate drain connections must be properly trapped and primed before operating the unit. Failure to properly trap a drain will result in flooding
the drain pan and potential water damage to the unit or building.
Slope the piping from the trap downward in direction of flow. The trap must be primed before startup
by filling the “U” portion of the trap with water. Drains that are not properly trapped and primed will not
operate correctly. Each drain connection must be individually trapped.
Drains that are inactive will dry out and air will be drawn through the drain, preventing water flow.
Inactive drains should be plugged or connected to a shutoff valve. On outdoor units that operate during
freezing weather, install a heat trace around trap piping. Refer to the following figure to determine the
correct trap height.
Drain Sizes and Locations
Drains are located on the access side of all units and are sized as shown in the following diagrams.
DUCT AND CONDENSATE DRAIN CONNECTIONS
Figure 33: AR-DR / AR-DE 11-XX, 21-XX, and 31-XX Chassis Drain
Sizes and Locations.
Table 11: AR-DR / AR-DE 11-XX, 21-XX, 31-XX, and 35-XX Chassis
Drain Sizes and Locations.
Chassis Size
A (in.)
B (in.)
Diameter (in.)
11-XX
58
7
1.0
21-XX
65
7
1.0
31-XX
75
7
1.0
35-XX
119
4
1.0
Duct Connections
The contractor is responsible for providing transitions to accommodate difference in sizing between the unit and the building ducts. Duct
connections to collar-type openings can be made with S-cleats or overlapping joints. Apply caulk around each duct connection. Failure to
seal duct connections can cause air leakage and system performance problems.
A straight duct for a distance of three (3) to six (6) duct diameters from the unit discharge should be used to develop a full dynamic head.
Branching and turning closer to the discharge causes system effect losses.
When an air duct which carries supply air or warm air passes through a combustible roof, a clearance of one inch must be maintained between the
outside perimeter of ductwork and any combustible materials, per NFPA Standard 90A.
Figure 32:
Trap Specifications.
Figure 34: AR-DR / AR-DE 35-XX Chassis Drain Size and Location.
