Ductwork; Roof Curb; Filters; Condensate Drain - York R-410A Installation Manual

288429-YIM-A-0307
1
Figure 6: Roof Curb

Ductwork

These units are adaptable to downflow use as well as rear
supply and return air duct openings. To convert to downflow,
use the following steps:
1. Remove the duct covers found in the bottom return and
supply air duct openings. There are four (4) screws securing
each duct cover (save these screws to use in Step 2).
2. Install the duct covers (removed in step one) to the rear
supply and return air duct openings. Secure with the four
(4) screws used in step one.
3. Seal duct covers with silicone caulk.
Duct work should be designed and sized according to the
methods of the Air Conditioning Contractors of America
(ACCA), as set forth in their Manual D.
A closed return duct system shall be used. This shall not
preclude use of economizers or ventilation air intake. Flexible
joints may be used in the supply and return duct work to
minimize the transmission of noise.
When fastening duct work to the side duct flanges on
the unit, insert the screws through the duct flanges only.
DO NOT insert the screws through the casing. Outdoor
duct work must be insulated and waterproofed.
1. 8" Roof Curb also available.
Unitary Products Group
NOTE: Be sure to note supply and return openings.
Refer to Figures 4 and 5 for information concerning rear and
bottom supply and return air duct openings.

Roof Curb

On applications when a roof curb is used, the unit must be
positioned on the curb so the front of the unit is tight against the
curb.

Filters

Single phase units are shipped without a filter or filter racks. It is
the responsibility of the installer to secure a filter in the return air
ductwork or install a Filter/Frame Kit (1FF0114).
A filter rack and high velocity filters are standard on three phase
units.
Filters must always be used and must be kept clean. When
filters become dirt laden, insufficient air will be delivered by the
blower, decreasing your units efficiency and increasing
operating costs and wear-and-tear on the unit and controls.
Filters should be checked monthly; this is especially important
since this unit is used for both heating and cooling.

Condensate Drain

A condensate trap is recommended to be installed in the
condensate drain. The plumbing must conform to local codes.
Use a sealing compound on male pipe threads. Install the
condensate drain line (3/4" NPTF) to spill into an open drain.
7