437758-YIM-A-0409
Johnson Controls Unitary Products
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Figure 6: Roof Curb
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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.
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 (1FF0110, 1FF0112 or
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.
1. 8” Roof Curb also available.
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RECOMMENDED
DUCT SIZE
17-1/8" x 21-1/2"
RECOMMENDED
DUCT SIZE
17-1/2" x 16-3/4"
OPENING FOR
RETURN AIR DUCT
OPENING FOR
SUPPLY AIR DUCT
42-2/3
40-3/4
17-5/8
17-1/4
43-1/4
22
45-1/8
3-1/2
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