York PHG6A24 Installation Manual page 7

DUCTWORK
NOTICE
All units are shipped in the horizontal supply/return configuration. It is
important to reduce the possibility of any air leakage through the bot-
tom duct covers (resulting from cut, torn, or rolled gasket) due to
improper handling or shipping processes. To ensure a good tight
seal, it is recommended that silicone caulk and/or foil tape be applied
along the cover edges.
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.
2. Install the duct covers (removed in step one) to the rear supply and
return air duct openings.
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 are recom-
mended to be used in the supply and return duct work to minimize the
transmission of vibration and noise.
NOTICE
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.
FILTERS
Proper filter size is very important. Filter size, type and pressure drop
should always be considered during duct system design.
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.
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 must be installed in the condensate drain. The
plumbing must conform to local codes.
CAUTION
!
Hand tighten only.
Use Teflon tape or pipe thread compound if needed.
Johnson Controls Unitary Products
Model A B
24, 30 10 21.5
36, 42, 48, 60 14 13.5
FIGURE 4: Bottom Duct Dimensions (inches)
Model
24, 30
36, 42, 48, 60
FIGURE 5: Rear Duct Dimensions (inches)
5322625-UIM-A-0417
C D E
5 4.5 47.5 32
5 3.5 47.5 42
A B
9.6 22
13.6 14
F
7