5
• The unit should not be positioned directly above any
obstruction.
• The unit must be installed square and level.
• The condensate drain should have sufficient downward
slope (1 in. per 100 in.) in any horizontal run between
unit and drain.
Step 3 — Install Ductwork
UP-FLOW INSTALLATION — If return air is to be ducted,
install duct flush to the floor. Only use the return-air opening
provided. All return air must pass through the coil.
HORIZONTAL INSTALLATIONS — Be sure installation
complies with all applicable building codes, which may require
installation of a secondary condensate pan.
NOTE: To ensure proper drainage for horizontal installations,
unit must be installed so it is within
1
/
8
in. level of the length
and width of the unit.
1.
Arrange support for unit by setting it in or above second-
ary condesnate pan.
2.
When suspending unit from ceiling, dimples in casing in-
dicate proper location of screws for mounting metal sup-
port straps.
DUCT CONNECTIONS — Connect supply-air duct over
outside of
3
/
4
-in. flange provided on supply-air opening. Se-
cure duct to flange with proper fasteners for type of duct used,
and seal duct-to-unit joint.
Duct connection flanges are provided at the discharge air
unit connection.
Use flexible connectors between ductwork and unit to pre-
vent transmission of vibration. Ductwork passing through un-
conditioned space must be insulated and covered with vapor
barrier.
DUCTWORK ACOUSTICAL TREATMENT —
Metal
duct systems that do not have a 90-degree elbow and 10 ft of
main duct to first branch takeoff may require internal acoustical
insulation lining.
As an alternative, fibrous ductwork may be used if con-
structed and installed in accordance with the latest edition of
SMACNA (Sheet Metal and Air-Conditioning Contractors’
National Association) construction standard on fibrous glass
ducts. Both acoustical lining and fibrous ductwork shall com-
ply with National Fire Protection Association Standards 90A or
B as tested by UL (Underwriters Laboratories) Standard 181
for Class 1 air ducts.
Step 4 — Connect Piping
CONDENSATE PIPING — The unit is supplied with a
3
/
4
-in. female pipe thread drain connection to connect drain
piping. When installing the unit, follow these recommenda-
tions:
• Condensate piping should slope downward in the direc-
tion of condensate flow, with a minimum gradient of
1 in. per 100 inches.
• Condensate piping should be installed in such a way that
it does not block the front service panel.
• A drain trap may be required by local codes and is rec-
ommended for odor control.
• The differential height between inlet and outlet should be
at least 3 inches. The differential height between the bot-
tom of the trap and oulet should also be 3 inches. See
Fig. 4.
• Auxiliary drain should be connected and run to a location
where it is easily visible when it becomes active, sug-
gesting a problem with the main drain system.
• When multiple units are connected to a common conden-
sate drain, ensure that the drain is large enough to cope
with the volume of condensate from all units. It is also
recommended to have an air vent in the condensate pip-
ing to prevent air locks.
• Insulate the drain line to prevent sweating and provide
proper support to prevent undue stress.
• Condensate piping must not be installed where it may be
exposed to freezing temperatures.
REFRIGERANT PIPING
When connecting from an indoor unit to an outdoor unit,
follow these procedures:
• Check for maximum height drop and length of refriger-
ant piping between the indoor and outdoor unit. If the
difference is more than 33 ft, consider mounting the out-
door unit above indoor unit.
• Refrigerant piping connection between indoor and out-
door units should be performed once the units are
secured at their respective installation locations.
• The refrigeration piping starts at the indoor unit and ends
at the outdoor unit.
• The number of bends in the refrigeration piping must be
fewer than 15.
• The refrigerant piping should be dry and free of dust and
other contaminants.
• The bending angle of the refrigerant pipe should not
exceed 90 degrees and the bending radius should be as
large as possible to prevent any breakage in piping.
• Use proper cutting and flaring tools to avoid leakage.
IMPORTANT:
If installed in the ceiling, be sure that
the ceiling grid is supported separately from the unit.
The ceiling grid must not be supported by any part of
the unit, grille, or any associated wiring or piping work.
CAUTION
When connecting from an indoor unit to an outdoor unit,
the isolation valve at the outdoor unit should be in the
closed position throughout the refrigerant piping process.
Failure to follow this procedure may result in equipment
damage.
UNIT
DO NOT OVERTIGHTEN
DRAIN FITTING
MAIN DRAIN
DO NOT OPERATE UNIT
WITHOUT CONDENSATE
DRAIN TRAP.
3 in.
3 in.
a40-1744
Fig. 4 — Condensate Drain Trap
