IMPORTANT:
If the unit is 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.
6
Step 3 — Install Ductwork
UPFLOW 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 INSTALLATIONSBe 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. pitch of the length
and width of the unit.
1.
Arrange support for unit by setting it in or above
secondary condensate pan.
2.
When suspending unit from ceiling, dimples in casing
indicate proper location of screws for mounting metal
support straps.
DUCT CONNECTIONS Connect supply-air duct over
outside of
3
/
4
-in. flange provided on supply-air opening.
Secure 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
prevent transmission of vibration. Ductwork passing through
unconditioned 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
constructed 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
comply 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
recommendations:
• Condensate piping should slope downward in the
direction 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
recommended for odor control.
• The differential height between inlet and outlet should be
at least 3 inches. The differential height between the
bottom of the trap and outlet should also be 3 inches.
See Fig. 4.
Fig. 4 — Condensate Drain Trap
• Auxiliary drain should be connected and run to a location
where it is easily visible when it becomes active,
suggesting a problem with the main drain system.
• When multiple units are connected to a common
condensate 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
piping 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
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.
When connecting from an indoor unit to an outdoor unit,
follow these procedures:
• Check for maximum height drop and length of
refrigerant piping between the indoor and outdoor unit. If
the difference is more than 33 ft, consider mounting the
outdoor unit above indoor unit.
• Refrigerant piping connection between indoor and
outdoor 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 F 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.
• Use a torque wrench for flare nuts. Refer to Table 3 for
flare nut torque recommendations.
Table 3 —Flare Nut Torque Recommendations
Outside Diameter (in.)
Recommended Torque (ft-lb)
1/4
15
3/8
26
1/2
41
5/8
48
