40MUAA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
11
Fig. 24 —Reassemble Upper Cover
14. Reinstall the filter and filter cover plate.
Fig. 25 —Reinstall Filter and Cover Plate
15. Connect the pipes.
16. Install the drainage pipes.
Step 4 - Installing Ductwork
Connect the supply-air duct over the outside of the 3/4in (19 mm) flanges
provided on the supply-air opening. Secure the duct to the flange, using
proper fasteners for the type of duct used, and seal duct-to-unit joint. If
the return-air flanges are required, install the factory-authorized accessory
kit.
Use flexible connectors between the ductwork and unit to prevent
transmission of vibration. When the electric heater is installed, use heat-
resistant material for the flexible connector between the ductwork and the
unit at the discharge connection. Ductwork passing through the
unconditioned space must be insulated and covered with a vapor barrier.
Units equipped with 20kW or greater electric heaters require a 1in
(25mm) clearance to combustible materials for the first 36in (914mm) of
supply duct. Follow the local codes.
DUCTWORK ACOUSTICAL TREATMENT
Metal duct systems that do not have a 90 degree elbow and 10ft (3m) 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 the
SMACNA construction standard on fibrous glass ducts. Both acoustical
lining and fibrous ductwork shall comply with the National Fire
Protection Association as tested by UL Standard 181 for Class 1 air ducts.
The air supply and return may be handled in one of several ways;
whichever situation is best suited for the installation (See Fig. 5 — on
page 6). A large number of issues encountered with split-system
installations can be linked to improperly designed or installed duct
systems. It is therefore very important that the duct system be properly
designed and installed.
Use of flexible duct collars is recommended to minimize the transmission
of vibration/noise into the conditioned space. Where the return air duct is
short, or where sound is liable to be a problem, sound absorbing glass
fiber should be used inside the duct.
Insulation of duct work must be installed according to local codes and
best practices. The supply air duct should be properly sized by use of a
transition to match unit opening.
This unit is not designed for non-ducted (freeblow) applications.
NOTE: Duct work should be fabricated and installed in accordance
with local and/or national codes.
A220799
Fig. 26 — Flexible Duct Collar Connection
Step 5 - Condensate Drains
The drainpipe is used to drain water away from the unit. Improper
installation may cause unit and property damage.
NOTE: Installation requires adapting the locally sourced drain line
to a “3/4” NPT female pipe thread connection.
RECOMMENDED FLEXIBLE
DUCT COLLAR
MINIMUM CLEARANCE
1”/25.4mm all sides
59”/1.5mm
The outlet side pipe length is 59”/1.5mm
• Insulate suction line to prevent condensation, which could lead
to water damage. Check the local codes.
• If the drainpipe is bent or installed incorrectly, water may leak
and cause a water-level switch malfunction.
• In
HEAT
mode, the outdoor unit may discharge water. Ensure
that the outdoor drain will not contribute to damage and
slippage.
•
DO NOT
pull the drainpipe forcefully. This could disconnect it.
CAUTION
