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Sheet metal ductwork run in unconditioned spaces
must be insulated and covered with a vapor barrier.
Fibrous ductwork may be used if constructed and
installed in accordance with SMACNA Construction
Standard on Fibrous Glass Ducts. Ductwork must
comply with National Fire Protection Association as
tested by U/L Standard 181 for Class l Air Ducts.
Check local codes for requirements on ductwork and
insulation.
The duct system must be designed within the range of
external static pressure the unit is designed to operate
against. It is important that the system airflow is
adequate. Ensure that the supply and return duct
work, grills, special filters, accessories, etc, are
accounted for in total resistance calculations.
4. Refrigerant Pipe
DANGER
Use refrigerant spec. according to the outdoor unit
nameplate. When carrying out the leakage check
and test, do not mix in any oxygen, acetylene, or
any sort of flammable/reactive gas, as these gases
may result in explosion. It is recommended to use
nitrogen to perform these procedures .
4.1 Pipe Material
(1) Prepare the copper pipe on-site.
(2) Choose dust -free, non-humid, clean copper pipe.
Before installing the pipe, use nitrogen or dry air
to blow away any dust or impurities on the pipe.
(3) Select the copper pip ing according to outdoor
manual.
4.2 Piping Connection
(1) The connection positions of the pipe are shown in
Fig. 4.1.
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Fig. 4.1. Connection Positions of the Piping
Refer to the "Outdoor Unit Installation Instructions"
for details on piping size selection, piping
installation, and charging information.
The coil is shipped filled with Nitrogen. Evacuate
the system before charging with refrigerant.
Install refrigerant lines so that it does not block
service access to the front of the unit.
Nitrogen should flow through the refrigerant lines
while brazing.
Use a wet rag or an approved heat paste to protect
the TXV sensing bulb during the brazing process.
The indoor units has a field supplied with primary
and secondary 3/4-in. NPT drain connections.
When making drain fitting connections to the drain
pan, use a thin layer of Teflon paste, silicone, or
Teflon tape and install. Hand-tighten afterwards.
When making drain-fitting connections to drain pan,
do not over-tighten.
All horizontal drain pipes must be pitched downward
away from the unit at a minimum of 1/8" per foot to
provide problem-free drainage.
Do not connect the drain pipes directly to sewage
pipes, to avoid ammonia odors. The ammonia in the
sewage can enter the indoor unit through the drain
pipes and corrode the heat exchanger.
Do not twist or bend the drain hose, as excessive force
is applied during twisting or bending and may also
(Unit: in.)
cause leakage.
The drain line should be insulated where necessary, to
prevent sweating and damage due to condensate
forming on the outside surface of the pipe.
Test condensate drain pan and drain pipe after
installation is complete. Pour water into drain pan,
enough to fill drain trap and line. Check to make sure
4
drain pan is draining completely, no leaks are found
in drain pipe fittings, and water is draining from the
termination of the primary drain pipe.
4
NOTES:
7
If unit is located in or above a living space where damage may
result from condensate overflow, a field-supplied, external
condensate pan should be installed underneath the entire unit,
and a secondary condensate line (with appropriate trap) should
be run from the unit into the pan. Any condensate in this external
condensate pan should be drained to a designated place. The
owner of the structure must be informed that when condensate
flows from the secondary drain or external condensate pan, the
unit requires servicing, or water damage will occur. Install traps
in the condensate lines as close to the coil as possible.
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Installation and Maintenance
5. Drain Piping
Condensate Drain Trap
Do not over-tighten
drain fitting. Unit must
be slightly pitched
toward drain connection.
Do not operate unit without
a condensate drain trap.
To Approved Drain
(Unit: in.)
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