Haier AC-8888-107 Service Manual page 19

Commercial Air Conditioner
Model: heat pump, 10SEER UNITS
Figure A Figure B
Figure C
Fig. 8-2
Only refrigeration-grade copper piping (dehydrated and sealed) should be used. Take extreme
care to keep the refrigerant tubing clean and dry prior to and during installation. If in doubt,
blow out the tubing with dry nitrogen to remove any chips or debris before connection. Always keep
tubing sealed until it is in place and the connections are to be made.
Refrigerant piping should be as short as possible, with a minimum of elbows or bends, to avoid
capacity loss and increased operating costs.
Refrigerant lines must be adequately supported. If metal strapping is used to secure the tubing, do
not allow the strapping to directly contact the tubing. Use a closed cell insulation to separate the
strapping from the tubing. Do not kink or twist the tubing.
Refrigerant piping should not be installed in a cement slab, as this limits access to the refrigerant
should a leak be suspected.
To ensure good oil return to the compressor, it is important to pitch the horizontal suction line
toward the compressor, approximately 1/2" for every 10' of line.
8.6 Line Insulation
Suction line requires insulation in order to prevent condensation from forming on the piping
and to prevent heat gain caused by surrounding air. Generally 3/8" wall thickness of Arm flex
or equivalent is satisfactory. In severe application (hot, high humidity areas) greater
thickness may be required. Apply the line insulation by sliding it on the sealed tubing before
cutting and making connections.
Liquid line does not necessarily need insulation, however, if they are exposed to high
ambient temperatures (i.e. kitchen, boiler rooms, hot attics & rooftop surface), then, they
should be insulated. Make sure to use the proper size tubing for the liquid line to prevent
liquid refrigerant flashing to a vapor within the liquid line.
Do not allow the vapor line and liquid line to touch together. This would cause an
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