Line Set Installation; Important Tubing Installation Practices - Rheem A18AZ Series Installation Instructions Manual

4.5 Line Set Installation

1. Use care in routing tubing and do not kink or
twist. Use a good quality tubing bender on the
vapor line to prevent kinking.
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Item Number
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Figure 5: Temporary Hanger and Permanent Hanger
2. Route the tubing using temporary hangers; then
straighten the tubing and install permanent hang-
ers. The tubing must be adequately supported.
3. Isolate the vapor line from the building structure.
If the vapor line comes in contact with inside
walls, ceiling, or flooring, the vibration of the
vapor line in the heating mode will result in noise
inside the structure.
4. Blow out the liquid and vapor lines with dry nitro-
gen before connecting to the outdoor unit and
indoor coil to remove debris that can plug the
expansion device.
Figure 6: Isolate Vapor Line from Building Structure
4.5.1 Important Tubing Installation
Practices
Observe the following when installing correctly sized
type "L" refrigerant tubing between the outdoor unit
and indoor coil:
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Description
Temporary Hanger
Permanent Hanger
ST-A1226-05-00
• Check Table 5 for the correct vapor line size and
liquid line size.
• If a portion of the liquid line passes through a
very hot area where liquid refrigerant can be
heated to form vapor, insulating the liquid line is
required.
• Use clean, dehydrated, sealed refrigeration-grade
tubing.
• Always keep tubing sealed until tubing is in place
and connections are to be made.
• A high-quality biflow filter drier is included with all
R-410A heat pump units and must be installed in the
liquid line upon unit installation.
• When replacing an R-22 system with an R-410A
system and the line set is not replaced, blow out
the lines with dry nitrogen to remove as much of
the remaining mineral oil as possible. Check for low
spots where oil may be trapped and take measures
to drain the oil from those areas.
Figure 7: Debur Cut Tubing Ends
• If tubing has been cut, debur the ends while holding
the tubing in a position to prevent chips from
falling into tubing. Burrs such as those caused by
tubing cutters can affect performance dramatically,
particularly on small diameter liquid lines.
• For best operation, keep tubing run as short as
possible with a minimum number of elbows or bends.
• Locations where the tubing will be exposed to
mechanical damage should be avoided. If it is
necessary to use such locations, the copper
tubing should be protected by a housing to prevent
damage.