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Remodel, Retrofit, or
Replacement
Inevitably, older condensing units and evaporator systems will
need to be replaced or retrofitted. Due to the phase-out of
many of these older refrigerants, the major components for
those older units or systems may no longer be available. The
only option will be to convert the system to R-410A, POE oil,
and R-410A components.
When upgrading an existing refrigerant split system due to
remodel, retrofit, or replacement, the entire system must be
reviewed for compatibility with R-410A and POE oil. Each and
every part of the split HVAC system MUST be compatible with
the properties of R-410A refrigerant and POE oil. In addition,
ensure the existing electrical service is adequate for the
product being installed.
WARNING
R-410A Refrigerant under Higher
Pressure than R-22!
Failure to use proper equipment or components as
described below, could result in equipment failing and
possibly exploding, which could result in death,
serious injury, or equipment damage. The units
described in this manual use R-410A refrigerant which
operates at higher pressures than R-22. Use ONLY R-
410A rated service equipment or components with
these units. For specific handling concerns with R-
410A, please contact your local Trane representative.
Every part of an existing split system needs to be analyzed to
determine if it can be reused in an R-410A and POE oil system:
•
R-22 condensing units will not work with R-410A; they
must be replaced.
•
Most older evaporator coils were not pressure- and cycle-
rated for R-410A pressures. If they weren't, they will need
to be replaced. If they were properly pressure-rated for R-
410A, existing coils must be modeled to determine if they
will meet capacity requirements, are properly circuited,
have correctly sized distributor tubes, and employ
acceptable distributors and orifices.
CLCH-SVX009L-EN
Coil Piping and Connections
•
The required R-410A line sizes may be different than the
existing line sizes. The lines need to be re-sized and
compared to existing lines for reusability.
•
Suction lines 2-5/8 OD and smaller of type L copper are
suitable for use with R-410A. Suction lines 3-1/8 OD must
use type K or thicker wall.
•
Discharge lines, liquid lines, heat pump vapor lines, and
hot gas bypass lines 1-3/8 OD and smaller of type L copper
are suitable for use with R-410A. These same lines sized
at 1-5/8 OD or 2-1/8 OD must use type K or thicker wall.
•
Expansion valves need to be reselected. Expansion valves
are refrigerant specific.
•
Any gasket or o-ring should be replaced. Shrinkage of the
original seal may occur after an HFC conversion,
potentially causing a refrigerant leak. Components
commonly affected are Schraeder cores, solenoid valves,
ball valves, and flange seals. But all external seals in
contact with refrigerant should be viewed as potential leak
sources after a retrofit.
•
All other valves, filters, valve packing, pressure controls,
and refrigeration accessories must be researched through
their manufacturer for compatibility with the pressures of
an R-410A system, and for their compatibility with the
newer POE oil.
•
For the best performance and operation, the original
mineral oil should be removed from the components of the
system that are not being replaced. Any component of the
system that is suspected of trapping oil (piping, traps, and
coil), should be dismantled, drained, and reassembled.
After all components have been drained, the amount of
residual mineral oil will have a negligible effect on
performance and reliability
NOTICE
Compressor Damage!
POE oil is hygroscopic – it absorbs water directly from
the air. This water is nearly impossible to remove from
the compressor oil and can cause compressor failures.
For this reason, the system should not be open for
longer than necessary, dry nitrogen should flow in the
system while brazing, and only new containers of oil
should be used for service and maintenance.
All Codes take precedence over anything written here.
45
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