SS-APG008H-EN
15
Remodel, Retrofit, or Replacement
Inevitably, older condensing unit/evaporator systems that
are designed for use with a refrigerant other than R-410A
will need to be upgraded. Due to the phase-out of many of
these older refrigerants, the major components for those
older condensing unit/evaporator 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
and protection are correct 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.
•
Per EPA rulings, it is not acceptable to replace R-410A
refrigerant with any A2L refrigerant.
•
Most older evaporator coils were not pressure and
cycle rated for R-410A pressures. If they weren’t, they
will need to be replaced. Check with the manufacturer.
•
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.
•
R-410A refrigerant line sizes may be different than the
existing line sizes. The lines need to be re-sized and
compared to existing lines for reusability.
•
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.
Important:
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.
NOTICE
Equipment Damage!
This is POE oil, which readily absorbs moisture.
Always use new oil and never leave containers open
to atmosphere while not in use.
All Codes take precedence over anything written here.
