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http://www.tecumsehcoolproducts.com/inside/File_attachments/Service%20Guidelines%20HCFC%20R22%20to%20HFC%20Blends-RD-0003-E.pdfRefrigerant R22 is widely used for residential and commercial air conditioning, as well as commercial refrigeration
applications. Tecumseh has supplied reciprocating and rotary compressors, along with condensing units with
reciprocating and rotary compressors, for the above mentioned applications.
Driven by the 1992 amendment to the Montreal Protocol that calls for the phase-out of HCFCs, refrigerant
manufacturers developed HFC alternatives. Original Equipment Manufacturers selected R404A/R507, R407C and
R410A to replace R22. They found that system changes were necessary for this conversion and made appropriate
design changes to meet application requirements and regulatory demands.
In order to support the service and maintenance of equipment, refrigerant manufacturers introduced HFC blends as
a replacement for R22. HFC blends can vary in performance when compared to R22. Regardless, system
adjustments must be made to insure that performance differences (between R22 and HFC blends) are minimized.
Suggested system adjustments are highlighted in this document.
Tecumseh Products Company does not endorse any particular retrofit refrigerant. Given that an independent
decision has been reached to use R417A or R422 blends, the following guidelines are provided to assist in better
applying Tecumseh compressors. The application should be reviewed carefully prior to making decisions regarding
retrofit or replacement refrigerants as oftentimes there can be capacity and efficiency losses.
Consult Tecumsehs Refrigerant Matrix for additional HFC blends. The matrix may be viewed on line under the
Technical Resource Center section of Tecumsehs North American Compressor Group web site at
http://202.56.127.90/nacg/. Considerations should be given to oil compatibility, refrigerant temperature glide, heat
exchanger compatibility, operating pressure differences, system performance and pressure drop. The greater the
difference in performance between R22 and the alternate refrigerant, the more complex the system adjustments
may be, increasing the likelihood that compressor reliability will be adversely affected
LUBRICANTS
A) Types, Miscibility and Charge
POE Polyol Ester Oil
MO Mineral Oil
SA Synthetic Alkylate (also referred to as
Alkylbenzene, AB)
1. Consult Tecumseh Products Companys Policy
Bulletin no. PB105 to verify original oil type.
2. R417 and R422 blends contain a small
percentage of hydrocarbons to promote oil
return. The hydrocarbon component of the
refrigerant provides only partial miscibility with
MO or SA oils. Whenever practical, the
compressor oil should be changed to POE.
3. Do NOT use MO or SA oil with HFC blends in
systems using a receiver tank. MO or SA will
suspend on top of the refrigerant and collect in
the receiver. In such systems the MO or SA oil
must be replaced with POE oil.
B) Moisture
1. POE oil is more hygroscopic than MO or SA
oils and will absorb moisture quickly. POE oil
along with moisture and heat of the operation
will cause acid and alcohol to form in the
system resulting in reduced system efficiency
and capacity, reduced compressor bearing
lubrication, component corrosion, blockages,
and coppering of parts.
2. Care should be taken not to leave
B) Moisture
1. POE oil is more hygroscopic than MO or SA
oils and will absorb moisture quickly. POE oil
along with moisture and heat of the operation
will cause acid and alcohol to form in the
system resulting in reduced system efficiency
and capacity, reduced compressor bearing
lubrication, component corrosion, blockages,
and coppering of parts.
2. Care should be taken not to leave the system
open to the atmosphere for more than 10
minutes. Pull a system vacuum to a minimum
of 500 microns. This applies to any retrofitting
process using any type of oil.
C) Compatibility
1. POE acts as a solvent and can dislodge
deposit debris in older systems operating with
MO. The liquid line filter drier must be
changed to keep the system free of debris.
Multiple refrigerant and liquid line filter drier
changes may be needed.