Which lubricant is typically used with the HFC refrigerant R-134a in stationary equipment?
Substitute refrigerants and oils · EPA 608 Core. The correct answer, and the reasoning behind it.
Why there are no true drop-in replacements, and fractionation in blends.
The question
Which lubricant is typically used with the HFC refrigerant R-134a in stationary equipment?
- Mineral oil
- Polyolester (ester) oilCorrect answer
- Alkylbenzene
- Ordinary motor oil
Why “Polyolester (ester) oil” is correct
HFCs such as R-134a and R-410A do not mix well with the mineral oils used with CFCs, so stationary systems use synthetic polyolester (POE, ester) lubricants. Always follow the compressor maker's oil specification.
Source: EPA: Test Topics
Why the other answers are wrong
- Mineral oil — Mineral oil is not miscible with HFCs and will not return well to the compressor.
- Alkylbenzene — Alkylbenzene is associated with HCFCs such as R-22.
- Ordinary motor oil — Motor oil is never used in a refrigeration compressor.
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