- ACFCs only
- BHCFCs only
- HFCs and HFOs
- DAll refrigerants
Correct answer
HFCs and HFOs
Why
POE oils are required for HFC refrigerants like R-410A and R-134a, and HFO refrigerants, because they are miscible with these refrigerants.
The concept behind this question
Substitute refrigerants have to be evaluated as a system with their lubricant, not swapped in isolation. Mineral oil works with CFCs and HCFCs but does not circulate properly with most HFCs, which is why HFC systems generally use polyolester (POE) oil — and POE is strongly hygroscopic, so it absorbs atmospheric moisture fast when left open. Substitutes must also be approved for the specific end use under EPA's SNAP program, and newer A2L refrigerants are mildly flammable, which changes the handling and equipment rules that apply.
More questions on this topic
- What is the Global Warming Potential (GWP) used to measure?
- What type of refrigerant is R-410A?
- At what pressure does R-410A typically operate on the high side compared to R-22?
- What is a 'blend' refrigerant?
- What is 'fractionation' of a refrigerant blend?
- How should zeotropic refrigerant blends be charged?
Exam-style practice question. Not an official EPA exam question.