MACS 609 Certification Practice Exam

HFO-1234yf has been tested and found compatible with which type of oil?

1. Mineral oil

2. PAG oil

3. Esther oil

4. Polyol ester oil

The correct answer is: PAG oil

HFO-1234yf, a refrigerant commonly used as a replacement for HFC-134a, has been tested and found highly compatible with Polyalkylene Glycol (PAG) oil. This oil type is particularly well-suited for HFO-1234yf due to its ability to provide excellent lubrication properties under temperature and pressure conditions typical of automotive air conditioning systems. PAG oils are hygroscopic, meaning they can absorb moisture, which makes them effective at maintaining performance in the presence of water. Compatibility with PAG oil ensures that the refrigerant maintains its performance standards, prevents oil breakdown, and minimizes the risk of system failure. This relationship is key when selecting lubricants for use with HFO-1234yf in various applications, particularly in automotive settings where efficiency and system longevity are critical. The other oils listed—mineral oil, ester oil, and polyol ester oil—have different chemical properties that may not perform as effectively with HFO-1234yf, leading to reduced efficiency or potential system issues. This compatibility aspect is crucial for ensuring optimal performance and reliability in air conditioning systems utilizing HFO-1234yf.