What is a major problem with POE oil?

The major problem with POE (polyol ester) oil is that it absorbs moisture from the air very quickly. This property is significant because moisture contamination can lead to various issues in refrigeration systems. When moisture is present in the oil, it can create acids that may corrode metal components, degrade the lubricating properties of the oil, and lead to the formation of sludge or ice in the refrigerant system.

Understanding this characteristic of POE oil is crucial since it necessitates careful handling during the servicing or charging of refrigeration systems. Technicians must ensure that the oil is kept sealed and dry to prevent moisture-related issues.

In contrast to the other choices, which present valid concerns associated with lubricants and oils in refrigeration, the quick absorption of moisture by POE oil is the most critical issue that directly impacts the operational reliability and longevity of the system.