POE Oil, or Poly Olester Oil, is a synthetic oil that is used in refrigeration compressors and the refrigeration system with Hydroflurocarbon refrigerants. These oils really became popular with the debut of R-410A refrigerant about ten years ago. But it can be used with other refrigerants such as R-22. Just do not mix mineral oil with Poly Olester Oil and always check the compressor to see what they call for.
A points of note on these oils:
- POE oil is hygroscopic. What that means is that when they come in contact with air they have the ability to absorb it’s moisture. If you are working on a unit that uses POE oil then you need to ensure that the system is open and exposed to the atmosphere in as short as time as possible. Otherwise you risk damaging the compressor or other vital components.
- You may have noticed that when working with POE oil that it comes in a metal container rather than a plastic one. This is done because Poly Olester Oil can actually absorb moisture through the walls of a plastic container.
- When moisture does get in your POE oil it is very difficult to remove. The moisture will stay dissolved in the oil and cannot be removed by applying a vacuum. The only way it can be removed is by using a desiccant.
- Standard servicing procedure is to replace the liquid line drier when a system is opened for servicing. This is even more important when working with POE oils.
- Always always check what type of oil the compressor and the unit takes before adding more. Even if you think you know it is always better to be safe then sorry.