Polyolester

[3] These oils are used with chlorine-free hydrofluorocarbon (HFC) refrigeration systems, as they provide better lubrication and stability and are more miscible with HFC refrigerants compared to synthetic and mineral oils of similar application.

[4] The dispersion behavior of POE oils has been studied for applications in nanotechnology.

POE oils are more hygroscopic,[6] and react in air to form carboxylic acids.

The same properties that make POE oil a solvent for oils also make it a solvent for other pieces of matter left behind during the manufacturing of a unit, such as dust, dirt, residue from soldering, small metal bits, and oxidized metal from the tubing.

The residues collected can clog the system filters and cause excessive wear or damage to components such as the vanes or valves.