Polyolester

Polyolester oil (POE oil) is a type of synthetic oil used in refrigeration compressors that is compatible with the refrigerants R-134a, R-410A, and R-12.[1] HFC-134a with POE oil as the lubricant is a replacement for CFC-12 with mineral oil as the lubricant[2] as HFC-134a does not mix well with mineral oil.[3] These wax-free oils are suggested for use with chlorine-free HFC systems as they provide better lubrication and stability and are more miscible with HFC refrigerants. They can match the lubricity properties of mineral oils used with CFCs and HFCs. They are compatible with most lubricants in the market.[4] The viscosity of the oil decreases with temperature.[5] The dispersion behavior of this oil has been heavily studied.[6] It is also considered by some to be a good additive to engine oil.[7]

Not to be confused with Polyester.
Polyolester of pentaerythritol
Polyolester of di-pentaerythritol

Problems

The same properties that make it a good solvent for oils also make it a good solvent for undesired things 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 critical components such as the vanes or valves. Therefore, it is important to check that components are machined properly, deburred, and cleaned. Another problem with these oils is that they are hygroscopic in nature and thus can absorb moisture from the atmosphere. Hence, when technicians open these units, they should not leave them open for long.[8]

POE oils typically have lower viscosity indexes than polyalkylene glycol (PAG) or poly-alpha-olefin (poly-α-olefin, PAO) oils so that a higher viscosity grade is required in order to attain a certain kinematic viscosity at higher oil temperatures.

See also

References
  1. "Definition of POE oil". Archived from the original on 2007-08-14.
  2. Ananthanarayanan (1 April 2005). Basic Refrigeration and Air Conditioning. Tata McGraw-Hill Education. p. 83. ISBN 978-0-07-049500-5. Retrieved 30 October 2012.
  3. Frank Kreith; Shan K. Wang; Paul Norton (6 December 1999). Air Conditioning and Refrigeration Engineering. CRC Press. p. 113. ISBN 978-0-8493-0057-8. Retrieved 30 October 2012.
  4. "Polyolester Oils: Handling the New Lubricant in R-410A Systems". Archnews. Retrieved November 1, 2012.
  5. Theo Mang; Kirsten Bobzin; Thorsten Bartels (11 January 2011). Industrial Tribology: Tribosystems, Wear and Surface Engineering, Lubrication. John Wiley & Sons. p. 408. ISBN 978-3-527-32057-8. Retrieved 30 October 2012.
  6. Advances in Nanotechnology Research and Application: 2011 Edition. ScholarlyEditions. 3 January 2012. p. 2034. ISBN 978-1-4649-2058-5. Retrieved 30 October 2012.
  7. Bonnier Corporation (October 1978). Popular Science. Bonnier Corporation. p. 46. ISSN 0161-7370. Retrieved 30 October 2012.
  8. "Working With POE Oils Requires Forethought". Airconditioning news. Retrieved November 1, 2012.
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