ACHRNEWS

Looking at a New Lubricant

March 7, 2011

While polyvinylether (PVE) oil first started to be used by OEMs in 2010, it continues to draw interest, especially as a possible alternative to polyolester (POE) oils with HFC refrigerants.

“So far in the States, we have two manufacturers using PVE extensively,” said Eric Schweim, manager of refrigeration lubricants for Idemitsu Lubricants America Corp., which introduced the oil. “Additionally, we have many trials going on with various OEMs.

“Also, we are continually getting calls from the aftermarket. Some people are buying a compressor with a POE and dumping the oil to switch to PVE.

Schweim noted that “already many Japanese, Korean, and Chinese air conditioning makers are using PVE.”

In printed information, Idemitsu cited benefits of PVE as:

• Compatible with all HFC refrigerants.

• No hydrolysis (reaction to water) which can happen with POEs.

• The bond energy of PVEs enhances anti-wear effectiveness.

• Solubility with process fluids.

• Regarding capillary tube blockage, “superior resistance due to lack of hydrolysis.”

In addition, the company said it was “possible to eliminate HVAC system filter driers.”

MID-YEAR SUPPORT

The product got a mid-year boost in 2010 when an application engineer with the compressor manufacturer Bitzer teamed up with a chemical engineer at Idemitsu Lubricants America to produce an extensive article that ran in the May 3, 2010 issue of The NEWS. It was a highly technical and detailed analysis of the oil. Among more general points made:

• “PVE is innovative refrigerant oil specially formulated for HFC refrigeration systems. In addition to providing lubricating properties, it also has a number of other applied advantages that help to increase the reliability of the refrigeration system where it is applied.”

• “PVE oil provides equal to or better properties for each of these categories when compared with alternative lubricants such as POE oils for R-410A air conditioning applications. Thus, PVE not only provides better lubrication, but also provides additional applied benefits such as improved miscibility, no hydrolysis, and better chemical stability when compared to alternative lubricants.”

• “Because of its lubricating properties and other applied benefits, the use of PVE refrigeration oil for all types of HFC applications has been growing around the world. It is particularly popular in R-410A air conditioning applications in Asia and is also being utilized for CO2 systems. This versatile oil is being specified by more and more refrigeration and air-conditioning system manufacturers around the world. As would be expected from the increased usage, the commercial availability of PVE oil is expanding, and many large distribution wholesalers are beginning to stock the oil to meet the aftermarket requirements.”

In the paper, the engineers said, “PVE is a polymer-based lubricant consisting of chains of monomers. The composition and ratio of these monomer units provide some of PVE’s unique properties such as better stability and better lubrication.”

Idemitsu’s Schweim added, “PVE is rather flexible in terms of chemical structure, so we can adapt PVE for many applications.”

SEARCH FOR AN ALTERNATIVE

Schweim said Idemitsu engineers began looking at an oil alternative a number of years ago when POE oils began to be promoted as the primary lubricant for HFC refrigerants - at a time when there was some concern over the hydrolysis of POEs. “Compressor makers wanted a more stable lubricant,” he said.

Regarding the research, he said, much attention was paid to “solubility, lubricity, stability and so on.”

As the product begins to draw more attention from OEMs, it continues to also be promoted in retrofit options, although Schweim said “less than 5 percent of POE residue is recommended” after the changeout.

For more information, visit pag-idemitsu-usa.com.

Publication date: 03/07/2011