Refrigerants and Oil

[mcewans]

I just wanted to clarify some information. Is the reason that AB or mineral oil cannot be used with the retrofit refrigerants is beacause they don't mix to well with these oils and thus you would have poor lubrication in your compressor?

[absrbrtek]

AB and mineral oil can be used in certain conversions as well as POE. The miscibility between oil and refrigerant determines which oils can or can not be used. Basicaly what happen is the oil will not return from the system to the comp if the oils not compatable with the refrigerant. On close coupled systems its not so much of an issue as on long piping runs.

[mcewans]

I guess I was refering to a retrofit in which an HFC refrigerant takes the place of an HCFC or a CFC refrigerant. All of the information I have read says you have to use POE oil(PAG for new automotive R134a applications since 1994) with all of the HFC refrigerants. When a retrofit is done generally 5% or less of mineral or AB oil is OK.

[rocket]

lubricaton guide

HFC 95% POE

CFC R12 any percentage mixture of AB and/or Mineral oil
(no POE)

all other CFC (and HCFC) any percentage mixture of AB/Mineral/POE