Refrigeration Oil for Mini Splits
 

This question is for any one that knows , but especially for Xringer . I think I read that you bought some refrigeration oil for your Sanyo , before you brazed / silver soldered the pin hole leak ?

When I installed my mini split , I dumbed up and moved the high pressure line and caused a leak . While insulating the last part of both copper lines & service valves with black sticky " cork tape " .

I lost the R410a & some oil . The " factory tech " I spoke to on the phone said not to worry about it , they are charged with extra oil , in case a long line set is used .

He said to vacuum it down and re-charge it by weight . Which is what I did . All seems to be well . But I still have a nagging concern .

If something should happen ( I dumb up again ? ) and I should loose oil again ?

I have done some research & my unit ( with a Toshiba non-inverter 12,000 BTU compressor ) uses POE oil . But Johnstone supply ecatalog has several kinds / viscosity of POE oil for HVAC .

I do not know what kinds / viscosity of POE oil is used in mini splits .

I have used 100 " weight / viscosity " POE oil , from O'Reilly Auto Parts , for a R12 -> R134a conversion . But , that is my only knowledge / experience with POE oil .

Thanks ,
God bless
Wyr

The majority of the HVAC manufacturers recommend ISO VG32 weight oil for use in residential units. In Alaska, as well as in low-temp refrigeration, they use VG22 due to its -40 degC pour point. Cuz contractors can't be expected to keep their oil warm. It just has to pour.

The things about POE oil to remember are:
A. the same type will mix. POE will mix with POE.
B. POE is turbine oil, used in jet engines and power plants near you.
C. It gets stale when opened. Don't save it for long; it absorbs water from the air like brake fluid. Unlike mineral oil, you can't vacuum or filter the water out of the oil.

The VG100 oil you referenced is used in autos mainly due to the high operating temps under the hood. Thicker oil protects better across the entire temp range, but doesn't flow as well when it's cold. In an auto a/c system, you won't be using the a/c while it's cold, so the oil doesn't have to be so thin.

Here's a good reference page:
POE Oils that match Compressor OEM Specifications

I imagine the differences in specific oils are (trace) additives.

So the VG32 would be such as

https://www.johnstonesupply.com/stor...ep?pID=B85-560

Thank you very much . :-)
God bless
Wyr

To be compliant with the list, you want the VG32-3maf oil, which is this product

But the stuff you linked to is basically the same oil with another additive package. Like Shell vs. Chevron gas. Do you want techron or v-power?

Strangely, Emerson/sporlan/copeland says to top off with VG22 oil, while doing changeouts with VG33. Huh. Go figure.

My mini split has a Toshiba non-inverter compressor . I tried to find out from Toshiba what their spec was / is for oil . Never found a good link / email address , in my googling .

Thanks a bunch ! :-)
Wyr
God bless

I read reccomendations to use POE oil when retrofitting auto A/C from R-12 to R-134a . Any idea how well this oil would work ? Or not work ?

How would the viscosity compare to the oigional mineral oil ?

God bless
Wyr

The big things to do are these:
1. Flush everything out with brake cleaner and blow out with compressed air
2. Change the filter/drier
3. Change the orifice out with a new one
4. drain old oil out of compressor
5. change o-rings on fittings you take apart
6. Deep vacuum after leak check

Not doing these things will ensure you have a compressor burnout eventually. I have drained oil out of compressors (still working) that looked like used engine oil. They call it the "black death". I don't care what the salesmen say, old oil and new oil (even the same type) don't play well together.

POE oil or PAG oil ?

I think the R134a GM systems , from the 1990's & early 1980's I have workoned use PAG oil ( Pag 150 , I think ? ) .

But I have read POE oil is more tolerant of any residual amounts of mineral oil ?

God bless
Wyr

If you don't flush, use PAG oil. If you flush, use POE.

Read this:

General Retrofit Procedures

I'm pretty sure PAG is only used for low voltage compressors. It has a low breakdown voltage. And it's even more hygroscopic than POE, hence it's becoming less commonly used.