Compatability 134a

[driftamile]

I have been under the impression that 134a is compatable with alkabenzine oil. I was told that this is not true by a reputable distributer. Any useful information would be greatly appreciated. Thanks

[icemeister]

Any HFC refrigerant such as R134A must have POE oil. If there is ant MO present it should be less than 5% or you will have problems.

Check out DuPont's refrigerant retrofit guide:
http://www.dupont.com/suva/na/usa/pr...pdf/h96126.pdf

You can use the old CFC refrigerants like R12, R502 and R22 with POE or AB. Maybe this is the source of your confusion.

[rocket]

Though no compressor mfr reccomends it, many in Europe have used with R134a and R407C
Also cap tube clogging on small R134a systems seems to not clog with Zerol so it is being used here
As no manugacturer reccomends AB with R134A,you are on your own if you use it

Here's quote from Shrieve Cemical - maker of Zerol AB oil
"New studies are underway that show that ZEROL® alkylbenzene oil can be used with HFC refrigerants such as R134a, R407C, and R410A in specific applications. These applications include household refrigerators, window air conditioning units, and small split systems. Major advantages of using ZEROL® alkylbenzene oil instead of polyolester oil in these HFC systems include significant cost saving in both oil and in handling procedures, and also superior lubrication in certain systems."
link http://www.shrieve.com/htmls/refrigeration.htm

[RobY]

driftamile, it depends on your definition of compatible. AB can't be used in all R-134a systems. AB may be able to be used sucessfully in some R-134a systems. The problem is how to tell which systems are which.

AB and R-134a are not very soluble in each other, so the oil is not diluted by dissolved refrigerant. This causes the viscosity of the oil in the suction line to be higher (thicker)and may lead to poor oil return. On the flip side, since the oil is less diluted by refrigerant it may be thicker in the compressor bearings. However, if all the oil is out in the system and none is in the compressor, the bearing viscosity doesn't matter.

As a general rule, close coupled systems running at medium temperature are the best candidiates for use of AB with R-134a. The ABs looked at in low temperature R-134a systems (like refrigerators) are not the ones typically sold in supply houses. The refrigerator ABs are much thinner (less than ISO 10 or 60 SUS) so they will travel back up the suction line better.

You may be able to mix some POE in with the AB to make the AB return better. The AB and POE mix well, and R-134a is more soluble with POE mixed in. Low temp systems can tolerate a lot more residual AB than they can residual mineral oil. Shrieve made a good case for flushing with AB to remove mineral oil prior to doing a POE retrofit.

As rocket said, you're on your own if you use AB with R-134a.