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View Full Version : r134a as a substitute for r22?



m-nelson
24-08-2007, 05:26 PM
I have a commercial walk-in refrigerator purchased used. It was built in 2003. It looks like it's designed for R22 according to the paperwork.

Do I have the option of using R134a instead? What about compatability with the oil that is currently in the compressor?

note.. The reason for wanting to go this way is that I'm not a professional. As a layman, it's a lot easier to get R134a. The few technical papers I've seen indicate that performance is off only 2-3% by moving to R134a & that is a negligible penalty for me.

Mike

monkey spanners
24-08-2007, 05:57 PM
Where has the R22 gone? The mineral oil will go lumpy in the evaporator if use with R134a and not return to the compressor to provide lubrication.
The expansion device will be wrong etc,etc

Short answer "NO"

Jon

col j rebel
24-08-2007, 07:52 PM
I believe R407c, R411a and R290 can all be used as retrofit for R22 but the filter drier, TEV and Lubrication may need to be changed to suit?

EngFBN_BR
24-08-2007, 09:09 PM
R407c is "usually" the choice to replace R22. "Usually", you can use the same TEV. The operation pressures and refrigerant charge are similar. You must use POE oil, clean the circuits and change the dryer filters.
You see, there are a lot words like of "usually", "may", etc... Find yourself a good professional to do the job and be happy :).

m-nelson
24-08-2007, 10:12 PM
OK. You guys have answered my question. I get the message that this is not trivial. I'll go for the professional & simply get him to re-charge it with R-22.

(as to where the old charge went... the unit was de-commissioned & broken down into a pile of parts for transport)

The MG Pony
24-08-2007, 11:16 PM
It most certainly isn't trivial unfortunately for most.

R-290 is a very nice refrigerant that will work with an R-22 TXV Perhaps look into ES-R22a it is a premade Hydrocarbon blend suitable for stationary equipment and is a long term replacment.