View Full Version : R290 Drop in??

30-08-2016, 10:08 AM
Hi, i am after some advice regards a fridge running on R290. The system has lost its full charge and is in need of a re-gas, it says on the unit data plate insulation gas R134a. Does this mean that the unit would run fine if R134a was put in instead?

I don't work with flammable refrigerants so know very little about them, i have a customer who wants it pressure testing and re-gassing but obviously as i don't deal with R290 i can't re-gas with that. Basically i am wondering if it can be re-gassed with anything else or is it worth just leaving alone?


31-08-2016, 08:44 AM
You can't charge it with R134a. R290 systems use Mineral oil. 134a uses synthetic.

31-08-2016, 02:39 PM
You can't charge it with R134a. R290 systems use Mineral oil. 134a uses synthetic.

R-290 works with synthetic oil as well, it much more efficient than 134 and you just have to know how to handle it safely.
To be sure what kind of oil is in the compressor, read the manufacturer label.

Rob White
31-08-2016, 04:00 PM

290 is more closely matched to 404a and they use the same comp.
You will often find 404a compressors with 290 inside.

As for changing it, don't.

The system is a 290 system and it works best with 290, do a days
awareness training / exam and get qualified to work with it and
then get the refrigerant.




01-09-2016, 09:03 AM
Thanks for all the responses, normally with these types of gasses I don't waste my time with them hence why I know very little about them. This is the first one I've seen that says it has an insulation gas of r134a, which made me wonder if it could be swapped over.

Thanks again! ��

01-09-2016, 01:09 PM
Excuse me, I may be misreading but you have twice said that the 'insulation' gas is134a. That's just what was used to blow the foam.

If that is true then it has nothing to do with the refrigeration side of things does it?

01-09-2016, 05:20 PM
What do you mean insulation gas?

The MG Pony
12-09-2016, 08:24 PM
The gas that makes the foam inflate to fill the voids. back in the day it was R-12, and now it is a mixed bag depending on the goals.