Use of R417a replacement on MitsE VRV system

[Makeit go Right]

Has anyone replaced R22 with R417a in a Mitsubishi VRV system and had good/bad results?

Target system is PURY250YMF, 10 years old.

I had heard talk that the compressor could possibly suffer with the alternate gas and wanted to hear from others who had some results from such changes.

[The Viking]

To start with you would have to replace the oil, considering how much of it is in the system, you are probably looking at at least 5-6 changes of the oil in the compressor (whilst it's running on R22, mineral oil can not lubricate when the system is running on new gasses)
This can be done, but will cost.

Then you got the bigger problem.
All VRV/VRF systems are highly tuned with lots of adjustments done electronically depending on pressures and temperatures.

I have never tried it but my bet is that it wouldn't work and if it did, you would lose performance.

Please keep us updated if you decide to go ahead with it....

[Makeit go Right]

Hi, Viking.
Far as I know, the oil is the same in R417a, as is in R22, which is why it is a popular drop-in replacement.

[If changing to R407c etc it would be a whole clean-out game, which I think would be prohibitive on that alone, as there would always be a worry thatthe compressor would find some of the old oil somehow, and fall over. And then we have to cough.]

With a change from R22 to R417a, maybe there is too much too little oil and we'd need to correct that(?) Anyone able to comment?

[nike123]

Why do you have to change from R22 to R417?
It is still legal to service equipment with R22 from what I know? Maybe in your country it is not?
If it is not illegal, I suggest that you leave system with R22 in it.

[Makeit go Right]

Yes, still legal here in UK for another few months (Dec 2009 deadline). Then no new R22 gas can be legally obtained - just salvaged, which will become scarce with time.

We have a compressor and Inverter pack to swap, and the customer may swap the gas too at this point.

[nike123]

If I was you, I will leave it on R22. It could last to end of life of that system.