Hello - New Refrigerant Chemist on board

[doctor freon]

Hello everyone - I just came on board here and I am looking forward to getting to know and working with everybody. I am a chemist by training and have been working as a refrigeration consultant for about 20 years. Currently I spend most of my time helping with the phase out of R22 and conversion of old systems to new refrigerants. I hope my background and experience can be of help. Please feel free to reach out to me if you think I may be of assistance.

[monkey spanners]

Hi Doctor*****,

Welcome to RE :)

I'm sure your knowledge will soon be put to the test!

Jon :)

[doctor freon]

Thanks Jon, looking forward to it.

[chemi-cool]

Just in time doc,

I am going to install 6 condensing units on a milk tank.
Up to now I have used R-22.
Evaporating temp is between -5°C to 10°C.
Ambient is between 5°C to 40°C [head pressure is controlled with condenser fans.

Refrigerants available are R-404 and R-507.

Any suggestions?

Thanks and welcome.

[desA]

Good to have you aboard, Doc.

Your input will be most appreciated.

[mikeref]

Hello Doc, nice to see new faces.

[doctor freon]

Just in time doc,

I am going to install 6 condensing units on a milk tank.
Up to now I have used R-22.
Evaporating temp is between -5°C to 10°C.
Ambient is between 5°C to 40°C [head pressure is controlled with condenser fans.

Refrigerants available are R-404 and R-507.

Any suggestions?

Thanks and welcome.


Thanks for the welcome. If you are converting R-22 systems to 404A/507 there are a few issues to look at. First is lubricant which will need to be converted from mineral oil to a POE type lubricant. Also, since 404a/507 have higher mass flow rates, you should check out line sizing and TXV sizing as these may need to be upsized as well. Operating pressures will be increased also , so you should verify pressure ratings, relief devices etc are adequate for any of the components, piping etc. I hope this helps. There are other refrigerants that are closer matches to R-22 but I do not know what your limitations are. Good luck.

[doctor freon]

Thanks everyone for the welcome.

[mikeref]

Hey Doc, just thinking the way Chemi worded his post.. maybe he was asking which refrigerant would you choose of the two and why? Also, can you expand on the closer matches for R22.. mike.

[chemi-cool]

Thanks for the welcome. If you are converting R-22 systems to 404A/507 there are a few issues to look at. First is lubricant which will need to be converted from mineral oil to a POE type lubricant. Also, since 404a/507 have higher mass flow rates, you should check out line sizing and TXV sizing as these may need to be upsized as well. Operating pressures will be increased also , so you should verify pressure ratings, relief devices etc are adequate for any of the components, piping etc. I hope this helps. There are other refrigerants that are closer matches to R-22 but I do not know what your limitations are. Good luck.

What are the other refrigerants that are closer to R-22?

My thoughts are going for R-507, Everything you have mentioned is has been planed upsize allready.

[doctor freon]

Ok, R507 and R404A will be very similar in just about every aspect. R422D, R422A, and R407A will have closer pressures and mass flow rates to R-22 so are less likely to need to change any piping , valves etc. But if as you say everything has been upsized for the higher flows and pressures, R507 will definitely have the best capacity and is a good choice.

[chemi-cool]

Thanks doc. that was my thought too.

can you please elaborate on the other refrigerants and their recommended uses? R-422D, R-422A and R-407A?

[Bobbyu]

Can you mix 422d with m099