R-410a Compressors

[Crew Chief]

New to this site.

I'm in the process of designing a new air cooled chiller capable of operating at -20F/-29C brine temperatures. The unit will be air cooled and I would like to use R-410a provided I can find a suitable compressor.

Capacity target is 10 tons /35kW at -20F/-29C.

Can anyone recommend a compressor that's capable of this application?

[NoNickName]

Not easy. 35kW at -35°C boiling point, 45 to 55°C condensing temperature and 42 bar design pressure....

[US Iceman]

Why not use R-507? The pressures will be lower , which reduces some of your problems with the compressor selection but also the air-cooled condenser.

[Crew Chief]

R-507 is an option. I was trying to utilize the 410a option because I just designed a new air conditioner platform and wanted to use the same basic components. Also, R-507 requires a little more horsepower than R-410a as well as thermodynamics.

[US Iceman]

R-507 is an option. I was trying to utilize the 410a option because I just designed a new air conditioner platform and wanted to use the same basic components. Also, R-507 requires a little more horsepower than R-410a as well as thermodynamics.

OK, how much of an increase will this mean? Can you lower the condensing temperature 1° or so to compensate for it?

Or, look at the total power (compressor + condenser fans). What kind of options can you find then?

Air-cooled with R-410 is asking for a challenge... unless the peak ambient temperatures are low enough to allow reasonable discharge pressures.

[cleanNcold]

Im not sure you will find a 410a compressor for this application. Instead of 507, I would go with 404a which is essentially the same refrigerant except that 404a has 134a added to control discharge pressure. The 134a in the mix does not affect evaporator performance much at all as it is a much lower pressure refrigerant.

[NoNickName]

We've got these: http://www.frascold.it/pdf/CATALOGUES/FCAT22-01.pdf but you will need to build a rack and have liquid injection or head fan.