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View Full Version : Using R410A In Low -Temp Applications-Why isn't it used?







dan9679
22-07-2014, 12:13 AM
r410a A/C applications are very common. You will even find R410A in some Medium Temp applications, but neither Copeland or Tecumseh show compressors for Low-temp using r410A.
Found the following paper showing benefits of using r410a vs r404a for low temp: https://www.ideals.illinois.edu/handle/2142/24063.

Would love to know the answer to this, and I can't figure it out. Thank you!

mikeref
22-07-2014, 09:35 AM
Off the cuff and flying blind, i would say R410a was designed for high temperature applications only.
(Compressors need to keep discharge temperatures low enough to avoid refrigerant and oil breakdown.)

R410a in a/c kits usually has a suction line pressure of around 120 PSI ( + or -) and the refrigerant passes through the compression stage without any significantly ELEVATED heat transferre....at the designed volume per second.
Low temp applications would lower the suction pressure. Low suction pressure on R410a = reduced performance and higher discharge temps.

dan9679
23-07-2014, 11:18 PM
I believe you are right. Thank you mikeref.

I guessed that the work done by the compressor was proportional to the increase in pressure and the flow rate. But I believe it is proportional to the compression ratio. Therefore, for such a great swing in temperature (Low temp applications) and the characteristics of R410A, such high work on it makes it get very hot (140C vs 100C for similar application vs r404a) and I believe this is a critical application for POE oils and compressors in general.

So while the study shows greater COPS for r410a vs r404a, this means nothing if the system would be unreliable and or have a short service life. I'm no expert, I would love to get some critique on this analysis moving forward.
Cheers,