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Originally Posted by doug30293
If I may expand somewhat on Jeff's comments:
R410A has roughly 40% greater saturation vapor density than R22. The higher working pressures allow smaller cross section in the same sense that high voltage lines permit smaller wire cross section.
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I'm still having trouble with this notion. I just don't see how higher pressure equates to lower friction ("the smaller lines do not hinder flow like in r22 systems").
The electrical metaphor isn't doing it for me either.
The rest makes perfect sense.
Quote:
Originally Posted by doug30293
This has multiple benefits. Smaller tubing has lower hoop stress for a given pressure, allowing for thinner walls. Thinner walls increase heat transfer and lower cost. More tubes in a given HX area further increase heat transfer. Higher fluid velocity also increases heat transfer.
R410A gets a bad rap because it doesn't work in old equipment. Systems designed for R410A can outperform R22 and R290.
Ref. " Effects of refrigerant properties on refrigerant performance" Prapainop and Suen. 2012
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A well-thought response.
I tried to find a copy of the Prapainop and Suen paper you mentioned, but none of the links I tried were live.
Do you have a working link to the paper?
-AC