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Old 10-03-12, 03:53 PM   #1329
AC_Hacker
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Quote:
Originally Posted by berniebenz View Post
My Q is more specific regarding this rating as a measure of HX performance, i.e. the specific “standard conditions“ if any, of this rating.
1. Heat source side Delta T, Flow rate, Fluid thermal and change of state parameters.
2. Sink side, same conditions.
3. Delta T across the exchange surfaces, ect.
Well berniebenz, you have correctly identified nearly all the factors that would affect heat transfer across a HX.

The capacity value (Tons) that is associated with each HX is a simplified number that assumes typical working conditions that would be encountered in the HVAC trade. There are variations from refrigerant to refrigerant, but these variations are pretty modest.

If you wanted to use a refrigeration HX for water-to-water, the differences would be large enough that you would need to re-evaluate the capacity. Conversely, if you found water-to-water HXs that you wanted to re-purpose for refrigeration, the differences would be large and, again you'd need to re-evaluate.

To be able to delve into heat exchangers in the depth and detail you seem to be seeking, you should pick up some books on HX design and dive into the real nitty-gritty... for this, you will certainly need to brush up on your calculus skills, as this is how the design criteria are discussed and developed.

If, along the way you discover anything that could be of value to this humble thread, please feel free to share.

Best,

-AC
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