The Homemade Heat Pump Manifesto

[pick1e]

Originally Posted by AC_Hacker

No, this is not correct. I used the 'LS press' reading to refer to a PT chart for R-290 to see what the temperature should have been at that particular pressure (actually I did a curve fit on the PT chart for R-290 and derived the formula for the entire PT chart in order to save myself from interpolating every value). Then I subtracted the actual temperature from the calculated temperature to determine Sub Cooling.

Ditto Super Heating. I derived values for Sub Cooling and Super Heating, to be used in system tuning. Since the only fine adjustment I could make was refrigerant pressure. I used an excessively high Sub Cooling value to discover that I needed to lower my refrigerant pressure. I did adjust that, and the efficiency increased accordingly.

That is interesting. I don't remember you mentioning that in the thread, sorry if you did. Hopefully I will avoid that necessity by not disassembling my AC unit. I would like to use it as is, sacrificing some efficiency for simplicity.

Originally Posted by AC_Hacker

I used a power meter to determine power into the compressor for each time interval. I also knew the volume, and thus the weight of the water for each time period.

Okey dokey, thanks.