ReplyYou cant just use a single measurement, you have to take everything into account. Centrifugals, I pay more attention to discharge SH, along with approach. Etc.
Ive never used subcooling or approach alone on a flooded machine, too many variables.
Regular Guest
Happy Sunday! Simple question, I've always adjusted a refrigerant charge on a liquid cooled (tower) chiller using the evaporator approach method. Yes, tubes need to be in good shape. I have a 2 pass evaporator and I'm at at a 8 degrees when chiller is loaded (80%). We have a young engineer that keeps trying to tell me that approach method for charging is incorrect. It should be charged by subcooling calculation. Question; who's wrong or are we both right??
Professional Member*
You cant just use a single measurement, you have to take everything into account. Centrifugals, I pay more attention to discharge SH, along with approach. Etc.
Ive never used subcooling or approach alone on a flooded machine, too many variables.
Regular Guest
Good advice. Thank you!
SDC/Educational/Membership Committee*
Is it a flooded evaporator or direct expansion?Originally Posted by Chilly56
Regular Guest
Flooded chiller. I went by running compressors at 90% capacity and charged by the sight glass that's right before the TXV. Approach is now 7 degrees on a 2 pass evap. Running well.
Last edited by Chilly56; 09-30-2019 at 08:22 PM. Reason: Typo
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