Messing with a chiller, the mixture is Dowcal N 25%, approx freezing temp for the mix is -10degC/14degF. Measuring in the plate exchanger where the temp probe is placed i got -9degC/15,8degF, on outgoing water there's -6,5degC/20,3degF, can i turn down the thermostat (Carel PCO) or can the exchanger freeze over if i do so? The chiller is serving a bunch of disks at a grocery store, the manager want a li'l bit colder in a pair of disks, by this i have to lower the outgoing temp.
By general. Which temperature is most critical? Exch. temp or outgoing temp?
The chiller is running on 404A -18degC/-0,4degF evap, 40degC/104degF head. 8degC/14,4degF superheat, 5degC/9degF subcool.