Hi Frank,
I have installed Cold Room its set point in -22 C but the compressor does not off except defrosting time means remains on and some times temperature reaches to -18 C I measured its super heat which details are below.
Suction line pressure 20 PSI convert to PT chart R-22 temperature is -5 F
Suction line temperature is 71 F so that according to calculation super heat is (71 - (-5) ) = 76 F ? (71-5) = 66 F ?
In both condition the super heat is too high so my question is that in cold room what super heat is ideal at evaporator and compressor side as in A/C
Compressor side Super heat 20~25 is ideal kindly reply I am really confused.