Is it necessary to overheat in a cold room?

Yes, overheating is something to a certain extent desired, because in addition to avoiding wet suction in the compressor, also ensures that all refrigerant injected into the evaporator has evaporated producing the desired effect. When multiple evaporators are used in a single cold room the expansion valves shall maintain superheat regulated. In the case of refrigeration lines with configuration that require the maintenance of low overheating values, or with internal volumes which can not, for example, avoid the injection of large volumes of liquid in the compressors in hot gas defrosting situations, Temperatures, the use of an overheating control valve for the intake in the compressor must occur. In such applications a level of coolant superheat of the order of 6 ° C is desired which allows dry suction and suitable cooling of the hermetic and semi-hermetic type compressor motors. It should also be noted that in low temperature applications maintaining high values ​​of overheating will cause high overheating will cause high discharge temperatures which may cause damage to compressor valve plates, oil carbonization, and in some cases Until the decomposition of the refrigerant has reached its critical temperature.