To calculate superheat in a non-azeotropic refrigerant, which formula should be used?

To accurately calculate superheat in a non-azeotropic refrigerant, the appropriate relationship involves the temperature of the refrigerant vapor and its corresponding dew-point temperature. Superheat is defined as the difference between the actual temperature of the vapor refrigerant and the temperature at which it begins to condense (dew-point).

In this context, the term "actual heat" refers to the actual temperature of the refrigerant vapor in the system. By subtracting the dew-point temperature from the actual vapor temperature, you effectively measure how much the vapor temperature has exceeded the dew-point, indicating the degree of superheating that has occurred.

This measurement is critical in refrigeration and air conditioning systems, as it ensures the refrigerant is in a superheated state before it enters the compressor, preventing potential damage due to liquid refrigerant entering the compressor. Therefore, using the formula that subtracts the dew-point from the actual refrigerant temperature accurately reflects the superheat level in a non-azeotropic refrigerant system.