What does the term "superheat" refer to in refrigeration?

The term "superheat" in refrigeration specifically refers to the increase in temperature of refrigerant above its boiling point. When refrigerant is in a vapor state, superheating occurs after it has completely evaporated but before it enters the compression phase. This process is important because it ensures that the refrigerant is entirely in vapor form to avoid liquid refrigerant entering the compressor, which can cause damage.

Understanding superheat is essential for efficient refrigeration system operation. Monitoring superheat helps in optimizing system performance and ensures that the evaporator is functioning correctly, thus preventing issues such as inadequate heat transfer or compressor damage.

In the context of the other options, compressing refrigerant at high pressure refers to the process that occurs within the compressor, but does not specifically define superheat. Cooling down refrigerant below its condensation point describes subcooling, which is a different process. The phase change from liquid to gas is part of the vaporization process but does not address the temperature increase above the boiling point, which is the core concept of superheat.