What refrigerant condition does 'superheating' refer to in a refrigeration cycle?

Superheating is a term used to describe a condition in a refrigeration cycle where a refrigerant gas is heated to a temperature that is higher than its boiling point at a given pressure. This is a crucial aspect of the refrigeration process as it ensures that the refrigerant vapor is completely in the gaseous state before entering the compressor.

When the refrigerant is superheated, it not only increases the efficiency of the refrigeration cycle but also helps prevent issues such as liquid slugging which can damage the compressor. By ensuring that the refrigerant is entirely vaporized, the system operates more effectively, maximizing the cooling capacity and preventing compressor overheating.

The other options refer to various states of refrigerant that do not align with the definition of superheating. For instance, gas only would not capture the essence of the temperature aspect, while liquid only does not pertain to the process of superheating at all. Similarly, a gas and liquid mixture does not reflect the condition of superheating, as it requires the refrigerant to be exclusively in the gaseous phase after it has been heated beyond its boiling point.