In refrigeration, what does the term "vapour" primarily refer to?

In refrigeration, the term "vapour" primarily refers to a gas-state refrigerant. This reflects the phase of the refrigerant when it is in a gaseous state, typically after it has absorbed heat and changes from a liquid to a gas during the refrigeration cycle.

In this cycle, the refrigerant undergoes phase changes to absorb and release heat efficiently. The vapour state is significant because it is when the refrigerant can carry thermal energy away from the area that is being cooled. Understanding this phase is crucial, as it affects the efficiency and effectiveness of the refrigeration system.

Recognizing the differences between the phases is important; liquid-state refrigerants refer to those that are condensed and can absorb heat at low temperatures and pressures, while solid-state refrigerants do not play a role in standard refrigeration cycles.