Which of the following is a characteristic of a vapor-compression refrigeration system?

A key characteristic of a vapor-compression refrigeration system is that it involves the compression of refrigerant vapor. In such systems, the refrigerant undergoes several stages, including compression, condensation, expansion, and evaporation. During the compression phase, the refrigerant, initially in its vapor state, is compressed to a higher pressure, which raises its temperature. This process is essential for the system's operation, as it allows the vapor to flow through the condenser where it releases heat and changes into a liquid state.

The compression of vapor is a fundamental mechanism in achieving the cooling effect provided by the refrigeration cycle. By using the pressure and temperature differences created by this compression, the system facilitates heat exchange processes that are central to refrigeration and air conditioning applications.