What is the main purpose of a compressor in a refrigeration cycle?

The main purpose of a compressor in a refrigeration cycle is to increase the pressure of the refrigerant and circulate it. The refrigeration cycle relies on the transformation of refrigerant between gas and liquid states, absorbing heat from the environment and releasing it elsewhere. The compressor plays a crucial role in this process by taking low-pressure refrigerant gas from the evaporator and compressing it into high-pressure gas.

This compression process elevates the refrigerant's pressure and temperature, allowing it to subsequently flow through the condenser where it will release heat and condense into a liquid. By increasing the pressure, the compressor facilitates the proper functioning of the cycle, enabling the refrigeration system to effectively move heat from the cooler interior of a refrigerated space to the warmer external environment.

The other options do not accurately capture the primary function of the compressor within the refrigeration cycle. Cooling air is a result of the entire refrigeration process, not the sole function of the compressor. While the compressor does decrease the volume of refrigerant gases during compression, this is a secondary aspect of its operation. Insulating refrigerant lines is unrelated to the function of the compressor itself, as insulation is concerned with minimizing heat transfer in the system rather than facilitating the cycle.