In most refrigeration systems, where does the phase change from liquid to gas occur?

The phase change from liquid to gas occurs in the evaporator of refrigeration systems. This component is designed specifically to absorb heat from the environment and facilitate the transformation of the refrigerant. As the refrigerant enters the evaporator as a low-pressure liquid, it absorbs heat from its surroundings, which allows it to evaporate and turn into a gas. This process cools the area surrounding the evaporator, which is the fundamental purpose of a refrigeration system.

In contrast, the condenser's role is to reject heat and cause the refrigerant to condense from a gas back into a liquid. Similarly, the compressor is responsible for increasing the pressure of the refrigerant gas, not facilitating phase changes. The receiver is a storage component that holds liquid refrigerant but does not play a direct role in the evaporation process.

Thus, understanding the function of the evaporator clarifies why it is the correct answer, as it is the critical component where the transition from liquid to gas occurs in a refrigeration system.