ICC Commercial Mechanical Practice Exam

A mechanical refrigeration cycle is a fundamental process used to transfer heat from one location to another, maintaining a lower temperature in a designated area, such as in refrigeration and air conditioning systems. The cycle typically includes four primary components: evaporation, compression, condensation, and expansion.

In the evaporation phase, the refrigerant absorbs heat and changes from a liquid to a gas inside the evaporator coils, which cools the surroundings. The compressor then increases the pressure of this refrigerant gas, which raises its temperature. Next, in the condensation phase, the hot, high-pressure gas moves through the condenser coils where it releases heat to the outside environment, condensing back into a liquid. Finally, the refrigerant passes through an expansion device, which reduces its pressure, allowing it to cool further and begin the cycle anew.

This combination of phases is essential for the refrigeration process to function effectively. Understanding this cycle provides insights into the principles of heat transfer and the operation of mechanical systems in HVAC applications. The other options either omit essential components of the refrigeration cycle or include processes that are not part of this specific cycle.