ESCO Air Conditioning Practice Exam 2026 – Complete Study Resource

The expansion valve plays a crucial role in an air conditioning system by regulating the flow of refrigerant into the evaporator while also reducing its pressure. This process is essential for the cooling cycle to function effectively. When the refrigerant flows through the expansion valve, it undergoes a sudden drop in pressure, which results in a decrease in temperature. This cooled refrigerant then enters the evaporator, where it absorbs heat from the indoor air, thereby providing a cooling effect within the space.

In addition to its primary function of pressure reduction, the expansion valve also ensures that the correct amount of refrigerant is delivered to the evaporator based on the cooling demand. This regulation helps maintain system efficiency and prevents issues like excessive flooding of the evaporator or insufficient refrigerant flow, both of which can lead to reduced cooling performance or system damage.

The other options describe functions that do not align with the primary responsibility of the expansion valve in the context of air conditioning systems. Understanding the distinct roles of various components is essential for grasping how an air conditioning system operates as a whole.