Red Seal Appliance Service Technician Practice Exam

What is the role of the expansion valve in a refrigeration system?

1. To regulate the compressor speed

2. To control the amount of refrigerant released into the evaporator coil

3. To enhance the compressor efficiency

4. To maintain the temperature setting

The correct answer is: To control the amount of refrigerant released into the evaporator coil

The function of the expansion valve in a refrigeration system is crucial for the proper operation of the system. Its primary role is to control the flow of refrigerant into the evaporator coil. By modulating this flow, the expansion valve ensures that the correct amount of refrigerant is introduced to effectively absorb heat from the surrounding environment in the evaporator. This control is vital because if too much refrigerant enters the evaporator, it can flood the system, while too little can lead to inadequate cooling. The correct regulation of refrigerant flow not only optimizes the cooling process but also maintains the overall efficiency of the system. A properly functioning expansion valve contributes to the balance between the high and low-pressure sides of the refrigeration cycle, ensuring that the system operates at its best performance level.