ESCO Air Conditioning Practice Exam

What is the primary function of a thermostatic expansion valve in an A/C system?

1. Control the flow of refrigerant to the evaporator

2. Monitor the compressor's efficiency

3. Regulate the heat exchange process

4. Store excess refrigerant

The correct answer is: Control the flow of refrigerant to the evaporator

The primary function of a thermostatic expansion valve (TXV) in an air conditioning system is to control the flow of refrigerant to the evaporator. The TXV works by sensing the temperature and pressure of the refrigerant leaving the evaporator coil. By adjusting the valve opening based on these parameters, the TXV regulates the amount of refrigerant entering the evaporator, maintaining the proper superheat in the system. This ensures optimal cooling efficiency and performance of the air conditioning system. The other options are incorrect: - Monitoring the compressor's efficiency is not the primary function of a thermostatic expansion valve. - Regulating the heat exchange process is a general function of the entire air conditioning system, not specific to the role of a thermostatic expansion valve. - Storing excess refrigerant is not a function of a thermostatic expansion valve; its main purpose is to regulate the flow of refrigerant to the evaporator.