ESCO Air Conditioning Practice Exam 2025 – Complete Study Resource

The NTC thermistor plays a pivotal role in monitoring temperature changes within the thermal electric expansion valve system. NTC stands for Negative Temperature Coefficient, meaning that the resistance of the thermistor decreases as the temperature increases. This characteristic allows the thermistor to provide precise readings of the refrigerant temperature traveling through the system.

By continuously monitoring temperature changes, the NTC thermistor can provide valuable feedback to the system's control mechanisms. This information is crucial for optimizing the expansion valve's performance, as it helps ensure that the correct amount of refrigerant enters the evaporator based on current temperature conditions. This facilitates energy-efficient operation and helps maintain the desired temperature within the system, preventing overheating or overcooling.

The other options do not accurately represent the function of the NTC thermistor. It does not act as a pressure regulator or directly control the valve's opening and closing; rather, it provides data that influences these actions. Additionally, it does not store liquid refrigerant; its primary function is to measure temperature.