ESCO Air Conditioning Practice Exam 2025 – Complete Study Resource

The correct answer identifies the three operating pressures of the thermostatic expansion valve as compressor pressure, spring pressure, and sensor bulb pressure.

The thermostatic expansion valve plays a crucial role in the refrigeration cycle by controlling the flow of refrigerant into the evaporator. The sensor bulb, typically located on the outlet of the evaporator, detects the temperature of the refrigerant. This pressure is vital for adjusting the valve to allow the correct amount of refrigerant to flow into the evaporator based on its cooling demand.

Spring pressure affects the opening of the valve. The spring tension reacts to changes in pressure and assists in maintaining the proper refrigerant flow rate. Compressor pressure provides a reference for the system’s operational conditions, ensuring that the heat exchange process remains efficient.

Together, these three pressures enable the thermostatic expansion valve to effectively balance the system's performance, optimizing the refrigeration process and enhancing energy efficiency. Understanding these operating pressures is essential for diagnosing issues in HVAC systems and ensuring proper maintenance and efficiency.