How does an expansion valve function?

The expansion valve plays a critical role in the refrigeration cycle by allowing the refrigerant to expand and cool. It serves as a metering device that reduces the pressure of the refrigerant as it passes through. When the high-pressure refrigerant liquid enters the expansion valve, it is allowed to expand into a low-pressure mixture of liquid and vapor. As this process occurs, the refrigerant experiences a drop in temperature due to the energy absorbed from the surrounding environment. This cooling effect is essential for the evaporator coil, where the refrigerant absorbs heat from the indoor air, providing the necessary cooling for HVAC systems.

The function of the expansion valve is vital for maintaining the efficiency of the refrigeration cycle and ensuring that the system can cool effectively. By controlling the flow of refrigerant into the evaporator, the expansion valve helps to optimize the amount of refrigerant that can absorb heat, thereby enhancing the performance of the system.