What is the purpose of an expansion valve in an HVAC system?

The primary function of an expansion valve in an HVAC system is to regulate the flow of refrigerant into the evaporator coil. By controlling the amount of refrigerant that enters the evaporator, the expansion valve ensures that the refrigerant can adequately absorb heat from the indoor air. This regulation is crucial for maintaining the desired temperature and humidity levels in a space.

The expansion valve operates by allowing the high-pressure liquid refrigerant to expand and drop in pressure, transforming it into a low-pressure vapor. This process is essential to facilitate effective heat exchange within the evaporator. As the refrigerant evaporates, it absorbs heat from the environment, thereby helping to cool the air that is circulated throughout the building.

In summary, the expansion valve plays a critical role in the overall efficiency and effectiveness of the HVAC system by ensuring proper refrigerant flow and pressure, directly impacting the system's cooling performance.