What is the primary function of the expansion valve in an HVAC system?

The primary function of the expansion valve in an HVAC system is to control the flow of refrigerant into the evaporator. This component is crucial because it regulates the amount of refrigerant that enters the evaporator coil, allowing for the proper evaporation process to occur. By maintaining the appropriate pressure and flow of refrigerant, the expansion valve ensures that the refrigerant can absorb enough heat from the surrounding air, facilitating effective cooling within the system.

When refrigerant passes through the expansion valve, it experiences a drop in pressure, which causes it to expand and cool before entering the evaporator. This cooling effect is essential for the system's overall efficiency, as it enhances the refrigerant's ability to absorb heat, thereby optimizing the cooling process within the HVAC system. The precise control the expansion valve provides is critical to the proper functioning of the air conditioning cycle.