What function does the expansion valve serve in an AC system?

The expansion valve plays a critical role in an AC system by reducing the refrigerant pressure and allowing it to expand into the evaporator. This is important because, as the refrigerant enters the evaporator, it is in a low-pressure state, which enables it to absorb heat from the indoor environment effectively.

When the high-pressure refrigerant from the condenser reaches the expansion valve, the valve creates a pressure drop, cooling the refrigerant and allowing it to expand into a gaseous state. This process is essential for the refrigeration cycle, as the refrigerant must be in a low-pressure, low-temperature state as it enters the evaporator to maximize heat absorption from the surrounding air.

Understanding this function is fundamental for anyone working in HVAC, as it directly relates to the efficiency and effectiveness of the cooling process in an air conditioning system. By allowing the refrigerant to expand and change its state, the expansion valve ensures that the system can produce cold air and maintain the desired indoor temperature.