Air Conditioning Repair Certification (ETI) Practice Exam

The expansion valve plays a crucial role in the operation of an air conditioning system by regulating the flow of refrigerant into the evaporator. It is designed to control the amount of refrigerant that enters the evaporator coil based on the cooling demand.

When the refrigerant exits the condenser, it is in a high-pressure, high-temperature state. As it passes through the expansion valve, the refrigerant experiences a drop in pressure, which allows it to expand and cool significantly before entering the evaporator. This expansion is critical because it prepares the refrigerant to absorb heat from the indoor air inside the evaporator coil.

By controlling the amount of refrigerant that flows into the evaporator, the expansion valve ensures that the system operates efficiently. If too much refrigerant enters the evaporator, it can lead to inadequate cooling and potential system problems; too little can cause the evaporator to freeze. Thus, the expansion valve is vital for maintaining optimal system performance and efficiency.