What component is responsible for controlling the flow rate of refrigerant into the evaporator?

The expansion valve is the component responsible for controlling the flow rate of refrigerant into the evaporator. Its primary function is to reduce the pressure of the refrigerant as it passes from the high-pressure side of the system (condenser) to the low-pressure side (evaporator). By doing so, the expansion valve also controls the amount of refrigerant entering the evaporator, which is crucial for maintaining the desired temperature and pressure within the system.

By precisely regulating the flow of refrigerant, the expansion valve ensures that the evaporator can absorb heat effectively while preventing liquid refrigerant from returning to the compressor, which could cause damage. The operation of the expansion valve is essential for the optimal performance of refrigeration and air conditioning systems, where appropriate refrigerant flow is critical for efficient heat exchange.

Other components, like the compressor and condenser, play vital roles in the overall refrigeration cycle but are not involved in controlling the flow rate into the evaporator. The filter drier, while important for maintaining system cleanliness and moisture control, also does not manage refrigerant flow.