Which part of an air conditioning system directly facilitates the cooling process?

The evaporator coil is fundamental to the cooling process in an air conditioning system. During operation, the refrigerant enters the evaporator coil in a low-pressure state. As warm air from the indoor space is blown over the coil, the refrigerant absorbs heat from this air. This heat absorption causes the refrigerant to evaporate and turn into vapor, thereby cooling the air that is then circulated back into the living spaces. This direct interaction with the warm air allows the evaporator coil to effectively lower indoor temperatures, making it a critical component in the cooling cycle.

The compressor, on the other hand, pressurizes the refrigerant and moves it through the system but does not directly cool the air itself. The refrigerant line serves to transport the refrigerant between components but also does not engage directly in the cooling process. Finally, the thermostat is responsible for regulating the overall operation of the air conditioning system based on temperature settings, but it does not directly contribute to the cooling effect in the same way the evaporator coil does. Thus, the evaporator coil is the component that directly facilitates the cooling process within an AC system.