1. Compressor: The heart of the system, the compressor is a pump that pressurizes and heats refrigerant (a special fluid) that's in a gaseous state. This high-pressure, hot refrigerant is then sent to the condenser.
2. Condenser: The condenser is a radiator-like unit located in front of the car's radiator. As the hot, high-pressure refrigerant flows through the condenser's fins, the heat is dissipated into the outside air, causing the refrigerant to change from a hot gas to a high-pressure liquid.
3. Expansion Valve (or orifice tube): This component restricts the flow of the high-pressure liquid refrigerant, causing a dramatic drop in pressure. This pressure drop also causes a significant drop in temperature, turning the liquid refrigerant into a very cold, low-pressure liquid/gas mixture.
4. Evaporator: The cold, low-pressure refrigerant flows through the evaporator, a heat exchanger located inside the car's dashboard. As the refrigerant absorbs heat from the air inside the car, it evaporates, cooling the air. A fan blows this cooled air into the car's interior.
5. Cycle Repeats: The low-pressure refrigerant gas then returns to the compressor, restarting the cycle.
In short: The system uses the refrigerant's properties to move heat from inside the car to outside the car. The compressor provides the energy needed to drive this process. The pressure changes are crucial for the temperature changes that achieve cooling.
