What is the principle of car air conditioning?
2 Answers
Car air conditioning works by: receiving signals from various sensors that detect the temperature inside the car, the temperature of the evaporator, the engine coolant temperature, and other relevant switch signals to output control signals. These signals control the operation of the radiator fan, condenser fan, compressor clutch, blower motor, and air control motor to automatically regulate the temperature inside the vehicle. The car air conditioning system consists of a refrigeration system, heating system, air purification device, and control system. Its functions are: 1. to adjust and control the temperature, humidity, air cleanliness, and air flow inside the cabin to an optimal state; 2. to provide a comfortable riding environment for passengers, reducing travel fatigue; 3. to create favorable working conditions for the driver, ensuring driving safety.
The principle of a car's air conditioning system is actually similar to how a small refrigerator works. From my driving experience, it uses a refrigerant cycle to absorb heat and cool. The compressor pressurizes gases like R134a into a high-pressure, high-temperature state, then sends them to the condenser (radiator) at the front of the car, where the fan helps dissipate heat, turning it into liquid. Next, it passes through an expansion valve or small tube, where pressure and temperature drop, before entering the evaporator behind the dashboard. There, the refrigerant evaporates and absorbs heat, while the blower blows air across it, sending cool air into the cabin. The remaining hot air is expelled outside. The entire system is easy to maintain—just regularly check refrigerant levels and filters. Otherwise, the AC won't cool effectively in summer and will waste fuel. I once had a noisy compressor issue, but replacing a part fixed it. Maintenance is crucial.
