How Does a Car Air Conditioning System Work?
3 Answers
The working principle of a car air conditioning system is as follows: 1. The compressor pressurizes the low-pressure gaseous refrigerant to turn it into a high-pressure gaseous refrigerant; 2. The condenser cools the pressurized gaseous refrigerant through the cooling fan, turning it into a medium-temperature, high-pressure liquid refrigerant; 3. The refrigerant then flows through pipes to the receiver-drier, where the medium-temperature, high-pressure liquid refrigerant is filtered to remove moisture and impurities, while also being throttled to become a clean and stable liquid refrigerant; 4. The medium-temperature, high-pressure liquid refrigerant flows through pipes to the expansion valve, which acts like a nozzle, spraying the medium-temperature, high-pressure liquid refrigerant into very fine droplets and injecting them into the evaporator to turn them into liquid refrigerant; 5. The low-pressure gaseous refrigerant in the evaporator is then sucked back into the compressor through the low-pressure pipe, entering the next cycle.
As a veteran driver who frequently takes long trips, I find the air conditioning to be a lifesaver in summer. Simply put, it works through a circulation system: the compressor first draws in low-pressure, low-temperature refrigerant gas, compresses it into high-pressure, high-temperature gas, and then sends it to the condenser to dissipate heat and turn into liquid, much like the radiator fan at the front of the car helps expel heat. Next, the liquid passes through the expansion valve to reduce pressure and enters the evaporator, where it absorbs heat from the cabin and evaporates into cold air, which is finally blown out as cool air from the vents. The entire process relies on the circulation of refrigerants like R-134a. If the refrigerant leaks or the compressor ages, the air won't be cold enough. Remember to regularly check the system's sealing to avoid scrambling when the heatwave hits.
Let me explain the air conditioning principle from a maintenance perspective—it's quite ingenious. It operates on the heat exchange principle: the refrigerant is compressed and heated in the compressor, then flows to the condenser where it cools and turns into liquid. Once the expansion valve releases the pressure, it enters the evaporator, vaporizes, and absorbs heat, transforming the hot air inside the car into cool air. Key components include the compressor, condenser fan, expansion device, and evaporator box—all indispensable. When using it, avoid turning the fan to maximum immediately after startup; let the engine run for a few minutes first to stabilize the system. If you detect an odd smell, it might be mold on the evaporator, so an annual cleaning is recommended.
