Is It Normal for Water to Leak Under the Car Chassis After Turning on the Air Conditioning?
2 Answers
It is normal for water to leak under the car chassis when the air conditioning is turned on. The refrigerant flows into the evaporator inside the car, where it absorbs heat from the cabin air through contact with the evaporator. It is then compressed and expanded again, repeating this cycle to gradually remove heat from the cabin air. Since the air contains a lot of water vapor, when it encounters the extremely cold evaporator, it condenses into water, which then flows out from under the car chassis. Here are some precautions for using the car air conditioning: First, turn on the external air circulation: It is recommended to fully lower the windows for ventilation. After a few minutes, when the engine warms up, close the windows and start driving. At this point, do not rush to close the windows. Instead, set the air conditioning to maximum airflow and drive with the windows open for two to three minutes to allow the hot air inside the car to dissipate. Then, press the cooling button, and the cooling effect will be much better. Avoid using the air conditioning for too long after parking: Some car owners, seeking coolness, tightly close the doors and windows and rest in the car with the air conditioning on. This can easily lead to a dangerous increase in carbon monoxide concentration inside the car, potentially causing poisoning.
I had the same question when I bought a new car. Water leaking from the chassis after parking with the AC on is actually a normal phenomenon. It's the condensation water discharged by the air conditioning system. The principle is simple: when you turn on the AC for cooling, the moisture in the hot air inside the car comes into contact with the cold evaporator and condenses into water droplets. These water droplets slowly flow out from under the chassis through the drainage pipes. The amount of water depends on the AC intensity and air humidity, usually clear water with no color or odor. More dripping after long drives in summer indicates the AC is working properly. However, if the liquid leaking from the chassis is colored or has an odor, such as green coolant or oil stains, then it's not normal and may involve a cooling system leak, requiring a check at the repair shop. Regular maintenance of the AC filter can prevent problems.
