Is it normal for a car to leak water when the air conditioning is on?
2 Answers
It is normal for a car to leak water when the air conditioning is on. This water is the condensate from the air conditioning system. When the air conditioning is cooling, the temperature of the evaporator and the air ducts leading to the passenger compartment is very low. The water vapor in the outside air will liquefy and condense on the walls of the air conditioning pipes and housing at such low temperatures. If there is no way to drain it, it can cause dampness around the air conditioning system and corrosion of components. When designing a vehicle, pipelines are reserved to collect and drain the condensate. The outlet to the outside of the car is usually located directly below the center of the dashboard, which, when projected to the underside of the car, is basically at the front of the transmission. Therefore, in summer, if you start the engine, turn on the air conditioning, and leave the car parked for a while before driving away, you will often see a puddle of water on the ground. This puddle is actually the result of water vapor in the air condensing due to the cold, which is a normal phenomenon.
I recently noticed that whenever I turn on the car air conditioning, water drips from underneath the car. At first, I was really worried that something was wrong with the car. Later, I learned that this is a normal phenomenon when the air conditioning is cooling: the hot air inside the car is cooled, and the moisture condenses into water droplets, which are then discharged through the drainage holes in the chassis, just like how a cold drink bottle 'sweats'. As long as the water drips onto the ground, is clear and cool, and has no strange odor, it's completely fine. However, it's important to distinguish this from situations where water leaks into the cabin or appears discolored with oily traces, which could indicate a clogged drainage pipe or a leak in the air conditioning system, requiring timely repair. In the summer, I often take a quick look at the water stains on the ground after parking, making it a habit to prevent small issues from becoming big problems. In short, don't panic—this is normal operation, and it ensures the air conditioning runs efficiently.
