What Causes Water Leakage from Car Air Conditioning?
2 Answers
Water leakage after turning on the car air conditioning is a normal phenomenon. The reason is that the refrigerant flows into the evaporator inside the car, absorbs the heat from the air inside the car through contact with the evaporator, and then compresses it, expands it again, and repeats the cycle to remove the heat from the air inside the car. Since there is a lot of water vapor in the air, when it encounters the very cold evaporator, it turns into water and flows out from under the car chassis. The car air conditioning system is a device that cools, heats, ventilates, and purifies the air inside the vehicle. The purpose of the air conditioning system is to provide a comfortable environment for passengers, reduce driver fatigue, and improve driving safety. Water leakage after turning on the car air conditioning is condensation water from the air conditioning. 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 the housing at such low temperatures. If there is no way to drain it, it will cause dampness around the air conditioning system and corrosion of components. When designing the vehicle, a pipeline is reserved to collect and drain the condensation water. The outlet to the outside of the car is generally located directly below the center of the dashboard, and when projected to the underside of the car, it is basically at the front of the transmission.
I've been repairing cars for over a decade and have seen many cases of air conditioning leaks. The most common issue is a clogged drain pipe. When the AC cools, it produces condensation, which should normally drain out through the pipe under the car. However, dust and leaves can get in and block the pipe, causing water to back up and leak into the cabin. Another possible cause is an evaporator leak, where refrigerant escapes, also leading to leaks. I once encountered a case where the car's carpet was completely soaked because the owner neglected regular checks. You can start by inspecting the drain pipe, usually located near the rear wheels underneath the car. Try clearing it with a wire or air pump. If that doesn’t work, you’ll need to visit a professional repair shop. Don’t forget to clean it regularly, especially during humid seasons, to prevent mold or electrical shorts.
