Does the Bottom of the Car AC Leak Water in Summer?
3 Answers
Does the Bottom of the Car AC Leak Water in Summer? The bottom of the car AC may leak water in summer. It is normal for a vehicle's AC to produce water leakage because condensation occurs when cold air meets warm air. The water drains through the evaporator's drainage pipe to the outside, which is why water leakage can be observed under the chassis. Function of the AC Drainage Outlet: During AC operation, the evaporator absorbs heat from the surrounding air, causing moisture in the air to condense into water, which is then discharged through the AC drainage outlet. Hazards of a Clogged AC Drainage Outlet: If the AC drainage outlet is clogged, water may seep into the passenger footwell through the connections, soaking items like floor mats. Cleaning Method: Crawl under the chassis and use a thin wire to unclog it—the process is relatively simple. Among the various drainage holes on a car, the most prone to clogging are those in the sunroof and engine compartment, as these areas are often overlooked, allowing debris to accumulate and worsen the blockage. Car owners should regularly clean the interior and maintain all components to prevent drainage holes from getting clogged.
I often encounter water leakage under the car air conditioner in summer. That time when I was driving on the highway, as soon as I turned up the air conditioner, I felt the right foot mat getting wet, which was really annoying. After getting out of the car to check, I found that the condensed water produced by the evaporator inside the air conditioning system didn't drain out of the car but leaked into the floor. The main reason was a clogged drain hole. In the humid summer, the air conditioner is used more frequently, producing more condensed water. Once the drain hole is blocked by dust or debris, the water flows back. At that time, I cleaned it myself—it was quite simple. I located the drain hole (usually near the passenger side footwell) and used a thin wire to unclog it. Since then, before every summer, I ask the mechanic to check it during maintenance to prevent similar issues and avoid soaking the car carpet or causing odors. If the leakage isn't resolved in time, it may also damage electronic components, increasing repair costs.
Air conditioner leakage isn't a major issue, but it's particularly common in summer. Having driven for many years, I've noticed that during hot seasons, when the AC cools, the evaporator tubes get cold, causing water vapor in the air to condense into droplets. Normally, these should drain out through the drainage holes at the bottom of the car. If water drips inside the car or accumulates underneath, it's likely due to clogged drainage holes or aged/cracked pipes. Higher humidity leads to more condensation, increasing the risk of water backflow. Last time I encountered this, a friend suggested it might be poor AC system sealing or improper installation, but a simple check and unclogging fixed it. Don't ignore this minor issue—it affects cabin dryness and may cause mold or part corrosion long-term. Address it promptly to avoid slippery floors increasing driving risks. Always ensure the AC is off before DIY fixes.
