Is it normal for water to come out of the air vents when the car's air conditioning is on?
3 Answers
This is a normal phenomenon. Because the car's air conditioning system is equipped with an evaporator inside the vehicle, the surface temperature of the evaporator becomes very low when the air conditioning is turned on. The moisture in the hot air inside the car condenses on the heat-absorbing fins of the evaporator and is collected by the plastic casing of the evaporator, which then drains the water outside the car. If water drips under the dashboard inside the car, it means the air conditioning is too cold: Moisture in the air will condense on the outside of the air vents, creating a phenomenon resembling white smoke. Moisture will also condense on the plastic casing of the evaporator or the outer surface of the plastic ducts that deliver cold air, resulting in dripping. Car models with poor insulation in the plastic casing of the evaporator or the plastic ducts delivering cold air are more prone to this issue. High humidity inside the car: There are two main reasons for high humidity inside the car. The first reason is the continuous use of the external air circulation function, which constantly introduces high-humidity outside air into the car, preventing the internal humidity (moisture) from being reduced (or expelled outside). The second reason is poor vehicle sealing, allowing high-humidity outside air to continuously seep into the car. Another typical sign of high humidity inside the car is the condensation of water droplets around the vents, which car owners can observe to check if this phenomenon occurs.
I've been driving for over a decade. It's normal to occasionally see small water droplets at the air vents when using the AC in summer. This occurs when cold and warm air meet during the cooling process, causing moisture to condense into water, especially after rain or in high humidity conditions. However, if there's excessive water droplets or actual water flow, the drain pipe might be clogged. I recommend first checking yourself - crouch down to see if there's water flowing from the AC drain hole under the car chassis. If not, it indicates a clog, which you can clear using a soft tube to blow through or by visiting a repair shop. Leaving it unattended for long may cause moldy odors or reduced AC efficiency. It's best to clean the AC filter and system annually. While winter heating dries the air, summer brings more moisture - this phenomenon is quite common and nothing to worry about.
As a new car owner for just a year, I was also surprised when I noticed small water droplets at the air conditioning vents. After researching, I learned this is the condensation effect – during cooling, the low temperature of the evaporator causes moisture in the air to form droplets, which is a normal design feature. However, persistent dripping or excessive water might indicate a clogged drain pipe. That thin pipe is prone to dust blockage, so I usually open the car doors after parking to allow ventilation and drying inside. Additionally, high humidity inside the cabin can worsen this issue; switching to some fresh air mode helps. My advice is regular maintenance – request internal AC system cleaning during car washes to prevent bacterial growth and keep the air fresher.
