Why is there water dripping under the car when the air conditioner is on in summer?
2 Answers
The reason for significant water dripping under the car when the air conditioner is on: It is condensation water caused by the operation of the air conditioner, which is a normal phenomenon related to the principle of the air conditioner. The specific reasons for significant water dripping under the car when the air conditioner is on are as follows: 1. Evaporator configuration: Since the car's cooling system is equipped with an evaporator inside the dashboard, when the air conditioner is on, the surface temperature of the evaporator is very low. The moisture in the hot air inside the car will condense on the surface of the evaporator's heat-absorbing fins and be collected by the plastic casing of the evaporator. 2. Compressor: Sometimes, the exterior of the compressor installed in the engine compartment may also condense moisture from the air, causing water to drip onto the ground. 3. Lack of insulation foam: If the low-pressure pipeline is not wrapped with insulation foam, the surface of the pipeline is prone to condensing moisture from the air, and water droplets often condense and accumulate at the lowest point of the pipeline, dripping down.
It's completely normal for a car to drip water underneath when the air conditioning is on in summer, which indicates the AC system is working efficiently. A key component called the evaporator cools the air as cold refrigerant flows through it, but moisture from the warm air condenses into water droplets upon contact with the cold surface—much like condensation on an ice cube. To prevent water accumulation and mold growth inside, a drain tube is designed to channel this water directly outside the vehicle. This is especially noticeable in hot, humid summers—a small puddle under the car occasionally signals proper functioning. However, if you observe a continuous heavy flow or no dripping after parking, the drain tube might be clogged. Debris buildup can breed bacteria, leading to musty odors when the AC runs. Many owners overlook this until costly repairs arise, so routinely checking the drip area while parked helps—don’t panic over minor issues, but address major ones promptly.
