Is It Normal for Car Air Conditioning Water to Drain from the Chassis?
2 Answers
It is normal for car air conditioning water to drain from the chassis, which is related to the principle of air conditioning. The function of the air conditioning drain is to continuously absorb moisture from the surrounding air during the heat exchange process of the evaporator when the air conditioning is in use, then condense it into water and discharge it through the air conditioning drain. The air conditioning compressor compresses the refrigerant and then expands it through a valve. The expansion releases heat, causing the temperature of the refrigerant to drop. The refrigerant flows into the evaporator inside the car, absorbs the heat from the air inside the car through contact with the evaporator, and is then compressed and expanded again. This cycle repeats to remove 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.
I've been driving for several years now. I remember when I first bought my new car, I used to see water dripping from the bottom frequently and thought there was a major problem. I got so scared that I immediately drove to the repair shop. The mechanic took one look and laughed, explaining that it was just normal air conditioning drainage. When you turn on the AC in hot weather, the evaporator inside the car condenses moisture, which then flows out through a small tube under the chassis. This is completely normal, and you can often see a large puddle of water under the car in summer after parking. It would actually be troublesome if it didn't drain, as water trapped in the evaporator can lead to mold growth, causing unpleasant odors in the car and potentially short-circuiting components. So don't panic unless the dripping liquid has color, like green or yellow—that might indicate coolant leakage, which needs immediate attention. Nowadays, whenever I use the AC, I make it a habit to glance at the parking spot to confirm proper drainage.
