What Causes the Foul Odor When Turning on the Car Air Conditioner?
2 Answers
Car air conditioner emits foul odor when turned on: mold growth in the evaporator box and ventilation ducts. The car air conditioning system is a device that cools, heats, ventilates, and purifies the air inside the vehicle cabin. It provides a comfortable environment for passengers, reduces driver fatigue, and enhances driving safety. Functions of car air conditioning: 1. The air conditioner can regulate the cabin temperature to a comfortable level; 2. It can remove humidity from the air; 3. It can intake fresh air, providing ventilation; 4. It can filter the air, removing dust and pollen.
Last summer, I noticed a musty smell in the car whenever I turned on the air conditioning, which was quite annoying. I asked a mechanic, who said that moisture and dust had accumulated on the internal evaporator of the AC, fostering mold growth that releases odors. Additionally, a dirty or clogged cabin air filter restricts airflow, and a blocked drainage pipe causes moisture retention. I learned to perform regular cleaning, such as using AC cleaning sprays to disinfect the vents or turning off the cooling a few minutes before parking and running the fan at high speed to dry out the interior and reduce humidity. If left untreated, the odor could worsen, affecting breathing and even damaging AC components. Now, I check and replace the filter every three months to ensure the system stays dry and fresh.
