What Causes Odors in Car Air Conditioning?
3 Answers
The reason for odors in car air conditioning is: not turning off the air conditioning before parking, but directly shutting off the engine. Methods to quickly remove car odors include: 1. Opening windows for ventilation; 2. Turning on the internal circulation; 3. Placing activated charcoal in the car; 4. Installing an air purifier in the car; 5. Turning on the external circulation of the air conditioning; 6. Placing grapefruit or orange peels in the car to use the fruit fragrance to counteract the odors. Functions of air conditioning: 1. Achieving cooling effects through the continuous cycle of refrigerant; 2. Removing dust, odors, smoke, and toxic gases from the car air to freshen the air, humidifying the car air, and increasing the relative humidity of the air inside the car.
When the air conditioner emits strange odors, my biggest concern is health issues. That musty or sour smell is usually caused by mold growing on the evaporator, as water vapor condenses during the cooling process, and poor drainage leads to stagnant water breeding bacteria. A dirty air conditioner filter also easily accumulates dust, releasing foul odors when the fan is turned on. Even worse, if external air intakes have accumulated leaves or small animal carcasses, the odors become more intense. Inhaling these can be harmful to children or people with allergies, potentially causing coughing or headaches. I recommend regularly checking the filter element and replacing the filter screen every six months; before turning off the air conditioner, switch off the cooling mode and let the fan run for five minutes to dry out the moisture, which can significantly reduce issues. It's also important to park in well-ventilated areas to avoid the accumulation of debris.
I find the musty smell from the AC quite annoying, but it's something you can easily handle yourself. The main culprits are mold growth on the evaporator or filter due to trapped moisture after parking, or a clogged drain tube causing stagnant water to stink—especially common during rainy seasons. First, locate your cabin air filter (usually behind the glove compartment), remove and clean it or replace it cheaply. If the odor persists, gently flush the drainage outlet under the car with a hose. I always remember to use fresh-air mode (external circulation) more often when running the AC to introduce outside air and minimize recirculation to reduce dampness. During routine maintenance, have the evaporator checked for cleanliness—it saves both money and hassle.
