Your Car’s Air Conditioner Can Spread Germs — How Often Should You Clean It?

Your car’s air conditioner can feel like instant relief on a hot day, but the same system can also move dust, pollen, moisture, odours and microbes through a small enclosed cabin. The risk is usually manageable, but it becomes more noticeable when the filter is old, the vents smell musty, or the system stays damp.

The practical answer is simple: replace the cabin air filter at least once a year or every 12,000 to 15,000 miles, and clean or service the AC system sooner if there is a persistent smell, weak airflow, visible dust or allergy-like symptoms after using it. AAA says most vehicles need a cabin filter replacement in that yearly or mileage range, though dusty roads and poor air quality can shorten the interval.