Does Idling with Air Conditioning On Affect the Car?
3 Answers
This is a normal phenomenon. The reason why car windows often frost up in winter is due to the significant temperature difference between the inside and outside of the car. The air inside the car is more humid than outside, so when it comes into contact with the colder glass surface, it condenses into frost. Idling with the air conditioning on does not harm the car. Idling with the air conditioning running is a normal operating condition during regular car use. Automobiles are designed and manufactured with various usage scenarios in mind, so it does not cause any particular damage to the car, only normal wear and tear. Below is additional information: The hazards of idling with air conditioning on: When idling with the air conditioning on, the engine operates only at idle speed, leading to incomplete combustion of gasoline. Unburned gasoline produces toxic substances such as carbon monoxide. Additionally, occupants inside the car exhale large amounts of carbon dioxide. In summer, the hot weather causes higher oxygen consumption inside the vehicle compared to other seasons. As the oxygen level in the enclosed car gradually decreases, prolonged exposure can cause dizziness, nausea, and weakness in the occupants—clear symptoms of carbon monoxide poisoning. Therefore, in summer, never rest or sleep in an enclosed car with the air conditioning on for extended periods.
I've driven a taxi for twenty years and often had to idle while waiting for passengers, so I'm all too familiar with running the AC at idle. The engine keeps running but the car doesn't move, burning extra fuel—consuming two to three liters more per hour than normal AC operation. The most annoying issue is carbon buildup; poor fuel-air mixture in the combustion chamber leaves black sludge caked on the intake valves, making acceleration sluggish over time. The battery also suffers—running headlights plus AC overwhelms the alternator's power supply. And doing this in underground parking is especially dangerous; exhaust pipes in enclosed spaces can leak carbon monoxide into the cabin. A colleague of mine was hospitalized last year because of this. So now, if I'm waiting over half an hour, I shut off the engine and roll down the windows.
Last time I took my child to piano lessons, it was so hot in the summer that I turned on the air conditioning in the car while waiting. My husband later called and said I was harming the car. In fact, it's fine for a short time, but doing this long-term really does more harm than good. The engine temperature doesn't come down, and the water temperature can easily spike—my best friend's old car had to undergo major repairs because of this. Moreover, exhaust fumes always linger around the car, and breathing them in too much is bad for your health. Now, I turn off the air conditioning after waiting no more than fifteen minutes. Additionally, a mechanic told me that long-term idling with the air conditioning on can cause carbon buildup on the oxygen sensor, leading to failed emissions tests during annual inspections, and repairs can be quite expensive. Actually, when taking my child to lessons, I'd rather bring a small fan and wait under the shade of a tree.
