Can a Car Run the Air Conditioner While Idling?
4 Answers
It is not recommended to run the air conditioner while the car is idling. Here are some additional details: 1. How the car air conditioner works: It operates in two modes, cooling and heating. While driving, the internal combustion engine generates heat through combustion, and the air conditioning system directs warm air into the cabin via ducts and a blower system to provide heating. In winter, using the air conditioner for heating does not significantly increase fuel consumption. 2. Warm engine: If you drive for a while before stopping, the engine temperature will be higher. Turning on the air conditioner to blow warm air will cause the engine speed to rise slightly, but not excessively. 3. Cold engine: If you start the car cold and turn on the air conditioner, the water temperature will be very low. The engine needs to run at a higher speed to quickly raise the temperature in the engine compartment and blow warm air, resulting in higher engine speed.
It is completely feasible to run the air conditioning while the car is idling, a method many people use during summer traffic jams or while waiting at red lights. Based on my years of driving experience, although the engine runs at a lower RPM when idling, it can still power the compressor to keep the cabin cool. However, two potential risks should be noted: first, fuel consumption will increase significantly—idling for an hour may burn an extra one to two liters of fuel, which isn’t wallet-friendly; second, if used for extended periods in enclosed spaces like garages, exhaust fumes can accumulate, posing a high risk of carbon monoxide poisoning. Therefore, it’s advisable to use this method only briefly, such as waiting for five minutes. If parking for a break, choose a well-ventilated area or simply turn off the engine and use a fan instead. Regular maintenance checks on the air conditioning system can reduce the likelihood of malfunctions and ensure the compressor operates properly.
I occasionally idle with the AC on, especially on scorching days when the car feels like a sauna. Although the engine runs at low RPM, it doesn't stall, and the AC still blows cold air, providing instant relief. However, honestly, watching the fuel gauge drop rapidly pains me, as idling burns fuel without power output. I've also encountered a friend's car with a drained battery from frequent idling with AC, indicating increased load may harm the vehicle. It's advisable to use it briefly (under 10 minutes) in open air or with windows slightly open to avoid waste and trouble. To save money in summer, park in the shade or turn off the AC early and roll down the windows.
Idling with the AC on is fine, as the engine maintains the minimum RPM to ensure the AC works. It cools down within seconds when I'm waiting at traffic lights. However, it's best to keep it short-term, as prolonged use may increase carbon buildup and affect engine lifespan. Most importantly, avoid using it in confined spaces due to the danger of exhaust fumes.
