Does running the car air conditioner without driving harm the car?

[EverettFitz]

Running the car air conditioner without driving can cause some damage to the car. Here are the relevant details: 1. Running the car air conditioner usually refers to using the cooling function in summer. If the car is left idling with the air conditioner on for a long time, it can have a certain impact on the engine. 2. When the cooling function is used in summer, the engine control unit increases the engine speed by about 100 RPM. This increases the engine's air intake, which in turn increases fuel injection, resulting in a richer air-fuel mixture. 3. The engine computer uses this method to improve engine stability. However, a richer mixture can lead to incomplete combustion of gasoline. Prolonged idling with the air conditioner on can cause increased carbon buildup, making the engine less fuel-efficient. 4. Additionally, after turning on the air conditioner, the engine needs to lower the heat from the air conditioner condenser, so the cooling fan will keep running. If there are issues with the cooling or heat dissipation systems, it can cause the engine's water temperature to rise, affecting the engine. 5. Prolonged idling with the air conditioner on in poorly ventilated areas or garages can also pose a risk of carbon monoxide poisoning for the occupants.

[EmersonDella]

I think idling the car with just the AC on can indeed be harmful. The main issue is prolonged engine idling, which leads to incomplete fuel combustion, causing carbon buildup that makes ignition difficult and significantly increases fuel consumption, wasting money. The battery also bears a heavy load, making it prone to discharge or even failure. During hot weather, I usually turn on the AC for a few minutes to cool down before switching it off, or take short drives to keep the car moving. This approach better protects the engine and battery while also reducing emissions.

[Georgia]

We often encounter this issue during maintenance. When the car runs the AC without moving, problems may not be noticeable in the short term, but long-term idling can accelerate wear on internal engine components, such as carbon buildup causing piston ring sticking. The AC compressor is also prone to failure due to excessive load, and the battery may not charge fully, leading to faster aging. It's recommended not to idle for more than half an hour. If it's too hot, turn off the engine and open the windows, or schedule regular vehicle inspections to ensure the system is functioning properly.

[DeCamila]

From an energy-saving perspective, idling with the AC on is a waste of resources, increases carbon emissions, and harms air quality. For the vehicle, prolonged idling causes significant engine temperature fluctuations and uneven wear, potentially shortening its lifespan. In my driving habits, I avoid this practice—using the external air circulation for ventilation when parked is sufficient. Occasional short durations are acceptable.