Does idling with the AC on harm the car?

[McLola]

Yes; The air conditioning compressor is driven by the engine, while the blower fan is powered by the battery. When the car is idling, it may not necessarily charge the battery. Excessive power consumption by the blower fan can lead to long-term battery depletion. Hazards of idling with the AC on: 1. Engine damage: Starting the AC immediately after the engine starts increases the engine load, which can damage the engine over time. Turning on the AC when the interior temperature is very high makes it difficult to cool down quickly. Instead, open the doors and windows, turn on the external circulation to release the hot air inside. Once the interior and exterior temperatures are similar, close the windows and doors, turn on the AC and switch to internal circulation. This method lubricates the engine and improves AC cooling efficiency. 2. Carbon monoxide poisoning: During prolonged traffic jams or waiting, if the AC is left on, the engine remains in idle mode, which also places a heavy burden on it. Moreover, incomplete fuel combustion during idling produces high concentrations of carbon monoxide. If the surrounding air circulation is poor (e.g., in a garage), the carbon monoxide emitted by the engine can enter the car and cause poisoning to the occupants.