Does turning on the air conditioning when the car is turned off affect the car?
2 Answers
Turning on the air conditioning when the car is turned off does have an impact on the vehicle. Not turning off the air conditioning before shutting down the engine can cause the car to start with the air conditioning compressor running the next time it is turned on, increasing the load and potentially causing long-term damage to the engine. Leaving the air conditioning on when the engine is off means the compressor will start together with the engine during the next ignition, placing additional strain on the motor. Generally, it is not advisable to turn on the air conditioning when the engine is cold, as it can harm the engine. Correct usage of car air conditioning: Turn off the air conditioning a few minutes before reaching your destination while keeping the blower running to evaporate moisture from the condenser, ensuring the relative dryness of the air conditioning system. This helps reduce bacterial growth and odor formation. The air conditioning should also be turned on only after the engine has started. During daily use of the air conditioning, even though there is an air filter, a small amount of dust can still enter the ducts. If the air conditioning is consistently used at low fan speeds, dirt can accumulate inside, leading to odors over time and affecting health. In hot weather, it is best to start by opening the external circulation, lowering all windows, driving for a few minutes before closing the windows, and then switching back to internal circulation. This method ensures the fastest temperature drop.
I often encounter car owners asking about running the air conditioning after turning off the engine, and I have to say this habit is not ideal. The cooling function of a car's air conditioning relies entirely on the engine driving the compressor. When the engine is off, the compressor stops working. Pressing the air conditioning button only turns on the fan, which runs on battery power. Prolonged operation can gradually drain the battery. Once, while repairing a car, I met an owner who had left the air conditioning fan on for half an hour in a parking lot, resulting in a dead battery and an inability to start the car, which eventually had to be towed for service. Although most cars will issue a warning when the battery is low, frequent use in this manner significantly damages the battery's lifespan. Under normal usage, a battery can last three to five years, but frequently running the air conditioning with the engine off may shorten its life to just two or three years. Therefore, I recommend developing good habits: if you need the air conditioning to cool the car, always start the engine first to get it running. If you need a quick cooldown, you can briefly use the fan, but don’t expect it to provide cooling, and it's best not to exceed ten minutes. By the way, regularly checking the car battery's condition can also prevent similar issues and avoid breakdowns on the road.
