Can the car air conditioner still be used when the car is parked?

[LiamDella]

Can the car air conditioner still be used when the car is parked? The car air conditioner can still be used when the car is parked. Running the air conditioner while the car is stationary has a slight impact on the engine, leading to carbon buildup, which can cause the exhaust pipe tailpipe to become full of carbon deposits, and it also increases fuel consumption. Although running the air conditioner while the car is stationary does not cause significant harm, it is recommended to minimize this situation. Below is an introduction to car air conditioner maintenance: 1. Do not arbitrarily adjust the air conditioner vent direction: When using the air conditioner, not paying attention to adjusting the direction of the air flow can hinder the effectiveness of the air conditioner. According to the principle that cold air sinks and hot air rises, the correct approach should be to point the vents upward when cooling and downward when heating. 2. Regularly start the air conditioner in winter: In some regions where winters are relatively mild, some car owners do not use the air conditioner at all during the winter. Prolonged disuse can cause the rubber seals to age, and the lubricating oil on the internal components of the air conditioner can dry out. Regularly starting the air conditioner allows the components to be lubricated, maintaining good condition. Therefore, it is best to start the air conditioner at least once a week during winter. 3. Avoid using the air conditioner for too long each time: Running the air conditioner continuously after getting into the car can cause excessive pressure on the condenser, which can damage the cooling system. Therefore, it is advisable not to use the air conditioner for too long each time. If the interior temperature has reached a comfortable level, you can turn off the air conditioner and turn it back on after a while. 4. Ventilate and cool down before driving in summer, then switch to internal circulation: In hot summers, many car owners habitually turn on the internal circulation of the air conditioner as soon as they get into the car, thinking it will cool the interior faster. However, since the interior temperature is higher than the outside temperature, this approach is ineffective. Upon entering the car, you should first open the windows for ventilation and turn on the external circulation to expel the hot air. After the interior temperature has dropped, you can then switch to internal circulation.

[LeMalia]

I've been researching this for quite a while and found that whether the car's AC can be used while parked entirely depends on the vehicle and AC type. Generally speaking, if you're driving a traditional gasoline-powered car, the AC stops working once the engine is turned off because it relies on the engine to drive the compressor for cooling. Without power to the compressor, the fan just blows hot or ambient air, unable to cool the air at all. I've tested this several times in my garage—trying to take a short nap on a hot day, only for the AC to fail immediately, causing the car's temperature to skyrocket, forcing me to restart the engine to cool down. However, some hybrid or electric vehicles have AC systems powered by batteries, allowing them to operate briefly even after the engine or motor is turned off. For example, my friend's hybrid Honda can keep the AC running for about ten minutes while parked, supported by the backup battery. Overall, for fuel efficiency and safety, it's best to use the AC only when the engine is running. Leaving it on for too long while parked can drain the battery or make it difficult to start the car. Paying attention to these details while using your vehicle will help you understand how to avoid such issues.

[VanMichael]

My buddy and I often chat and rest in the car, and we've encountered several situations where the air conditioning stops working when the car is parked. At that time, as soon as the engine was turned off, the fan could still blow, but the air wasn't cool at all—it felt like hot air blowing in our faces. Later, we checked the manual and found out that the air conditioning compressor only works when the engine is running. Once the engine stops, the cooling system completely fails. In hybrid or electric vehicles, this issue is less common, allowing for a few minutes of quiet enjoyment of cool air. For regular cars, using the air conditioning briefly while stopped at a red light is manageable, but if the engine is turned off, the air conditioning immediately becomes ineffective. It's advisable to keep the engine running when parked, though this consumes more fuel. I've tried saving fuel by turning off the engine before, but the heat inside the car became unbearable. The best approach is to start the engine before using the air conditioning—it's both safer and more comfortable. Keeping these tips in mind makes daily car use much more convenient.