Should the car's air conditioning use internal or external circulation when cooling?
2 Answers
When using the car's air conditioning for cooling, it is best to use the internal circulation mode. Using internal circulation in summer is more fuel-efficient and provides the best cooling effect. However, it should not be used for extended periods as this prevents air circulation inside the car. To achieve maximum air conditioning cooling efficiency, internal circulation should be used in summer. More information about car air conditioning is as follows: 1. Internal and external circulation: Internal circulation means the air inside the vehicle is recirculated, meaning the air coming out of the vents is from inside the cabin, and the cabin is sealed off from the outside atmosphere. External circulation means outside air is drawn into the cabin, so the air from the vents comes from outside, and the cabin is open to the atmosphere, not sealed. 2. Advantages and disadvantages: Internal circulation means the air blown by the blower circulates inside the car, with no outside air involved, offering advantages like fuel efficiency and faster cooling (or heating), but the disadvantage is poor air renewal inside the car. External circulation means the blower draws fresh air from outside into the car, ensuring better air quality inside, but cooling (or heating) is slightly slower and less fuel-efficient. Car owners should regularly clean and maintain the air conditioning system to ensure a fresh air environment inside the car.
When driving in hot weather and turning on the AC, I always switch to recirculation mode first to cool down quickly by circulating only the air inside the car, which significantly improves cooling efficiency. After a few minutes when the temperature drops, if the air starts to feel stuffy or the windows begin to fog up, I switch to fresh air mode to bring in outside air. Alternating between these modes helps prevent odor buildup or driver fatigue caused by prolonged recirculation, especially during long drives—I frequently do this to ensure the cabin stays comfortable. On highways, I’ve tried using fresh air mode to save some fuel, as it might reduce engine load, but it depends on road conditions—for example, in city traffic, fresh air mode can draw in more exhaust fumes. For regular car maintenance, I make it a habit to check and clean the cabin air filter periodically, as keeping it clean ensures both modes work efficiently. The key is to switch flexibly—don’t just stick to one mode all the time.
