Should the car's air conditioning use recirculation mode?

[Ella]

The car's air conditioning should use recirculation mode, but it can also alternate between recirculation and fresh air modes depending on the situation. Recirculation helps maintain the interior temperature. If you want to quickly warm up or cool down the car, turn on the heating or cooling system first, then activate recirculation. Once the temperature is comfortable, switch to fresh air mode to prevent excessive carbon dioxide buildup and avoid oxygen deprivation. The recirculation mode prevents outside air from entering the car, circulating only the air already inside the vehicle. Its main function is temperature retention. However, since the car's interior space is limited, prolonged use of recirculation with windows closed will quickly fill the cabin with moisture from breathing and reduce oxygen levels. When driving on highways, don't keep recirculation mode on continuously. Otherwise, the air inside will become stale. On highways with fewer vehicles and good airflow, fresh air mode is sufficient as it allows outside air to enter the cabin, maintaining air freshness. Car air conditioning should alternate between recirculation and fresh air modes, using different circulation patterns for different environments, as follows: If there are odors inside the car, use fresh air mode to let the odors flow out with the air current while fresh outside air enters. If the outside environment is polluted, use recirculation mode to prevent dust from entering the cabin. For temperature retention, use recirculation mode, as it allows both cooling and heating systems to take effect quickly. If the interior side of the windshield fogs up in winter, use fresh air mode to reduce the temperature difference between inside and outside, which will eliminate the fog on the glass.

[VonCharlotte]

I've been driving for over a decade, and honestly, using the air recirculation mode with the AC is quite practical. Especially during hot summers when I first start the car, I turn on recirculation to let the cool air quickly lower the interior temperature without drawing in hot air from outside. Once it's cooler, I switch to fresh air mode for ventilation. The same goes for heating in winter—recirculation warms up the cabin faster. In traffic jams, using recirculation helps reduce exhaust fumes from entering the car, which is particularly important in big cities with poor air quality. However, you shouldn't keep recirculation on all the time because the air inside the car can become stale after prolonged circulation, making you drowsy or uncomfortable. I usually switch to fresh air mode every half hour or so to let in some fresh air. Also, make sure to check and replace the cabin air filter regularly to maintain air quality. Using recirculation is a good habit, but it's important to adjust flexibly based on the situation—safety and health come first.

[DiElisa]

I'm quite particular about car usage awareness. Using the internal air circulation when turning on the AC can save a lot of trouble. It's highly efficient for rapid cooling or heating. For instance, when having breakfast in the car with internal circulation on, the temperature remains stable without sudden fluctuations that could affect appetite. However, don't develop lazy habits - prolonged internal circulation leads to poor air flow, which can cause odors or bacterial growth. Once I left stuff piled in my car without cleaning up, and after extended internal circulation, I even detected a musty smell. Since then, I've developed the habit of regularly opening windows or switching to external circulation. In areas with poor air quality, such as near industrial zones, internal circulation is safer. During daily commutes, I adjust based on weather conditions - keeping internal circulation on longer in hot weather to cool down before switching. The ultimate goal is comfortable driving - don't neglect air exchange just for quick convenience.

[Lena]

I just got my driver's license not long ago, and I didn't understand why to use the recirculation mode before. But after driving for a few months, I've learned my lesson. When turning on the AC, immediately pressing the recirculation button makes the cabin temperature change super fast. For example, on my way home from work when it's unbearably hot, recirculation cools things down instantly. However, my driving instructor warned me not to keep recirculation on all the time because the air inside gets reused, which can make you feel stuffy and dizzy after prolonged use - I actually experienced this dizziness myself. Now I switch to fresh air mode every ten minutes or so to get some clean air. When there are multiple passengers in the car, it's even more important to ventilate regularly to keep everyone comfortable. Developing this small habit has significantly improved my driving experience.