Is the correct way to use the air recirculation to press and light up?

[DeSamantha]

When the button is pressed and the indicator light is on, it means the air recirculation is activated, and when the indicator light is off, it means the external air circulation is activated. The default ventilation starts with the external air circulation. Here is additional information: 1. Air recirculation: Air recirculation is a state of the car's air conditioning system. In this state, the air exchange channels between the inside and outside of the car are closed. When the fan is off, the airflow inside the car does not circulate, and when the fan is on, the incoming airflow comes only from inside the car, forming an internal airflow circulation. 2. External air circulation: External air circulation refers to the car's air conditioning system opening to allow air from outside the car to circulate inside the vehicle.

[LaMaverick]

Having driven for over a decade, I'm well-versed in the use of the air recirculation button. Pressing the button to light it up activates the internal circulation mode, where the air inside the car circulates; turning it off switches to external circulation, drawing in outside air. In traffic jams or when passing through tunnels, I always turn on the internal circulation to prevent exhaust fumes from entering. On highways or in areas with fresh air, I switch to external circulation for ventilation. However, don’t keep the internal circulation on for too long—after more than half an hour, the rising carbon dioxide levels inside the car can make you drowsy. I usually open the window for some fresh air before switching. In summer, turning on the internal circulation first helps the air conditioning cool faster, but remember to switch back to external circulation once the temperature stabilizes. On smoggy days, it’s essential to keep the internal circulation on the whole time to protect your respiratory system—this tip is worth its weight in gold.

[VonLena]

I just figured out this feature on our new car last month. The illuminated button indicates the activation of the internal air circulation mode, while the light turns off when it automatically switches to external air circulation. The most practical use is pressing to activate internal circulation during rush hour traffic—instantly blocking exhaust fumes from the car ahead, with the air quality monitor showing an immediate 50% drop in PM2.5 levels. On rainy days when the windshield fogs up, I tried using external circulation with the defogger button, and it cleared up in three minutes. Last week on the highway, I noticed a detail: the fuel consumption gauge showed lower readings with external circulation on, possibly because the fresh air reduced the air conditioning load. Now whenever we pass a waste treatment plant, my wife rushes to press the internal circulation button.

[KevinFitz]

Health-conscious car owners all know this trick. When the button is pressed to light up and activate the recirculation mode, the cabin air filter purifies the interior air by recirculating it; pressing it again to turn it off switches to fresh air mode, drawing in outside air. During my daily commute through the industrial zone, I always turn on recirculation and immediately press the button if I smell chemical odors. Tests show that after ten minutes of activation, the formaldehyde concentration inside the car decreases by 70%. However, when traveling with children, I switch to fresh air mode every hour to ventilate and prevent carbon dioxide buildup, which can cause motion sickness. After a workout, I find that turning on fresh air mode quickly removes sweat odor—much more effective than air fresheners.

[McAsher]

Studying the car manual revealed the ingenious design of the air recirculation system. When the button light is on, it indicates the air vent is closed, activating the recirculation mode. When the light is off, the vent opens, switching to fresh air mode. As the physics class representative, I conducted a test: with recirculation on, the AC output temperature was 5°C lower than ambient, cooling faster. However, after two hours, the oxygen level dropped to 18% according to the detector, which is why the manual recommends alternating modes. My routine is to use recirculation in tunnels to save energy, then immediately switch to fresh air upon exiting to renew the air. For defogging on rainy days, fresh air mode must be used to accelerate air exchange.

[OAxel]

As a car function enthusiast, I've summarized the optimal usage of buttons. The illuminated internal recirculation is suitable for polluted environments, while the extinguished external recirculation works best on fresh-air routes. Actual urban fuel consumption tests show: when using internal recirculation, the AC load decreases, saving 0.3L per 100km. After last week's barbecue, ten minutes of external recirculation completely eliminated the smoke smell. Beginners should pay attention to dashboard indicators - when the arrow-inside-car icon lights up, it means internal recirculation is on. During my monthly AC filter cleaning, I always inspect the air door motor to ensure smooth switching. For highway cruising, external recirculation is recommended as natural airflow better alleviates driving fatigue.