Which one is the air recirculation mode, a or m?

[DiPaislee]

Both a and m represent air recirculation modes, where m stands for manual air recirculation and a for automatic air recirculation. If the air quality outside the vehicle is poor with severe pollution, the a mode will automatically select air recirculation. Choosing between air recirculation and fresh air mode: Consider road conditions: On highways, it's advisable to use the fresh air mode. Firstly, due to wind resistance and high speed, opening windows is not suitable. Prolonged use of air recirculation can lead to brain hypoxia, impairing reaction and judgment, which is highly dangerous. Secondly, the air quality on highways is generally good with low exhaust concentration, making fresh air mode a suitable choice. In urban areas, especially during congested traffic or peak hours when vehicle exhaust concentration is high, it's best to switch to air recirculation. Consider vehicle condition: New cars typically contain higher concentrations of toxic gases like formaldehyde. Therefore, for the first three to six months after purchasing a new car, it's recommended to use the fresh air mode along with opening windows to enhance air circulation and dilute the concentration of toxic gases inside the car. Function of fresh air mode: The fresh air mode ventilates the car interior, expelling stale, oxygen-depleted air and bringing in fresh air. In winter, if the heater is on, remember to switch to fresh air mode to avoid dizziness and chest tightness. Function of air recirculation mode: Air recirculation helps maintain a constant temperature inside the car. In winter, it keeps the interior warm, and in summer, it retains the cool air. However, prolonged use of air recirculation can lead to an increase in carbon dioxide exhaled by passengers, resulting in stale air. Therefore, it's good practice to switch to fresh air mode every hour to refresh the air. Air recirculation prevents the entry of external pollutants. Activating air recirculation closes the airflow channel, stopping external air from entering. When the fan is off, there's no airflow, and when it's on, it circulates the air inside the car. This effectively blocks external pollutants from entering the vehicle. For instance, during sandstorms, smog, congested roads, or construction zones, air recirculation should be activated to prevent pollutants from entering the car.