What is the function of the car's internal and external circulation?

[DelJune]

The function of the car's internal and external circulation is to improve the air quality inside the vehicle. The following are specific introductions about the car's internal and external circulation: 1. Principle: The external circulation state uses a fan to draw air from outside the car into the interior, meaning the air passage between the outside and inside of the car is open. The air blown by the fan comes from outside the car, and even if the fan is not turned on, there is still airflow being drawn into the car while driving, replenishing fresh air inside the car. 2. Usage method: Use internal circulation during traffic jams and external circulation on highways. The use of internal and external circulation should be combined with the air conditioning and heating system. By using external circulation, you can breathe fresh air from outside the car. When driving on highways for a long time, the air inside the car may become stale, making people uncomfortable. Since opening the windows is not an option, using external circulation can bring in some fresh air.

[LaArthur]

The main function of the car's internal and external air circulation is to regulate the air quality inside the vehicle. When driving, I often use the internal circulation to recirculate the air inside the car, preventing external pollutants such as exhaust fumes and dust from entering. Especially in heavy traffic or highly polluted urban areas, turning on the internal circulation makes the cabin air much fresher, and the air conditioning works more efficiently, saving fuel in summer by cooling faster and improving heating efficiency in winter. However, don't keep the internal circulation on for too long, as the air can become stale, potentially causing dizziness or drowsiness, which could affect safe driving. At this point, you should switch to external circulation to let in some fresh outside air and stay alert. Remember to replace the cabin air filter regularly to maintain its effectiveness. Flexible switching between the two modes ensures a more comfortable and safer driving experience.

[LaRebecca]

The recirculation and fresh air modes play a crucial role in car air conditioning, helping to optimize energy usage and air quality. When I select fresh air mode, it allows outside air to enter the cabin, which is ideal in places with fresh air like suburbs or after rain—it refreshes the mind and prevents stuffiness and fogging inside the car. However, this increases the AC load and consumes slightly more fuel. Recirculation mode is more eco-friendly and energy-efficient, reusing the interior air, which helps avoid inhaling pollutants in contaminated areas or tunnels while maintaining good air quality without wasting energy. In daily use, I flexibly switch between modes based on urban conditions and weather: using recirculation more often in poor air quality and fresh air mode when conditions are good. This approach protects health while reducing carbon emissions—a win-win. Don’t forget to check the AC system and ensure the air filter is clean.

[LePreston]

The car's internal and external air circulation functions are significant, combining both to manage air. Internal circulation blocks external wind, only circulating the air inside the car, keeping warmth in winter by preventing cold air from entering, and cooling faster in summer to save some fuel costs. On long drives, it's easy to get drowsy, so I often use internal circulation to avoid inhaling dust, making the drive steadier. But don't overdo it, or the car might get stuffy and cause discomfort. External circulation, on the other hand, draws in fresh outside air, refreshing the cabin on good weather days by opening the windows for ventilation, and clearing fog for better visibility during heavy mist. Pay more attention to comfort, simply switching to avoid fatigue. Develop the habit of safe driving.