What is the function of the car's internal and external circulation?
3 Answers
The internal circulation of a car refers to the circulation of air inside the vehicle when it is closed, indicated by an icon of a closed car interior with a circulating arrow. The external circulation, on the other hand, involves drawing air from outside the vehicle into the interior, represented by an icon of a car with an external air arrow pointing into the car. Internal circulation means the air inside the car is heated or cooled and then recirculated within the car. External circulation means the air from outside is heated or cooled before being introduced into the car, facilitating gas exchange between the inside and outside of the vehicle. Additional notes: Whether using the heater or air conditioning, it is advisable to start with internal circulation. However, prolonged use of internal circulation can lead to an increase in carbon dioxide exhaled by passengers. Therefore, it is best to switch to external circulation every hour to refresh the air. Window opening tip: If the outside air quality is poor, such as in heavy traffic areas with high exhaust emissions or in underground parking lots with poor air, avoid using external circulation. When driving on the highway, do not open the windows; instead, use the external circulation system.
I drive to and from work in the city, and the air conditioning's recirculation mode is super practical. The recirculation mode cycles the air inside the car repeatedly, filtering out external dust, exhaust fumes, and odors without opening the windows—perfect for reducing inhalation of pollutants during traffic jams. On the other hand, the fresh air mode draws in outside air, which is especially refreshing on clear days or during highway driving, ensuring ample oxygen levels to keep you alert. I often use recirculation on smoggy days to protect my health and switch to fresh air on sunny days to enjoy natural breezes. Recirculation also improves cooling or heating efficiency, helping the cabin reach the desired temperature faster. However, avoid keeping recirculation on for too long, as the air can become stuffy—switch to fresh air for a few minutes every half hour to ventilate the cabin, making the drive more comfortable and safer. Remembering these tips can significantly enhance your daily commute experience.
As a homemaker who frequently shuttles the kids around, in-car air quality is absolutely crucial. The recirculation mode is activated during pollen season or when passing industrial areas, locking the cabin air to prevent external allergens from entering and protecting the kids from excessive sneezing. The fresh air mode is used when driving by parks or on highways, drawing in outside air to refresh the cabin environment—this helps prevent motion sickness and dizziness during long trips. We've developed the habit of using fresh air mode in the crisp morning air, then switching back to recirculation during midday heatwaves for rapid cooling. These simple, practical operations ensure the whole family travels in comfort and health, especially preventing stuffiness when children nap in the car. Cultivating these habits makes every journey pleasant and worry-free.
