What does the car's recirculation mode mean?

[LeLeilani]

Here is relevant information about the car's recirculation mode: 1. Recirculation and fresh air modes: The car's recirculation mode means the air inside the vehicle is heated or cooled before being recirculated back into the cabin; the fresh air mode draws outside air into the vehicle after heating or cooling it, allowing gas exchange between the interior and exterior. 2. Proper use of recirculation: When driving in urban areas, the car often fills with exhaust fumes. Even when driving in open areas or on highways, you may sometimes feel dizzy or chest discomfort. The reason is improper use of recirculation and fresh air modes while driving. 3. Fresh air mode: This mode uses a fan to draw outside air into the cabin, meaning the vehicle's air ducts connect the interior and exterior. The fan blows outside air, and even when the fan is off, airflow still enters the cabin while driving to replenish fresh air. Sometimes you may feel airflow even with the fan off because the system is set to fresh air mode. During traffic congestion in cities, the cabin fills with exhaust fumes due to using fresh air mode. 4. Recirculation function: The recirculation mode closes the airflow channels between the interior and exterior. Without the fan, there is no airflow circulation, and when the fan is on, it only draws air from inside the cabin, creating internal airflow circulation. The recirculation mode mainly prevents external dust and harmful gases from entering the cabin, such as when driving through smoke, dust, areas with strong odors, or in heavy traffic where it blocks harmful exhaust from vehicles ahead. Another function is maintaining cabin temperature.