What does the vehicle's internal circulation mean?
2 Answers
Car's internal circulation refers to the process where the air inside the vehicle is heated or cooled and then recirculated back into the cabin. More related information is as follows: 1. External circulation principle: External circulation mode uses a fan to draw outside air into the vehicle, meaning there's an airflow passage between the exterior and interior. The air blown by the fan comes from outside, and even when the fan is off, moving the vehicle still draws in outside air to replenish fresh air inside. Sometimes you may feel airflow even with the fan off, which is because the external circulation is set. In urban traffic jams, the cabin may fill with exhaust fumes due to external circulation use. 2. Internal circulation principle: Internal circulation mode closes the airflow passage between inside and outside. Without the fan, there's no airflow circulation, and when the fan is on, the air drawn in comes solely from inside the vehicle, creating an internal airflow loop. Internal circulation primarily prevents external dust and harmful gases from entering the cabin, such as when driving through smoke, dust, foul-smelling areas, or in heavy traffic where it blocks harmful exhaust from preceding vehicles. Another function is maintaining cabin temperature.
When I'm driving, I often use the recirculation mode, which means the air in the car is no longer drawn from outside but circulates within the car itself. It's a bit like using only the air inside the car when the air conditioning is on, preventing external pollutants such as dust, smoke, or unpleasant odors from entering. For example, on smoggy days in the city or when encountering exhaust fumes in a parking lot, I press a button to switch to recirculation, immediately feeling the air fresher. It also saves a bit of fuel since the air conditioning doesn't have to cool or heat outside air anew. However, this trick shouldn't be used for too long, as the oxygen level in the car will decrease over time, making people feel stuffy. So, I usually switch back to fresh air mode on clean road sections. Remember to check the cleanliness of the cabin air filter during each maintenance to ensure better recirculation performance.
