Can a car keep the internal air circulation on all the time?
2 Answers
Internal circulation means closing the airflow channel between the inside and outside of the car, and the blower drives the air inside the car to circulate, allowing the air to flow directly inside the cabin. The oxygen content in the car is limited, so in most cases, it is still necessary to turn on the external circulation to maintain air flow between the inside and outside of the car. However, in some special cases, internal circulation is required. 1. Internal circulation: Stops outside air from entering and circulates the air inside the car, then blows air or hot gas through the blower. 2. Advantages of internal circulation: Because the air is involved in circulation, the temperature difference of the air itself is not high, cooling or heating is faster, and it is more economical. If the air environment outside the car is poor, it can avoid pollutants from outside the car, but keeps the air inside the car beneficial.
After driving for so many years, I've realized that the recirculation mode shouldn't be kept on all the time. While it effectively blocks external dust and exhaust fumes, making it convenient for short-term use, prolonged operation prevents proper air circulation inside the car, causing carbon dioxide levels to spike dramatically. I've personally experienced feeling stuffy and dizzy while driving due to this. Experts consistently warn that extended use of recirculation leads to stale air, increased humidity, window fogging, and even bacterial growth that can affect health. This is especially problematic during summer AC use when high humidity can make breathing difficult. My recommendation is to only use recirculation briefly on highways or in areas with poor air quality, switching to fresh air mode every 20-30 minutes for ventilation during normal driving. This maintains fresh cabin air for safer, more comfortable driving. Regularly checking your cabin air filter is equally crucial - don't let a worn-out filter compound these issues. Simply put, recirculation is a temporary tool that shouldn't be overused.
