Should You Turn on the Internal Air Recirculation When Using the Car Air Conditioner?
4 Answers
Whether to turn on the internal air recirculation when using the car air conditioner depends on the specific conditions inside your vehicle. Below are the differences between internal and external air recirculation in cars: External Recirculation: The function of external recirculation is to replenish fresh air. When external recirculation is activated, the air intake located at the firewall is opened by the air conditioning computer, and the vehicle's blower draws outside air through the micro-dust filter into the two heat exchangers (cooling and heating) inside the evaporator. The air processed by the heat exchangers is then blown out through the air vents. Internal Recirculation: In the internal recirculation mode, the airflow channel between the inside and outside of the vehicle is closed. Without the blower, there is no airflow circulation. When the blower is on, the air drawn in comes solely from inside the vehicle, creating an internal airflow cycle. Internal recirculation primarily serves to promptly and effectively block external dust and harmful gases from entering the vehicle, such as when driving through areas with smoke, dust, strong odors, or in dense traffic, preventing harmful exhaust emissions from preceding vehicles from entering the cabin.
I think using the air recirculation mode when turning on the AC is quite important, especially during hot summers. It allows the cool air to circulate more efficiently inside the car, cooling it down quickly. For example, when I just start driving, the car feels like an oven, but once I turn on recirculation, it cools down significantly within minutes. However, don't keep it on all the time, as the air inside can become stale and the buildup of carbon dioxide can make people drowsy. It's recommended to switch to fresh air mode after 10 to 15 minutes of recirculation to let in fresh air, which helps prevent window fogging and maintains health. In congested urban areas, using recirculation avoids inhaling exhaust fumes, making it safer. But on highways or during long drives, prioritize fresh air mode to ensure smooth breathing. Also, remember to clean or replace the cabin air filter regularly to maintain air quality. Developing this habit can greatly enhance driving comfort.
I believe that using the internal air circulation mode while driving with the AC on can be beneficial for health, as it reduces the entry of external pollutants and dust into the car, especially in heavily polluted urban areas. However, over-reliance on it can have the opposite effect, as stagnant air can promote bacterial growth or cause stuffiness. I often adjust based on weather conditions: using internal circulation on rainy days to prevent external humidity from entering the car, but switching to external circulation after 20 minutes on sunny days to introduce fresh air and avoid dizziness or fatigue. Seasonal factors should also be considered; using internal circulation with the heater in winter warms up the car faster, but prolonged use may cause fogging, so a combination is recommended. Regularly checking the AC system to ensure there are no refrigerant leaks is a simple yet effective way to protect both the driver's and passengers' health.
When I first started driving, I learned that using the air conditioner in recirculation mode saves fuel and cools down the car faster. My instructor taught me to start the AC with recirculation on to recycle the cold air, making the car comfortable quickly. But don't forget to switch to fresh air mode later to defog and avoid obstructed vision. Now, I use this habit: recirculation during traffic jams to avoid exhaust fumes, and fresh air on highways for ventilation—it feels practical. In short: recirculation helps cooling, fresh air keeps it fresh, just adjust flexibly based on the situation.
