Should You Use External or Internal Air Circulation for Air Conditioning in Winter?
2 Answers
Winter air conditioning should use external air circulation. The choice between external and internal air circulation when driving with the air conditioning on depends on the situation, as explained below: 1. External air circulation mode uses a fan to draw outside air into the car, meaning the air passage between the outside and inside of the car is open. The air blown by the fan comes from outside, and even if the fan is off, airflow is still drawn into the car while driving, replenishing fresh air inside. 2. Internal air circulation mode closes the airflow passage between the inside and outside of the car. Without the fan, there is no airflow circulation, and when the fan is on, the airflow drawn in comes only from inside the car, creating internal airflow circulation. Internal circulation mainly prevents external dust and harmful gases from entering the car effectively and also helps maintain warmth. 3. Internal circulation is mostly used in traffic jams, while external circulation is preferred on highways. The use of internal and external circulation should be combined with air conditioning and heating. External circulation allows you to breathe fresh air from outside. 4. Turning on the air conditioning is to lower the temperature inside the car, so external circulation should not be used at this time. You can occasionally switch to external circulation to let in some fresh air.
It really depends on the situation. In winter, both internal and external air circulation have their advantages when using the car's heating system. If the car interior is freezing cold when I first get in, I'll turn on internal circulation for a few minutes to let the warm air circulate quickly and warm up faster. Once the temperature rises, I switch to external circulation to bring in fresh outside air. Otherwise, keeping it sealed for too long can easily cause the windshield to fog up, affecting visibility while driving and making breathing uncomfortable. Especially when stuck in traffic behind trucks, the exhaust fumes can give you a headache - internal circulation helps block those odors. On highways, I mostly use external circulation for ventilation since the high speed keeps dust from blowing in anyway. The key is not to stick to just one mode all the time.
