What is the difference between internal circulation and external circulation in a car?
2 Answers
The difference between internal circulation and external circulation in a car is: 1. The indicator for internal circulation is an arrow pointing inward; the symbol for external circulation is from outside to inside. 2. Different functions: Internal circulation effectively prevents external dust and harmful gases from entering the car, improving the cooling and heating efficiency of the air conditioning; external circulation draws fresh air from outside into the car, maintaining air quality inside the vehicle. The methods for using car air circulation are: 1. Use internal circulation during traffic jams and external circulation during high-speed driving; 2. The use of internal and external circulation should be combined with air conditioning and heating; 3. Use external circulation during long-distance driving to allow fresh air from outside to enter the car, avoiding excessively low oxygen levels inside the vehicle.
I've researched this issue several times. Simply put, the recirculation mode circulates the air inside the car, while the fresh air mode draws in outside air. When stuck in traffic or driving in dusty areas, using recirculation prevents exhaust fumes from entering the cabin. In summer, AC cools faster with recirculation and saves fuel; in winter, heating warms up quicker too. However, prolonged use can make the cabin stuffy, and increased CO2 levels may cause drowsiness. Fresh air mode works best on highways or in suburban areas with good air quality - it's more ventilated and comfortable. During smoggy days, you'll need to combine fresh air mode with the air filter. I usually switch between both modes while driving, adjusting flexibly based on road conditions and weather - that's the smartest approach.
