What Do the Internal and External Air Circulation Modes in a Car Mean?
2 Answers
Here is a detailed introduction to the internal and external air circulation modes in a car: 1. External air circulation refers to drawing air from outside the vehicle, directing it through the air conditioning system for heating or cooling, and then blowing it out through the vents. Essentially, external circulation replenishes fresh air to improve the air quality inside the car. It is used in situations like defrosting in winter or defogging in summer because the air drawn from outside is richer in oxygen and drier, making it more effective for defrosting or defogging. 2. Internal air circulation, on the other hand, draws air from inside the vehicle, creating a cycle of airflow within the car. The primary function of internal circulation is to promptly and effectively block external dust and harmful gases from entering the car. It helps the car warm up faster in winter and cool down more quickly when the air conditioning is on in summer. It can also be used on smoggy days. Internal circulation keeps the air inside the car circulating, helping to maintain the interior temperature more effectively.
The car's air conditioning system's recirculation mode means using the air inside the vehicle in a closed loop, without drawing in outside air. This allows for rapid cooling or heating—I can feel the cool air immediately in summer and warmth in winter. However, the downside is prolonged use can make the air stuffy, affect breathing, and even cause drowsiness. Therefore, I adjust it based on road conditions: switching to recirculation in heavy traffic or polluted areas to avoid exhaust fumes, and using fresh air mode (outside air) on highways or in rural areas with clean air to stay alert and prevent window fogging—ensuring both safety and comfort. Seasonal adjustments are recommended. For automatic climate control, setting the temperature lets it switch modes automatically, saving energy and offering convenience.
