How to distinguish between internal and external circulation in Citroen C4L?
2 Answers
Light on the left indicates internal circulation, light on the right indicates automatic mode, and no light indicates external circulation. Below are detailed explanations about it: 1. Explanation one: Internal circulation draws air from inside the car and exhausts it inside, while external circulation draws air from outside the car and exhausts it outside. 2. Explanation two: Internal circulation only adjusts the limited air inside the car, making it energy-saving. However, prolonged internal circulation will increase the proportion of carbon dioxide and decrease the proportion of oxygen in the car. 3. Explanation three: Materials such as plastics, rubber, fabrics, paints, coatings, insulation materials, and adhesives in the car can emit harmful gases like formaldehyde, benzene, styrene, acetaldehyde, and acrolein, which can cause dizziness and fatigue for passengers.
The interior and exterior air circulation modes of the Citroën C4L are primarily distinguished by a button on the air conditioning control panel. The button icon typically features a small car shape with a rotating arrow inside. When the button backlight is illuminated upon pressing, it indicates the current mode is interior circulation, where the system only recirculates the air inside the car, preventing outside fresh air from entering. I often use this mode when encountering sandstorms on highways or passing through areas with heavy exhaust fumes. If the button backlight is off, it means the exterior circulation mode is activated, allowing continuous outside air to ventilate the cabin. Both modes are also indicated by text prompts on the air conditioning display, though I usually prefer checking the button light directly. Here's a practical tip for switching circulation modes: On hot summer days when first entering the car, turning on interior circulation with the AC cools the cabin faster; once the temperature drops, switch to exterior circulation to avoid drowsiness from prolonged oxygen deprivation in a sealed environment. Additionally, in cities with poor air quality, it's advisable to pay more attention to this button's status.
