How to Use the Car's Internal and External Air Circulation?
2 Answers
The methods for using the car's internal and external air circulation are: 1. Shortly after entering the car, you should open the windows or turn on the external air circulation ventilation system to introduce fresh air. Do not drive for long periods with the windows and doors closed. 2. When using the air conditioning or heating, employ the mode that allows air exchange between the inside and outside of the car. 3. In areas with heavy traffic or when following vehicles that may have excessive exhaust emissions, temporarily switch the air conditioning or heating to the internal circulation mode. Vehicles driving with windows open should temporarily close them. The purposes of external and internal circulation are: 1. When turning on the air conditioning for cooling or heating, activating the internal circulation can quickly lower or raise the temperature inside the car. 2. When the outside air quality is poor, turn on the internal circulation.
The recirculation mode recycles the air inside the car without introducing outside air, which helps prevent dust, pollen, or exhaust fumes from entering the cabin. I often use it when driving in congested urban areas or in environments with unpleasant odors, such as passing by a landfill—just press the button on the AC panel to activate it. When cooling the car in summer, I first use recirculation to quickly lower the temperature. Once the cabin feels comfortable, I switch to fresh air mode to let in outside air, avoiding stuffiness that could affect alertness. Prolonged use of recirculation may lead to oxygen deprivation or even driver fatigue, so I make it a habit to switch to fresh air mode for a few minutes every half hour to maintain stable air quality. Cleaning or replacing the AC filter is also crucial. I check and replace it regularly to prevent clogging and ensure optimal performance, especially during seasonal transitions—this keeps cabin ventilation healthier and safer.
