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Should the Car Air Conditioner Use Internal or External Circulation in Winter?

4 Answers
VanBrayden
07/28/25 1:14pm
In winter, the car air conditioner should use internal circulation. More related information is as follows: 1. Internal circulation means the air circulates inside the car without exchanging with the outside air, resulting in higher heating efficiency. However, during winter driving, the car is usually in a closed state. Prolonged use of internal circulation can lead to a decline in air quality inside the car. For short-distance driving, using internal circulation is sufficient as it heats up quickly, and the air quality inside the car won’t deteriorate too rapidly in a short time. 2. External circulation exchanges air with the outside, which results in slower heating efficiency but better air quality inside the car. For long-distance driving, you can consider using internal circulation first and switch to external circulation periodically. If the outside air quality is poor, be cautious when using external circulation.
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VonLondon
08/11/25 5:54pm
In winter, whether to use the air recirculation or fresh air mode for the AC, I have my own method. Having driven for over a decade, I usually start with the recirculation mode when it's extremely cold right after getting in the car. This way, the AC only circulates the air inside the vehicle, warming up much faster. If the car is too cold, switching from fresh air mode helps the warm air come in quicker. Once the car is warm, usually after about five minutes, I switch to fresh air mode to let outside fresh air in. Otherwise, keeping it on recirculation can easily cause fogging and stuffiness inside, especially during long drives, which might even lead to dizziness. I've seen many people use only recirculation, resulting in foggy windshields that impair visibility and safety. When it's particularly cold or snowy, using fresh air mode more often prevents fogging more effectively. In short, flexibly switching between modes based on the situation ensures both comfort and safety—I recommend everyone give it a try.
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Amara
09/28/25 8:21am
When driving in winter with the air conditioning on, I pay close attention to air freshness. Using the recirculation mode can quickly warm up the car, which is suitable for the initial period after getting in. However, I've noticed that keeping only the recirculation mode on for a long time makes the air dry and stale, easily causing throat discomfort or fogging up the windows, especially on smoggy days. Therefore, I usually start with recirculation to warm up the car and then switch to fresh air mode for a few minutes once the temperature stabilizes. This not only allows for fresh air but also prevents window frost, making it much safer. Cars with automatic air conditioning can switch modes by simply pressing the AUTO button, which is hassle-free. If there are elderly or children in the car, maintaining air circulation is even more important to prevent dizziness or stuffiness. In short, balancing comfort and health is key.
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ZoeMarie
11/12/25 3:26am
In winter when using the car's air conditioning, I prefer the recirculation mode first. Recirculation makes the AC blow only the interior air, heating up faster and saving fuel, otherwise it takes more time to handle the cold air. But using recirculation all the time isn't good because the air doesn't circulate and humidity rises, making windows prone to fogging and blurring visibility. I usually start with recirculation for three to five minutes after a cold start to warm up, then switch to fresh air mode to introduce outside air and prevent fogging. With automatic AC, just press the AUTO button and it switches by itself. Simple operation, don't overcomplicate it.
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