Should the internal circulation be turned on when AC is on?

[MacBrooklyn]

After turning on the AC, if cooling is required, the internal circulation must be activated; otherwise, it would be ineffective. Below is an introduction to internal circulation: Function introduction: Internal circulation is a state of the car's air conditioning system. In this state, the air exchange channels between the inside and outside of the car are closed. When the fan is off, the air inside the car does not circulate; when the fan is on, the air drawn in comes only from inside the car, forming an internal air circulation. Principle: Car air conditioning systems generally have an electric or manual internal/external circulation switch. When external circulation is used, the air conditioning draws air from outside the car, while internal circulation reuses the air inside the car.

[LucilleLynn]

I think whether to turn on the recirculation mode when using AC depends on the specific weather and driving conditions. With over a decade of driving experience, I always immediately engage the recirculation button when using AC in city traffic jams. The advantage is that the car cools down much faster this way. Especially during hot summer days, it prevents hot outside air from entering, reduces the load on the AC compressor, and indirectly saves some fuel. However, I rarely keep recirculation on for too long - I switch to fresh air mode after about 30 minutes to prevent window fogging and maintain healthy air quality inside. In short, using AC with recirculation mode works best when coordinated properly, but safe driving remains the top priority.

[DeJonathan]

From an energy-saving perspective, using the recirculation mode with AC is definitely helpful. I've noticed that in stop-and-go city traffic, recirculation allows the AC system to work more efficiently. By not drawing in hot outside air, the cabin cools down faster, reducing engine load and saving some fuel. However, prolonged use of recirculation has a drawback: CO2 buildup inside the car may cause drowsiness. My recommendation is to use recirculation for rapid cooling when AC is on, then switch back to fresh air mode after 15 minutes for ventilation. This approach is both eco-friendly and practical, making driving more comfortable.

[GenevieveFitz]

From a health perspective, whether to use the internal circulation when the AC is on depends on personal needs and circumstances. I usually turn on the internal circulation with the AC to block external pollen or pollution, keeping the air inside the car fresher. However, it's important to note that prolonged use can lead to moisture buildup, causing window fogging or a musty smell. If not used, fresh outside air continuously enters, but cooling efficiency decreases. The key is to balance using the internal circulation with the AC for quick cooling and occasionally switching to external circulation for ventilation, ensuring a comfortable and safe environment inside the car.