When to Generally Turn on the Internal Circulation?

[SanElla]

There are generally the following situations when turning on the internal circulation in a car: 1. Turn on the internal circulation during traffic jams, as the more congested the traffic, the higher the density of exhaust fumes in the air. At this time, the internal circulation can effectively prevent external exhaust from entering the car, avoiding harm to passengers. 2. Turn on the internal circulation when encountering windy, sandy, or dusty weather. When the temperature is too high or too low, you can first turn on the internal circulation to seal the car, then turn on the air conditioning. After the temperature drops, switch to external circulation every half hour to keep the air inside the car fresh. Extended content: 1. The working principle of external circulation is to use a fan to bring outside air into the car and expel the air inside the car through the fan, achieving ventilation without opening the windows. 2. The principle of internal circulation is simple: it circulates the air inside the car, especially when turning on the heater in winter or the air conditioning in summer, to promote air circulation inside the car.

[McHope]

After years of driving, I've found that the best times to use the air recirculation mode are mainly in congested areas or places with poor air quality. For example, during peak traffic hours when there's heavy exhaust fumes mixed with dust outside, turning on recirculation effectively blocks these pollutants, making breathing much easier. On scorching summer days when the car interior is unbearably hot upon entry, activating recirculation before turning on the AC makes the cooling effect come much faster - you'll feel comfortable within minutes. When passing through tunnels, garbage dumps, or roads with strong odors, temporarily switching to recirculation is the most effective way to block unpleasant smells. However, it's not advisable to keep it on continuously - switch back to fresh air mode after 20 minutes to replenish oxygen and prevent drowsiness. Don't forget to replace the cabin air filter during regular maintenance, as this ensures the recirculation function remains effective longer and makes driving more worry-free.

[VanJoel]

When driving in the city, I find using the recirculation mode super convenient, especially during traffic jams or unusual weather conditions. Whenever stuck in traffic with all the exhaust fumes outside, turning on recirculation filters out most of it, making breathing much smoother. On scorching summer days when starting the car, activating recirculation first speeds up the cooling airflow—temperature drops way faster than with fresh air mode, saving time. When passing through highways or construction zones with dust flying around, recirculation also protects the cabin air quality. For short trips, using recirculation can even save some AC energy consumption, helping the car operate more efficiently. Just remember not to keep it on continuously—switch to fresh air mode every 15 minutes for ventilation, otherwise stale air may increase fatigue. Regular cabin maintenance with clean filters makes it work even better.

[KevinRose]

I always prioritize health, so I typically use the recirculation mode when external pollution is severe or allergens are present. For example, during smoggy weather or pollen season, turning on recirculation reduces inhalation of harmful particles and protects the respiratory tract. When passing by barbecue stalls or industrial areas with strong odors, I quickly switch to recirculation to avoid unpleasant smells affecting my mood. When driving with friends, if it's too noisy or dusty outside, I also activate recirculation to provide a quieter and more comfortable space. However, remember not to use it for extended periods—turn it off every half hour to let the fresh air mode replenish oxygen. Maintain the car's air conditioning system properly, replace filters regularly, and ensure recirculation truly serves its protective purpose.