Many customer response: When driving in the urban area，The taste of the car is often filled with the taste of the car，Even in an open place or on a high -speed road，Sometimes I feel dizzy and chest tightness。Why is this? The reason，It is the riders during the driving process，It is not caused by the internal and external circulation。

What is external circulation and what is internal circulation?

1, outer cycle: supplement fresh air

outer circulation status is to use the fan seabet myto draw the air from the outside of the car into the inside of the car，That is to say, the airway outside the car and the inside of the car is circulating，The wind from the fan comes from outside the car，Even if the fan is not opened，Vehicle still has airflow inhaling in the car，Fresh air in the car。Sometimes I feel that it is still windy when the fan is turned off，Because the owner sets an external cycle。When driving in the city, when you encounter a congestion in the city，The inside of the car will be full of tail odor，This is caused by the use of external circulation。

2, internal cycle: blocking dirty air

Inner circulation status is to close the air flow channel inside and outside the car，Without the ventilator, there is no air circulation，The airflow inhaled when the ventilation is in the car is only from the car，Form the air flow cycle inside the vehicle。Inner circulation is mainly to timely and effectively prevent external dust and harmful gases enter the car，For example, through smoke during exercise、Dust、Stricken area or vehicle densely compact driving，Stop the harmful tail gas from the front car。Another role is insulation。

Under what circumstances uses external circulation，Under what circumstances do you use internal circulation?

1、In the case where the external air quality allows，Recommended external circulation，Because there is no reason to refuse fresh air。

1)、High -speed driving，After seabet appa long time, I feel that the air in the car is turbid，People are uncomfortable，Can't open the window，You should use the external circulation to make some breeze in;

2)、It feels too hot when sending warm wind，You can turn off the fan，Open the outer cycle，Keep both the temperature in the car，There are fresh air，It feels more comfortable。

2. The following situations are recommended to use internal circulation.

1)、Internal circulation when traffic jams，It can prevent tail gas from entering the car;

2)、If the air conditioner is turned on to quickly reduce/increase the temperature in the car，It is recommended to open an internal circulation at this time，Available time to open the outside cycle，Replace some fresh air;

3)、Usually parking is best set to internal circulation status，Due to the external circulation state，The dust from the wind is easy to enter the car，increase the dust in the car;

4)、When turning on the air conditioner in summer or warm air in winter，In order to keep the internal circulation of the internal circulation，But from time to time, you should drive the outside loop to replace the air in the car。