1. First, manual air volume adjustment: after the controller of the fresh air system is powered on, after 5 seconds, press the ON button, and a manual operation mode icon and an air volume adjustment icon will appear on the LCD screen, and then press the air volume switch button to switch freely between high, medium and low air volumes.

2. Secondly, automatic air volume adjustment: press the up and down keys on the interface of the fresh air system controller to enter the automatic operation mode, and the LCD screen displays the automatic operation mode icon.

3. Finally, the filter service time reminder setting: press the setting selection key, and "F" will be displayed on the LCD screen, and the filtering time will flash; Then press the up or down key to select the time.