To use auto mode on your Classic Pro air purifier:
- Press the Auto button on the control panel.

- While in Auto mode, the Classic Pro will automatically adjust the fan speed based on the sensor measurement of PM1, PM2.5, or PM10 levels for the CP7i model. The CP9i model will automatically adjust the fan speed based on the sensor measurement of PM1, PM2.5, PM10, or tVOC levels.