This depends on the typical air quality of your home and the size of the space where you want to have clean air. In a typical 250 square foot bedroom, we recommend at least fan speed level 2 (one speed higher than lowest) for maintenance of clean air, with an increase in speeds due to seasonal changes or personal preferences. The lowest fan speed can be used for the quietest operation of Molekule Air Mini in smaller rooms.
With Air Mini+, we recommend using Auto Protect mode. The Air Mini+ has a sensor to measure airborne particulate matter levels. Auto Protect uses these levels to regulate fan speed automatically for optimal air purification.