Mi Air Purifier 3H, Now Updated with an All-New 360° Pressurized Airflow System Redesigned high efficiency air duct system delivers 6330 liters of purified air per minute. The Mi 3H achieves a 22% increased CADR rating to 380 m³/h. Designed to continuously run twenty four hours a day and automatically steps up the speed when needed. Engineered for Twenty Four Seven operation. 360° Intake enters a pressurized system, then a rear-tilting centrifugal fan and brushless motor pushes up to 6330 liters of air quietly and efficiently. Extremely Quiet, Barely audible 33 decibels when in auto mode, this unit is designed to run 24 hours a day and won't disturb your sleep.