The HEPA Air Purifier Replacement Filter Kit includes 2 replacement filters for the HEPA Air Purifier. The lifetime of these filers is 1800 hours, which is approximately 1 year of use in a school setting.
The portable HEPA Air Purifier is designed for an average classroom that is 750 sq ft, with ceilings at 8 ft height. Fan speed, ceiling height, age of HVAC, and other ventilation are all variables that affect total air changes per hour.