The AeraMax Pro AM3S PC is the perfect portable air purifier for shared/enclosed spaces delivering 3-5 air changes per hour (ACH) in 300-550 square feet. AeraMax Pro is the only air purifier that automatically responds to occupancy and air quality levels and then shows you when the air is clean. The 4-stage True HEPA filtration system removes 99.97% of all airborne contaminants and the activated carbon filter reduces odors and VOCs.