For heavy chemical abatement. Safe effective air filtration for your better health. 2 MicroSupress filters, suppress bacteria, antigens and pathogens around carbon bed. Filter chamber sealed with felt gaskets. All metal housing ensures no plastic vapors are emitted. Virtually silent. Variable speed motor. Unimpeded airflow. Certified by the Environmental Technology Laboratory. HEPA Filter - as long as 5 years in normal use. Pre-filters - can be vacuumed from the exterior of the unit and should be changed every 12 months. Carbon Filter - should be changed as needed in heavy applications and at least every 24 months in normal use. Pressure seal on the filter chamber lets all unfiltered air pass through without leakage. Hepa-Barrier post filter.. 26 lbs. Carbon filter absorbs airborne chemicals, noxious gases and odors. Approximate treatment area is 2,000 square feet. Particle removal: HEPA-Barrier post particle filter. Odor and chemical suppression: 26 lbs. carbon filter 3 in. deep carbon bed. Free Air Flow: 560 cubic feet per minute free flow, delivers 440 cfm with filters. Pre-filter: 570 sq. in. and 1 in. deep. Housing: Powder cost steel. Voltage Options: 115 or 220 volts. Watts: 120 on High 40 on low. Noise: 28.1 db on low 62.3 db on high. Normal room sound is 25.1 db. 15 in. L x 15 in. W x 23 in. H (45 lbs.).