UV= Ultraviolet Light - when exposed to UV, bacteria and viruses are killed on contact. HEPA=High Efficiency Particulate Air - filter traps tiny airborne particles. Rated 99.97% removal at 0.3 microns in size. Ion=Ionization - ions attract and attach themselves to airborne irritants, including smoke, dander, and bacteria. The irritants are then drawn into the filter or dropped to the ground out of the air. Plasma=Plasma Generator - patented system creates hydroxyl (OH) molecules that destroys airborne microorganisms without producing ozone. Carbon=removes common household odors from cleaners, paints, solvents, and other chemical substances. Zeolite=a volcanic material with absorptive properties, removes gases and odors. Nano-silver=a filter treatment that neutralizes viruses and bacteria on contact and prevents bacterial growth inside the unit. Life expectancy of any filter media is dependent on the concentration of the contaminants to which the system is exposed. Chart is based on information provided by the manufacturer. Results may vary.