This document is the operating and maintenance instructions for Model 2200, 2250, and 2400 High Efficiency Air Cleaners. The efficiency of the air cleaner increases with use and can effectively remove pollutants from the circulated air. There is pollution in the air everywhere, even in fresh outdoor air. By keeping doors and windows closed as much as possible, the infiltration of outside air into the home is minimized, thereby improving indoor air quality. The air cleaner has a high removal efficiency for pollen, mold, spores, dust, and other airborne allergens. It can also reduce household dust, tobacco smoke particulate, and smudging particles in the air.