When purchasing an air purifier, the two things to look for is the CADR (Clean Air Delivery Rate) and the recommended room size, both of which, Delonghi provides with great results. With a rate of 130 CADR and a room size of 20'X 10'(200 Sq.Ft.), the Delonghi APDL130 provides coverage and assurance through innovative technology. One of the top functions is the CADR which indicates the volume of filtered air being passed through and helps rid the air of pollutants such as dust, pollen and tobacco smoke. The more pollutants that are in the air, the faster the unit will filter it using the a 3-stage filtration system and ionizer. The three filters work with the CADR using a washable pre-filter, a True HEPA filter and an active carbon filter adding with a unique curve design to eliminate air bypass for efficient clean air delivery. Then a separately controlled ionizer provides added purification and helps freshen air. A 4-speed fan system provides a quiet and flexible operation. Place the APDL130 in any office or home for ultimate convenience and maximum efficiency.