Just fine for the price. Of course, he has not the power of a model which costs 3 to 4 times more expensive, but leave the "work" in substance at medium speed in a room (for example) ensures cleaner air for a good night. At top speed, you quickly eliminate strong odors (tobacco, cooking ...) in minimum speed, it makes little noise enough and does not disturb sleep. Function switchable ionizer: You have a choice of using or not ... very valuable and surprising in this price range. As a guide, I use it in a room of 20 m2 and I am very happy. A small star less because of the maintenance costs generated by the periodic renewal of Hepa filters, too expensive for my taste, but that's true of all air purifiers of this type.