For a year now, the device CA 3x / week running for a few hours in the bedroom, especially if one of us is ill (then still daytime with ozonator). A reduction of the dust in the air, I could not watch though, yet some is stuck in the filter. Disadvantage: With about 7 watts quite high standby consumption, the better off today, so only 4 stars! A simple power strip with a switch or wireless socket solves the problem. Then the device must however always be switched back to the desired mode, if it stays on the net is the last setting stored. Very good is the way the supply of spare consumables such as filters and UV lamp directly by the manufacturer, in Amazon the parts were not available.