when I ordered this it arrived defective. It was shipped back the next day. I did not get a replacement for over a week but when I called them they sent me one prompty, 2nd day delievery. So they tried to make things right for me. I have been using this for 3 weeks now. It has not taken care of my problem completely but I think it does a great job. There has been alot of smoke from a neighbor who has been having fires in a fire pit in the back yard. I do think this air purifer has made all the difference in being able to stay in my home while the fires are giving off alot of smoke, other wise I would of had to leave my home. When there are no fires, this a GREAT machine, very quiet, makes the air is my home fresh and clean. I recommend this air purifer and I recommend this company for striving to provide good customer service. Also I think the purifier cuts down on the dust in my home.