Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Works great

My family has had this for years and has been working great in a smoking home with 3 people smoking. When off, you can smell smoke throughout the house and when I turn it on, It cleans the air on the first floor within a hour. We leave it on speed 1 most of the time and 2 to clean the air more quickly. I highly recommend this air cleaner but be warned the filters can get a little expensive but not to bad because they pretty much last for a year. I am buying a new one for my place for when I move in.New update: Don't waste your time and buy the carbon filters because they are worthless. Now, what I did was go to home depot after I bought the new filters on Amazon and purchased Web Absorber Electrostatic filters. It comes on a 20*25 sheet but I cut to size to cover the grid openings on the door. This works much better with smoke and keeps the new filters much cleaner. At 9.99 I thought it was a good buy