Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Have had one for years

I really like ours. It has helped with having inside dogs keep the air fresh and clean. Once when we were remodeling the house, we moved all the furniture and our air purifier was moved and left unplugged for a few days. I did not realize how it effected the air for a few days and then when I plugged back in there was that fresh clean smell and feel to the air. I have no scientific test to prove what it does but I do not that nose and eyes smell and feel the difference when it is on.