Works perfectly for my little apartment. Very quiet on the first two settings but there's a very noticeable hum on the highest setting. I ran it on high overnight for the first couple of nights then on medium during the day and now I have it on the lowest setting for a few hours every day. The timer is perfect so I don't have to remember to cut it off myself. There has been a noticeable difference in air quality and my sinuses have cleared up so I will definitely keep using this air purifier.