Its a little louder than I expected when its on high but I just turned it down a couple notches and its been fine. I think its doing what it should. We received it and 3 of the 4 of us in our house were sick. The sickness only seemed to last 34 days vs the normal 7ish days so I do think its killing germs. Weve only had it about a week so I dont have much more input than that. The only reason it got 4 stars was the noise factor