my last dehumidifier was a much smaller, highly-rated GE unit i purchased in 2012 and that thing was much louder than this. The loudness probably what I was worried about the most with this. I've had it for one month running pretty much constantly and I'm happy to report it is not very loud. My air purifier is louder. The sound it makes is smooth and sounds like mostly like a fan, but does have a little hum to it. It doesn't make any kind of rattling or uneven, vibrating kind of sound.