Humidity in my bedroom was 15% before I turned the penguin on, after 24 hours it was only up to 19%. That is almost nothing. It just doesn't put out enough vapor. Yes the fan was all the way on. My bedroom is 17 by 17 feet. My old Welbilt humidifier that I bought some 15 or 20 years ago works well and will take the bedroom up to 40% humidity. Guess I will have to clean it up and start using it again.