I have an 1100 sq. ft. unit and this humidifier works perfectly. I set it on F1 so it's quiet. I live in Wisconsin and set it on 30 and during the winter everything is hunky dory. This unit was a replacement. Unfortunately they don't last forever. I change the filter yearly. Get generic ones off the Internet for about half price. They look exactly the same.

I already have the smaller model that looks the same, but has less than half the water tank capacity at 2 gallons, and is not heavy enough when fully loaded with water to need any wheels. Love it. Love the new big one too. The big version is simple to operate, construction design makes it most unlikely to leak, it is quiet at low speeds and effective in a large space. Four speeds for the fan, as opposed to three on the small one, but it also has a speed marked A for automatic. This is a fantastic additional feature. The further the humidity drifts away from the desired setting, the faster the fan speed, and vice versa. No need to constantly monitor the humidifier and reduce noisy fan speed by hand. The MA 1201 does it for you. Recommended.