Having only baseboard heat in the Northeast I have gone through a series of freestanding humidifiers. Ultrasonic was rejected years ago after the white dust from the minerals in the water stuck to a variety of surfaces from static electricity. That they needed to be basically disinfected almost daily to prevent the dispersing of viruses and bacteria sealed their fate. I have used a variety of warm mist/steam humidifiers as they eliminate both of those unacceptable flaws from ultrasonic. I used the Vicks brand that took over the Bionaire brand that disappeared. I have been nursing a 2.5 dual tank version, with a humidistat, since they stopped making them supplementing with smaller 1.5 gallon version with just high and low. All flimsy plastic and the too small tanks filled from the bottom which was messy and a bit of a pain. Every season I searched for an alternative dumbfounded none was being sold as I surely was not alone in my situation. This year my seasonal search found the Y & O Steam humidifier...finally some smart company filled this need. It not only has 2 large water tanks but they fill from the top and are also removable. I removed them initially but purchased a 2.6 gallon container I now use to fill with the tanks in the machine without removing them and made the filling process easier and without dripping water removing the tanks. After purchasing one in the beginning of the heating season I was so pleased I bought a second one as I believed, and found it to be the case, that 2 of these would cover my entire 3,000 SF house. Unfortunately, this product was obviously such a big hit as while the first one showed up in days, the second one was delayed due to being sold out. Having read some less than positive reviews about support I was extremely pleased when one of the units got stuck on high that the company committed to replacing it at no cost. I cut them some slack as it obviously was something with a computer chip and they can fail, especially in a young product. Unfortunately they are out of stock again but fortunately the winter is over. In speaking to customer support raving about the design and build quality (plastic but very solid) I said the only complaint I had was there was only 3 preset humidity levels for automatic operation of 50%, 605 and 70%. I seek between 30-40% as ideal and would love if they had a variable humidistat that my very old 2.5 gallon Vicks had. They said they are working on an improved 2.0 version and I told them I would wait for that one which they agreed to. Despite the issue I had I am very pleased not only with the product but the unflinching support they offer. It also looks pretty good which while unnecessary to me pleases my wife.