Nona
After wearing out 4 cool mist humidifiers and dealing with all of the absolutely impossible cleaning, I have switched to using a warm mist ultrasonic model (an AIR-O-SWISS 7147 Digital)that I have in my bedroom. I have a whole house model installed in my central air system, but started growing bizarre cultures with the humidity cranked up @ 50% for the whole house.
This one is also MUCH quieter than any of the cool mist units I had.
Kevin