Steam-to-steam humidifiers use a heat exchanger and the heat of treated steam to create a secondary steam for humidification from untreated water. The secondary steam is typically at atmospheric pressure, placing increased importance on equipment location.
The use of ionic beds in steam-to-steam humidifiers will reduce the amount of maintenance and improve the overall performance of the unit. Ionic beds are made from fibrous media, and with these in the tank, scale will build up on the media (the beds)—not on the heat exchanger. So you have a humidifier that stays clean except, of course, for the beds. And once they have absorbed their capacity of solids, you can change them in about 15 minutes. Remarkable ionic bed technology: It provides a longer life for the heat exchanger and more efficient heat transfer. (Ionic beds are not available on all models.)