One version of a natural humidifier uses a stainless steel bowl, partially filled with water, covered by a towel. A waterproof weight is used to sink the towel in the center of the bowl. There is no need for a fan, because the water spreads through the towel by capillary action and the towel surface area is large enough to provide for rapid evaporation. The stainless steel bowl is much easier to clean than typical humidifier water tanks. This, in combination with daily or every other day replacement of the towel and periodic laundering, can control the problem of mold and bacteria.
