The Honeywell Reverse Osmosis (RO) filtration system removes dissolved solids and organic matter from water by passing it through a membrane which separates and flushes minerals and impurities from the water. Install this system upstream of the steam humidifier's water inlet. It is recommended that the RO system's filters be replaced at least once per year to ensure optimal humidifier performance.

For homes with water pressure lower than 45 psi. It includes a permeate pump which helps to boost water flow for these lower pressure applications.