Can the H4i water chambers be used with the HumidAire 3i docking station?
Yes, by replacing the HumidAire 3i top cover and seal with the H4i Conversion Kit (PN 26959 – new top cover, seal, H4i tub and cleaning plug). With the kit, you can use either the standard or cleanable H4i water chambers on a HumidAire 3i docking station. However, you cannot use a HumidAire 3i water chamber on the H4i docking station.