Is Rosahl waterproof?
Rosahl dehumidifiers work by passing gasses through the polymer membrane to the outside of an enclosure. To achieve this, they must be porous to gas and vapour. However, they are not porous to solid particles or liquids under normal conditions. Go here for information on membrane porosity
The nature of the device makes it difficult to specify an IP rating. When installed correctly, IP66 is achievable. In theory, IP67 is also achievable, although the membrane will not operate when submerged.
Rain cover for direct installation
When using Rosahl to dehumidify an enclosure, it is important to that the surfaces are clean and dry. Membranes installed outdoors, must be protected against the elements to prevent rain drops and insects from entering the moisture discharging area.
Installers may wish to develop their own solution, or rain covers and adaptor sets are available. The adapter set is designed for retrofit installations where making square holes in existing cabinets is difficult.