System for controlling humidity within a space, e.g. a room or a museum case, involves embedding hygroscopic substances such as salts in the pores of objects or surfaces within the space, e.g. in wallpaper

摘要

A system for achieving a specified and required range of atmospheric humidity in a space, in which (a) free surfaces (of objects) in contact with the air or regions near the surface with a low resistance to water vapour diffusion show (at least partly) a free pore volume and (b) substances with a hygroscopic action (I) are embedded in the free pore volume by harmless physical means.