Experimental determination of the hygroscopic inertia of building materials

A set of experiments is reported that tests the contribution of building components to the overall hygroscopic inertia of a room and its effect on the relative humidity variation. All the experiments were produced in an innovative flux chamber explicitly built for this purpose. The samples used in the tests included not only common renderings with different applied coatings, but also other materials that can be found inside buildings, such as paper. The tests focused on daily cycles of relative humidity variation, similar to those found in bedrooms or office spaces. The results revealed that even renders with low hygroscopicity can have a relevant contribution to the moderation of inside relative humidity variations, thereby placing a focus on the selection of coatings.