Cross-comparison of Measured Behavior of Highly Hygroscopic and Vapor Permeable Walls Exposed to Different Real Climates

Abstract Experimental measurements are often used to validate or calibrate numerical models. Many authors report good agreement between experimental measurements and numerical simulations of thermal behaviour of walls, and notice stronger discrepancy while assessing moisture transfers. One of the possible reasons for this discrepancy is the difficulty to measure precisely and robustly hygrothermal transfers under real climate variations. In order to check the robustness of hygrothermal measurements, in the present work records from two different experimental facilities are compared. Both have controlled indoor climate and similar, but not identical outdoor conditions (they are situated at about 400 km distance). The same vapour open and hygroscopic wall assembly is investigated on both cells. The results analysed show strong similarities in qualitative behaviour. Quantitative analysis using normalised values show good agreement in stable conditions. In strong dynamic conditions the analysis is more difficult; more work is needed in order to overcome the amplitude of boundary conditions.