Experimental measurement of material’s drying coefficient for internal insulation: new approaches for laboratory testing

Abstract

Materials’ drying behaviour plays an important role in the renovation of historic buildings since internal insulation is frequently used to avoid intervening on the outer finish. However, the use of internal insulation in many cases requires the verification of the insulated wall system by means of hygrothermal dynamic simulations. As simulation models are a mathematical simplification of the physical reality, there is no guarantee that the model describes the hygrothermal performance accurately. A qualitative comparison of simulations with a drying coefficient that is based purely on experimental data provides additional security and clarity in the adoption of capillary active insulation materials. New approaches for the laboratory tests developed in parallel in two different research projects, Interreg AS ATLAS and HyLAB, are presented in this paper. An analysis of the drying apparatus designed by Scheffler revealed a series of limitations that could be further improved. The results of the material calcium silicate of two different experimental set ups, with considerations to the usability and accuracy of the apparatus, are presented, compared and discussed in the following paper. Further simulations resulted in comparable drying coefficients for the two experimental set-ups and were able to identify possible discrepancies in the results of the measurements.