Moisture-Buffering Effect—Experimental Investigations and Validation

Well-balanced conditions of thermal, moisture, and air quality are very important in buildings because an imbalance of these factors could have significant influences on the construction and the inhabitants. The focus is the influence of different materials on the fluctuation of relative humidity, specifically humidity peaks. In lieu of complicated and expensive laboratory testing, several different software tools have been developed to estimate the indoor environmental conditions of buildings. In the context of the IEA Annex 41 project, a common exercise was carried out. For the common exercise at the free field investigation area in Holzkirchen (Germany), two identical rooms were used to measure the moisture buffering capacity of several interior finish systems. To address the questions of buffering capacity, the Fraunhofer-Institute of Building Physics developed a hygrothermal simulation tool, WUFI®-Plus (Holm et al. 2006). Using the measurement data from the common exercise, calculations were carried out with several software tools for its validation. In this paper, the results of the laboratory tests and simulation results are described.