The standardised Glaser method for calculation, prediction and evaluation of moisture performance is considered as rarely applicable. The present state of knowledge, analytical as well as experimental, concerning heat, air and moisture demands updating of standards. This paper presents five numerical benchmark cases for the quality assessment of simulation models for one-dimensional heat, air and moisture (HAM) transfer. In one case, the analytical solution is known and excellent agreement between several solutions from different universities and institutes is obtained. In the remaining four cases, consensus solutions have been found, with good agreement between different HAM models. The work presented here is an outcome of the EU-initiated project for standardisation of HAM calculation methods (HAMSTAD WP2).

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Hygric properties of porous building materials are important for hygrothermal analysis. Their experimental determination is however not always reliable, shown by the discrepant results from different laboratories on the same materials. In this study, a recent round robin campaign initiated by KU Leuven (Belgium) and participated in by eight institutes from different countries is reported. Ceramic brick was selected as the target material. The bulk density and open porosity from vacuum saturation tests, the capillary absorption coefficient and capillary moisture content from capillary absorption tests, and the vapor permeability from cup tests were measured. Results were analyzed statistically and compared with a previous round robin project, EC HAMSTAD. The reproducibility errors for determining the capillary absorption coefficient were noticeably reduced when compared with the EC HAMSTAD project, and the different laboratories in the present study obtained similar results from vacuum saturation tests and capillary absorption tests without a common protocol. For cup tests, large inter-laboratory discrepancies still exist. However, with a stringent common protocol different laboratories achieved consistent results. For all properties a common protocol did not change the average results of all laboratories.

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To better understand the similarities and differences between moisture and volatile organic compound (VOC) diffusion through porous media, a dual chamber experimental system was developed. The diffusion and partition coefficients of moisture and selected VOCs in materials were compared. A pilot test with gypsum wallboard and oriented strand board (OSB) showed similar diffusion kinetics between moisture and VOC. To further establish the similarity relationship between VOC and water vapor transport, calcium silicate was used as a reference material to develop the concept of a similarity coefficient and its application in combined heat, air, moisture and pollutant simulation (CHAMPS) in buildings. The diffusion resistance factor calculated for moisture from the dual chamber tests agreed well with that from the conventional dry cup test method. The diffusion behavior of each particular VOC in porous media is predictable as long as the similarity coefficient of the VOC is known. Future experiments will extend this to materials with significant VOC emissions in buildings.