Experimental and numerical modelling of hygrothermal transfer: Application on building energy performance

•Heat and mass transfer characteristics are studied experimentally and numerically.•Real climatic conditions as solar radiation and rainfall are selected for the study of building envelope elements at wall scale.•An eco-concrete wall with a replacement of cement by 20% of glass powder is tested.•A new experimental set-up was designed which can generate solar radiations and rainfall.•Sensitivity analysis of heat and moisture transfer model was performed. This work deals with the hygrothermal behavior of building envelope wall composed of an eco-concrete made of glass powder. The material was chosen in order to satisfy the RE2020 requirements regarding the carbon footprint reduction of building materials. The wall is tested and subjected to wetting/drying cycles by T/RH variations with/without solar radiations and rainfall. The last two climatic conditions are real and rarely taken into account in the study of hygrothermal behavior. Therefore, an experimental set-up was designed and a numerical model was proposed. The numerical and experimental results were compared for the both tests. The results obtained highlighted the ability of the numerical model to reproduce the hygrothermal behavior of the wall. For Test 1, the RMSE value is about 0.24 °C, 4.78 % and 2.28 W.m−2 for T, RH and thermal flux, respectively. Whereas, it is about 0.23 °C, 3.47 % and 7.79 W.m−2 for Test 2. The impact of rainfall is 3.33 time more than the test without rain for a material with porosity about 14.18%. As for drying, the solar radiations has an important intensity of about 820 W.m−2 and induces a significant heat flux at the external border.