No abstract

In this paper, a mathematical model dealing with a coupled heat, air, and moisture transfer in a building envelope was developed. Based on the three‐following driving potential: vapor pressure, dry air pressure, and temperature, an application on a hygrothermal behavior of a real wall was carried out for different climatic conditions. For this purpose, a characterization of the heat and moisture properties of the materials constituting the wall made with red brick and cement mortar was carried out in the laboratory. This was used to evaluate experimentally the input parameters of the model as a function of relative humidity. To validate the numerical model, an experimental platform was improved. The wall was set up in a double‐climatic chamber with different boundary conditions, and then the temperature and humidity evolutions were recorded using several sensors within the wall thickness. The results have highlighted a good agreement between numerical simulation results and experimental ones.

Electricity consumption of the Egyptian building sectors has an increasing rate from 2014 until now according to annual report for electricity ministry [1].Hence, this research examines the common building envelope systems after increasing the thermal resistance of exterior envelopes to achieve high energy efficient buildings. That will be attained by: 1-field results for the case under study is used to validate numerical model. Then, the thermal performance for the case study is increased by exterior thermal insulation panels, reduced air infiltration through double glass windows instead of infiltrated single glass windows.2-Three-dimensional numerical results -TRNSYS v17 program, which demonstrated that, only 0.35 m thick straw panels for the external walls, double glass windows with 1.5 m horizontal shading and 0.6 ach ventilation rate save 26.6 % cooling energy for the building under study. While 0.15 m and 0.2 m expanded polystyrene panels can save 24 % and 23 % respectively.