Comparison of the Position of the Maximum Humidification Zone when Using the Methods of Stationary and Non-Stationary Heat and Humidity Regime

The basic formulas for mathematical modeling of the heat and moisture regime of building envelopes in stationary and non-stationary settings are given. It is noted that the mathematical model uses third kind boundary conditions. Objective of the study: to check whether the moisture maximum plane position in the thickness of building envelopes is confirmed assessing non-stationary moisture conditions. Two methods for verification are used: the graphical method for determining the plane of maximum moisture and the method for assessing the non-stationary moisture regime, based on the Gagarin and Kozlov moisture potential. It was found that the maximum moisture is confirmed both for facade systems with mineral wool insulation and for facade systems with expanded polystyrene insulation. In the case of mineral wool, the maximum moisture is located outside the insulation layer. For expanded polystyrene insulation, the maximum moisture is determined inside the insulation layer. Thus, it was confirmed that the maximum moisture in the thickness of the enclosing structure, determined by the graphical method, is confirmed by mathematical modeling of a non-stationary heat and moisture regime.