Mathematical Modeling of Heat and Moisture Regimes of Building for the Facade Thermal Insulation Composite System with Mineral Wool Insulation

Abstract

Nowadays, construction industry is running into a controversial problem of using unsteady-state calculation methods because the level of difficulty of physical processes calculation in modern building materials is increasingly higher than in classical materials which were used previously. It should be stated that it is crucial to develop new methods which allow engineers to use simple equations to calculate complicated tasks. Such method was obtained by Kozlov and it gives an opportunity not to calculate unsteady-state moisture behavior of enclosing structures and evaluate the moisture maximum plane position inside enclosures. The mathematical model of unsteady-state moisture regime was obtained to provide evidence of the Kozlov’s theory. Two computer programs were created. The first program simulated unsteady-state moisture regime inside enclosing structures during a year. The second program calculated the moisture maximum plane position during the period with negative average monthly temperatures. The comparison between these calculation methods was made for an enclosing structure with aerated concrete base and mineral wool insulation. As a result, it was shown that according to the Kozlov’s method the position of moisture maximum is between insulation and exterior stucco. The same result was obtained by unsteady-state moisture regime calculation, which made Kozlov’s theory evidence-based.KeywordsMoisture regimeMathematical modelThe moisture maximum planeEnclosing structureMineral woolVapor permeability