PLANNING A MULTIFACTORIAL EXPERIMENT TO STUDY THE EFFECT OF MOISTURE CONTENT OF THERMAL INSULATION MATERIAL ON ITS THERMAL CONDUCTIVITY

An analysis of domestic and foreign studies shows that improving the energy efficiency of the thermal insulation envelope of buildings is an essential way to implement the decarbonization program. To reduce heat loss through external enclosing structures, building materials with certain thermophysical, environmental, and economic characteristics are used. The thermal conductivity of thermal insulation materials changes under the influence of anthropogenic and natural climatic factors throughout the life cycle of buildings. A significant negative factor of thermal insulation materials is their hygroscopicity, which causes an increase in moisture content. As a result, the density of the thermal insulation material increases and, accordingly, the thermal resistance of the enclosing structures decreases. The lack of systematic research on the effect of the moisture content of thermal insulation materials on their thermal conductivity led to a search for the influence of determining factors on the target function, namely the thermal resistance of enclosing structures. To develop a methodology for conducting a field experimental study of the effect of the moisture content of thermal insulation material on its thermal conductivity, it is advisable to use the results of planning a multifactorial experiment. Mathematical planning of the experiment was carried out to identify the determining factors that characterize the physical properties of thermal insulation material for the target function. Response surfaces of the target function of thermal resistance and their confidence intervals depending on moisture content were constructed. A regression model was obtained for the response functions of parameters characterizing the thermophysical properties of thermal insulation material. The priority of the influence of thermal insulation material parameters on their thermal resistance was revealed. It was established that moisture content significantly affects the thermal conductivity of thermal insulation.