Mathematical modelling of renewable construction materials for green energy-efficient buildings at permafrost regions of Russia

The main goal of this work is to assess the influence of moisture transfer processes on the operational properties of complex structures with wooden elements. A physical-mathematical model of the combined heat and moisture transfer in the walls of insulated timber with connectors has been presented in the paper. The model is intended for use in the climatic conditions of the northern territories. The model has been confirmed by experimental data on moisture sorption isotherms in wood, as well as the dependence of moisture conductivity and thermal conductivity coefficients on the temperature and humidity. Based on numerical simulation of nonstationary heat and moisture transfer in external building envelopes made of thermal insulating profiled timber with connectors, heat and mass fluxes in the selected inhomogeneous fragments have been calculated, and their thermal properties have been evaluated. It is shown that moisture transfer processes result in a decrease in thermal properties of walls made of insulated timber with connectors by 6-8%. The presence of connectors does not lead to the formation of any local zones with a significant accumulation of moisture. The studied properties and characteristics of green building materials enabled to development of the methodology of energy-efficient buildings and provide the background for the calculation of energy systems. The results of this work may be combined with other research on renewable or low-carbon energy technology to create a new strategy of sustainable construction in Russian permafrost regions