The implementation of the energy saving program in construction, adopted in the Russian Federation, has led to a signifi cant change in the design decisions of building envelopes. To achieve the normative values of heat transfer resistance, various facade systems are currently widely used for insulation of external walls using polymeric materials as heaters, which have low values of the coeffi cient of thermal conductivity with a relatively high value of the coeffi cient of vapor permeability. Therefore, when choosing a textured layer of facade systems, it is necessary to take into account the value of its resistance to diff usion of water vapor in order to avoid the accumulation of moisture in the outer walls. The problem associated with the possible accumulation of moisture is especially relevant when designing both three-layer exterior walls and walls with internal insulation. To eliminate the formation of molds on the inner surfaces of the enclosing structures, leading to dangerous diseases of skin and respiratory tract organs, as well as the destruction of building structures, it is necessary to accurately calculate the humidity mode of the enclosing structures in order to protect them from overmoistening. The article presents a methodology for determining the position of the plane of possible condensation in multilayer enclosing structures, based on the use of the dimensionless characteristics method.

The article presents a method for determining the minimum permissible value of the heat transfer resistance of the outer wall, at which the minimum energy consumption is achieved during the operation of buildings with variable thermal conditions. A review of the sources devoted to this problem showed the presence of high costs of thermal energy during the heating of premises. On the basis of studies of all components of energy consumption in the operation of premises with intermitt ent heating systems, the authors of the article propose a method for determining the minimum permissible resistance to heat transfer, which provides minimum energy consumption. According to the described method, the calculation was made for external walls made of various materials. The analysis of the obtained results showed that a signifi cant infl uence on the minimum permissible value of the heat transfer resistance is exerted by a complex of thermophysical values cρλ. The presented graphical dependence R0 усл on the complex cρλ allows the designer to rationally choose a wall material that provides a minimum of energy consumption during the operation of the building. In the context of rising energy tariff s, such optimization of thermal protection characteristics is especially important for country cott ages operated in intermitt ent heating conditions.

An updated method of heating calculation of buildings operated in the conditions of intermitt ent heating is considered. On the basis of the conducted studies, analytical dependences were obtained for determining energy consumption during heating of building enclosing structures, taking into account the infl uence of the order of location of thermal insulation and structural layers, as well as temperature changes during heating of each layer. Formulas for fi nding the change in the temperature of the internal air during the heating of the premises and the internal surface of the enclosing structures are obtained. On the basis of the proposed refi ned methodology, the calculation of the heating of the living room of a country cott age located on the territory of the Samara region was performed.