Buildings and structures are among the fixed assets that have the longest shelf life. Therefore, during its operation throughout the term, respectively, there is the largest gap between the technical condition and functional properties of the building, such as fifty years ago, and the current technological and innovative level of construction, due to scientific and technological progress. Technologies related to their energy efficiency, energy saving, greening, simplicity and reliability of operation and eco-friendly utilization are decisive in modern mass construction. Therefore, regardless of the application of the latest energy-saving solutions in engineering systems to ensure the microclimate and the degree of use of renewable energy sources, thermal protection of buildings is constantly increasing. Thus, not only buildings of the 60s and 90s of that year need complex thermal modernization, but also buildings of a much younger age, and it is probable that this process is sustainable for the same building. The aim of the dissertation research was the theoretical and experimental substantiation of the improved energy efficient heating system compatible with the sustainable complex thermal modernization of the building. Based on a critical analysis of literature sources and patent research, according to the goal formulated tasks, which are physical and mathematical modeling of thermal conductivity under boundary conditions of the first kind through a multilayer wall of the outer enclosure with internal vertical heating pipes and changes in thermal inertia intensity. Thermal inertia and verification of experimental and theoretical data, as well as the development of methods of engineering calculation and feasibility study for the introduction of energy-efficient heating systems compatible with sustainable integrated thermal modernization of buildings. The object of study is energy efficient heating systems compatible with sustainable integrated thermal modernization of the building, and the subject - non-stationary processes of thermal conductivity and thermal inertia under boundary conditions of the first kind through a multilayer wall of external enclosure with internal heat sources formed by vertical supply and return. Modern physical-mathematical and experimental methods of theoretical researches of nonstationary processes of thermal conductivity under boundary conditions of the first kind through a multilayer wall of an external protection with the internal heat sources formed by vertical supply and return pipelines with the heat carrier of two-pipe heating system are applied. Methods of numerical modeling, experimental laboratory and field research on the basis of modern theories of formulation, execution, mathematical processing and obtaining reliable data on the results of thermos physical experiment. The probability of the obtained results, their analysis, conclusions and recommendations are due to the satisfactory convergence of the results of theoretical and experimental studies. The scientific novelty of the obtained results lies in the theoretical substantiation and experimental confirmation of the improved energy efficient heating system compatible with sustainable complex thermal modernization of the building on the basis of the developed physical and mathematical model of thermal conductivity under boundary conditions of the first kind. Of return pipes of heating system with coolant, water, in the middle of them, theoretical substantiation and experimental confirmation of increase to 10% of thermal inertia of the offered design of a wall of an external protection with preservation of rather higher and constant temperature in a design thickness at periodic sharp changes of external thermal influences, especially at the minimum ambient temperatures, or the intensity of solar radiation. The method of experimental studies of thermal conductivity under boundary conditions of the first kind has been improved due to the proposed design of a multilayer heterogeneous wall of external enclosure and further substantiation of scientific substantiation of sustainable complex thermal modernization of buildings on the basis of energy efficient heating systems. And operational efficiency of the heat source and the heating system as a whole.
