Aspects of selecting the most effective refrigerating machine for air conditioning systems, taking into account the comparative analysis of the energy efficiency of the refrigerating machine are considered. The purpose of the work is to improve the regulatory framework governing the design, construction and operation of buildings and structures, to obtain sufficient theoretical and reliable calculated data to determine the standardized parameters and clarify the requirements for the design, construction and operation of buildings and structures. The requirements should be focused on ensuring safe for human health conditions of residence and stay in buildings and structures and the energy efficiency of buildings and structures in order to implement the requirements of the Federal Law of December 30, 2009 No. 384-FZ “Technical Regulations on the Safety of Buildings and Structures”. The aim of the study is to ensure the protection of the life and health of citizens, property of individuals and legal entities, state or municipal property, to bring methods for determining operational characteristics and assessment methods to the uniformity, to ensure mutual consistency of existing regulatory technical documents in the construction industry. The object of the study is the refrigeration and air conditioning systems of public buildings.

The air quality in the premises with the presence of people affects the performance and health of a person. In the context of the spread of infections and various respiratory diseases, air exchange in the room, the presence of fresh, clean air become a mandatory requirement to prevent the development of diseases. During the construction of apartment buildings, an important issue is the choice of ventilation systems to ensure comfortable and safe living conditions for people. For many years, natural exhaust ventilation systems have been used in apartment buildings in many countries. Practice and our research show the inefficiency of natural systems, especially when the outside air temperature is above +5 degrees Celsius. In this work, the analysis of mechanical and natural ventilation systems is carried out; their advantages and disadvantages are revealed on the basis of the experience in the construction of apartment buildings of the PIK Group of Companies. Unfortunately, for many developers, the economic component is crucial. A separate economic justification requires a comparison of costs. So with an increase in capital costs (the cost of fans, but a lower consumption of air ducts due to higher air velocity), the area of apartments is freed up due to the smaller size of

In various fields of engineering, such structural elements are widely used that, from the point of view of their strength calculation, can be referred to thin shells (tanks, reservoirs, cylinders, etc.). When calculating thin-walled shells, a number of hypotheses are adopted to simplify the solution of the problem. The problem is most simply solved within the framework of the momentless theory of shells, according to which only the force normal to the section (the membrane force) is different from zero, and all moments and transverse forces are equal to zero. The paper presents an analysis of dynamic loading of the material carried out by the method of electric explosion of conductors (EEC). A composite cylinder, which is a thick-walled cylinder made of polymethylmethacrylate with an axial hole pressed into an aluminum shell, was chosen as an experimental sample. The sample is loaded by applying an electric voltage to a conductor in the form of a copper wire placed inside the axial opening of the sample. The equation of state at electric explosion of the conductor is obtained; experimental and calculated graphs of dependence of pressure in the air channel on the expansion coefficient of EEC products are constructed. A theoretical model describing the change in the radial stresses arising in the process of loading with regard for the boundary and initial conditions is built. The accuracy of the built model is justified by comparing the obtained results with the experimental data. The circumferential stress, at which the rupture of aluminum shell directly occurs, is estimated.