This article emphasizes the significance of understanding the actual thermal properties of thermal insulation materials, which are crucial for avoiding errors in building design and estimating heat losses within the energy balance. The aim of this study was to analyse the thermal parameters of selected thermal insulation materials, particularly in the context of their stability after a period of storage under specific conditions. The materials chosen for this study include commonly used construction insulations such as polystyrene and mineral wool, as well as modern options like rigid foam composites. Experimental studies were conducted, including the determination of the thermal conductivity coefficient λ, as well as numerical analyses and analytical calculations of heat flow through a double-layer external wall with a window. The numerical analyses were performed using the TRISCO software version 12.0w, based on the finite element method (FEM). A macrostructural analysis of the investigated materials was also performed. The findings indicated that improper storage conditions adversely affect the thermal properties of insulation materials. Specifically, storing materials outdoors led to a deterioration in insulating properties, with an average reduction of about 4% for the standard materials and as much as 19% for the tested composite material. Insufficient understanding of the true thermal properties of insulation materials can result in incorrect insulation layer thickness, degrading the fundamental thermal parameters of external walls. This, in turn, increases heat loss through major building surfaces, raises heating costs, and indirectly contributes to greenhouse gas emissions.

Currently, when calculating the heat-shielding qualities of external enclosing structures, the ability of fencing surfaces to reflect the heat flux by radiation is not taken into account. All this leads to an underestimation of heat-shielding characteristics in comparison with reality. Studies have shown. that a number of factors affect the thermal protection of air layers - the difference in temperature on the surfaces of the interlayer, its thickness. But the most important is the coefficient of elimination of the air gap surface. The use of reflective heat insulation with a low emissivity on one of the surfaces of the air gap makes it possible to increase its thermal protection 2.5–3 times. The article presents the calculations of thermal protection of air gaps with different emissivity coefficients of surfaces and conclusions about the effectiveness of the use of reflective insulation.

Currently, a very big problem of cities in Europe and the world is air pollution with combustion products of car fuels, generation of heat and electricity. These impurities affect the microclimate of cities significantly. Pollution not only affects the area outside buildings, but getting into their interior through ventilation systems, which has an adverse effect on the indoor environment of buildings. High concentrations of CO ₂ , cause a weakening of concentration in working people, which affects the deterioration of safety and work efficiency. For assessing air quality improvement on “green roofs”, a field study of CO ₂ content has been carried out on the “green roof” of a four-storey building, on a completely identical non-greened building, and on a highway with high-density traffic near them in Kiev. It was found that greening the roof significantly reduces the CO ₂ content from 501 ppm on the road and 452 ppm on the roof without protection to 410-415 ppm. It improves the conditions in which people work and rest.

The energy-efficient provision of indoor comfort for buildings is one of the most important requirements for modern construction. The greening of buildings is a natural measure to achieve this, for which the most limiting factor is the lack of systematic research on its positive effects. At the Kyiv National University of Construction and Architecture, a series of research on thermotechnical benefits and gas exchange in plant layers has been performed. The cooling effect of plants is up to 4 K. Semi-intensive green roofs on rooms have paths, which absorb solar radiation and load the air-conditioning systems. The proposed solution is to build the paths on the auxiliary premises with low microclimate requirements. The work aims to estimate the heat distribution in green roofs with paths to test the recommendation. Simulation using the Fourier–Kirchhoff equation shows that the path has a trace of higher heat transfer on the ceiling up to an additional 1.8‒2.0 W·m−2. Thus, aligning the paths above the auxiliary premises is recommended, if possible. A better solution is to allow planting of the paths. Using plant-permit pavements and barefoot-in-dew systems such as ZinCo Soft Landscape are examples of such solutions. It is necessary to use grass that can be walked on.

Thermal insulation of pipelines is used in different industries including agricultural technologies. Energy efficiency depends on heat losses, which, in turn, are limited by heat insulation. Decentralized ventilation is effective in rural low-rise buildings. One such device used is a regenerative ventilator like Blauberg Vento or Vents TwinFresh. There is a task to improve the efficiency of its operation. Investigation of heat recovery processes in thin ducts is taking place. Experimental uncertainty decreases with better heat insulation of the experimental setup. But in heat transfer literature, there is a notion of the critical radius of insulation. More the insulation radius should decrease its effectiveness due to the development of the outer surface. In the theory, the heat transfer coefficient of the outer surface is assumed to be constant. In this study, laminar convective flow around the outer horizontal cylindrical insulation surface of a large thickness is considered. The formula of the average heat transfer coefficient is used that takes into account the Grashof number. While the insulation thickness is increased, the surface temperature and the heat transfer coefficient are decreased. The function of thermal resistance dependence on the outer diameter related to the inner one and its derivative have been analysed. As a result, an asymptotic increase of thermal resistance was observed without extremums. So, there are no critical diameters if the insulation is so large to obtain laminar convective flow. The maximum radius of thermal insulation should be determined not as critical, but as expedient. Thus, it can provide 5-20% lower heat transfer resistance than the asymptotic one. The radius of thermal pipe insulation of technological devices should be accepted based on technical and economic justification.