In the paper the authors have investigated the influence of thermal mass of the building envelope on the alignment of temperatures between the external and internal environments without IntroductionThermal mass of the envelope is to be understood as its heat capacity. It means that the envelope with large thermal mass needs to absorb a lot of heat energy before the temperature on the surface of the envelope changes. And the envelope of small thermal mass reaches the surrounding temperature reasonably fast. The impact of heat retention rate on the thermal load of the zones ventilated by night in the climate of China was investigated in the work [1]. The works on thermal comfort had been already carried out for many years. In the publication [2], the authors were considering thermal inertia in terms of the experienced thermal comfort, and more specifically, the impact of thermal inertia on the total thermal load of the system. The investigation studies were carried out with the application of numerical analyses, using the Fourier equation.Many works involve also the impact of temperature distribution in the room on thermal comfort. Such research works were carried out among others in the work [3]. The authors demonstrated that thermal comfort of rooms depends on the temperature of the outdoor environment. They also divided the rooms into thermal comfort zones, and they determined the minimum and maximum temperatures for thermal comfort. Research studies involving the influence of temperature loss of the room as a time function on energy savings have been carried out worldwide. Even the most recent literature is still occupied with this problem [4]. It is also quite significant in terms of energy savings in the building engineering industry to understand the role of heat accumulation of the envelope. The consumption of heating, cooling or ventilation energy is still rising, and therefore the systems of energy storage are becoming more and more apparent for researchers. In the work [5] the researchers found out that in the areas of high temperature difference between day and night, thermal insulation mounted on the external surface of the envelope yields better results than that mounted on the internal surface. As they explained, it was caused by a different heat accumulation of the envelope with external insulation than that with the internal one. The subject of heat accumulation of the envelopes and its influence on energy efficiency of buildings has been undertaken by many

The article aims to assess the effects of soil temperature measured in situ on the heat loss analyses of a building. Numerical analyses and in situ measurements of soil temperature profiles for real conditions under a residential building (profile I) in Poland and under the area outside the building (profile II) were performed. Based on the measurement results, a proprietary geometric model of the partition was proposed. The heat flux and heat flow results obtained for reliable models are 4.9% and 6.9% higher compared to a model based on a typical meteorological year for the wall–foundation system and 10.0% and 10.1% higher for the slab-on-ground structure for profile I. The adoption of temperatures from the area outside the building as the boundary condition (profile II) results in greater differences between the obtained results. The difference in heat flow obtained in the numerical analyses for profiles I and II is about 2 W/m2, both for the wall–foundation system and for the slab-on-ground structure calculations. The adoption of temperatures for the ground outside the building led to overestimation in the heat flux calculations, this being due to lower temperatures in these particular layers of the ground.

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Thermal properties of building envelopes are often described using thermal conductivity or thermal resistance. And the opposite task involves the identification of thermal parameters of building envelopes based on the measurements of their cooling process. In this article, the authors proposed a method of identifying thermal parameters of a building envelope based on cooling measurements, using a multiple regression model for this purpose. To satisfy the research objectives, two basic experiments were carried out. The first experiment was performed in laboratory conditions. The research model was a cube of the dimensions of 1.1 m × 1.1 m × 1.1 m. The second experiment was carried out in semi-real conditions, and the used model was a small house of the dimensions of 6.0 m × 4.15 m × 5.2 m. The measurement results were also used to calibrate numerical models made in the ESP-r program. The research studies have demonstrated that the model can be used to identify thermal parameters of a building envelope. Based on the measurements and simulations, the cooling equations of the object were determined and the 95% confidence interval for the heat retention index was estimated. On that basis, using the multiple regression model, such parameters of the model as density, specific heat, and thermal conductivity were estimated. It turned out that using the Gauss–Newton approximation, we obtained the correlation of the measurement results and the analytical model with the correlation coefficient of 0.9971 (for the laboratory scale). And the multiple regression improved not only the correlation between the measurement and the analytical model, but it also allowed to obtain “almost identical” results. Similarly, promising results were obtained for the semi-real scale.

Knowledge of temperature distribution in relation to time and depth is necessary in many applications. These include: designing GSHP (ground source heat pump) and EAHE (earth-air heat exchangers) systems, calculating heat loss in buildings, in determining foundation depth for buildings and structures with consideration of frost penetration depth, designing pavement of roads and airports or designing underground systems of energy transmission. Regular measurements and perfecting models describing temperature in the ground is therefore extremely valuable. This article presents authors’ own research on ground temperature changes in time and distribution of temperature at different depths, up to c. 2.0 m beneath ground level. The tests were performed in the Silesia region over a period of 6 months between May and October, using thermistors installed in the ground at various depths. The measurements were compared with temperature of the air, measured at test stations using a meteorological multisensor in order to find a correlation. Aside from readings of temperature over time and profiles of ground temperatures the paper contains selected elements of statistical analysis of the measurements. It was noted that the temperature distribution is closely related to depth below ground level, and the influence of outside temperatures decreases with depth.