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.

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.

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.

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 the input of either heating or cooling sources. It is commonly known that when the source of thermal energy is no longer active and the temperature difference between the inside and outside of the building is positive, the building envelope starts to transfer the heat outside. Such a process is repeated until the temperatures in both environments become equal. Hence, the decision to undertake such an analysis in the present paper. In the work the authors have attempted to investigate the impact of thermal mass of the building envelope on the cooling process of the whole internal air. Also, the influence of the shape of the investigated object on the cooling process of the internal zone has been analyzed.

ETICS is a popular external wall insulation system, which is not without possible defects and damages. A frequent cause, direct or indirect, of damage to buildings is the impact of water (moisture). This article presents, among others, the results of tests of the moisture content of ETICS layers, the water absorption and capillary absorption of the render by means of the Karsten tube method, numerical thermo-moisture simulations, and tests of interlayer adhesion, in sample residential buildings. Mass moisture content testing of the wall substrate showed acceptable moisture levels (1–4%m) within masonry walls made of silicate blocks, as well as locally elevated moisture levels (4–8%m) in the case of reinforced concrete walls. Moisture testing of the insulation samples showed a predominantly dry condition, and testing of the reinforcement layer showed an acceptable level of moisture. Severe moisture was found in the sample taken in the ground-floor zone at the interface between mineral wool and EPS-P insulation underneath the reinforced layer. Capillary water absorption tests helped classify silicone render as an impermeable and surface hydrophobic coating. Tests of the water absorption of the facade plaster showed that the value declared by the manufacturer (<0.5 kg/m²) was mostly met (not in the ground-floor zone). The simulation calculations gave information that there was no continuous increase in condensation during the assumed analysis time (the influence of interstitial condensation on the observed anomalies was excluded). The tests carried out indicated the occurrence of numerous errors in the implementation of insulation works affecting the moisture content and durability of external partitions.

Contemporary solar power engineering enables the conceptual interlocking of the shape of a building object with its location, structural design, and external envelope, as well as applied materials. Suitably selected solutions involving the structure, shape, construction, and location of a building can significantly improve the thermal balance of rooms in a building. Particularly valuable and warranted are studies involving various solutions for building partitions contributing to a considerable improvement in the thermal balance of a building. This article presents the results of research on temperature changes on the surface of the external part of a partition coated with layers of different colors. For the lightest coating (white), both the average temperature obtained on the and the maximum temperature obtained on the surface were the lowest. With the darker coatings, these temperatures were both higher. The back analyses that were performed indicated lower and higher absorption coefficients, respectively, for the coating compared with the base value for the red coating. Additionally, it was demonstrated that the average surface roughness (Ra) after tests in a natural environment decreased by 12.1% for the base (red) coating. For the grey and white samples, a more than two-fold increase in roughness was reported, of 198.6% and 202.0%, respectively. The SEM analysis indicated material loss and discoloration on the sample surfaces.