Aleksander Starakiewicz

Energy savings issues are important in the context of building operation. An interesting solution for the southern external walls of the building envelope is the thermal storage wall (TSW), also known as the Trombe wall. The article considers four variants of the wall structure, including three containing phase change material (PCM). The purpose of this study was to determine the influence of the amount and location of phase change material in the masonry layer on the storage and flow of heat through the barrier. Each wall is equipped with a double-glazed external collector system with identical physical parameters. The research was carried out in specially dedicated testing stations in the form of external solar energy chambers, subjected to real climatic loads. The distribution of the heat flux density values was determined using experimental tests and was subjected to comparative analysis for the various variants considered using statistical analytical methods. A comparative analysis was performed between the heat flux density values obtained for each barrier in the assumed time interval from the one-year research period. The Kruskal–Wallis test and the median test were used for analyses performed in the Statistica 13.3 programme. The purpose of these analyses was to determine the occurrence of significant differences between individual heat flux flows through the barriers tested. The results obtained indicate that the use of PCM in thermal storage walls extends the time required to transfer the accumulated heat in the barrier to the internal environment while reducing the amplitude of the internal air temperature.

In the European Union, buildings account for 42% of the energy consumption and 36% of the direct and indirect energy-related greenhouse gas emissions. Reducing thermal power for heating purposes is crucial to achieve climate neutrality. The main purpose of this article is to identify the places in the building where it is possible to significantly improve energy efficiency through the use of appropriate construction and material solutions. This article contains a multi-aspect approach to the heat balance of a building. Solutions that have a direct impact on building energy consumption were analysed, taking into account architectural, technological, and material aspects. Particular attention was paid to energy-efficient design and material solutions for non-transparent and transparent external walls and thermal storage walls (Trombe walls). An analysis of heat transfer through building elements was carried out, along with the optimisation of energy-efficient solutions for non-transparent and transparent barriers. Two methods for determining the equivalent heat transfer coefficient U_e for solar active partitions are presented. The analysis presented in the work using the original method of the balanced heat transfer coefficient U_e is a testing ground for identifying unfavourable features of the building structure, as well as the most energy-efficient solutions that can be used in establishing standards for the construction and modernisation of buildings. The value of the U_e coefficient illustrates the actual heat transfer through the partition. Having U_e values for various structural solutions of building envelopes, the designer can easily select the most effective ones. The use of the presented methodology will allow for the optimisation of technical solutions for building elements to improve its energy efficiency.

Among the technological solutions for external walls, the Trombe wall is an interesting proposition for obtaining solar radiation energy. The aim of the presented research is to determine the influence of glazing parameters on the thermal performance of the Trombe wall containing a phase change material (PCM). In the experimental tests, three glazing (G1, G2, and G3) with different heat transfer coefficient (Ug) and total solar energy transmittance factor (g) were used. The tests were carried out under laboratory conditions in a small-scale simulation chamber. The thermal energy of absorbed solar radiation was simulated with a heating panel. All of the walls are characterized by high dynamics of operation in the first two days. From the moment of heating, the walls achieve the minimum value of the heat flux after 16–18 h. In practice, this means the highest thermal efficiency of the wall during the night of the next day. A noticeable influence of the type of glazing on the operation of the barrier was found. The obtained results suggest that the most effective barrier for “sunny days” is the B1 barrier. The B2 barrier is suitable for alternating days in the cycle: “sunny day”, “cloudy day”. However, the B3 barrier is the most advantageous in periods with a predominance of “cloudy days”. In addition to the experimental studies, a numerical model of the B1 barrier was developed and simulation was carried out using the finite element method. The simulation results were consistent with the experimental tests. The second numerical simulation confirmed the rightness of using the heating panel in experimental tests.

The Moon’s environmental conditions present limited opportunities for waste heat dissipation, so internal heat gains (IHG) are a key component of thermal balance in a lunar building. Despite the significant development in energy saving and energy storage technologies of the last thirty years, the issue of IHG in lunar buildings has not been readdressed since the early 1990s. This study is based on an inspection of internal heat sources conducted aboard LUNARES, the first European extraterrestrial analogue habitat. The equipment absent on LUNARES, but indispensable for an actual lunar base, was identified and accounted for, along with additional laboratory and maintenance equipment. Three main groups of internal heat sources were identified and studied in detail. Waste heat generated by electric devices was accounted for, along with occupational heat loads adjusted for lunar partial gravity conditions. Assuming a photovoltaic power source for the studied building, two alternative energy storage systems (ESS) were analysed as another source of waste heat. Depending on the time of lunar day and applied ESS, the nominal IHG were between 73 and 133 W/m². The most significant internal heat sources in a lunar base are life support systems and potentially, regenerative fuel cells; thus, lithium–ion batteries were recommended for ESS. Within assumed parameter range, parametric study exhibited differences in IHG between 41.5 and 163 W/m².

The article presents four equivalent methods for checking mold growth on the surface of building barriers and checking water vapor condensation on their surface. Each method applies to two parallel phenomena that may occur on a building barrier. The first method is to calculate and compare temperature factors. In the second method, the characteristic humidity in the room is calculated and compared. The third method is to calculate and compare the characteristic temperatures in the room. The fourth method is based on the calculation and comparison of characteristic water vapor pressures. Three boundary conditions are presented for each method and phenomenon: when a given phenomenon can occur, when it begins or ends, and when it does not occur. The presented methods systematize the approach to the problem of mold development and surface condensation. The presented calculation results relate to the selected building barrier functioning in specific indoor and outdoor climate conditions. The calculation results confirm the compliance of the presented methods in identifying the phenomenon of mold growth or condensation on the surface of the barrier. A graphical interpretation of the results for each method with periods of occurrence or absence of a given phenomenon is also presented.

The article presents a comparative analysis carried out using three methods, determining the heat transfer coefficient U for a ceramic product modified with a phase change material (PCM). The purpose of the article is to determine the convergence of the resulting thermal characteristics, obtained using the experimental method, numerical simulation, and standard calculation method according to the requirements of PN-EN ISO 6946. The heat transfer coefficient is one of the basic parameters characterizing the thermal insulation of a building partition. Most often, for the thermal characteristics of the partition, we obtain from the manufacturer the value of the thermal conductivity coefficient λ for individual homogeneous materials or the heat transfer coefficient U for the finished (prefabricated) partition. In the case of a designed composite element modified with a phase change material or other material, it is not possible to obtain direct information on the above parameter. In such a case, one of the methods presented in this article should be used to determine the U factor. The U factor in all analyses was determined in stationary conditions. Research has shown a significant convergence of the resulting value of the heat transfer coefficient obtained by the assumed methods. Thanks to obtaining similar values, it is possible to continue tests of thermal characteristics of partitions by means of numerical simulation, limiting the number of experimental tests (due to the longer test time required) in assumed different partition configurations, in stationary and dynamic conditions.

This article presents the results of numerical analysis of the dynamic temperature distribution in driveway construction, for example, for emergency response vehicles - such as: ambulance, fire brigade, police and so on. It is assumed that the driveway is equipped with a heating mat, which is responsible for maintaining the road surface at a positive temperature. The purpose of this solution is to eliminate icing of the surface under difficult climatic conditions when the outdoor air temperature is negative. The presented calculations were performed in four stages. The first step involves comparing solutions containing different thicknesses of the heating plate from 6cm to 12cm. In the second stage - for the solution chosen from the first stage - a variable position of the heating mat in the plate is assumed. In the third stage two versions were compared:a solution with side insulation at the curb and without such insulation. Stage four contains a comparison of adriveway in the form of an overpass with a solution arranged directly on the ground. The whole analysis is designed to determine the best proposal for driveway construction - so that it is effective in terms of the energy delivered to the system, which is necessary to maintain a positive surface temperature.

The article presents the concept of improving the thermal insulation properties of a window thanks to the installation of an additional internal window. The resulting quasi-box window can be an alternative to the thermo-modernization of windows by replacing them. Measurements of the thermal parameters of the prototype and the unmodified window were made in an office space during its standard use. A quantitative and qualitative analysis of the compared solutions was made.

The paper presents the results of experimental studies on the consumption of hot water, energy obtained from the solar installation in the production process and the degree of coverage of usable and final energy with solar collectors. Thermal energy measurements from solar collectors cover the measurement period from 2011 to 2017. During this period, the annual final energy obtained from solar collectors ranged from 1033-1576 kWh. Monthly and annual demand for usable and final energy for the demand for hot water is presented depending on the amount of hot water used. Monthly actual consumption of hot water in the measurement period ranged from 3.57-9.16 m3. During this period, the number of residents has changed from 3 to 5 people. Annual coverage of energy useful for heat and energy by solar panels in the years 2011-2017 fluctuated from 38.0%-63.9% and 25.2%-42.3% for final energy. Monthly energy coverage ranged from 5.5% to over 100%. Covering energy above 100% in practice means getting a higher temperature of hot water in the outlet valve than expected.

Solar radiation is the primary source of life energy on Earth. The irradiance of the upper atmosphere is about 1360 W/m², and it is estimated that about 1000 W/m² reaches the ground. Long-term storage of heat energy is related to the use of a suitable thermal energy carrier. It may be either artificial or natural water tank, or artificial gravel-water tank, or aquifer or soil. It is justified to store the generated energy in large heating systems due to the nature of solar thermal energy. Typically, in such a solution storage space is a large solar collector farm. The reason for this is the proportionally small unit profits, which only in the case of large number of units provides sufficient energy that can be accumulated. It should be noted that Poland, a country located in a temperate and less harsh climate such as Scandinavia and Canada, has a relatively high potential for solar revenue. In the last decade, it has caused mainly small and individual heating installations. However, much of the municipal and industrial economy continues to rely on energy from non-renewable resources. This is due not only to the lack of a high-efficiency alternative to non-renewable energy resources, but also to the thermal state of buildings throughout the country, where old buildings require thermomodernization. This has the effect of both polluting the environment and the occurrence of smog, as well as pollutants in water and soil. This directly affects the occurrence of civilization diseases and other societal health problems. Therefore, the surplus of thermal clean energy that occurs during the spring and summer period should not only be used on a regular basis, but also stored for later winter use. The paper presents the concept of housing estate, which consists of 32 twin housing units. The solid character of buildings consistently refers to passive construction, and the materials meet the requirements for the passive buildings.