Miroslav Čekon

Obtainable Method of Measuring the Solar Radiant Flux Based on Silicone Photodiode Element

Solar radiation exposure and its monitoring does have not only the importance for climate science and meteorology however is equally of highly relevant use for the field of Building Science as primarily those of analyzing thermal aspects in building physics. Here the measuring of solar irradiance by means of well-established solar instruments can be applied whose advances have been undergoing steep progress. Currently, a silicon photodiode element, as a truly obtainable form, may have a feasible exploitation in the field of building applications concerning the solar radiant flux quantifying. It represents a small optoelectronic element and has a several exploitable advantages. The paper presents a perspective alternative to monitor solar irradiance. Own measurement assembly is proposed and introduced. Initial in-situ measurements are performed and final comparability with existing commercial solar instruments is presented. An obtained correlation with existing types demonstrates its applicability to the field of building science and solar energy.

Thermal Bridges Minimizing through Window Jamb in Low Energy Buildings

Building envelopes with high thermal resistance are typical for low-energy buildings. Detailed specification and calculation of each thermal bridge in these buildings should be taken into account. This paper is focused on thermal bridges minimizing through typical window systems in building envelopes. The aim of this article is to analyze the window position influence, as regards on thermal performance and to point out the installation modality in accordance with the characterization of the windows performance. This can be done by quantifying the percentage increment of the window jamb thermal transmittance. The calculated results also demonstrate that there is significant difference between results obtained by various available calculation approaches. This can be significant especially in buildings with high thermal protection.

Analysis of Energy Consumption in Building with NZEB Concept

The trend in the components of residential buildings is low energy demand buildings in relation to the minimum costs spent by users for their operation. The main aim of their construction is to improve the energy economy of buildings, to reduce the environmental load in energy consumption, to improve the quality of the interior, to ensure the minimum cost level in the operation of buildings and their maintenance in the life cycle. The consequence of increased energy prices and the possible implementation of tax policies in the countries of Europe is more frequently designing and implementing energy self-contained buildings. This means that energy necessary for the general use of a building can be produced in it to certain extent. The concept of such buildings is not only in high quality heat insulating properties, but also in suitable installed devices utilizing alternative sources. The objective indicator of saving and proof of the required level of a building is an analysis of its real energy consumption. The paper analyzes the energy consumption in a specific house which, in the design phase, met the criteria for designing a nearly zero energy building. The analyzed building has a high thermal protection and uses photovoltaic energy as an alternative source. The main aim is to evaluate the concept of the designed nearly zero energy building and to assess it in relation to the really consumed energy.

Experimental Full-Scale Test Cell Optimizing for Research of Novel Concepts towards Climatically Active Solar Façade Design

The passive solar test facilities have recently been created in many research centers all over the world to analyse dynamic outdoor phenomena on buildings and their components. The main objective of these research activities is primarily to evolve a methodology, improve test methods, validate numerical models and measure real thermodynamic properties of building components under outdoor climate conditions. An integration of advanced material solutions into buildings need to be investigated within specific conditions related specifically to outdoor test methods. A research project on Contemporary concepts of climatically active solar facades at the Brno University of Technology does have an ambition to create an experimental full-scale test cell for research of thermal aspects in progressive advances of future solar façade concepts exposed to the real climate conditions. This paper describes the design optimization phase preceding the test cell assembly. This phase includes the analysis of energy and thermal properties based on parametric study features. Computer simulations based on finite element and volume methods are involved in the optimization process. The proposed optimized test cell design is confronted with parametrization of typical thermal aspects to present final test cell demonstration.

Operative Temperature Predicting of a Room in Summer: An Approach for Validating of Empirical Calculation Models

Temperature stability of a room is of a high relevance to achieve an optimal level of built environment. Standardized calculation models of temperature stability are determined by international standard ISO 13792 based on recently developed empirical models whose approximations can finally be applied. It basically describes two models, however both demonstrate approaches that may not have the best conformity when confronted with the reality. Thus the research objective is to point out an applicability of given calculating models. The paper presents a validation proposal with aim to find an applicable correlation related to current methodology. Finally as result of this study, proposed approximations could demonstrate better consequence to the reality.

Thermal Bridges Minimizing through Typical Details in Low Energy Designing

Energy demand reduction in buildings is an important measure to achieve climate change mitigation. It is essential to minimize heat losses in designing phase in accordance of building energy efficiency. For building energy efficiency in a mild climate zone, a large part of the heating demand is caused by transmission losses through the building envelope. Building envelopes with high thermal resistance are typical for low-energy buildings in general. In this sense thermal bridges impact increases by using of greater thickness of thermal insulation. This paper is focused on thermal bridges minimizing through typical system details in buildings. The impact of thermal bridges was studied by comparative calculations for a case study of building with different amounts of thermal insulation. The calculated results represent a percentage distribution of heat loss through typical building components in correlation of various thicknesses of their thermal insulations.

Spectral emissivity properties of reflective coatings

Spectral emissivity properties of reflective coatings This article deals with the spectral radiative properties of coatings consisting of hollow ceramic microspheres. They were selected from the commercial coatings available in the Slovak and Czech Republics. The aim was to measure and compare their spectral emissivity properties with standard facing coatings by means of infrared spectroscopy. The measured data demonstrates that the coatings have the same radiative properties as a standard building coating. Two reflective measurement methods (DRIFT and ATR) were used for this purpose. These results have been compared, and the DRIFT method was finally recommended for determining the spectral radiative properties of the materials measured.

Cardboard Based Packaging Materials as Renewable Thermal Insulation of Buildings: Thermal and Life Cycle Performance

Cardboard-based packaging components represent a material that has significant potential as a renewable source for exploitation in buildings. This study presents the results of thermal and environmental analyses of existing packaging materials compared with standard conventional thermal insulations. Experimental measurements were performed to identify the thermal performance of studied cardboard packaging materials. Real-size samples were experimentally tested in laboratory measurements. The thermal resistance and conductivity of all the analyzed samples were measured according to the procedure indicated in the ISO8032 standard. A life-cycle assessment according to ISO 14040 was also performed to evaluate the environmental impacts related to the production of these materials. The results show that cardboard panels are a material with thermal and environmental properties on par with contemporary thermal insulations. Depending on their structure, the measured thermal conductivity varies from 0.05 to 0.12 W·m–1·K–1 and their environmental impacts are much lower than those of polyisocyanurate foam or mineral wool.

Thermal Bridges Impact on Energy Need for Heating in Low Energy Wooden House

Energy need for heating is depend on the heat loss of the builing. It is essential to minimize heat losses when designing and building energy efficient buildings. For an energy-efficient building in a cold climate, a large part of the space heating demand is caused by transmission losses through the building envelope. The low-energy buildings are enevelope construction with high thermal resistance. The impact of thermal bridges was studied by comparative calculations for a case study building with different amounts of insulation. In the low-energy buildings are envelope construction with high thermal resistance. When more insulation is used the relative impact of thermal bridges increases. In these buildings is necessary to specify each thermal bridges. This thesis deals with the influence of thermal bridges on energy need for heating in low energy wooden houses.

Thermodynamic Properties of Reflective Coatings

As a part of introducing new technologies and materials, reflective coatings are among many other materials ones, which have to be taken into account. This article presents the results of a comparative nature aiming to investigate the thermodynamic properties of selected reflective coatings on energy balance for periods of heating. In order to investigate their thermal performance at the external building surfaces dynamic outdoor testing was used. Two comparative coatings and reference standard facing coating were used for various samples. The measured data demonstrates that the representative coating consisting of hollow ceramic microspheres have the same thermodynamic properties as a standard facing coating, while the reflective coating have distinctive thermal performance effect depending on thermal insulation functions of measured samples.