AdMaS EGAR - Pozemní stavitelství


Recent Submissions

Now showing 1 - 5 of 7
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    Study of Surface Temperature Monitoring in the Field of Buildings
    (Elsevier, 2016-09-01) Slávik, Richard; Čekon, Miroslav
    Surface temperature monitoring and its aspects does have not only a useful merit for thermal analysis of the buildings and their direct or indirect implementation in virtual simulations, however is equally of highly relevant use for the field of building physics as primarily those of more complex analyzing concerning on specific thermal phenomena. The measuring of surface temperatures at the building envelopes by means of well-practiced commercial temperature sensors are typically applied whose attributes can successfully be employed especially for the field of thermal building performance aspects. In addition, besides of their certain own accuracy level and final implementation for instance as an input parameter into the simulation model, typical methods of their final application related to the opaque and transparent building surfaces and their contact and non-contact modes may have the significant influence. The paper presents a representative confrontation of surface temperature monitoring of several temperature sensors as finally compared with the form of their final application on standard vertical building surfaces. Three typical ways of installation are demonstrated on opaque and transparent building component under real climate conditions applying of commercial thermocouples, digital temperature and infrared sensors. Experimental measurement assemblies are proposed and introduced with aim to point out deviating indicators in the presented area. Representative in-situ measurements are performed and final comparability of sensors based on typical methods of their final installation is presented. An obtained result, both at existing and comparing types, demonstrates its application relations to the field of buildings. In spite of that, an additional confrontation based on non-contact regime as compared with contact ones reveals a feasible option directly concerning on building surface temperature measuring.
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    A nondestructive indirect approach to long-term wood moisture monitoring based on electrical methods
    (MDPI, 2019-07-24) Slávik, Richard; Čekon, Miroslav; Štefaňák, Jan
    Wood has a long tradition of use as a building material due its properties and availability. However, it is very sensitive to moisture. Wood components of building structures basically require a certain level of moisture protection, and thus moisture monitoring to ensure the serviceability of such components during their whole lifespan while integrated within buildings is relevant to this area. The aim of this study is to investigate two moisture monitoring techniques promoting moisture safety in wood-based buildings (i.e. new structures as well as renovated and protected buildings). The study is focused on the comparison of two electrical methods that can be employed for the nondestructive moisture monitoring of wood components integrated in the structures of buildings. The main principle of the two presented methods of the moisture measurement by electric resistance is based on a simple resistor–capacitor (RC) circuit system improved with ICM7555 chip and integrator circuit using TLC71 amplifier. The RC-circuit is easier to implement thanks to the digital signals of the used chip, whilst the newly presented integration method allows faster measurement at lower moisture contents. A comparative experimental campaign utilizing spruce wood samples is conducted in this relation. Based on the results obtained, both methods can be successfully applied to wood components in buildings for moisture contents above 8%.
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    Life Cycle Assessment of Solar Façade Concepts Based on Transparent Insulation Materials
    (MDPI, 2018-11-15) Struhala, Karel; Čekon, Miroslav; Slávik, Richard
    Contemporary architects and the construction industry are trying to cope with increasing requirements concerning energy efficiency and environmental impact. One of the available options is the active utilization of energy gains from the environment, specifically solar energy gains. These gains can be utilized by, for example, solar walls and facades. The solar façade concept has been under development for more than a century. However, it hasn’t achieved widespread use for various reasons. Rather recently the concept was enhanced by the application of transparent insulation materials that have the potential to increase the efficiency of such façades. The presented study evaluates the environmental efficiency of 10 solar façade assemblies in the mild climate of the Czech Republic, Central Europe. The evaluated façade assemblies combine the principles of a solar wall with transparent insulation based on honeycomb and polycarbonate panels. The study applies Life-Cycle Assessment methodology to the calculation of environmental impacts related to the life cycle of the evaluated assemblies. The results indicate that even though there are several limiting factors, façade assemblies with transparent insulation have lower environmental impacts compared to a reference assembly with standard thermal insulation. The highest achieved difference is approx. 84% (in favour of the assembly with transparent insulation) during a modelled 50-year façade assembly service life.
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    A non-ventilated solar façade concept based on selective and transparent insulation material integration: an experimental study
    (MDPI AG, 2017-06-08) Čekon, Miroslav; Slávik, Richard
    A new solar façade concept based on transparent insulation and a selective absorber is proposed, tested and compared with conventional insulation and a non-selective type of absorber, respectively. The presented study focuses on an experimental non-ventilated solar type of façade exposed to solar radiation both in the laboratory and in outdoor tests. Due to the high solar absorbance level of the façade, high- and low-emissivity contributions were primarily analysed. All of the implemented materials were contrasted from the thermal and optical point of view. An analysis was made of both thermodynamic and steady state procedures affecting the proposed solar façade concept. Experimental full scale tests on real building components were additionally involved during summer monitoring. An indicator of the temperature response generated by solar radiation exposure demonstrates the outdoor performance of the façade is closely related to overheating phenomena. From the thermal point of view, the proposed transparent insulation and selective absorber concept corresponds to the performance of conventional thermal insulation of identical material thickness; however, the non-selective prototype only provides 50% thermal performance. The results of the solar-based experiments show that with a small-scale experimental prototype, approximately no significant difference is measured when compared with a non-selective absorber type. The only difference was achieved at the maximum of 2.5K, when the lower temperature was obtained in the solar selective concept. At the full-scale outdoor mode, the results indicate a maximum of 3.0K difference, however the lower temperature achieves a non-selective approach. This solar façade can actively contribute to the thermal performance of building components during periods of heating.
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    Cardboard Based Packaging Materials as Renewable Thermal Insulation of Buildings: Thermal and Life Cycle Performance
    (Scrivener Publishing, 2017-04-28) Čekon, Miroslav; Struhala, Karel; Slávik, Richard
    Cardboard based packaging components represent a material with a significant potential of renewable exploitation in buildings. This study presents the results of thermal and environmental analysis 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 analysed 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 with 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.