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Thermal, Energy and Life Cycle Aspects of a Transparent Insulation Façade: A Case Study
(IOP Publishing, 2018-11-01) Čekon, Miroslav; Struhala, Karel
Research and development in the façade engineering field highlights the need for comprehensive system solutions integrating advanced materials and renewable energy use. The real performance of such solutions is highly relevant issue as they can contribute towards the European energy and environment policies: e.g. the implementation of nearly-Zero Energy Buildings required by the Energy Performance of Buildings Directive. Presented study focuses on implementation of Transparent Insulation Materials (TIMs) in a façade concept. The concept is based on sensible use of (renewable) solar energy to reduce the heating demand of buildings. The concept integrates TIMs into a Transparent Insulation Façade (TIF) based on more common ”solar wall” or “Trombe wall” systems. The study presents analysis of thermal, solar energy and environmental performance of the concept on a case study basis. Firstly, thermal analysis based on standard calculation is introduced to describe thermal and solar performance of the concepts. Secondly, energy balance calculations are used to compare the concepts with conventional façade systems. Finally, a Life-Cycle Assessment (LCA) evaluating the environmental impacts of the façade concept is introduced. The results show that the proposed concept performs better in both energy consumption and environmental impacts compared to a common facade with external thermal insulation. The TIF has higher heating energy demand than a common façade, however this is offset by up to 178 kWhm-2a-1 solar heat gains. The difference in environmental impacts (up to 80%) is also in favour of the TIF.
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.
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.
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%.
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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