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In recent years, many researchers have addressed the issue of interior climate and how it affects human health. Investigations performed at schools and office buildings have found that CO2 concentrations often exceed the limit value of 1500 ppm given in Decree No. 20/2012 Coll., on technical requirements for buildings. In addition, interior space often exhibits very low relative humidity. This results in poor conditions that are detrimental to human health and not conducive to studying and work. One means of improving the interior microclimate is implementing green walls. These walls can help generate a much better climate and greatly enhance the mental well-being of the inhabitants. In addition, they greatly improve dust levels and acoustics in the room. The research compared the interior conditions in two classrooms at the Faculty of Civil Engineering, Brno University of Technology. One had a green wall installed while the other was in its original configuration. CO2 concentration, temperature, and relative humidity were measured. A survey was conducted to assess the influence of the green wall on students and teachers (mental well-being, efficiency, productivity, creativity, etc.). Results obtained thus far show that the room with the green wall provides far better interior conditions, mainly in terms of lower CO2 concentration and higher relative humidity, improving students’ and teachers’ mood and health (as confirmed by the survey as well).

Autoclaved aerated concrete (AAC) and its hygric parameters are a highly important issue in the field of building physics. There are several methods currently available to determine the equilibrium moisture content of building materials. Beside the conventional ones, new methods are constantly being introduced. This study explores the sorption/desorption properties of of three types of commercially produced AACs with three different bulk densities and demonstrates the application of the relevant methods available to characterize these parameters. The reliable characterization of the studied material was done through the conventional static approach, using the desiccator and an environmental chamber, and a new automated method of dynamic vapor sorption is implemented. The goal is to compare and identify the reliability of all methods used with respect to the efficiency of the data measurement process. Sound consistency between the results of the conventional methods and the experimental data obtained indicates the dynamic vapor sorption technique is highly reliable when measuring the equilibrium moisture content—particularly exemplified during the AAC sample testing. Therefore, the methodology developed in this study is expected to provide the reference for measuring the sorption/desorption isotherms of building materials with both static and automated techniques. [ABSTRACT FROM AUTHOR]

A conversion of shortwave to longwave radiation heat transfer in building envelope system represents an substantial part in low-energy design campaing. For that reason, an experimental test sample of a novel solar façade element based on a Transparent Insulation Material (TIM) with a selective and a nonselective absorber was developed. The investigated element is a part of an opaque lightweight structure of a building envelope. The capability of one widely used Building Energy Simulation (BES) tool is analyzed in terms of its ability to model the performance of the TIM façade element. The good consistency between the simulation results and the experimental data obtained specifically via cooling period indicates that the reference simulation model based on high emisivity of solar absorber was reliable when predicting the energy performance of TIM based façade models. However, the low emissivity of solar absorbers in the façade cavity gives rise significant limitations. They were identified concerning the BES calculation methods and modeling principles. The computational results are significantly underestimated in case of low emissivity internal surface. The methodology developed in this study is expected to provide a reference for simulating the thermal and energy performance of TIM-based building elements with different solar absorbers. [ABSTRACT FROM AUTHOR]

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 2.5 K, when the lower temperature was obtained in the solar selective concept. At the full-scale outdoor mode, the results indicate a maximum of 3.0 K 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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%. [ABSTRACT FROM AUTHOR]

Contemporary architecture and construction industry are trying to cope with increasing requirements concerning energy efficiency and environmental impacts. 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 has not 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 favor of the assembly with transparent insulation) during a modelled 50-year façade assembly service life. [ABSTRACT FROM AUTHOR]