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Hygrothermal response of building components
Slávik, Richard ; Šťastník, Stanislav (referee) ; Vertál´,, Marián (referee) ; Kalousek, Miloš (advisor)
This dissertation thesis is focused on the study of simultaneous transport of heat and moisture in building components. First, the introduction briefly summarises current international state of the art in assessment and evaluation of building components focused on moisture. Besides description of methodological approaches and analysis of differences between them, the approaches are modelled using examples which help to identify their properties and explain the application framework of the methods. These examples do not only illustrate the procedures; they also indicate their limits and identify the pitfalls of models’ application in comparison with each other. Next, the thesis includes basic introduction to material parameters necessary in numerical modelling. Moreover, solutions to questions from the assignment are discussed from the point of view of the theory of heat and moisture transport. To fulfil the thesis’ objectives, theoretical analysis and calculations were implemented. Calculations were carried out not only by well-known methods, but also using an own-developed complex algorithm which implements simultaneous heat and moisture transport modelling based on finite element methods and which allows to implement nonlinear behaviour of material properties. Furthermore, the thesis contains description of and results from two experiments. A brief description of an electronic device developed and used for the experiments is included. Experimental results are confronted with both simplified and advanced theoretical models. At last the thesis concludes with discussion of acquired findings, brief summary of potential contribution of this work to the field of building science and engineering practice, and indication of the directions for further development.
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Study of utility properties thermal-reflective insulations in the buildings
Holeček, Dominik ; Skříček, Darek (referee) ; Šťastník, Stanislav (advisor)
The diploma thesis is partly dedicated to energetic efficiency of buildings and describes possibilities how to evaluate energetic efficiency of buildings in the Czech Republic. We also get to know with distribution of thermal insulators by material base and use in construction. There are also mentioned methods how to determine thermal insulations characteristics of heat insulations, so called heat conductivity coefficient. The last and the crucial chapter of theoretic part is dedicated to thermal-reflective insulations. There are mentioned some of the basic characteristics of insulations, material composition and heat transfer mechanism in their structure as well. Practical part describes measurement of thermal resistance of chosen samples of thermal-reflective insulations per measuring device on the principal of Hot Box method. In the next step was determined emissivity of aluminium foils which forms the surface of chosen samples of thermal-reflective insulations. In the end of thesis are defined possibilities of use thermal-reflective insulations in building structures especially in passive and low-energy buildings in climatic conditions of the Czech Republic.
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Modification of silicate materials for floors
Šlechtický, Luboš ; Ing. Miroslav Šťenko, Ph.D., LB Cemix (referee) ; Šťastník, Stanislav (advisor)
The thesis is devoted to the issue of flooring materials, cement and plaster. In the first part are discussed general properties and general requirements for flooring, as well as presents the most important properties of selected flooring materials. The work is dedicated to the modulus of elasticity, adhesion to the substrate and strength parameters of the tested materials. It also evaluates the effects of redispersible polymer powders in silicate compositions intended for floors.
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Development of environmental friendly materials
Peterková, Jitka ; ,, Milan Machatka, (referee) ; Plachý, Jan (referee) ; Šťastník, Stanislav (referee) ; Zach, Jiří (advisor)
Increasing demand for new progressive construction materials requires development of modern environmentally friendly materials with excellent end-use properties and reasonable price. One of the main objectives of material research in building industry is using renewable resources of raw materials of industrial waste for development of new construction materials. Current trend of thermal insulation of building constructions results in development of environmentally friendly insulation materials based on renewable material resources from agriculture and stock farming, which could became alternative for current common use insulation materials in the future. The thesis describes research and development of insulation materials based on natural fibres of agricultural origin; in particular fibres of hemp, flax and jute. Hydrothermal behavior of developed materials is studied including computational simulation of behavior of researched materials after building in the construction.
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Study of acoustic properties of enclosed rooms
Kovařík, Filip ; Fišarová, Zuzana (referee) ; Šťastník, Stanislav (advisor)
The bachelor thesis deals with the acoustics of enclosed spaces, its behaviour and impact on the clarity and quality of presentation. Here is written transmission of acoustic energy, behaviour of spatial and building acoustics, which builds their diagnostic methods. The work also includes legislative requirements stipulated by the acoustics of enclosed spaces and the achievement of these requirements using different types of acoustic absorption capacity of materials, applications, and more specifically their basic properties. In the experimental part, the measurement of reverberation time in a selected room and the adaptation of acoustic properties so that attained legislative requirements
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Assessment of ventilated floors construction
Jurka, Jiří ; Kmínová,, Hana (referee) ; Šilarová,, Šárka (referee) ; Šťastník, Stanislav (referee) ; Škramlik, Jan (advisor)
Air insulation, especially its efficiency, is often underestimated and most often it is recommended as combination of several methods by our experts. It is known that flowing air used to eliminate excessive humidity in lower construction is insignificantly promoted. Already our ancestors in ancient Rome had experience with implementation of air insulations. However, nowadays such design is connected with many doubts and it forces us to use sense, especially knowledge of construction physics. So it urges higher technical precision when designing functional ventilation system. Each building is actually a unique object, with regard to its position and used properties, that is why certain natural conditions must be accepted when designing. It is more complicated and figuratively speaking it can be written in c. 20 equations of twenty unknowns. Other problems arise in unknown coefficients to individual parameters and their effects. From another point of view it is the issue of changing air during the day, passing fronts, annual cycles and all of these in relation to internal environment of the building, materials used in the construction, land properties of rocks, and last but not least, relation to the terrain around the building. Then there are the effects of the building's altitudes etc. In total they are cycles with sine character of dampening and drying. The thesis discusses how to test the functionality of AIR insulations designed for the floor ventilation in historic buildings and follows on from the previously published articles. A flow analysis is being performed on an object of the city of Žirovnice which has been registered in the list of cultural monuments and was built as a brewery in the years 1589-1592 on the site of an older medieval building. This article brings new air-flow element. The aim of the article is to analyse in detail the air flow in a specific floor void with the aid of modern CFD programs and experimental measurements using the ALMEMO
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