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Archiv článků od 18.1.2010 do 25.10.2010

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25.10.2010
Ing. Barbora Součková

This article is referring to former article called Examination of building underground of block of flats in light of civil heat engineering [3]. It extend previous article by other variants of detail of giving thermal insulation on foundation constructions and basement parts from exterior of building. This article concentrates on solving of these others details of building underground. The type of this block of flats is the system BP-70. This article deals with differences of continuance of temperatures and water vapour pressures on various types of the foundation and basement part of a building with thermal isolation too.

11.10.2010
doc. Ing. Hana Gattermayerová, CSc., Ing. Jiří Karas, CSc.

In relation with the transition to European standards, as of March 2010 the standard CSN 73 00 35 Loading of structures becomes valid for the group of standards EN 1990 Basis of design, strength and durability and EN 1991 Actions on structures, constant, variable, extraordinary. The Czech versions of these documents are have been available since 2004-2008. The amendment in the map of snowy regions was received with a relatively high awareness. This amendment resulted in the appendixes CSN 73 0035 and BS EN 1991-1-3 Actions on snow, in effect since 1-1-2006. The current overlapping of CSN 73 0035 with CSN 1991-1-4 Actions on wind thus far, has not resulted in any critical reaction. This contribution should warn designers against an insufficient number of anchors for contact insulation, something that very often occurs. This number depends on the wind load, which in turn, is dependent on normative values. These are listed in a separate standard and are increasing, just like the snow loads.

4.10.2010
Ing. Jiří Nováček, Ph.D., Stavební fakulta, ČVUT v Praze

This paper follows the text [9] on a prediction of the Sound Reduction Index of single building structures published last year. Present paper focuses on multi-layered walls, especially on a part represented by double structures that give the higher sound insulation than single walls, having the same surface mass. However, much more complicated prediction process of the SRI of such structures is an obvious problem. This paper is based on author´s PhD thesis.

13.9.2010
Ing. Jaroslav Vychytil, ČVUT v Praze, Fakulta stavební, katedra konstrukcí pozemních staveb, ČVUT v Praze, Fakulta stavební, katedra konstrukcí pozemních staveb

In the last few years more and more construction companies have started to project and build wooden houses, some even with more than one floor. However, during the design of the structure they often forget the requirements of ČSN 73 0532, that deals with impact and noise insulation. The problem lies in the fact that, in practice, the only methods used are those to determine the weighted sound reduction values for silicate based structure, while they will fail in a wooden construction. This paper presents a computational procedure for determining the airborne sound reduction of cellular type soffits. When designing or renovating buildings a comprehensive account of all aspects should be given (construction, structural, architectural, financial and others). Nowadays the financial aspect is very crucial and therefore, more and more clients are interested in the energy performance of buildings. However, in terms of comfort of the people living in the interior the aspects of acoustics, lighting and heating are more important.

6.9.2010
Ing. Jiří Skřipský, DiS., Ing. Viktor Zwiener, Ph.D.

The diagnostics of Atelier DEK measured the tightness of 150 buildings with a Blower-door test. Roughly two thirds of the measured buildings where family houses and from them, more than 60 were built with wood-based technologies. One and two storey buildings with full wall panels and fleeting installation systems were measured, they had ventilated façades and bearing contact insulation systems. We monitored the relationship between the measured intensity of the exchange air value (n50) as determined by the Blower-Dorr test and the construction aspects. The aim was to evaluate the potential of the design principles to achieve the required airtightness. It was also our intention to identify in the different structural principles the characteristics of leakage that on them are often repeated. In this paper we present the conclusions of our analysis.

30.8.2010
Ing. Zuzana Fišarová, Ing. Karel Šuhajda, Ph.D., Ing. David Bečkovský, Ing. Radim Kolář

The paper describes the possibilities how to maintain and improve the physical properties of lightweight slab (floor structures) in the field of building physics with all of it's fundamental drawbacks throughout their erection. The thermo-technical properties are solved in conjunction with problems in the field of building acoustics together with the analysis of unknown factors like the influence of electroiont microclimate.

9.8.2010
Ing. Vladimír Galád

Sophisticated heating solutions lead to the fact that if at any given stage of the thermal insulation a TRV is properly fit and adjusted and, at the same time, a sophisticated substation solution is installed, one that will “know” how to prepare and maintain the required parameters, mainly during the heating season, then there will be nothing to renovate or solve during the lifespan of the heating station, other than adjusting the temperature and hydraulic parameters correctly.

9.8.2010
Ing. Jiří Frankl, PhD, Ústav teoretické a aplikované mechaniky, v.v.i., Akademie věd České republiky

From a large group of wood-damaging fungi, only a few species participate on degradation of wood built in various building constructions. In spite of that, these species often cause significant damage by their activity. The contribution summarizes knowledge gained during surveys of various wooden constructions of buildings in the last ten years. It describes vulnerable places of constructions with frequent occurrence of wood-damaging fungi, usual extent of damage, causes of creation and development of infestation by wood-damaging fungi and the most common directions of their further spreading. The contribution contains also statistical analysis of generic structure of wood-damaging fungi in particular vulnerable places.

26.7.2010
doc. Ing. Vladimír Jelínek, CSc.

The following contributions, which deal with this problematic, consider the impact of high heat resistance of the walling on the thermal comfort and the design of heating ventilations systems, which are still perceived, as it is the case in buildings with classical walling, therefore, to have lower thermal resistance. For instructions to formulate the effect of walling on the thermal comfort and technical equipment, a general comparison of both the following cases is made, which is simply called building with high thermal resistance of external walls for a low-energy house, and a building with classical walling parameters (e.g. housing estate from the past) as a standard house. The articles are not of exact technical nature and deal with regularly updated dependencies and sometimes refer to previously applicable legal provisions.

12.7.2010
Ing. Petr Bohuslávek, redakce

The standards ČSN 73 1901 Designing of roofs – basic provisions, ČSN P 73 0600 Waterproofing of buildings – Basic Provisions and ČSN P 73 0606 Waterproofing of buildings – Continuous sheet waterproofing – Basic Provisions have been revised in 2010. What kind of new requirements do these new standards bring? How will their approach change compared to previous regulations? We asked the people behind them about this. The current standards for roof designing have been applied since 1999. According to the proposers of the revision, the many implementations of roofs that have taken place since then have been the source of many new findings, which will be now generalised and reflected in the new standards by clarifying certain provisions or establishing new ones. Developments in European and Czech legislations and standardisations are also necessary to be taken into account.

5.7.2010
doc. Ing. Jan Kaňka, Ph.D., člen TNK 76 Osvětlení, ČKAIT Praha

The attenuation of sound wave with bends is mostly used in the design of noise walls, curtains and barriers along ways with intensive traffic (roads, rail and tram). Noise reduction from stationary sources with curtains is less common because it is always better to place the noisy device in the machine hall. This is then ventilated through a system with big enough dimensions so as to absorb sound, which then blocks the source of sound and the fan noise. Let's look at some specific installations seen in this context as well as calculations of the sound attenuation bend.

7.6.2010
doc. Ing. Jaroslav Solař, Ph.D., VŠB TU Ostrava

The article deals with the issue of unwanted condensation of water vapour on internal surface of building structures. Building and physical conditions of surface condensation of water vapour is analysed. It discusses possibilities of technical solutions leading to elimination of the mentioned negative phenomenon – change of use, adjustment of peripheral structures, reaching the required parameters of internal air by natural ventilation or through air-conditioning.

26.5.2010
Vlastimil Růžička, redakce

The Czech Council for Green Buildings and the British Council, in addition to their other activities, are organising the so-called Biohouse seminars, which include visits to selected buildings. We have attended one of them and we had a look at three interesting buildings in the surroundings of Prague. The first stop of the mini-bus was Pikovice, where an untraditional low energy wooden house, with a gazebo is located. We were expected by the investor, the architect and the projector. The second building, which had almost passive standards, we shown to us by the investor, who personally devised to ideological concept of the house in the outskirts of the village Tehov u Říčan. The third building, located in the garden of the former parish house in Sluštice u Prahy, was shown to us by a representative of the investor, who took us to the world of children. It is a beautiful wooden building projected as a pre-school in a Waldorf style.

26.4.2010
prof. Ing. Jiří Vaverka. DrSc., VUT v Brně, Fakulta stavební

The basic importance of the use of inert gas in the space between insulating glasses is its lower thermal conductivity, i.e. the ability to provide greater resistance to heat transfer. Simply put, the inert gasses (argon, krypton, xenon) have this property because in principle their molecules do not create in structure among themselves or with particles from other gasses and strictly occur in monomolecular arrangements, which significantly reduces the transfer of kinetic energy between the molecules, which is the driving force of heat. The paper analyses the variabilities of the heat transfer coefficient of Ug glasses depending on changes in the concentration of inert gases and the width of the space between insulating glasses.

19.4.2010
Roman Jirák, DECOEN znalecký ústav s.r.o., ČVUT Praha

Windows, as fillings of peripheral orifices in the structure of buildings, are a construction product, which either must be tested or verified for their compliance with the various Czech regulations and standards. One of the most important criteria that window structures must meet is the one prescribed by ČSN 730540-2 Thermal Protection of Buildings from April 2007 The compliance of the inner surface temperature factor with the standard ČSN 730540-2 must be verified separately for each orifice filling structure. So far, there are no universally applicable rules that determine which edge of glazing units can be applied to with structure. The area of the glazing joints is among the riskiest parts of the whole structure, and that is why two basic design rules were derived in order to provide an increase the internal surface temperature in that area.

15.3.2010
doc. Ing. Jan Kaňka, Ph.D., člen TNK 76 Osvětlení, ČKAIT Praha

The aim of the diurnal lightning proposal is to rectify rooms' access to sunlight, which is dispersed in the atmosphere, and to rectify the visual comfort of the users of the interior during daylight hours; i.e. the appropriate lightning conditions for visual work carried out in the interior. The specifications of diurnal lightning are formulated in IEC-730580-1 to 4. These specifications are binding because the relevant articles mentioned in the standards are determined as binding laws and decrees 268/2009 on the technical requirements for construction, 258/2000 on Public Health, 410/2005 on hygiene requirements for educational facilities and the education of children, Government Decree 361/2007 on sanitary conditions at work. In situations where controls of calculations of measurements are not possible or too difficult, it is then necessary to maximise the transparency of computational procedures. In particular, it is necessary to include all the variables that enter into the calculation (factors of brightness shading barriers, factors of transmission and reflection of light). When assessing the accuracy of the calculations, it is also necessary to require detailed descriptions of the computational models used in determining the individual components of the diurnal lightning factors.

1.2.2010
Ing. Martin Varga, Ing. Tomáš Kupsa, DEKPROJEKT s.r.o.

The ČSN EN ISO 13370 Thermal performance of Buildings – Heat Transfer via the ground – Calculation methods has been valid since 2000. Until 2008 it was concurrent with the ČSN 06 0210, which was used to floor structures on soil. After its repelling, the above mentioned ISO standards became the only applicable basis for the design and evaluation of floor constructions and the conclusions arising from their use are not yet sufficiently known among the scientific community. The use of these ISO standards introduces entirely new principles of design, which are vastly different from those that have been used for several decades. The article illustratively solves the problem of the calculation of the heat transfer coefficient from floor structures built on the ground, focusing mainly on surface (indoor) objects.

25.1.2010
Ing. Marek Ženka, ČVUT, Fakulta stavební

A commonly used procedure of calculation by (2) assigns to a transparent structure the same output value of a correction factor and total throughput screening of solar radiation on a monthly basis for the whole year. The question is to what extent this simplification is appropriate for low- energy and passive houses. The paper deals with a comparison between a nominal and detailed methods of calculating passive solar gains in situations of normal shading with normal structures and surrounding barriers, and their subsequent impact on the need for heating. The calculations have showed that even in extreme cases based on the presented examples (windows only on the Southern porch, windows just to the west with grills) for buildings with heat requirements of 15-20 kWh/m2.year, the precision of the calculations of passive solar gains are affected resulting on a higher demand for heating of up to 10%.

18.1.2010
Ing. Jan Antonín, Pavel Kopecký

From the phase of architectural studies, the building process goes through steady changes. The expert "forecast" of the thermal behaviour of these buildings will almost always be hampered by the lack of input data. However, even in such cases there are ways to provide valuable information about future features of the project. The information doesn't need to be always accurate. For example, if we asked if the building will be low-energy, it would be enough to know, among other things, if the resulting heat needed for heating will not exceed a certain threshold. We are able to identify this already at the stage where we have a clear idea about, for example, the properties of windows or the exact shape of the building. In this case, it is appropriate to extend the standard calculation procedures to be able to describe not only one chosen object, but a number of variations that may occur depending on what the we know about the building at a given moment. This presents a method for design and estimation of thermal-technical properties of family houses with very low energy requirements. The method uses the creating of variants with the Monte Carlo simulation applied to the parametric model house (monthly calculation according to EN ISO 13790 and 730329 DESERT). The results show the influence of individual characteristics of the building on the heat balance and makes it possible to optimise the overall building.


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