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Výsledky měření koncentrace CO<sub>2</sub> v&nbsp;ložnici při přirozeném větrání oknem

Results of carbon dioxide concentration measurement in the bedroom

10.9.2018 | Ing. Petr Bohuslávek, redakce
The measurement of carbon dioxide concentration was made in my bedroom in February 2018 within one week. CO2 concentration during the night is evaluated under different ventilation modes. The results show a significant effect of ventilation on air quality. They prove that only natural ventilation through tight windows in current developmental residential buildings is inadequate.
2 comments, last 17.09.2018 10:45

Innovative methods for serial energy retrofitting of residetinal buidlings – examples from the Netherlands

20.8.2018 | Ing. Antonín Lupíšek, Ph.D., ČVUT v Praze, pracoviště UCEEB
The paper describes actual trends in serial deep energy retrofitting of buildings in the Netherlands. A set of photographs presents several Dutch pilot projects of energy retrofitting of post-war family houses in Heerlen, Melick and Soersterberg to net zero energy level and of one multifamily residential building in Arnhem to nearly zero energy level. The retrofitting projects were made utilizing prefabricated thermal insulation wall modules with timber structural system (that included new windows) and prefabricated roof panels. All presented projects also featured replacement of energy sources and in case of the family houses also installations of photovoltaic systems replacing roof tiles.

Roof Windows for Passive Buildings

7.5.2018 | prof. Ing. Jan Tywoniak, CSc., ČVUT Praha, pracoviště UCEEB
The paper presents the building-physical context of the use of roof windows in buildings with very low energy demand. It shows their relatively significant influence on the total heat loss of a single family house and the consequence of the specific disadvantageous set-up in the pitched roof. It is shown that the thermal transmittance should not exceed 0.7 W/(m2K) with a strict limitation of thermal coupling in the connection to the roof. In the second part, the paper shows the positive effect of the slanting of the inner lining on the quality of day lighting.

PVB and EVA temperature and loading ratio shear modulus assessment

30.4.2018 | Ing. Tomáš Hána, doc. Ing. Martina Eliášová, CSc., Katedra ocelových a dřevěných konstrukcí, Fakulta stavební, ČVUT v Praze, Ing. Klára Machalická, Ph.D., Ing. Miroslav Vokáč, Ph.D., Kloknerův ústav, ČVUT v Praze
In contemporary architecture there are many various types of glass load bearing elements such as beams, slabs, floors or even columns. Most of these elements are made of laminated glass. Individual glass plies in the panel are bonded with polymeric interlayer providing shear forces transfer between the plies. This transfer primarily depends on the interlayer´s stiffness which is ambient temperature and static load duration dependent and is the subject of a current research. Considering the fact that shear stiffnesses of most interlayers have not been experimentally verified yet, civil engineers are compelled to design laminated glass structures on the safe side. This approach results in robust and uneconomic structures. This paper deals with the initial PVB (Trosifol BG-R-20, Trosifol Extra Strong) and EVA (Evasafe) initial shear modulus assessment depending on the temperature and loading ratio, these interlayers shear stiffness comparison and important results summary.

A light pipe prototype temperature testing

5.2.2018 | Ing. Ayodeji Omishore, doc. Ing. Miloš Kalousek, Ph.D., VUT Brno, Fakulta stavební. Ústav pozemního stavitelství, Petr Mohelník, Centrum informačních technologií VUT Brno
A light pipe prototype with a concentrating mirror parabolic head was tested for temperature profiles under solar radiation. The purpose of the testing is to find maximal temperature and estimate potential risks with overheating in the position of the pipe installation into roof structures and materials.
Složitá rekonstrukce staršího bytového domu

Complicated Reconstruction of an Older Multi-family House

18.12.2017 | Ing. Jan Koláček, Ph.D., Ústav betonových a zděných konstrukcí, FAST VUT v Brně, doc. Ing. Zdeněk Bažant, CSc., Ústav betonových a zděných konstrukcí, FAST VUT v Brně,
In December of year 2016 has been finished the extensive reconstruction of the multi-family house built in the thirties of last century, located in the district Žabovřesky of the city Brno. Investor with architect desired the modern appearance of interior and facade of the house, which involved a number of difficult renovations and new structures that had to be consulted with structure engineer. The significant steps of the reconstruction of the multi-family house are described in detail in this contribution.
&copy; victor zastol'skiy - Fotolia.com

Differences in the Traditional and New Approach to the Daylight Evaluation of Buildings

11.12.2017 | Ing. et Ing. Lenka Gábrová, Ústav pozemního stavitelství, Vysoké učení technické v Brně, Fakulta stavební
The article deals with a comparison of a room area size which is suitable for reading and writing according to two daylight evaluation criteria. The first one is the daylight factor which is determined under the CIE overcast sky model and it is traditionally used for quantitative daylight evaluations of buildings. The second compared evaluation criterion is the daylight autonomy which is one of new daylight metrics whose calculation is based on daylight illuminance values throughout the year and for a specific location.
Fall colours in the Eastern Townships in Quebec, Canada &copy; mbruxelle - Fotolia.com

Hardwood from North America and its use in Eastern Europe

4.12.2017 | Dr. Eva Haviarová, Purdue University, Department of Forestry and Natural Resources, Purdue, Ing. Milan Šimek, Ph.D., Mendelova univerzita v Brně, Lesnická a dřevařská fakulta, Dr. Henry Quesada, Virginia Tech University, Department of Sustainable Biomaterials
In the last two decades, the US hardwood industry has experienced an important increase in their exports to key markets in Southeast Asia, and Western Europe. However, the export to Easter Europe is currently limited. In these emerging economies, production of furniture and many different kinds of wood products are on the rise. Favorable labor costs, progressive design, and available material resources are key factors that sustain the growth of these industries. The forest products industry is also significant consumer of hardwood lumber. Despite the fact that Easter European countries have its own hardwood material resources, the rapid industry growth, increased sustainability practices, and increased demand of high quality material may require the need for additional material sourcing.

Case study of heating savings due to glazing with increased solar factor

11.9.2017 | prof. Ing. Ivan Chmúrny, Ph.D., Stavebná fakulta STU Bratislava, Katedra konštrukcií pozemných stavieb
Case study of the energy need for heating of a family house depending on the thermal and optical properties of windows with triple glazing and the quantification of heat demand for heating.
Bytové domy v Praze &copy; TZB-info

What are the common parts of residential buildings in the Czech Republic?

19.6.2017 | Ing. Petr Bohuslávek, redakce
The definition of what is a common part of a residential building is essential especially when modifying the building structures and eliminating defects that affect both a common part and residential units. How common parts are defined affects who finances the modifications and reconstructions of such structures and parts. The definition of common parts is based on the new Civil Code (No. 89/2012 Coll.) and on the already abolished Act on Ownership of Housing (No. 72/1994 Coll.).
1 comment, 12.04.2018 22:40

Securing brick buildings against the influence of technical seismicity

29.5.2017 | doc. Ing. Jaroslav Solař, Ph.D., VŠB TU Ostrava
The contribution dealst with the problematics of statical defects, or more precisely with the formation of cracks in the brickwork caused by the effect of technical seismicity. It further deals with the construction principles which can be used when designing reconstruction of buildings which are located within the reach of the effect of technical seimicity. The problematics of historical buildings and conservation areas is also mentioned.

The Effect of Local Thermal Bridges on Thermal Performance of Curtain Walling

17.4.2017 | Ing. Roman Jirák, Ph.D., Ing. Petr Jaroš, Ph.D., DECOEN znalecký ústav s.r.o.
U-value calculation of curtain walling is one from more difficult calculation in the civil engineering. In according to trend of increasing glassing surface of building envelope, the curtain walling has big influence on thermal behaver of buildings. This is why it is necessary to calculate the thermal insulation properties with special attention. This article focuses on influence of different local thermal bridges on curtain walling U-value.

The invention, patent or utility model - who should sort?

8.3.2017 | Ing. Zdeněk Lyčka
The article explains the differences between the invention patents and utility model from the perspective of Czech legislation. Also highlights the confusion individual categories and purposeful fraud by producers and sellers of equipment.
1 comment, 08.03.2017 07:44

Nearly Zero-Energy Buildings

9.1.2017 | Ing. Jan Antonín, Ph.D., EnergySim, Ing. Magdalena Purkrtová
For more than a year, a nearly zero-energy standard has applied to certain buildings. In the Czech environment, specific technical parameters for such buildings have been known for three years. And for over six years, the Directive on energy performance of buildings has been in force, imposing the obligation upon EU member states to introduce this standard.

Nevertheless, it seems that for many experts, including those in the field of energy, this term is still quite unclear. Many imagine buildings coated with photovoltaic modules from the ground to the roof, buildings which are better than passive ones or buildings which are self-sufficient, i.e. completely independent of public energy networks. Given the fact that the concept of a nearly zero energy building is very distant from such notions, and because this standard will soon become obligatory for all buildings, including small family houses, let's have a look at what a nearly zero-energy building really is.
6 comments, last 12.01.2017 14:25

Sound insulation acoustic tests in laboratory in situ

4.4.2016 | Ing. Pavel Rubáš, Ph.D., Technický a zkušební ústav stavební Praha, s. p.
Windows and door designed for noise reduction can be measured by two methods: laboratory airborne sound insulation (EN ISO 10140) and in-situ airborne sound insulation (EN ISO 104-5). The in-situ method mandates for averaging results of measurements taken in surface of tested samples for specific angles of incidence. Furthermore, the article presents some original formulas which could be applied for Rw improvement if the door or window does not reach a minimum requirements or if there are specific requirements for noise reduction. During the measurement of in-situ airborne sound insulation on installed doors or windows, the result can be contaminated by some specific factors like geometry, sizes etc., compromising the compatibility with the laboratory results. It has been noticed how these practical problems, jointly with the acoustical design in the presented formulas, can significantly increase the laboratory values of the product. Results of in situ tests are discussed in comparison with results obtained through a traditional tests performed in the lab.

A questionnaire survey of the state of school buildings

22.6.2015 | Ing. Marek Begeni, doc. Ing. Vladimír Zmrhal, Ph.D., ČVUT v Praze, Fakulta strojní, Ústav techniky prostředí
The article describes a questionnaire survey for mapping the state of school buildings, with a focus on the indoor environment.
1 comment, 22.06.2015 16:05

Defects occurring when renovating opening panes of buildings in preservation zones

8.6.2015 | Ing. František Stránský
In buildings registered in preservation zones the preservationists require keeping of the division and shaping of the opening pane girts and respecting of the original look of the facade. Keeping the girt profile, it is nowdays permitted to glaze the window wings using insulation glass. The manufacturers of windows still make many mistakes affecting not only physical characteristics of the opening panes but also their durability – life time.

The methodology for estimation of the thermal factor at the inner surface in the corner of glazing

1.6.2015 | Ing. Roman Jirák, Ph.D., Decoen v.o.s.
The surface temperature as one of the most watched parametres of the opening panes and light enveopes not only in the Czech Republic is being assessed in a view of risk of water vapour condensation, or more precisely in a view of their health and a hygyenic flaws and ecologically sound environment where inbuilt. The mening is determination if the structure is suitable for the marginal conditions or whether is necessary to choose another structure.

The methodology for estimation of the thermal factor at the inner surface in the area of glazing groove

18.5.2015 | Ing. Roman Jirák, Ph.D., Decoen v.o.s.
The surface temperature as one of the most watched parametres of the opening panes and light enveopes not only in the Czech Republic is being assessed in a view of risk of water vapour condensation, or more precisely in a view of their health and a hygyenic flaws and ecologically sound environment where inbuilt. The mening is determination if the structure is suitable for the marginal conditions or whether is necessary to choose another structure.
5 comments, last 26.05.2015 13:08

Double window – issues of design and implementation of replacement windows with recessed external lintel.

11.5.2015 | Ing. Petr Pohl, projektant pozemních staveb a rozpočtář, jednatel stavební a obchodní firmy
In the article, I would like to draw attention to the issue with an outside window lintel on existing double glazed windows. The lintel is mounted below the other lintel and can therefore when replacing windows in modern window to form a problem. The article presents possible solutions window lintel. The most appropriate way is a solution that includes the total renovation of the building envelope with the replacement of windows.
2 comments, last 11.05.2015 23:09
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