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Archiv článků od 9.11.2009 do 8.2.2010

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8.2.2010
Ing. Miroslav Kotrbatý

How to define an intelligent industrial facility? In addition to achieving adequate micro-climatic conditions in the working area (not just heating), other technological conditions are also considered, both in the production processes themselves and in the implementation of energy systems, and consequently, operation and maintenance costs. All this with minimal consumption of all forms of energy, regardless of their source.

1.2.2010
Ing. Vladimír Valenta

For gas appliances, which are usually hot-water boilers and water heaters with atmospheric burners, combustion air is drawn from room where the appliance is located. The room gets a draft combustion air and exhaust gas path, i.e., duct and chimney, which creates a vacuum. In the paper, relations are given first to determine the quantity of flow of combustion and ventilation air, both cross-sections for dimensioning of air and exhaust gas paths. When sizing the exhaust gas path it should not be forgotten that some of its draught must be reserved for the combustion air, and that is why the whole thing is called exhaust air path. The best natural ventilation draft, called aeration, must be provided for the rest of the appliances.

1.2.2010
DI (FH) Erich Draxler, Ing. Peter Matej

The article describes a specific installation. This heat pump is installed in a family house in Pinkafeld, Burgerland, Eastern Austria. According to the recorded data, the energy flow of the heat pump was evaluated and the seasonal values of the heating factor in the hot water were determined during a period of one and a half years. The results of heat pump's water antifreeze mix show that the water heating corresponds to current energy demands and economical operation.

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%.

25.1.2010
Ing. Václav Matz, Ph.D.

The paper presents the possibility of heating regulation by using of zoning regulation systems. The paper describes the main functionality of zoning wired a wireless regulating systems. Detail description of wired and wireless zone systém differences is mentioned. By using of zone regulating systems it is possible to reduce heating costs and improve comfort in our homes.

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.

11.1.2010
J.V.Ráž, DiS.

This completes a series of articles dealing with modifications in heating systems in residential buildings. It contains thus far unpublished data on the impact of setting valves for heat savings, explains the causes of insufficient performance in heating systems and provides completely new project documents.

11.1.2010
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.

7.1.2010
Ing. Jan Hrdlička, Ph.D.

We kindly invite you to the international conference Energetics and biomass 2010 held under auspices of the Dean of the Faculty of Mechanical Engineering at CTU in Prague prof. Ing. František Hrdlička, CSc., on 10. - 12. February 2010.

4.1.2010
Ing. Zuzana Mathauserová

The author draws attention to the deterioration of the quality of indoor environments in flats where the original windows have been replaced by modern, tight windows, which although improve the flat's energy balance, they also limit the possibilities for ventilation. Moisture that has not been ventilated accumulates in the flat, which leads to mould growth, and in the case of gas appliances, there are also exhaust gases, which are are toxic substances that lead the health problems, intoxications and even death. In the Czech legislation there aren't sufficient basis for an unambiguous determination of the requirements for the quality of the indoor environment of flats, including the requirements for their security, i.e. ventilation. The information can be found in selected European Standards, the author cites ČSN EN 15251.

4.1.2010
Ing. Jiří Buchta, CSc., předseda sekce plyn ČSTZ soudní znalec - technické obory různé se specializací plynové zařízení (topné a technické plyny), CTI ČR

New systems with many advantages are constantly being developed for the construction of gas pipelines. They include, for example, easy installation, specially in inaccessible areas; time saving installation with a minimum number of connections, corrosion resistance, bends without fittings or a complete system of elements for a sepcific technology. The following article deals with the ALPEX system.

4.1.2010
prof. Ing. Jan Tywoniak, CSc., ČVUT Praha, pracoviště UCEEB

We can observe in the Czech press a significantly higher frequency of expressions suchs as passive house or energy-efficient construction, specially in connection with the subsidy program “Zelená Úsporám”. However, the reality is that the number of passive houses built is very low, moreover, in some of the so called passive houses there can certainly be doubts about their actual properties.

28.12.2009
Z publikace Prevence nehod, havárií a požárů ČSTZ

Many safety devices are used on gas pipelines and appliances. They are devices that control various parameters and respond in the event of non-compliance. The following section will describe only those devices that have a major impact on the safety of gas appliances, about which every operator and user should have at least basic information.

21.12.2009
Ing. Miroslav Kotrbatý, Ing. Zuzana Kovářová, Ph.D., Ing. Ondřej Hojer, Ph.D.

A number of important factors influence the design of heating of large-scale buildings. It depends on the way of heating, the dimensions of the building, the influence of technology and the location of the energy equipment. The key is how these factors affect the thermal comfort of a person.

14.12.2009
Tomáš Králík

The concentration of greenhouse gases in the atmosphere has been dramatically rising for the past 150 years. This fact and the possible link between GHG concentration and rising temperature of the Earth caused that the reduction of greenhouse gases has recently emerged as widely discussed issue.
First step to cut CO2 emissions is to identify countries with the highest contribution to the worldwide emissions. From this point of view the emissions of China and USA are very similar.
However the information about absolute CO2 emissions per country is not fully correct for most of comparisons. Much better is to compare CO2 emissions per capita. From this point of view, which comes from idea that every people have the same right to consume the natural resources and produce waste, the emissions of China are much lower than that of the USA.
Information about CO2 emissions is relatively simple indicator. There are more complex indicators that should be used in case of sustainable development assessment.

23.11.2009
Ing. Josef Slováček

In this article, the author deals with the problematic of heat pumps within the “Zelená Úsporam” subsidy scheme, summarising the developments in the program and pointing to some weaknesses in the assignment of each device to the list of technologies and products.

16.11.2009
Bronislav Bechník, Radim Sroka

In the 1970's the interest in renewable energy sources increased considerably due to the energy crisis. At that time, the fist extensive and reputable studies were published, which talked seriously about the fact that conventional energy sources are exhaustible. The Czech republic adopted its first energy policy in 1992 in agreement with the regional environmental limits of coal.

9.11.2009
Ing. Jan Hrdlička, Ph.D., Erika Santlerová

The article deals with real experiences of growing of an energetic crop - the sorrel. There are described four selected locations concerning the crop production and applied treatment, including future outlook. The article also includes the price estimation of energy of 1 GJ from the sorrel, based on available data.

9.11.2009
J.V.Ráž, DiS.

The second article on heat saving when adjusting heating systems is focused on the importance of good transfer of heat between external and internal networks. including the effect on the activation of temperature sensors and economical operation of dynamic heating systems, including the effect on the activation of temperature sensors and high-economy operation of the dynamic heating systems (thermostatic valve reverse curve, the dependence of operating parameters on the system differential pressure and problem solving of the central heating supply thermal hydraulics)


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