More than 15 years TZB-info is focused to perspective equipment for building services with priority in heating. During this period the main question: "how to heat" shifted to question: "how to reduce heat loses". For example France is planning for new buildings only passive standard, and begining 2050 only so-called quasi-zero buildings. In Czech Republic one of significant impulses is subsidy program Zelená úsporám (Green for savings). Technical solutions are widely known in professional community, unfortunately high investment cost and long payback time are the main barriers for broader expansion of the solutions. Folowing article is the first from a serie focused to long time planing of reduction of energy consumption in the Czech Republic. From two ways - to prospect new energy sources or to reduce energy consumption - the second needs no to destroy another villages or towns.
How can heating for Czech homes be assured while at the same time get rid of the dependence on dirty coal and Russian gas? This is answered by the scholarly study by the DUHA movement – Clean Heating. The solution is based on a combination of investments on home insulation, solar collectors and biomass heating plants. Very important are the new standards for developers and provisional supply of coal from the Bílina mine. The calculations are based on those from the Pačes Commission. There are many opportunities. Increasing the energy efficiency of builings – i.e. insultaions – and the heating potential from renewable sources represent more than 300 million gigajoule. This surpasses the total current heating consumption of Czech homes. The possibilities of insulating Czech homes are also five and a half times higher than the controversial expansion of the coal mines around Most, which is linked with a further devastation of the North Bohemian landscape and the demolition of towns.
Archiv článků od 4.1.2010 do 19.4.2010
This article extends the article "Ventilation with heat recovery in flat - yes or no?" and it is concerning with pressure forced ventilation with electric heating coil. This unit includes ventilator, which sucks the external air in from the façade. The electric heating coil with the power of 250 W preheats the external air which is distributed to the rooms with the air distribution system. Nowadays there are a lot of these units on the market that differ in air volume and heating power. The aim of this article is to investigate whether this unit ensures good air quality and what are the costs. The paper was made within the framework of the R&D project performed by the experts in the company EkoWATT, Czech Republic. R&D project VAV-SP-3g5-221-07 is supported by the Ministry of Environment.
Today we have detailed, scientifically based evidence tested in practice, revealing that the construction of new buildings and the renovation of old ones can reduce their energy consumption to values lower than 10% of the current average. This ability of architects, planners, construction workers and companies has arrived just in time to help us avoid the worst consequences of climate change.
Overcoming conservative attitudes is a problem in passive constructions. Sometimes it is necessary to find solutions that are not linked to experiences with the established practice. Moreover, if a structural engineer categorically declares that “such solution can not be signed”, the architect has no other choice than to find a compromise. The article shows some inspiring examples from practice.
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.
The basis of any sort of traditional analysis of wooden objects is a visual survey, which is among the simplest and oldest non destructive methods used in technical construction surveys. Allows to detect biotic surfaces as well as any visible mechanical damage of the wood. Of course, a problem occurs when it is necessary to accurately define the total damage to the individual elements of the construction, in other words, identify the extent of the internal damage, locate the limit between the healthy and already damaged parts, eventually, determine the mechanical and physical properties that designers require as a basis for projecting the remediation measures.
On the beginning of the nineties the various technologies of wood buildings, especially of assembled types, developed. Although in the present time wood buildings have already their acknowledged place even in our country in spite of that we can meet their failures predominantly at the elevational planary wooden facings of load-bearing wooden framing. One such case is also south plywood- facade of family house in Middle Bohemia.
The author deals in his article with possibilities of a quality control with elements of intelligence. He passes on the readers by way of very precise, factual and interesting form his practical experiences from the area of control systems and draws attention to frequent mistakes that occur during the designing and implementation phases.
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.
As of the 1st Octo 2009 is in force in the Slovak Republic the decree 311/2009 Z.z., which lays down the details for he calculation of the energy performance of buildings and the contents of the energy certificate. It is a binding document resulting from the law 555/2005Z.z., in which the Directive 2002/91/EC on the energy performance of buildings is implemented.
Nowadays the ventilation and indoor air quality is a main issue because the quality of the interior environment is in focus of occupants. The main reason of interests is that the new windows are leak tight and natural infiltration is low as well as IAQ. Without the ventilation system the CO2 concentration is above the healthy standard (1200ppm). To achieve this CO2 level demands a lot of energy and to supply low temperature from outside directly cases also unsatisfactory thermal comfort. The ventilation with heat recovery is one of the possible solutions for energy savings. In article the deep economyy&energy calculation was performed by using building performance simulation tool IES<VE> and suggestion for manufacture was given. The paper was made within the framework of the R&D project performed by the experts in the company EkoWATT, Czech Republic. R&D project VAV-SP-3g5-221-07 is supported by the Ministry of Environment.
The article is dealing with a quality of living on the block of flats and it reveals innovative approaches of the retrofits. It tries to serve inspiration and solutions of sustainable potential of such building retrofits from the architectural point of view. Find attached case study of architectural solutions of complex block of flats retrofit. The three presented approaches represent various ways of possible solutions.
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.
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%.
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.
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.
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.
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.
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