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Archiv článků od 17.7.2017 do 20.11.2017

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20.11.2017
Ing. Josef Hodboď, TZB-info, redakce

The requirements for heating water quality are increasing with the increasing technical level of equipment from which the heating systems are assembled. Parameters of common water are therefore modified in various ways, altered to match as much as possible the desired ideal state. If these processes do not take place due to the material composition of the heating elements, damages occur. Even in a relatively short time since commissioning. The most common ways of changing water parameters are adding inhibitors, softening water and desalting water.

Analýza trvanlivosti preimyselných komínov © Imperium Obrazu - Fotolia.com
13.11.2017
prof. Ing. Juraj Bilčík, PhD., Ing. Ivan Hollý, PhD., Ing. Natália Gažovičová

Industrial chimneys are civil engineering works, which in addition to static and dynamic effects, direct and indirect loads, are also exposed to significant non-stationary environmental loads. Analysis of their durability focuses on the evaluation of vertical cracks, corrosion of concrete and reinforcement, which have a decisive influence on the resistance of the chimney's shaft with regard to the ultimate and serviceability limit states, as well as their durability.

6.11.2017
Ing. Petr Kubesa, Ing. Jiří Horák, Ph.D., Ing. Kamil Krpec, Ph.D., Ing. František Hopan, Ph.D., Břetislav Holešínský, Časopis Vytápění, větrání, instalace

This article aims to broaden knowledge about behaviour of different types of local wood-burning heaters in term of time course of heat delivery into the room. The article presents a comparison of performance of the selected heater – fireplace insert, which was gradually rebuilt and tested as stove with/without accumulation heat exchanger and closed fireplace with accumulation in different stoking regimes. In the end of the article, the measured results are compared with previously obtained hea t output course of individually built stoves.

30.10.2017
Ing. Jiří Novotný, doc. Ing. Tomáš Matuška, Ph.D.

Assessing energy performance of the building is also done from the point of view of the need for non-renewable primary energy. A common layman probably does not know what this means. At the same time, the need for non-renewable primary energy fundamentally influences the design of energy sources for heating, cooling, hot water preparation, etc. for a particular building. The need for non-renewable primary energy is one of the three main energy performance indicators of a building, and if it is assessed as too large, the building can not be validated.

23.10.2017
Ing. Jiří Matějček, CSc.

Heating systems, solar systems, primary circuits of heat pumps, etc. can be installed in the environment or exposed to operating conditions where their function must be guaranteed even at temperatures below zero degrees Celsius. In this case, pure water cannot be used to transmit heat energy. Low-setting (non-freezing) liquids consisting of a mixture of water and other substances are used to reduce the resulting freezing point to negative temperatures.

16.10.2017
Ing. Jiří Horák, Ph.D., Ing. Lubomír Martiník, Ing. Kamil Krpec, Ph.D., Ing. Petr Kubesa, Ing. Jiří Dvořák, Milan Holomek, Ing. Stanislav Buchta

Because of the emission of pollutants during the combustion of solid fuels in local household heaters (fireplaces and stoves) tightening requirements (emissions and efficiency) are gradually adopted in individual EU countries. The requirements are mainly aimed at manufacturers or importers of incinerators who have to prove their fulfillment when placed on the market. This is a different approach than hot-water boilers, where requirements are targeted not only on manufacturers and importers, but also on operators. This partly changes for the Czech Republic, where the Air Protection Act also introduces obligations for local furnace operators with a hot-water coil (part of the heat is supplied to the heating water from the source). The aim of this article is to provide an overview of valid and planned requirements and also to compare them.

9.10.2017
Ing. Imrich Sánka, Stavebná fakulta STU Bratislava, Katedra Technických zariadení budov

This study investigates the impact of energy renovation on the indoor air quality of apartment building during heating season. The study was performed in one residential building before and after its renovation. Energy audit was performed and energy certificate was calculated for the renovated and the non renovated condition of the dwelling. Objective measurements of CO2 concentration have been used for the evaluation. The average concentrations was much higher after the refurbishment. The air exchange rate was calculated, which was higher in the unrenovated apartments. This study shows that energy renovation of the residential buildings in Slovakia may reduce the quality of the indoor environment in the apartments especially in winter season.
Maintaining a healthy indoor environment requires much more intense air exchange after the reconstruction of the house as it is achieved. Although this is related to energy consumption, it is otherwise endangered by the health of the user. Reducing the thermal energy consumption of the house to the detriment of the quality of the indoor environment and the health of the users of the dwellings can not therefore be considered as a saving and can not be calculated when assessing the energy savings of the building's heating system after reconstruction.

2.10.2017
Ing. Petr Bican, Ph.D., Zdeněk Lovicar

The authors compare the measured data on the production and use of electricity produced by the solar photovoltaic power plant with the total electricity consumption in the production area of the company. The second part of the article is based on considerations about the use of overproduction of electricity for heating and hot water preparation and its economy.

25.9.2017
Ing. Petr Bican, Ph.D., Zdeněk Lovicar

The authors compare the measured data on the production and use of electricity produced by the solar photovoltaic power plant with the total electricity consumption in the production area of the company. The second part of the article is based on considerations about the use of overproduction of electricity for heating and hot water preparation and its economy.

18.9.2017
Dr. Ing. Petr Fischer, projektant se zaměřením na jednotrubkové soustavy

Investments in heating systems of apartment houses are large and still growing. New modern components of the heating system are coming to market, which are further increasing the investment. Systems become more complex and therefore more susceptible to malfunctions. One solution can be the single-pipe hot water system.

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.

© Robert Kneschke - Fotolia.com
4.9.2017
Ing. Jiří Matějček, CSc.

Although the heating water is in a non-life-saving environment, it contains a minimum of nutrients and has an elevated temperature, microorganisms can be propagated under certain conditions. Depending on their type and amount, problems with excessive occurrence of gases in the heating system, smell and corrosion may occur. The most frequent cause of the introduction of microorganisms into the heating system is the storage of pipes in the outdoor environment without their ends being blocked, and then, of course, the purity of the water that is impregnated into the system.

28.8.2017
doc. Ing. Tomáš Matuška, Ph.D., ČVUT v Praze, Univerzitní centrum energeticky efektivních budov

The paper deals with the experimental determination of heat losses of reservoirs (hot water storage tanks, heaters, heat reservoirs). It shows how the thermal loss of the tank itself, determined by the correct procedure in accordance with the standard, can be different from the loss of the reservoir connected to the thermal system.

21.8.2017
Ing. Ondřej Hojer, Ph.D., KOTRBATÝ V.M.Z. spol. s r.o.

This paper describes the method of determining the heat losses resulting from the heat transfer to the space according to ČSN EN 15316-2-1. Based on a detailed comparison of the different heating methods considered for rooms with a room height higher than 4 m, their heat-sharing efficiency is evaluated.

14.8.2017
doc. Ing. Tomáš Matuška, Ph.D., Ing. Vilém Ťopek

The article deals with the analysis of a possible solution of a non-energy residential building. The analysis shows what energy sources help to achieve a zero balance of non-renewable primary energy and what is not. In the contribution, the investment solution and the real operating costs of the energy-zero residential building compared to the current solution are shown for the selected solution and a simple payback period is set.

7.8.2017
Ing. Roman Vavřička, Ph.D., ČVUT v Praze, Fakulta strojní, Ústav techniky prostředí, Univerzitní Centru energeticky Efektivních Budov ČVUT v Praze

The article presents a concrete example of a real operational problem with the use of so-called double-walled hot water heaters. The example is aimed at destroying the reservoir of the construction system tank in the tank due to a malfunction of the operating mode.

© Fotolia.com
31.7.2017
Ing. Zdeněk Lyčka

The article summarizes the experience, the boiler control issues, boiler operating characteristics and evaluation of the boiler exchanges.

24.7.2017
Ing. Kamil Krpec, Ph.D., Ing. Jiří Horák, Ph.D., Ing. František Hopan, Ph.D., Ing. Petr Kubesa, Časopis Vytápění, větrání, instalace

With the advent of the EU Commission Regulation 2015/1189 on the ecodesign of the solid fuel boilers, there are beginning to emerge questions and ambiguities regarding the conversion of the efficiency and emission values reported in the protocols from the testing laboratories. The EU Commission Regulation introduces new evaluation of boilers specifications, which are seasonal efficiency and seasonal emissions. The calculation of the seasonal efficiency takes into account also the electricity consumption and potential production of electricity in a cogeneration boiler. The article mentions the formulas for the conversion of the boilers specifications according to the requirements of the mentioned Regulation. It also includes a model example.

Otopné těleco, ilustrační obrázek © Robert Kneschke - Fotolia.com
17.7.2017
Ing. Jakub Spurný, Ing. Michal Kabrhel, Časopis Vytápění, větrání, instalace

The article deals with influence of heat losses in distribution system and related cooling of heating water on the design of two-pipe counter-flow heating system. On the numerical reference model was studied the effect of distribution heat losses and cooling of the heating water on the heating system with mass flow rates designed by conventional calculation. In the following part were compared results from conventional design with design based on the numerical model which considered heat losses of the distribution system and cooling of the heating water. Mass flows rates were chosen as the compared variable, as they affect both thermal and pressure behavior of heating systems.


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