Archiv článků od 10.4.2017 do 17.7.2017

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Effect of Heat Distribution Losses and Cooling of Heating Water on Design of Heating System

17.7.2017 | Ing. Jakub Spurný, Ing. Michal Kabrhel, ČVUT v Praze, Fakulta stavební
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.
7 comments, last 19.07.2017 10:06

Law and expert: Aerating of heating systems

10.7.2017 | Ing. Jiří Matějček, CSc.
Revealing the cause of a faulty heating system in a residential building by over-aerating it can be far more complex than it appears at first glance. The impetus for the expert opinion was the complaint to the heating system operator that one riser of the heating system was repeatedly aerated and the heating element on the last floor was decommissioned.

Thermal Stress and Noise Aspects of the Pipeline Networks Operation

3.7.2017 | Ing. Roman Vavřička, Ph.D., ČVUT v Praze, Fakulta strojní, Ústav techniky prostředí, UCEEB - Univerzitní centrum energeticky efektiních budov, ČVUT v Praze, Časopis Vytápění, větrání, instalace
The paper is focused on the issue of the pipeline networks dilatation. From the perspective of the designer, it is a very simple and well-documented issue. However, as is shown in the article, if the basic requirements are not met when designing the pipeline networks, the results can be quite fatal.
1 comment, 06.07.2017 10:41

Is it possible to use the unused chimney vents to install drainage pipelines?

26.6.2017 | Ing. Jakub Vrána, Ph.D., Ústav TZB, Fakulta stavební VUT v Brně, Ing. Waltr Sodomka
The unused chimney flue or strong wall of the chimney body offers the possibility of using it for conducting pipes etc. It is a prerequisite to keep the flue gas safety and operating mode of other installations. The article highlights the important factors of a possible decision.

Verification of Function and Effect of Return Water Temperature Control on a Solid Fuel Boiler in Connection with a Thermal Storage Tank

19.6.2017 | Ing. Jiří Horák, Ph.D., Ing. Lubomír Martiník, Ing. Kamil Krpec, Ph.D., Ing. František Hopan, Ph.D., Ing. Petr Kubesa, Ing. Vendula Laciok, Ph.D., VŠB-TU Ostrava, Výzkumné energetické centrum, Časopis Vytápění, větrání, instalace
This article deals with verification of function of Laddomat 21 (which mixes supply heating water with return water), verification of the time needed to heat up the thermal storage tank when using Laddomat with different thermostatic cartridges (required temperature settings) and effect of using this system on the pollutants emission in the flue gas.
1 comment, 19.06.2017 11:28
Bytové domy v Praze © 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.).

Law and Experts: Lack of hot water with a double-jacket heater

12.6.2017 | Ing. Jiří Matějček, CSc.
The article presents a concrete example of a real operational problem with the use of so-called double-walled hot water heaters resulting from the heat-technical properties of such water heaters.

What parameters must meet the heating boilers for solid fuels? Legislation in the Czech Republic and Europe in 2017

5.6.2017 | Ing. Jiří Horák, Ph.D., Ing. Lubomír Martiník, Ing. Kamil Krpec, Ph.D., Ing. Petr Kubesa, Ing. Jiří Dvořák, Ing. Milan Holomek, Ing. Stanislav Buchta, Strojírenský zkušební ústav, s.p., BRNO, www.szutest.cz, Ing. František Hopan, Ph.D., VŠB-TU Ostrava, Výzkumné energetické centrum, Časopis Vytápění, větrání, instalace
Since the combustion of solid fuels in heating boilers is attended by emissions of pollutants, in individual EU countries are gradually adopted different tightening requirements (emission and efficiency), which the appliance must meet. Requirements are targeted both the producers or importers of the combustion devices and theirs' operators. The aim of this article is to provide an overview of current and oncoming requirements and also show their comparison.

Law and experts: Destruction of a solar thermal collector

29.5.2017 | Ing. Jiří Matějček, CSc.
The expert analysis reveals the cause of the mechanical failure of the solar collector as a result of non-adjustment of the control valves control to the operating states of the system. Simultaneous adjustment of the control valves eliminated the safety device from the function, when the pressure increased excessively and the collector leaked.

Changes of Flow Rate in the Counter-Flow Two-Pipe Heating System

29.5.2017 | prof. Ing. Jiří Bašta, Ph.D.
The paper seeks to provide a comprehensive view of counter-flow two-pipe heating system from the design perspective of the temperature parameters and related small or large flow rate through the system. It analyses the work of the thermostatic control valves, zone valves and riser valves in systems with small and large flow rate and on the basis of the analysis it evaluates their advantages and disadvantages. It also deals with hydraulic balancing of heating systems and works with the defined term “sensitivity to changes in flow rate”.
2 comments, last 29.05.2017 12:13

Solar collectors and heat pumps - what are their testing and parameters good for?

22.5.2017 | doc. Ing. Tomáš Matuška, Ph.D., Univerzitní centrum energeticky efektivních budov, ČVUT v Praze
The parameters and characteristics obtained from the laboratory test are used to compare products in terms of performance and efficiency. The results also serve for the correct design and evaluation of the year-round behavior of the element built into the entire thermal system.

Intermittent heating method and its effect on the heat demand

22.5.2017 | doc. Jaroslav Řehánek, DrSc.
Intermittent operation of a heat source called “on-off” affects the heat consumption for heating. The article gives a concrete example of a house for specific cycle interruption. For historically less thermally isolated house from overheating losses they are at a level of approximately 10.2% of the annual heating requirement. In a well-insulated house, this ratio falls below 5%.
8 comments, last 16.06.2017 14:35

Condensing Coal Boilers – Unwanted Child of Ecodesign

15.5.2017 | Ing. Zdeněk Lyčka
The effort to achieve the highest efficiency of the combustion heat source is associated with the reduction in chimney losses, and thus reducing the exhaust temperature. The result is condensation in the boiler and flue system. It arises aggressive corrosive substances that can shorten the life of the boiler unless it has adequate construction and supports the formation of deposits that reduce efficiency and increase maintenance costs. Disproportionate increase in the efficiency with which the fuel savings are associated is then reflected in increased operating costs.
6 comments, last 22.05.2017 09:50

Indoor environment monitoring platform

15.5.2017 | Ing. Jan Včelák, Ph.D., Ing. Daniel Adamovský, Ph.D., Bc. Jan Mrňa, Ing. Aleš Vodička, Ing. Marek Maška, Univerzitní centrum energeticky efektivních budov, ČVUT v Praze
Indoor environment quality is being more and more discussed topic. Technologies for indoor monitoring are becoming affordable and thus can be installed as autonomous monitoring and indicative systems. It can be used also in connection with ventilation system. In this article there are summarized the most important quantities related to the indoor air quality with its limit values. Particular technologies of sensors are mentioned and new sensor platform for complex monitoring of indoor environment with possible usage for controlling systems affecting indoor environment is introduced.

How it is made individual heating rate calculation

15.5.2017 | Jarmila Trčková, vedoucí rozúčtovacího oddělení společnosti ista Česká republika
The article deals with the definition of consumer and basic heating rate. It is recommended to use the ratio of 50 % basic nad 50 % consumer rate or 60 % consumer and 40 % basic if individual heat meters are used.

What are the rules for paying for hot water?

8.5.2017 | Jarmila Trčková, vedoucí rozúčtovacího oddělení společnosti ista Česká republika
For individual payment calculation for hot water we need an invoice from heat supplier with the total cost of the property in CZK and with the amount of GJ. In addition, we need the water supplier invoice, which includes the total cost of water and sewerage. For the calculation then we need water consumption from water meters.
20 comments, last 19.05.2017 20:46

Working with stakeholders of urban construction projects: inform, listen and plan together

8.5.2017 | Mgr. Martina Bacúrová, Mrg. Tomáš Vácha, Univerzitní centrum energeticky efektivních budov, ČVUT v Praze
The article describe the communication and cooperation of urban projects stakeholders. Inadequate communication can raise conflicts which could obstruct project realization.

Influence of hot water tank size on heat pump energy consumption

1.5.2017 | doc. Ing. Tomáš Matuška, Ph.D., Ing. Yauheni Kachalouski, Univerzitní centrum energeticky efektivních budov, ČVUT v Praze
Paper presents the analysis of water heating by a heat pump and influence of tank size, temperature setting and heat pump selection on annual use of electric energy.
7 comments, last 05.05.2017 12:11

Principles of the Safety Valve Installation

24.4.2017 | Ing. Roman Vavřička, Ph.D., ČVUT v Praze, Fakulta strojní, Ústav techniky prostředí, Časopis Vytápění, větrání, instalace
The article deals with the issue of safety valves installation for water heaters. Neglecting of the installation conditions often causes damage to the installed appliance, or (as shown in the paper) loss on the water and sewer charges in the case of a safety valve installed in the water heater safety group.
1 comment, 26.04.2017 09:23

Study of the properties of heating radiators and convectors

10.4.2017 | Ing. Jindřich Boháč, Ing. Roman Vavřička, Ph.D., Ústav techniky prostředí, Fakulta strojní, ČVUT v Praze, Univerzitní centrum energeticky efektivních budov, ČVUT v Praze
The paper focuses on the analysis and experimental comparison of operating characteristics of various types of radiators. The first part contains a brief search of radiators available on the Czech market. The following is the theoretical analysis of the thermal inertia of the selected objects, both in the phase of start-up and cooling-down. This analysis serves as a basis for evaluating operating performance. Additional consideration by the parameters of the radiator in this study are the geometrical characteristics (the criterion of the space occupied by the dimensions of the body and the size of the transfer surface on the air side), the weight criterion (radiators without heating fluid) volume criterion (heat-carrying substance in the body). Each of the above criteria is related to nominal thermal output.
12 comments, last 25.04.2017 10:29
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