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Archiv článků od 15.3.2021 do 7.2.2022

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7.2.2022
Ing. Vladimír Šulc, Ph.D., ČVUT v Praze, Fakulta strojní, Ústav techniky prostředí

Serious heat pump failures can be caused by liquefied refrigerant sucked into the compressor or excessive refrigerant temperature at the compressor outlet. The reasons must be sought in the construction of the heat pump and the insufficient expertise of the service personnel.

2.2.2022
doc. Ing. Vladimír Jelínek, CSc., Ing. Jiří Vrba

The article divides the openings into the chimney according to their purpose, states the method of making the individual openings, including the conditions based on ČSN 73 4201.

31.1.2022
doc. Ing. Zuzana Straková, PhD., STU v Bratislave, Stavebná fakulta, Katedra TZB

Ventilation infiltration in the form of leaking windows, doors is associated with unwanted heat leakage in cold periods. The size of the leakage depends on both the intensity of ventilation and the amount of energy contained in the air. The calculation should include not only the specific heat capacity of the dry air, but also the energy contained in the water vapor in the air.

28.1.2022
doc. Ing. Petr Horák, Ph.D., VUT v Brně, Fakulta stavební, Ústav technických zařízení budov

The article deals with the principles of calculating the monthly method of supplied energy for heating. Describes in a clear form the individual mechanisms of calculation according to the relevant standards. It is designed for the needs of energy specialists and the professional public.

26.1.2022
doc. Ing. Petr Horák, Ph.D., VUT v Brně, Fakulta stavební, Ústav technických zařízení budov

The assessment of the energy performance of buildings depends on a large number of calculations, which must comply with the applicable legislation. The article presents the related structure of legal regulations, including standards and their brief characteristics.

24.1.2022
Ing. Jiří Vrba, TNK 105 Komíny

The type of chimney determines the suitability, use, conditions of chimney installation and also plays a role in the flue gas discharge from solid, liquid and gaseous fuels. The distinction of chimneys into separate or common chimneys, system chimneys, individual and additionally lined chimneys, etc. will be described in this article.

17.1.2022
Ing. Petr Michal, Ing. Josef Hodboď

Even heat pumps with frequency-controlled compressors are not fault-tolerant. Examples are the destruction of the frequency converter, the suction of liquid refrigerant due to the faulty operation of the expansion valve, the ignorance of service technicians, etc. Mistakes that push the economic return of the Czech Republic into the distance can be avoided.

10.1.2022
Ing. Petr Michal, Ing. Josef Hodboď

Inadequate heat pump performance with ON / OFF compressor and an alarming number of compressor starts are real operating experiences. Mistakes that push the economic return of the Czech Republic into the distance can be avoided.

29.11.2021
Sandi Plaskan, Technical center team Schiedel

The general term stainless steel does not describe the differences that exist between different types of stainless steel. Therefore, in the field of chimney systems, it is necessary to pay increased attention to the selection of suitable steel. Both on the part of manufacturers and chimney companies in the production of various accessories for chimney systems and, to an increased extent, also for fuel appliance operators.

Teplotní koeficient deskových otopných těles závisí na výšce (Ilustrativní obrázek: Korado)
15.11.2021
prof. Ing. Jiří Bašta, Ph.D., Ing. Jindřich Boháč, Ph.D., Časopis Vytápění, větrání, instalace

The article considers the standard EN 442-2, which assumes a linear course of the temperature exponent with height for a given type of radiators. It focuses mainly on panel radiators, although it does not omit other kinds of radiators. It points to the fact that the dependence of the temperature exponent on height is not linear and increasing for a given type, as assumed by the characteristic equation of the type. Results are based on the evaluation of the data collected from the radiator manufacturers.

8.11.2021
Ing. Miloš Lain, Ph.D., ČVUT v Praze, Fakulta strojní, Ústav techniky prostředí

The heat pump with earth wells is a source of heat and cold for a university building in the center of Prague. Analyzes of measured data from the operation of this system are performed and the issue of parallel production of heat and cold in the context of sustainable development and buildings with minimal energy consumption is discussed.

2.11.2021
Dr.-Ing. Marek Miara, Fraunhofer-Institut für Solare Energiesysteme ISE, Německo

The common view that heat pumps are only suitable for new or refurbished buildings with a focus on energy can be considered obsolete. This is evidenced by the results of research at the Fraunhofer Institute (ISE) found in older buildings in several long-term projects.

25.10.2021
Ing. Barbora Junasová, doc. Ing. Michal Krajčík, Ph.D., Ing. Martin Šimko, PhD.

High quality of the indoor environment expressed by indicators such as air temperature, relative humidity, concentration of carbon dioxide, or lighting has great impact on human health, comfort and performance. Therefore, the contribution focuses on the effect of an increase in indoor temperature on energy consumption.

18.10.2021
prof. Ing. Dušan Petráš, PhD., Stavebná fakulta STU Bratislava Katedra technického zariadenia budov

The author describes a systematic procedure leading to the processing of the audit and provides an overview of the necessary documents. The elaboration of the audit and the implementation of the proposed measures is a basic prerequisite for savings. Without subsequent evaluation of results and adjustments of operating modes, etc. however, the expected savings effect may not occur.

18.5.2021
Ing. Vladimír Stupavský, redakce TZB-info, Klastr Česká peleta

The certification system ENplus 3.0 which came into force on 1 September 2015. The entire system is based on the rules in the manual ENplus 3.0, which has been tightened with some new quality parameters of wood pellets.

11.5.2021
Ing. Jiří Beranovský, MSC., Ph.D., MBA, Petra Horová, MSC., Gabriela Krajcarová, MSc.

The low heat loss in family houses enables comfortable hot air heating with air-to-air heat pumps. The authors give an example of the conditions for obtaining a subsidy from the „Nová Zelená úsporám“ (Green to Savings) program. Achieving the highest category of the NZÚ subsidy is also realistic in the „new buildings“ category.

15.3.2021
Ing. Josef Fík, Dr. Ing. Libor Čapla, Ing. Jiří Žahourek, CSc.

The authors analyze the possibility of burning natural gas with an admixture of hydrogen in gas appliances. The positive and negative aspects of the hydrogen content in natural gas and recommendations for its mixing into the natural gas distribution system are presented.

The contribution describes the effect of hydrogen content ranging from 0 to 25 mol% in a mixture with natural gas on burning in household appliances. Gaseous fuels with similar combustion characteristics, in particular Wobbe index and burning velocity, can only be used in a particular household appliance as a substitute. The various chapters describe the effect of hydrogen content in natural gas on the following: Wobbe index, composition of exhaust gases; emissions of CO2, CO and NOx; burning velocity; output of burners/energy demand of appliances, efficiency of appliances; flame stability; and temperature of combustion. Recommendations on hydrogen content in natural gas for household appliances, accepted from reference literature, are set out there. In conclusion, the authors discuss the pluses and minuses of hydrogen content in natural gas and offer recommendations for hydrogen injection into natural gas distribution systems from the perspective of burning these mixtures in household appliances.


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