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Větrání a klimatizace
Archiv článků od 31.3.2014 do 24.11.2014

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24.11.2014
Ing. Jiří Šála, CSc., ŠÁLA MODI, Praha

From a functional point of view is mechanical ventilation the only system that gives the guarantees necessary exchange of fresh air, which is necessary in spite provide fresh air in a given time and quantity. The advantage of this method is the possibility of air exchange energy-saving solution - first option controlled exchange according to the needs of individual spaces, which excludes excessive ventilation, secondly the possibility of installing ventilation heat recovery that often uses more than 80% efficient heat from exhaust air for preheating fresh (no mixing). In the case of radon risk would be appropriate to prescribe these systems.

27.10.2014
Ing. Stanislav Toman, Projektová kancelář ÚT+VZT

The published paper summarizes the crucial information about the actual topic – garage ventilation in the Czech Republic. The contribution is divided into three parts, due to the broad scope of the matters. The series of the papers is based on the legal and normative enactments. It reflects the new situation of natural gas powered vehicles parking possibilities and it discusses every ventilation system which can be found in garages. It deals with design principles of service ventilation, definition of emergency ventilation and basics of fire ventilation. The paper also deals with related issues such as control systems, operating regimes, detection and monitoring of pollutants, explosive atmosphere risk assessment and protocol determining external influences. The contribution is aimed not only to HVAC designers, but also to architects and designers of all related construction fields. Valuable information can be found also by the other interested groups such as investors, developers, suppliers, operators, building authorities, involved state administration bodies, etc.

Školní třída © Tyler Olson - Fotolia.com
15.9.2014
Jie Gao, Pawel Wargocki, Yi Wang

This article presents the measurements of indoor climate in classrooms in the same school in Denmark. The classrooms had different ventilation systems: Ventilation was achieved either by manually operable windows, or by automatically operable windows with and without an exhaust fan in operation, or by a balanced mechanical ventilation system. Indoor air temperature and carbon dioxide (CO2) concentration, as well as opening of windows were continuously monitored for one month in the non-heating and heating seasons; measured CO2 concentration was used to estimate average classroom ventilation rates. The results show that mechanical ventilation and natural ventilation with automatically operable windows with exhaust fan performed notably better than the other systems. They indicate also that opening of windows was largely affected by customs and habits. Present results can be used as the basis for rational selection of systems that ensure adequate classroom ventilation.

1.9.2014
Ing. Jaroslav Bambous

Nowadays implemented and operated buildings services do not fully utilise current technical industry standards. The reason is not only a pressure for investment cost cutting, but also professionalism level of investor’s consultants and planners. Another negative impact has reducing time for both project preparation and realization.
Disproportionate cost cutting of operation and energies leads to suppressed running of technical equipment. Additionally the reducing of staff and qualified personnel results in ineffective way of operation. Technical capabilities of installed devices are not properly and fully used, so the required technical parameters are not followed in air conditioned spaces.

dotace na zateplení rodinného domu
25.8.2014
Ing. Jan Antonín, Ing. Zdeněk Ročárek, Ing. Petr Kotek, Ph.D.

Which buildings can receive grants from the Green Savings Programme, amount of the grants and what technical details cover the energy audit? Part A in this article covers the specific questions (building’s envelope rennovation). A sample of 16 family houses that comply with all the required conditions of the New Green Saving Programme from 2013 is further described in this article.

18.8.2014
Ing. Martin Pospíšil, ČVUT v Praze, Fakulta strojní, Ústav techniky prostředí

The article presents an overview of the internal aerodynamics in perforated ducts with a focus on pressure loss and uniform distribution of the air in the ductwork. There are the factors that influence these losses and thus the uniformity of the outlet air. It explains assumptions and problems in determining of pressure losses in these ducts. These assumptions and problems are compared with the results of some individual experiments, CFD simulations and previously published results.

vzduchotechnika
4.8.2014
Ing. Jan KOLOMAZNÍK

The paper informs about principles and ways of standardization development both on the national and international level. Close attention is paid to currently effective National and European Standards in the field of HVAC systems. Their overview is published in the paper.

školní třída
21.7.2014
Ing. Roman Šubrt, Ing. Pavlína Charvátová

Ventilation of the houses is a very overlooked part of the natural life, although it has a great importance not only for comfort but also for health. Many health problems resulting from the poor ventilation are known, but it is likely that there are many consequences we don't know or even have an idea of. The paper is devoted to some aspects, which we do not realize in normal engineering practice, even though they are well known.

7.7.2014
Ing. Tomáš Klubal, doc. Ing. Milan Ostrý, Ph.D.

The paper shows a comparison of the influence of radiant cooling/heating and air conditioning on indoor environment. Cooling and heating based on thermally activated structures is a viable option of maintaining optimum thermal conditions without great demands on energy consumption. Presented system uses phase change materials (PCMs) as a latent heat storage medium for better absorption of heat. Microencapsulated PCMs Micronal® DS 5040 X and DS 5008 X were used as latent heat storage medium in combination with gypsum plaster. Activation of phase change materials is carried out by capillary tubes with cooled / heated water circuit. Detailed investigation is performed in the test rooms for comparative measurements. Radiant cooling and heating are one of the ways to reduce energy consumption and operating cost for cooling / heating. The Differential Scanning Calorimetry (DSC) was used for thermal analysis of the latent heat storage medium.

Bazén
9.6.2014
Ing. Petr Blasinski, doc. Ing. Aleš Rubina, Ph.D

The main requirements in the design of the HVAC system include removal of water vapor and flue trichloramine (NCl3) from an area where swimmers. This article aims to point out the problem with the releasing trichloramines from the water and the possibility of determining the amount of evaporated water vapor from the water. In conclusion, the article points out the conflicting requirements associated with removal trichloramine and increased evaporation of water vapor from the boundary layer above the surface of the pool.

školní třída
26.5.2014
Ing. Mohamad Kheir Mohamad

The actual indoor temperature is represented by a complex interaction between losses and gains, which contribute through a large number of variables on the energy balance. These variables are continuously changing, because the temperature outdoors is changing with time, as well as the solar heat gains and the internal heat gains.
In this work, a computer model has been designed by using TRNSYS software and MATLAB/SIMULINK software to simulate indoor temperature in summer. The building considered in this work is a lecture room at the Faculty of Mechanical Engineering at the Brno University of Technology. Where, the model of solar radiation incident on the external walls has been designed using TRNSYS software by exporting the real data taken from meteorological station in Brno (TUBO station) to the model, so that the intensity of solar radiation on each wall can be calculated and became usable in the SIMULINK model in order to calculate indoor temperature.
To make sure of the validity of the results, they have been compared with those recorded by a monitoring system installed in the building. Results have shown a significant convergence between simulation and measurements.

19.5.2014
Ing. František Jiřík

Multilayer metal chimneys have some advantages over chimneys with ceramic chimney casing, but their use with solid fuel appliances in wooden houses must strictly follow all the requirements of chimney manufacturer and be in accordance to current norms in order to secure the fire safety of the building. This concerns in particular the passages of chimneys and flues through wooden building structures.

ventilátory
12.5.2014
P.G. Schild, M. Mysen

This publication explains the principles of designing efficient ventilation systems with low fan power and hence little fan noise. The main topics are: definition, measurement, and rating of specific fan power and fan system efficiency; how the design of the air handling unit, distribution system, and controls influence pressure losses and fan system efficiency.

5.5.2014
P.G. Schild, M. Mysen

This publication explains the principles of designing efficient ventilation systems with low fan power and hence little fan noise. The main topics are: definition, measurement, and rating of specific fan power and fan system efficiency; how the design of the air handling unit, distribution system, and controls influence pressure losses and fan system efficiency.

okno s izolačním trojsklem
5.5.2014
Ing. Jan Schwarzer, Ph.D., Ing. Jiří Ježek

The article deals with the determination of effects of heat radiation on the quality of the indoor environment in winter season, while insulating by double and triple glasses. Effect of radiation through the fillings of the panels and building structures has been evaluated on the basis of knowledge of the mean radiation temperature and operative temperature in the given indoor environment. Isotherms of mean radiation and operative temperatures for different cases of application of insulated glasses having different coefficients of thermal transfer have been presented.

28.4.2014
P.G. Schild, M. Mysen

This publication explains the principles of designing efficient ventilation systems with low fan power and hence little fan noise. The main topics are: definition, measurement, and rating of specific fan power and fan system efficiency; how the design of the air handling unit, distribution system, and controls influence pressure losses and fan system efficiency.

manažer s provozním řádem
28.4.2014
Bc. Martin Hablovič, VŠB-Technická univerzita Ostrava, Fakulta stavební, Katedra městského inženýrství

This article focuses on the issue of creation of operating rules that pertain to the field of operational documentation. Operating rules are an essential part of the efficient operation of the property. This article is targeted to the content site of operating rules by various functional use of objects. A method of operation of the building affects the composition of future operating rules. In this article, the individual include the composition and structure defined according to the method of use of the building.

21.4.2014
P.G. Schild, M. Mysen

This publication explains the principles of designing efficient ventilation systems with low fan power and hence little fan noise. The main topics are: definition, measurement, and rating of specific fan power and fan system efficiency; how the design of the air handling unit, distribution system, and controls influence pressure losses and fan system efficiency.

14.4.2014
P.G. Schild, M. Mysen

This publication explains the principles of designing efficient ventilation systems with low fan power and hence little fan noise. The main topics are: definition, measurement, and rating of specific fan power and fan system efficiency; how the design of the air handling unit, distribution system, and controls influence pressure losses and fan system efficiency.

31.3.2014
Ing. Tomáš Kmoch

This paper informs reader with valid legislation and methodology verifications air-conditioner and fire breather systems, which is valid in Czech republic. Paper is intended not only for reader, who deal with installation these systems, but also for user air conditioning e.g. in shopping centres, office buildings, residential complexs etc.


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