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Compact Sensors for Evaluation the Thermal Comfort
Kazkaz, Mohammad ; Fiľakovský, Karol (referee) ; Šafařík,, Pavel (referee) ; Pavelek, Milan (advisor)
Teplota vzduchu je nejčastěji používaná k posouzení tepelného stavu vnitřního prostředí. Avšak teplota vzduchu sama o sobě, je v mnoha případech pro toto posouzení nedostatečná. Hlavním cílem disertační práce je vyhodnotit tepelný stav vnitřního prostředí a specifikovat parametry, které na něj mají vliv. Teplota vzduchu, střední radiantní teplota, rychlost vzduchu a vlhkost vzduchu jsou čtyři základní parametry, které určují tepelný stav vnitřního prostředí. Vzhledem k tomu, že tepelný stav prostředí závisí na mnoha aspektech, byly odvozeny veličiny, které zahrnují kombinovaný účinek několika nebo všech těchto parametrů k určení tepelného stavu prostředí. Jedná se např. o efektivní teplotu, teplotu kulového teploměru, operativní teplotu, ekvivalentní teplotu, PMV a PPD indexy... aj. V dnešní době existuje spousta vysoce přesných senzorů, které mohou zhodnotit tepelný stav vnitřního prostředí. Z důvodu jejich vysoké ceny jsou používané převážně pro účely výzkumu. Předkládaná práce se převážně soustředí na vývoj kompaktního deskového senzoru pro vyhodnocení tepelného stavu vnitřního prostředí. Zaměřuje se hlavně na nízkou cenu senzoru společně s dostatečnou přesností. K dosažení cíle této práce jsou provedeny následující postupy: • Analýza environmentálních faktorů ovlivňujících tepelný stav prostředí. • Studium dopadu teploty vzduchu, střední radiantní teploty a rychlosti proudění vzduchu na tepelné indexy: teplotu kulového teploměru a operativní teplotu. • Teoretické porovnání teploty kulového teploměru a operativní teploty. • Navržení, rozvoj a konstrukce nového deskového senzoru pro posouzení tepelného stavu vnitřního prostředí. • Navržení a konstrukce testovací komory pro porovnávání senzorů tepelného stavu prostředí. • Kalibrace zkonstruovaného senzoru měřením fyzikálních veličin charakterizujících tepelný stav prostředí. • Testy směrové závislosti vyvinutého deskového senzoru a porovnání s kulovým teploměrem v testovací komoře. • Srovnání teoretických řešení s provedenými měřeními v testovací komoře. Výsledkem této práce je vlastní teoretické srovnání teploty kulového teploměru a operativní teploty ve vybraném rozsahu teploty vzduchu, střední radiantní teploty a rychlosti vzduchu pro možnost hodnocení tepelného stavu vnitřního prostředí pomocí kulového teploměru. Hlavním výstupem je však navržení a zhotovení jednoduchého deskového senzoru, který by byl dostatečně přesný pro měření tepelného stavu prostředí. V rámci disertace byla postavena také testovací komora a bylo provedeno testování vyvinutého senzoru pomocí měřicího systému INNOVA.
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Airflow inside of a passenger car
Bělka, Miloslav ; Štětina, Josef (referee) ; Charvát, Pavel (advisor)
This bachelor thesis deals with hearting, air-conditioning, air distribution and airflow in a cabin of a passenger car. Ventilation of the cabin is needed for acceptable level of indoor air quality. The air supplied into the cabin is conditioned by heating or air conditioning system in order to achieve an appropriate level of thermal comfort of the passengers. Various arrangements of automotive heating and air-conditioning systems are described in the thesis. The thesis also includes the description and results of a set of measurements of air temperatures and air velocities inside of a passenger car cabin.
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Night Cooling in Condition of Czech Republic
Šíma, Jiří ; Katunský,, Dušan (referee) ; Plášek, Josef (referee) ; Šikula, Ondřej (advisor)
The PhD thesis deals with the theoretical evaluation of the potential use of night cooling techniques in condition of the Czech Republic. Mainly aims to evaluate the potential of night cooling, which uses the physical phenomenon of radiation against the night sky. This technique is widely used mainly in the dry and hot regions where there are the most suitable climatic conditions for this cooling method. The work is based on the current state of knowledge in the area of passive and low-energy cooling systems. These knowledges are applied to the conditions of Czech Republic and by using simulations of the energy, behaviour of the buildings explores the benefits in terms of improving of the internal microclimate and from the perspective of economy operation of conventional cooling equipment. In order to establish the benefits of night cooling on the operation of the building in the dynamically changing conditions, the modular simulation program TRNSYS was used, which is suitable for the analysis of energy systems of buildings and their behaviour. The results of simulation results were converted to thermal comfort parameters of the PMV and the PPD.
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Optimizing The Design of Dry Floors
Hlavsa, Petr ; Chybík,, Josef (referee) ; Klečka,, Tomáš (referee) ; Tuza, Karel (advisor)
This dissertation deals with the optimization of the dry floor design by solving the innovative floor composition supported by the development of a new floor element, doing so from the point of view of building physics – especially the heat and mass transfer in buildings – with the consideration for the benefits for acoustics. It is aimed at dry floors application to modern timber structure. In the area of heat and mass transfer in buildings, the impact of thermal stability of rooms and its increase in the use of a new floor structure is investigated with the inclusion of a proposed element improving the thermal storage capacity of the floor. All this in the context of ensuring the possible floor heating integration. In the evaluation of thermal stability in rooms, those operating conditions that are accompanied by interrupted heating, are considered to be key. After describing the current state of solving this issue, the main focus of this dissertation is its own development and design of a specific floor element and its integration into the floor composition. An important part of the dissertation consists of related numerical simulations, its own experiment, relevant measurements in the experimental object, and their evaluation.
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Evaluation System of Thermal Condition Environment and his Measurement Uncertainties Analyze
Košíková, Jana ; Němeček, Pavel (referee) ; Kureková, Eva (referee) ; Vdoleček, František (advisor)
The Ph.D. thesis deals with the evaluation of indoor thermal environment in which people are located. A great attention is paid to the thermal comfort. If a person in a given environment does not feel well, then makes mistakes. Thermal comfort is created many parameters that can be monitored and managed. These parameters include not only temperature but also other parameters such as the mean radiant temperature, operative temperature, humidity and air velocity and the draft. All these parameters can be measured. The standard ČSN EN ISO 7726 is written how and what the parameters are measured. Furthermore, this standard provides requirements for measuring equipment. There are many professional measuring devices. Unfortunately, these devices are very expensive. Therefore are within the project GACR 101/09/H050 - Research on energy- saving equipment to achieve the quality of the indoor environment at our faculty developed sensors for thermal comfort, which have showed comparable accuracy measurements as a professional , but it will be cheaper than professional. Knowledge of real parameters of the developed sensor thermal comfort environment is important, as with any other measurement devices, and also need to verified whether it has the required accuracy. In order to objectively sensors testing were developed two chambers - the testing and calibration chamber. The developed sensors were tested both in the open laboratory, and also in the test chamber. Then uncertainties measurement were calculated from the results of measurements This work deals with the evaluation of thermal comfort, the measurement of parameters of thermal environment, the evaluating the results of measurements and determining the measurement uncertainty of the sensors. In this thesis, based on these results, were recommended suitable sensors for measuring various parameters environment.
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Primary School
Forman, Daniel ; Manová, Ludmila (referee) ; Maceková, Věra (advisor)
Thesis Theme is a primary school, namely the outbuilding primary school Havlíčkův Brod, Konečná 1884. I suggest first grade pavilion and pavilion with school canteen with kitchens. Pavilions are based on the footings. Pavilions are designed as a two-way system from the wall HELUZ. Construction of ceiling are from ferroconcrete slabs are cross reinforced, single-layer roof is flat with a classic sequence of layers. In addition to construction and process layout I solved also the statics of building in specialize of concrete structures. The following are also evaluated heat and acoustic requirements and requirements for fire safety of buildings. New pavilions are solved as wheelchair accessible. Pavilion of the first grade has two floors with 5 classes of stem, 1 vocational and 2 classes are earmarked for after-school clubs. This pavilion is connected to the connecting neck between the former pavilon A and pavilion B. Dining pavilion has one floor, which is divided in the school canteen and kitchen is connected to the connecting neck leading to the gym. The land is mildly sloping to the south side. All consstructions comply with the applicable standards and recommendations ČSN.
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Analysis of influence of a roof construction on indoor thermal stability in summer season
Hofman, Petr ; Katunský,, Dušan (referee) ; Hirš, Jiří (referee) ; Mohelníková, Jitka (advisor)
The design of the building must respect the basic conditions for ensuring thermal comfort in the living space. The thermal comfort is influenced by several factors and one of them are the constructions of the building envelope. This work was focused on investigating influence of roof structures. The goal was to make analysis of influencing the selected modifications of the roof compositions to the thermal stability in the summer formed by experiments and detailed computer simulations. On the basis of these findings were defined suitable modifications. It has been worked out that the maximum indoor air temperature can be reduced by up to 1.5 °C in a suitable way. The cool roofs, thermal inertia and the ventilated air cavity layer have the greatest benefit. When evaluating the return on investment in a roof with high thermal inertia represented by a concrete layer of 100 mm, its return compared to a light roof and airconditioning is 12.1 years. The return on installation of external blinds on roof windows is 3.3 years compared to airconditioning.
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Measurement of indoor environment by means of thermal manikin
Ševeček, Jan ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
This dissertation deals with the measurement of the internal environment through thermal manikin Newton, especially in terms of thermal comfort. Measurements were performed in a typical office environment and cabins of small transport aircraft. The course of events and the time constants for the measurement in the office was given by real flow in the office when the sequences of events were unfolded from the usual transactions carried out during the day. In contrast, the second measurement, which took place in the model of small transport aircraft, the course of events and time constants, was performed exactly according to predetermined plan. The other parts of the thesis describe how to calibrate the manikin and then generate a diagram comfort zones. Following are compared individual test cases and events using the diagram comfort zones. Finally, individual test cases and events are compared using the diagram comfort zones and medics according to ISO 14505-2.
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Car cabin passive cooling system performance study
Viščor, Petr ; Hejčík, Jiří (referee) ; Fišer, Jan (advisor)
The work is focused on issue of passive cooling in a cabin of a car. The basic principles and mechanisms of heat transfer are described in the theoretical part and the quality of cabin environment in terms of thermal comfort and air quality is discussed as well. Next part of the work describing the principles of ventilation and air conditioning of cabins and possible methods of passive cooling are discussed. Passive cooling means decrease of temperature of cars interior, without need of energy supply from car battery, or fuel. The last part of the work includes numerical simulation of selected methods of passive cooling using the THESEUS-FE 3.0 software. Simulations were performed on model of Volkswagen Polo car and primarily were focused on testing of functionality of various methods of passive cooling.
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The study of passive radiation finishes in construction
Kopkáně, Daniel ; Steuer,, Radek (referee) ; Kmínová,, Hana (referee) ; Chybík,, Josef (referee) ; Šťastník, Stanislav (advisor)
One of the key issues of our society is to decrease energy demand. About 40 % of energy consumption in Europe is related to building operation, mostly for heating. The required thermal comfort is related mainly to temperature of air and temperature of surrounding surfaces. Especially in older buildings with low level of thermal insulation the inner surface of perimeter wall can be several degrees colder than air. In such case the perception of thermal comfort will be lowered also depending on the layout of the room. Other issue can be related to thermal radiation asymmetry. The amount of energy that is eradiated from a surface is driven by material property called emissivity. A surface with sufficiently low emissivity will became “thermal mirror”. It is possible to elaborate about intelligent thermal management of the internal space with usage of low-emissive surfaces; where thermal radiation can be suppressed or can be enhanced. This depends on the surface emissivity and its real temperature. Recently, growing interest about the low-emissive surfaces can be seen. They can represent reasonable complement to conventional insulation, but they have certain limits. Potentially, even higher energy savings can be reached with so called retro reflection. If the thermal radiation of an object is reflected back, its thermal loss will be lower. In such case it can be expected that equivalent thermal comfort can be reached even with lower overall temperature of the room. The aim of the work is study of material combinations with potential for utilization as low-emissive interior surfaces. Research has been conducted on low-emissive paints and low-emissive foils. Another part of the work is related to retro reflection of thermal radiation as a potential way to influence thermal comfort. The work shows, that energy saving up to 20% can be obtained.
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