|
|
Models for predicting the thermal sensation and thermal comfort of a person
Nahácky, Marek ; Pokorný, Jan (referee) ; Kopečková, Barbora (advisor)
The bachelor thesis is focused on mapping of the current development of thermophysiological models for prediction of human thermal sensation and thermal comfort in thermal environment. These models vary in broad spectrum of conditions of their use. The first part is dedicated to definition of terms thermal sensation and thermal comfort. The second part focuces on comparison and more precise description of chosen thermophysiological models. At the end it was made a summarizing table of inputs and outputs of these models for prediction.
|
|
|
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.
|
|
|
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.
|
|
|
Contribution to the construction of cost and energy efficient family houses
Čech, Josef ; Mohelníková, Jitka (referee) ; Gašparik,, Jozef (referee) ; MBA, Pavel Slováček, (referee) ; Hrazdil, Václav (advisor)
Dissertation focuses on the verification of construction family houses made of concrete shell block with internal thermal insulation system. The construction technology is transferred to the Czech Republic from France. The work focuses on building envelope. The suitability of implementation is assessed on the basis of verification selected thermal technical requirements placed on building envelope. Requirements are specified by legislation in force in the ČR. The verification was performed by using software simulations and measurements on realized buildings. Critical areas of construction technology were identified on the basis software simulations and measurements on site. It was suggested solution, in which critical areas comply the thermal technical requirements. The building envelope was checked also using the thermography imaging on site. Continuous measurement of interior temperature was used to evaluate thermal comfort in the room. In the completed buildings was tested airtightness of the building envelope, which revealed other critical areas of the building envelope. Critical areas are necessary to solve with sufficient care. The economic cost of implementing each variants of exterior walls made of concrete shell block with internal thermal insulation were compared with the economic costs of implementing external walls made of burnt clay hollow blocks and made of burnt clay hollow blocks with external thermal insulation system ETICS. Subsequently, the economic return was calculated for individual variants of external walls made of concrete shell blocks with internal thermal insulation. From the environmental viewpoint was made comparison of production greenhouse gas CO2 and SO2 (cause acid rains) during the life cycle of the individual variations of exterior walls made of concrete shell blocks with system of internal thermal insulation, exterior walls made of burnt clay hollow blocks and burnt clay hollow blocks with external thermal insulation syst
|
|
|
Determination of heat transfer coefficients from the surface of the thermal manikin
Fojtlín, Miloš ; Tuhovčák, Ján (referee) ; Fišer, Jan (advisor)
This thesis deals with an experimental determination of heat transfer coefficients from the surface of the thermal manikin. The main focus of the work lies on separating radiative and convective heat fluxes from the surface of the thermal manikin. Both nude and clothed, standing and seated postures were investigated respectively. The tests were conducted in a constant air temperature (cca 24°C) and a constant wind speed (cca 0,05 m.s-1) environment. The major part of the radiative heat flux was eliminated by a low emissivity coating applied to the surface of the nude thermal manikin, and in the case of clothed manikin by a low emissivity two-piece dress. Favorable results were achieved only in the case of the nude manikin measurements. The measurements were performed across 34 zones that logically represent parts of a human body. Experimental work confirms theoretical expectations in the means of a heat transfer. In addition, the results of this work were compared to results of a similar experimental work. The outcomes of this thesis provide essential information in order to create detailed computational models of a thermal environment. Such models require anatomically specific, separate values of convective and radiative heat transfer coefficients.
|
|
|
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.
|
|
|
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.
|
|
| |
|
|
Automotive ventilation system - comparison of an influence of boundary conditions on flow from various types of ventilation outlets
Brdečko, Radim ; Pokorný, Jan (referee) ; Lízal, František (advisor)
Diploma thesis deals with a research of the flow in front of three different automotive vents. The velocity field and intensity of the turbulence was measured in detail, using thermoanemometry. After that the same data was measured with PIV method and validation was performed. The difference between achieved data was investigated. The design among the vents was also investigated, because it’s fundamentally affects the air flow. The purpose of this thesis is to obtain data about the velocity field using two methods and their subsequent use to validate numerical simulations, which will be performed in the future. The diploma thesis also contains the calculation of measurement uncertainty.
|
|
|
The technique of smart school buildings
Drábková, Helena ; Mauder, Tomáš (referee) ; Štětina, Josef (advisor)
This bachelor‘s thesis briefly discusses about regulation of energy consumption in buildings with specialization on building intelligent systems and its application at schools. It briefly characterizes regulation of heating, ventilation, air-conditioning and lighting and its integration into centralized control component. Thesis discusses about systems from a few producers, short description of economic operation, a vision of these systems into the future and examples of implemented installations.
|
guest ::
