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Drivers clothing thermal resistance database for iHVAC system
Hrubanová, Kristýna ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
This diploma thesis is focused on measurement of thermal properties of clothes by thermal manikin and on application of results for prediction of thermal comfort in system iHVAC. First part of thesis is dedicated to research with relation to this topic and to definitions of main computational equations necessary for experimental measurement. The choise of method for measurement based on available standards is an important part of this thesis. The main focus of thesis lies on measuring 5 combinations of clothes at different calibration temperatures and same temperature of manikin surface. Then data are examined and also the analysis of uncertaities and repeatability is maked. According to assupmtion , the independence of value of heat transfer coefficient to ambient temperature is comfirmed and calculated heat resistance of every single clothes is compared to existing wardrobe for system iHVAC. The outcome of this thesis is specificied and completed virtual wardrobe which serves to prediction of thermal comfort in car.
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An influence of usual room temperature on BMI or obesity prevalence in a population sample
BEDNAŘÍKOVÁ, Renata
The main aim of the diploma thesis is to determine if BMI (Body Mass Index) in humans is related to the indoor room temperature. Lower room temperature can lead to the activation of brown adipose tissue (BAT), thereby increasing energy expenditure. Because the thermal comfort is individual to some extent, the task is to determine whether there is a correlation between BMI and the frequency of perceived thermal discomfort. The research was attended by 202 respondents in the age range of 3 to 27. All were measured and weighed, and then the temperature habits were recorded through questionnaire. A group of students underwent more detailed data collection. For the evaluation of the data was used PCA (Principal Component Analysis) and regression analysis, for determining the influence of the room temperature, data were weighed by the coefficient of the thermal insulation during the night. The results showed that BMI, respectively the percentile BMI class of respondents in-creases with increasing average bedroom night temperature. Results are less clear for the age categories with no dependency between BMI and room temperature in the youngest age category, significant correlation in adolescent females and adult men, but not signifi-cant correlation in adolescent males and adult females. Evaluation of 87 responses from adolescent and adult respondents to the question regard-ing the frequency of subjective cold feeling showed that the more they felt the coldness in their dwellings, the lower was percentile BMI class and BMI in different age groups. Based on these results we can state that the room temperature during sleep is another sig-nificant factor influencing BMI and lowering the temperature in the homes could lead to the reduction of population obesity.
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Measurement of Cabin Environment by Means of Thermal Manikin and Test Subjects
Toma, Róbert ; Tuhovčák, Ján (referee) ; Fišer, Jan (advisor)
In this thesis, there is processed design of test procedure for innovative HVAC system. This design was created in consecutive phases with use of thermal manikin Newton and climate chamber. Correlation between data from thermal manikin and tests subjects and possible design changes were evaluated after each phase. There are mentioned basics of human thermoregulation, factors which affect thermal comfort and ways in which is possible to measure and rate it with use of thermal comfort scales and comfort zones diagram. The thesis includes survey for testing thermal comfort and scales which are used to complete it. In the end, we mentioned some results alongside with our approach in evaluation of correlation between thermal manikin and test. There is also final design of test procedure for innovative HVAC system which would be used for its calibration and final functionality testing.
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Coupling of the Models of Human Physiology and Thermal Comfort
Pokorný, Jan ; Jícha, Miroslav (advisor)
The thesis deals with car cabin environment and thermal comfort inside. A car cabin heat load model was developed in Dymola/Modelica to investigate influence of ambient environmental parameters. The model was validated on the data set of eight test cases measured in a climatic chamber and in a real traffic. The main objective of the thesis was to develop a human thermal comfort model suitable for non-homogenous environments and for a car cabin environment especially. The Coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. The model allows predicting an overall human thermal comfort from local boundary conditions representing ambient and personal factors. The model was validated by 16 test cases taken from experiments in literature. Moreover three test cases were created in Theseus-FE to consider an asymmetrical heat load from Sun rays inside a car cabin. Prediction of the Coupled model was compared with Fiala model and experimental data. The Coupled model predicted mean skin temperature for moderate activities in neutral and warm environment well. In cold environment a predicted core temperature was very affected by ambient temperature and during high activity exercises, the predicted mean skin temperature was too high.
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Coupling of the Models of Human Physiology and Thermal Comfort
Pokorný, Jan ; Masaryk, Michal (referee) ; Kratochvíl, Zdeněk (referee) ; Jícha, Miroslav (advisor)
The thesis deals with car cabin environment and thermal comfort inside. A car cabin heat load model was developed in Dymola/Modelica to investigate influence of ambient environmental parameters. The model was validated on the data set of eight test cases measured in a climatic chamber and in a real traffic. The main objective of the thesis was to develop a human thermal comfort model suitable for non-homogenous environments and for a car cabin environment especially. The Coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. The model allows predicting an overall human thermal comfort from local boundary conditions representing ambient and personal factors. The model was validated by 16 test cases taken from experiments in literature. Moreover three test cases were created in Theseus-FE to consider an asymmetrical heat load from Sun rays inside a car cabin. Prediction of the Coupled model was compared with Fiala model and experimental data. The Coupled model predicted mean skin temperature for moderate activities in neutral and warm environment well. In cold environment a predicted core temperature was very affected by ambient temperature and during high activity exercises, the predicted mean skin temperature was too high.
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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
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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.
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Thermal comfort and its estimation
Žáková, Monika ; Vondra, Vlastimil (referee) ; Nováková, Zuzana (advisor)
This paper summarizes the problems of human thermoregulation and its measurement, with a focus on the method of indirect calorimetry in resting conditions at different ambient temperatures and during physical activity. It also introduces the issue of human thermal comfort and the methodology of its monitoring using thermal manikin. It describes PowerCube Ergo (Ganshorn, Germany) and Cardiovit AT-104 (Schiller, Switzerland), the diagnostic devices used to spiro-ergometry measurements. It introduces the options to export data. The work proposes the protocol for measuring the thermoregulation of the small group of volunteers, which is realized by the practical part. According to the same protocol is monitored thermal comfort of the thermal manikin. In MATLAB is created the application, allowing clear analysis of measurement records. The data are evaluated and discussed.
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Determination of HVAC air distribution within a passenger vehicle cabin
Planka, Michal ; Mlkvik, Marek (referee) ; Fojtlín, Miloš (advisor)
The aim of this bachelor´s thesis is to determine proportional coefficients of air distribution provided by heating, ventilating, and air conditioning system (HVAC) within a passenger vehicle cabin. The focus of this paper is to determine air flow rates from the outlets at predefined outside climatic conditions (ambient temperature and solar load). The simulation of outside climatic conditions was executed by placing the car into a climatic chamber. The air flow rates from outlets were determined by measuring air flow velocity method, specifically by determining mean value of air flow velocity profile and area of outlet crosssection. Hot-wire anemometry was used for air flow velocity measurement. The results of this experimental work are presented in a diagrammatic form and will serve as a groundwork for boundary condition setting for computer modeling of thermal load and thermal comfort within a vehicular cabin.
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