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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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Ventilated protective clothing for healthcare staff in contaminated environments
Štenclová, Kristýna ; Kopečková, Barbora (referee) ; Fišer, Jan (advisor)
Focus of the masters thesis is experimental verification of cooling effect of ambient air stream directed under a protective clothing of a human. The first part is a review of literature encompassing concepts related to thermal comfort and heat transfer. Possibilities of cooling a human who is moving in high ambient temperature environment are introduced in this part. The second part is focused on hypotheses devised and experiments performed. The last part is focused on results of the experiments and their comparison with an experiment described in literature.
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Local Control of Seat Ventilation and Its Impact on Human Thermal Comfort
Matuška, Jaroslav ; Toma, Róbert (referee) ; Fišer, Jan (advisor)
Diplomová práce je zaměřena na měření ventilovaného sedadla s ohledem na tepelný komfort člověka. Popisuje a shrnuje tepelný přenos lidského těla s okolím a termoregulaci člověka. Dále zachycuje a zhodnocuje vybrané přístupy hodnocení tepelného komfortu. Zabývá se komplexním přehledem tepelně komfortních jednotek v automobilu. Představuje použitou metodu měření tepelného komfortu u ventilovaného sedadla, načež analyzuje a vyhodnocuje jednotlivá získaná data.
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Design of heating of retirement home
Kouřilová, Klára ; Vyhlídalová, Karolína (referee) ; Horká, Lucie (advisor)
The main aim of this bachelor thesis is design of a heating system of the retirement home. The theoretical part deals with ensuring of thermal comfort and possibilities of building temperature regulation. The second part of this thesis, the calculation part, includes design of panel radiators, dimensioning of heating system, design of hot water preparation and design of heat source. As the heat source is chosen gas condensing boilers for heating system and hot water system. The third part contains documentation for construction of heating system.
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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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Assesment of the Thermal Environment in Vehicular Cabins
Fojtlín, Miloš ; Khoury, Roch El (referee) ; Havenith, George (referee) ; Jícha, Miroslav (advisor)
Ľudia žijúci vo vyspelých krajinách trávia väčšinu svojho života vo vnútorných prostrediach budov alebo dopravných prostriedkov. Z tohto dôvodu, záujem o výskum kvality vnútorných prostredím rastie, pričom hlavný dôraz je kladený na oblasti výskumu ľudského zdravia, produktivity a komfortu. Jedným z faktorov ovplyvňujúci kvalitu prostredí je ich tepelný aspekt, ktorý je najčastejšie popísaný teplotou vzduchu, radiačnou teplotou, vlhkosťou vzduchu a rýchlosťou prúdenia vzdu-chu. Zatiaľ čo tieto parametre je možné riadiť systémom pre vykurovanie, vetranie a klimatizáciu nezávisle na počasí, takéto zariadenia sa podieľajú na vysokej spotrebe energie a značnej uhlíkovej stope. V prostediach kabín áut a dopravných prostriedkov je riadenie parametrov tepelného prostredia komplikované z dôvodu ich asymetrickej a časovo premenlivej povahy. Táto situácia je obzvlášť kritická vo vozidlách na elektrický pohon s vlastnou batériou, kde je energia na úpravu vnútornej mikroklímy čerpaná na úkor dojazdu vozidla. Pre uvedené dôvody sa hľadajú nové, en-ergeticky účinnejšie spôsoby pre úpravu tepelných prostredí a zabezpečenia tepelného komfortu. Jedným z potenciálnych riešení sú zariadenia dodávajúce človeku teplo alebo chlad lokálne, ako napríklad vyhrievané a vetrané sedadlá a sálavé panely. Vzhľadom na to, že experimentálny výskum vnútorných prostredí je náročný s ohľadom na čas a potrebné vybavenie, trendy výskumu vplyvov takýchto zariadení na človeka smerujú k optimalizačným úlohám vo virtuálnych prostrediach pomocou modelov ľudksej termofyziológie a tepelného pocitu/komfortu. Avšak pre spoľahlivé výsledky modelovania sú potrebné presné vstupné parametre definujúce prostredie, odev, vplyv povrchov v kontakte s človekom (napríklad sedadlá) a pôsobenie systémov na lokálnu úpravu mikroklímy. Cieľom tejto dizertačnej práce je vytvorenie metodológie na hodnotenie tepelných prostredí v kabínach automobilov s ohľadom na pozíciu v sede a využitím technológii na lokálnu úpravu tepelných prostredí. Jedným z požiadavkov na takúto metodológiu je jej aplikovateľnosť vo virtuálnych ale aj reálnych prostrediach. V prípade hodnotenia reálnych prostredí, cieľom je vytvorenie demonštrátora, ktorý by bol využiteľný ako spätná väzba pre riadenie systémov pre úpravu mikroklímy na základe požadovaného tepeleného pocitu. Validita uvedenej metodológie bola demonštrovaná v typických podmienkach kabín automobilov (5–41 °C) a poznatky z tejto práce sú prenesiteľné do širokého spektra inžinierkych aplikácii. V oblasti osobnej dopravy a pracovných prostredí s vyššou tepelnou záťažou je táto metóda užitočná pre identifikáciu možných zdrojov diskomfortu. Navyše je táto metóda vhodná i pre rýchlo rastúci segment elektrických vozidiel, kde je možné sledovať tok energie potrebnej na dosiahnutie určitej úrovne komfortu a riešenie optimalizačných úloh za účelom úspory energie a predĺženie dojazdu. Obdobné aplikácie možno nájsť i v budovách a prostrediach s podobnými charakteristikami.
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Research of Systems for Providing the Quality of the Environment in the Car Cabin
Šíp, Jan ; Kavička, František (referee) ; Volavý, Jaroslav (referee) ; Lízal, František (advisor)
Optimal conditions of indoor environmental quality, especially thermal comfort and indoor air quality, are important because they lead to the active safety of passengers. Long-term exposure to inconvenient temperatures may cause thermal stress and negatively affects the driver’s cognitive functions. These include important abilities of drivers, such as concentration, vigilance, speed of decision-making and others. The inappropriate temperature in the cabin is one of the most dangerous factors causing car crashes. Air indoor quality is negatively affected by exhaust gases or particles from tire wear, which enter the car cabin during ventilation. This can be prevented by using an air recirculation system which does not supply outside air, but it is a closed circuit. This mode, however, causes high CO2 concentration in the cabin which can lead to excessive fatigue. This thesis deals with the influence of different ventilation systems on indoor environmental quality, i. e. thermal comfort and indoor air quality. A partial factor of thermal comfort is the flow field which was investigated downstream of a benchmark automotive vent. CFD was applied to determine the flow field downstream of a vent. The results were validated by experimental data acquired by Constant Temperature Anemometry. CFD has been also used for the evaluation of the thermal comfort of three novel ventilation systems (mixing, ceiling and floor ventilation). The results were validated by experimental data acquired by thermal manikin and climate chamber. Indoor air quality has been evaluated based on the Age of Air. The analytical empirical equation by Rajaratnam can be successfully used also to determine the throw of the jet, which is favorable, especially in light of the fact that both computational methods were not very accurate in velocity decay predictions. The Large Eddy Simulation and Reynolds-averaged Navier–Stokes method are suitable for evaluating the flow field downstream of the automotive vent. The diagrams of comfort zones were evaluated for all regimes based on equivalent temperatures. The best performance in terms of the highest level of human comfort was achieved by the ceiling ventilation in the summer conditions and by the floor ventilation in the winter conditions. From the point of view of the Age of Air, the ceiling air ventilation system is the most suitable for the winter conditions. In the summer conditions the Age of Air values for individual air ventilation concepts are very similar for both interior types.
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EV vehicle cabin thermal management strategy in hot and cold climates
Matušková, Lucie ; Charvát, Pavel (referee) ; Fišer, Jan (advisor)
The goal of the work is to conduct an experiment to measure the temperature at which optimal thermal comfort is achieved. The experiment is carried out in a climate chamber, where constant climatic conditions acting on the vehicle can be ensured. The iHVAC measuring system is used to measure thermal comfort. Then to compare the values with the previous measurement that took place for other vehicles. Part of the work is devoted to research that describe the issue of thermal management of vehicles.
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Ventilated protective clothing for healthcare staff in contaminated environments
Štenclová, Kristýna ; Kopečková, Barbora (referee) ; Fišer, Jan (advisor)
Focus of the masters thesis is experimental verification of cooling effect of ambient air stream directed under a protective clothing of a human. The first part is a review of literature encompassing concepts related to thermal comfort and heat transfer. Possibilities of cooling a human who is moving in high ambient temperature environment are introduced in this part. The second part is focused on hypotheses devised and experiments performed. The last part is focused on results of the experiments and their comparison with an experiment described in literature.
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