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The work presented in this thesis is devoted to further understanding heat transfer through clothing under different circumstances, in order to provide guidelines for the design and construction of clothing with regard to thermal comfort. In one part of this work, studies were concentrated on the clothing thermal insulation in windy conditions. In this part, a newly designed cylindrical togmeter and a theoretical model have been developed. The numerical solution derived from the theoretical model agrees well with the experimental findings from the cylindrical togmeter in a wind tunnel. The heat transfer mechanisms involved in the wind induced reduction of clothing thermal insulation have been better understood by examining the experimental and theoretical results. The effects of wind velocity, air permeability and stiffness of the outer fabrics, air permeability and thickness of the inner fibrous battings, and the dimensions of the human body on the clothing thermal insulation have also been examined and discussed. Furthermore, based on the understanding of the mechanism of air penetration into permeable clothing assemblies, methods have been proposed for the design and construction of wind resistant protective clothing by using permeable outer fabrics. These methods were evaluated on the cylindrical togmeter and are believed to have important practical values. The other part of this work was focused on the development and laboratory use of a fabric manikin. The "skin" of the manikin was made of coated water-proof fabric, and heated water was circulated inside the "body". The arms and legs of the manikin could be moved to simulate walking. The manikin was very cheap to construct when compared with that of a copper manikin and can be widely applied for routine tests for outdoor and military garments subject to some modifications in its design. With this fabric manikin, a series of experiments have been conducted to investigate the effects of body motion, clothing design and environmental conditions on the thermal insulation of clothing. Some useful information for the design of functional clothing and for the prediction of the thermal stress of a clothed person in different environmental conditions has been provided through this investigation.

The purpose of this research is to investigate human comfort criteria under steady-state conditions as a function of ambient air temperature, mean radiant temperature, relative humidity, air velocity, level of activity, and clothing insulation. Since the current ASHRAE Standard 55-1994 is for sedentary activity, this study will consider relative humidity (20% to 65%), dry bulb temperature (73 oF to 82 oF), air velocity (30 fpm and 50 fpm), and sedentary-to-moderate activity. The mean radiant temperature will be taken to be the same as the ambient air temperature. The experimental results collected at the Kansas State University Environmental Test Chamber are compared with the Fanger (1982) thermal comfort model and with ASHRAE Standard 55-1994. The experimental study results agreed well with ASHARE Standard 55-1994 for 1-met activity level (sedentary), and the thermal comfort for 1-met activity level was predicted with reasonable accuracy by Fanger?s (1982) Model. For 2.3 met activity level, the experimental results did not agree with ASHRAE Standard 55-1994 or the Fanger Model predictions.

This thesis presents a body of work conducted in the field of domestic thermal comfort. The aim of this research was to determine the suitability of the Predicted Mean Vote (PMV) index in homes within the UK. Two field studies were conducted with a sample of participants living in owner occupied properties in a UK city (London) and a UK provincial town (Loughborough). Research findings indicate that the PMV is indeed a good predictor of thermal sensation in homes when conditions are steady state and people are engaged in near-sedentary activities. When conditions are not steady state and people are engaged in a variety of household activities, the accuracy of the PMV index can be improved by using a metabolic rate coefficient of 1.7. Further research work is required to ascertain this and likewise the range of applicability of the Adaptive Model.

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Made available in DSpace on 2014-06-11T19:35:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T19:05:51Z : No. of bitstreams: 1 camargo_jr_dr_guara.pdf: 1019492 bytes, checksum: 2297d5279bcff4ccbedcb325ccb31939 (MD5) / O resfriamento evaporativo consiste na utilização da evaporação da água através da passagem de um fluxo de ar, provocando a redução na temperatura do ar e, apesar de utilizarem tecnologia relativamente simples, ainda são pouco utilizados para o condicionamento de ar em regiões de clima úmido. Este trabalho realiza um estudo dos potenciais e limitações de sistemas de condicionamento de ar por resfriamento evaporativo e evaporativo-adsortivo quando utilizados com o objetivo de propiciar conforto térmico ao homem e reduzir o consumo de energia. Apresenta-se, inicialmente, o princípio de funcionamento de sistemas de resfriamento evaporativo e de desumidificadores por adsorção. A seguir, apresentam-se os resultados dos ensaios de desempenho realizados em um resfriador evaporativo direto e propõe-se um novo sistema a ser utilizado em regiões em que as condições de conforto não podem ser supridas pelo resfriamento evaporativo somente. Estuda-se a aplicação desses sistemas a diversas cidades, caracterizadas por diferentes condições climáticas e conclui-se que os sistemas de resfriamento evaporativo acoplados a um desumidificador adsortivo apresentam perspectivas promissoras, principalmente para aplicação em condicionamento de ar onde existem fontes de calor de baixo custo ou calor residual disponível. A análise das condições do ar de insuflamento demonstra a viabilidade da utilização do sistema proposto para conforto térmico humano em regiões de clima úmido como uma alternativa aos sistemas convencionais de condicionamento de ar, poupando energia e protegendo o meio ambiente. / Evaporative cooling consists in using water evaporation through the passage of an air flow, thus decreasing the air temperature. In spite of using simple technology, it is seldon used for air conditioning in humid climate regions. This thesis develops a methodology that can be used to establish potentials and limitations of air conditioning systems by evaporative and desiccant cooling when used for human thermal comfort and lower power consumption. Firstly, the operational principles of evaporative cooling and dehumidification by adsorption systems are presented. Next, the results of performance tests developed on a direct evaporative cooler are described. Finally, a new system to be used in regions where the thermal comfort conditions cannot be supplied only by evaporative cooling is proposed. The applications of this system in several cities, characterized by different climate conditions are studied. It concluded that evaporative cooling systems coupled to a dehumidification adsorption system present promising perspectives, mainly to low cost air conditioning applications where residual heat sources are available. The analysis of the supply air conditions shows the feasibility of the proposed system for human thermal comfort in humid climates as an alternative to conventional air conditioning systems, saving energy and protecting the environment.

This thesis investigates the design of domestic glazed spaces in the United Kingdom, by studying the effect of a range of variables on the thermal properties of glazed spaces, in order to achieve a thermally comfortable environment while minimising the use of energy for heating and cooling. Earlier research work on domestic glazed spaces has concentrated on optimising the design of the space as a mechanism for reducing the space heating load of the parent house. Computer based dynamic thermal simulation is used in this study as the method of assessment and the variables tested are; glazing type, orientation and the degree of integration of the glazed space with the parent building. Unshaded, unventilated, and unheated, glazed spaces were found to be thermally comfortable for only a quarter to a third of the hours of possible use whatever the form, orientation or glazing type. Generally the higher the insulating value of the glazing the fewer the number of comfortable hours for all orientations and arrangements, due to discomfort being caused by high temperatures, even though the weather data used for the simulations only rose above 27'C for 25 hours during the course of the year. Further studies showed that significant reductions in the number of hours experiencing high temperatures could be achieved by the use of buoyancy driven ventilation. The studies indicated that glazed spaces integrated into the house plan tended to experience high temperatures for long periods but that the peak temperatures were much lower than those experienced for shorter periods in the exposed spaces. The effect of ventilation on overheating was therefore more marked in the integral than in the exposed glazed spaces. A study of the effects of roof shading blinds indicated that internal blinds had minimal effect in reducing high temperatures. External blinds had a greater effect than ventilation and a combination of external roof blinds and ventilation appears to provide the best strategy for the control of high temperatures. Studies on space heating loads for the houses and glazed spaces indicated wide variations in the heating loads of the glazed spaces depending predominantly on the insulating properties of the glazing. In terms of the reduction in the space heating load for the parent house, the thermal simulation results predict very little change due to the presence of the glazed space. A study on the effect of increasing the thermal storage properties of the floor construction of the glazed spaces, by substituting a clay tile finish for the original thin carpet layer, in order to reduce high temperatures proved inconclusive with minimal changes in the number of comfortable hours experienced. An investigation of thermal comfort during the Winter indicated that low surface temperatures did not reduce resultant temperatures below the lower limit of the comfortable range in the glazed spaces, during the heated period.

This thesis is about problematics of creating Computational Fluid Dynamics (CFD) model suited for analysis of airflow around sitting passive person. Thesis includes analysis of velocity field distribution, thermal distribution and thermal losses in the surroundings of sitting thermal dummy (computational model) and comparison of these values with experimental measurements. Thesis is a part of large experimental research (this research is not included here) focused on creating of functional method used for person-surrounding airflow analysis in future commercial use.

This research is based on the challenge in the field of thermal comfort between the steady state and adaptive comfort theories. It challenges the concept of standard ‘comfort zone’ and investigates the application of ‘adaptive opportunity’ in the workplace. The research question is: ‘Does thermal control improve user satisfaction in cellular and open plan offices? Norwegian vs. British practices’. Currently, centrally controlled thermal systems are replacing individual thermal control in the workplace (Bordass et al., 1993, Roaf et al., 2004) and modern open plan offices are replacing traditional cellular plan offices in Scandinavia (Axéll and Warnander, 2005). However, users complaint about the lack of individual thermal control (Van der Voordt, 2003), which is predicted as an important asset to the workplace in the future (Leaman and Bordass, 2005). This research seeks users’ opinion on improving their satisfaction, comfort and health in two environments with high and low levels of thermal control, respectively the Norwegian and British workplace contexts. Two air conditioned Norwegian cellular plan offices which provide every user with control over a window, blinds, door and the ability to adjust the temperature are compared against two naturally and mechanically ventilated British open plan offices with limited thermal control over the windows and blinds for occupants seated around the perimeter of the building. Complimentary quantitative and qualitative methodologies are applied, with a particular emphasis on grounded theory, on which basis the research plan is formulated through a process of pilot studies. Occupants’ perception of their thermal environment within the building is recorded through a questionnaire and empirical building performance through thermal measurements. These traditional techniques are further reinforced with semi-structured interviews to investigate thermal control. A visual recording technique is introduced to analyse the collected information qualitatively regarding the context and meaning. The ASHRAE Standard 55-2010 and its basis do not apply to the case study buildings in this research. This thesis suggests that thermal comfort is dynamic rather than fixed. Occupants are more likely to prefer different thermal settings at different times, which is in contrast with providing a steady thermal condition according to the standard ‘comfort zone’. Furthermore, the occupants of the Norwegian cellular plan offices in this research report up to 30% higher satisfaction, comfort and health levels compared to the British open plan offices, suggesting the impact of the availability of individual thermal control. This research suggests that rather than providing a uniform thermal condition according to the standard ‘comfort zone’, office buildings are recommended to provide a degree of flexibility to allow users to find their own comfort by adjusting their thermal environment according to their immediate requirements.

The main objective of the study was to analyze the thermal comfort of a naturally ventilated building in Kampala – Uganda. CEDAT building in Makerere University was selected as the case study representing an educational center which is a naturally ventilated building. DesignBuilderEnergyPlus simulation program was used to model and perform simulations. Simulations for thermal comfort were done on the baseline model with a WWR of 30 % to attain the baseline model comfort data based on Simple ASHRAE 55-2004 throughout the year. Simulations for different natural ventilation improvement strategies were then done through parametric analysis. The strategies simulated for improving occupancy thermal comfort were lighting control, mechanical ventilation without cooling (fans), mechanical ventilation with cooling and variation of window to wall ratio from 0% to 100% to establish its effect on the thermal comfort of the building occupants.   Results for predicted thermal comfort sensation of occupants revealed that baseline thermal comfort sensation was between hot and slightly warm with 35.15% discomfort hours against 64.85% comfort throughout the year. Lighting control thermal comfort sensation improved to between hot and neutral with 0.55% improvement in baseline occupancy thermal comfort hours.  Mechanical ventilation without cooling registered a negligible improvement in occupancy thermal comfort while on application of scheduled cooling thermal comfort improved between slightly warm and slightly cool with a 12% improvement in comfort hours. Variation of WWR revealed that thermal comfort generally increased negligible with increase in WWR.    It can be concluded that mechanical ventilation with cooling combined with lighting control can be great strategies and opportunity for improving the case study thermal comfort.