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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.

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.

Although the terms "Human Thermal Comfort" and "Indoor Air Quality (IAQ)" can be highly subjective, they still dictate the indoor climate design (HVAC design) of a building. In order to evaluate human thermal comfort and IAQ, one of three main tools are used, a) direct questioning the subjects about their thermal and air quality sensation (voting, sampling etc.), b) measuring the human thermal comfort by recording the physical parameters such as relative humidity, air and radiation temperature, air velocities and concentration gradients of pollutants or c) by using numerical simulations either including or excluding detailed thermo-physiological models. The application of the first two approaches can only take place in post commissioning and/or testing phases of the building. Use of numerical techniques can however be employed at any stage of the building design. With the rapid development in computational hard- and software technology, the costs involved in numerical studies has reduced compared to detailed tests. Employing numerical modelling to investigate human thermal comfort and IAQ however demand thorough verification and validation studies. Such studies are used to understand the limitations and application of numerical modelling of human thermal comfort and IAQ in indoor climates. This PhD research is an endeavour to verify, validate and apply, numerical simulation for modelling heat transfer and respiration of occupants in indoor climates. Along with the investigations concerning convective and radiation heat transfer between the occupants and their surroundings, the work focuses on detailed respiration modelling of sedentary human occupants. The objectives of the work have been to: verify the convective and radiation numerical models; validate them for buoyancy-driven flows due to human occupants in indoor climates; and apply these validated models for investigating human thermal comfort and IAQ in a real classroom for which field study data was available. On the basis of the detailed verification, validation and application studies, the findings are summarized as a set of guidelines for simulating human thermal comfort and IAQ in indoor climates. This PhD research involves the use of detailed human body geometries and postures. Modelling radiation and investigating the effect of geometrical posture has shown that the effective radiation area varies significantly with posture. The simulation results have shown that by using an effective radiation area factor of 0.725, estimated previously (Fanger, 1972) for a standing person, can lead to an underestimation of effective radiation area by 13% for the postures considered. Numerical modelling of convective heat transfer and respiration processes for sedentary manikins have shown that the SST turbulence model (Menter, 1994) with appropriate resolution of near wall region can simulate the local air velocity, temperature and heat transfer coefficients to a level of detail required for prediction of thermal comfort and IAQ. The present PhD work has shown that in a convection dominated environment, the detailed seated manikins give rise to an asymmetrical thermal plume as compared to the thermal plumes generated by simplified manikins or point sources. Validated simulation results obtained during the present PhD work have shown that simplified manikins can be used without significant limitations while investigating IAQ of complete indoor spaces. The use of simplified manikins however does not seem appropriate when simulating detailed respiration effects in the immediate vicinity of seated humans because of the underestimation in the amount of re-inhaled CO2 and pollutants from the surroundings. Furthermore, the results have shown that due to the simplification in geometrical form of the nostrils, the CO2 concentration is much higher near the face region (direct jet along the nostrils) as compared to a detailed geometry (sideways jet). Simulating the complete respiration cycle has shown that a pause between exhalation and inhalation has a significant effect on the amount of re-inhaled CO2. Previous results have shown the amount of re-inhaled CO2 to range between 10 - 19%. The present study has shown that by considering the pause, this amount of re-inhaled CO2 falls down to values lower than 1%. A comparison between the simplified and detailed geometry has shown that a simplified geometry can cause an underestimation in the amount of re-inhaled CO2 by more than 37% as compared to a detailed geometry. The major contribution to knowledge delivered by this PhD work is the provision of a validated seated computational thermal manikin. This PhD work follows a structured verification and validation approach for conducting CFD simulations to predict human thermal comfort and indoor air quality. The work demonstrates the application of the validated model to a classroom case with multiple occupancy and compares the measured results with the simulation results. The comparison of CFD results with measured data advocates the use of CFD and visualizes the importance of modelling thermal manikins in indoor HVAC design rather than designing the HVAC by considering empty spaces as the occupancy has a strong influence on the indoor air flow. This PhD work enables the indoor climate researchers and building designers to employ simplified thermal manikin to correctly predict the mean flow characteristics in indoor surroundings. The present work clearly demonstrates the limitation of the PIV measurement technique, the importance of using detailed CFD manikin geometry when investigating the phenomena of respiration in detail and the effect of thermal plume around the seated manikin. This computational thermal manikin used in this work is valid for a seated adult female geometry.

The Passivhaus standard is a building methodology that was established in Germany in the 1990s. It uses a passive design strategy to achieve built environment comfort with minimum energy consumption. However, research shows that not every Passivhaus project has been successful in terms of its comfort and energy performance. Passivhaus is a representation of a high-performance, low-energy prototype of sustainable buildings, which, as a new building typology, embraces new ideas of comfort and accommodates a range of occupants who have different attitudes and expectations. Thus, the social grounding of such a new typology needs to be reconsidered. Understanding the phenomenon of Passivhaus living in the UK context forms the starting point of my research. In reflection of existing Passivhaus post-occupancy evaluation (POE) research in the UK, the majority of this research is focused on performance and frequently adopts an approach using prediction and computer simulation. Only a few studies have examined the Passivhaus system from an architectural design point of view. Research into its energy performance lacks a deeper connection with the occupants' perception of comfort and the architectural design of the Passivhaus. This research focuses on the coherence of Passivhaus living and builds up a theoretical framework to understand the Passivhaus system in relation to occupants' daily lives. It argues that by providing more possibilities and opportunities within the design of the built environment for adaptive behaviours and norms of sustainable living, as opposed to stressing energy efficiency and technological advances, the sustainability embodied in the Passivhaus standard can be further actualised. Previous research into the POE field of Passivhaus has employed a predominantly quantitative method. However, the small amount of research conducted using a qualitative approach demonstrates the potential benefits of gaining a better understanding of sustainability in people's perceptions of comfort, their everyday practices and the nature of their energy use. The methodological approach for the proposed research will be qualitative in nature due to the need to understand highly context-bound experiential data. A mixed approach of quantitative and qualitative methods will be explored to collect and analyse data from various aspects related to the subject matter in order to draw valid conclusions. The research uses a combined framework of grounded theory methodology and a multiple case study approach as a way of taking a step back from empirical research and building up an inductive theory-building process. The combination of these two frameworks is tailored for this research, which enables them to complement each other. The research provides an exploration of Passivhaus living and an insight into the delicate relationship between the occupants and their domestic space. The study explores the shifting perception of comfort, the delicate relationship between habitat and inhabitant and the process of adaptation in the Passivhaus to understand the shaping of household behaviour in relation to different contexts and scenarios unique to the Passivhaus industry. The substantive theory that describes this relationship is summarised at the end of the thesis, with the aim of informing potential Passivhaus clients of the system's holistic sustainable design features and to make recommendations for better Passivhaus design to building professionals.