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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Thermal and lighting performance of toplighting systems in the hot and humid climate of Thailand

Harntaweewongsa, Siritip 30 October 2006 (has links)
This study evaluated the potential of toplighting systems in the hot and humid tropics by using Bangkok, Thailand (latitude 13.7°N) as a test location. The analysis tested both the thermal and lighting performance of three toplighting systems. Toplighting, designed for use in one-story buildings or on the top floor of taller buildings, yields a uniformly distributed light throughout a space. However, in lower latitude locations, where there is no heating period, heat gain is a critical design issue since it significantly affects the annual energy consumption of the building. Accordingly, the decision to use toplighting in these locations needs to be carefully examined before any design considerations occur. In this study, the thermal and lighting performance of three toplighting systems were compared. For the thermal performance, total cooling loads, heat gains and losses, and interior temperature were evaluated. The lighting performance parameters examined were daylight factor, illuminance level, light distribution, and uniformity. EnergyPlus was used as the thermal analysis tool, and RADIANCE, along with a physical scale model, was used as the lighting performance analysis tool. The sky conditions tested were overcast, clear sky, and intermediate sky. Results have shown that, for locations with hot and humid climates with variable sky conditions such as Bangkok, Thailand, the roof monitors perform better than the other two systems in terms of the thermal and lighting performance. With similar cooling loads, the roof monitor provides better illuminance uniformity than the skylights and lightscoops, with adequate illuminance level (at mostly higher than 500 lux).
2

An investigation of methods for reducing the use of non-renewable energy resources for housing in Thailand

Rasisuttha, Sakkara 29 August 2005 (has links)
The purpose of this research is to develop methods that reduce energy consumption in a residential building in a hot and humid climate region (Thailand) using efficient architectural building components and renewable energy (solar energy) to produce electricity, domestic hot water, and supplemental cooling by night sky radiation. Improving the architectural building components, including building materials, is an option to reduce energy consumption in a building. Using renewable energy sources is another option to reduce the consumption of non-renewable energy. In residential buildings, solar energy has been utilized for space heating and domestic hot water using active solar collector systems and for generating electricity using photovoltaic (PV) systems. One photovoltaic system, the hybrid photovoltaic-thermal (PV-T) collector system, has been developed by several researchers over the last 20 years. The hybrid photovoltaic-thermal (PV-T) collector system is a combination photovoltaic (for producing electricity) and solar thermal collector (for producing hot water). Theoretical and experimental studies of this collector have highlighted the advantages of the hybrid PV-T collector system over separate systems of PV and solar collector in term of system efficiency and economics. Unfortunately, very little experimental data exists that demonstrates the advantages of a combined system. Therefore, one of the objectives of this study conducted was an experimental study of this system as an auxiliary energy source for a residential building. Night sky radiation has also been studied as a cooling strategy. However, no attempt so far could be found to integrate it to a hybrid PV-T collector system. The night sky radiation strategy could be operated with the hybrid PV/T collector system by using existing resources that are already present in the solar system. The integration of the night sky radiation into the hybrid PV-T collector system should yield more productivity of the system than the operation of the Hybrid PVT system alone. The research methods used in this work included instrumentation of a case-study house in Thailand, an experimental PV-T collector system, and a calibrated building thermal simulation. A typical contemporary Thai residential building was selected as a case-study house. Its energy use and local weather data were measured and analyzed. Published energy use of Thai residential buildings was also analyzed as well to determine average energy consumption. A calibrated computer model of the case-study building was constructed using the DOE-2 program. A field experiment of the thermal PV system was constructed to test its ability to simultaneously produce electricity and hot water in the daytime, and shed heat at night as a cooling strategy (i.e., night sky radiation). The resultant electricity and hot water produced by the hybrid PV-T collector system helped to reduce the use of non-renewable energy. The cooling produced by the night sky radiation also has to potential to reduce the cooling load. The evaluation of the case-study house and results of the field experiment helped to quantify the potential reduction of energy use in Thai residential buildings. This research provided the following benefits: 1) experimental results of a hybrid PV-T solar collector system that demonstrates its performance compared to typical system of separate photovoltaic and solar collector, 2) results of night sky radiation experiments using a photovoltaic panel as a radiator to demonstrate the performance of this new space cooling strategy, and 3) useful data from the case-study house simulation results and guidelines to assist others in transferring the results to other projects.
3

Thermal and lighting performance of toplighting systems in the hot and humid climate of Thailand

Harntaweewongsa, Siritip 30 October 2006 (has links)
This study evaluated the potential of toplighting systems in the hot and humid tropics by using Bangkok, Thailand (latitude 13.7°N) as a test location. The analysis tested both the thermal and lighting performance of three toplighting systems. Toplighting, designed for use in one-story buildings or on the top floor of taller buildings, yields a uniformly distributed light throughout a space. However, in lower latitude locations, where there is no heating period, heat gain is a critical design issue since it significantly affects the annual energy consumption of the building. Accordingly, the decision to use toplighting in these locations needs to be carefully examined before any design considerations occur. In this study, the thermal and lighting performance of three toplighting systems were compared. For the thermal performance, total cooling loads, heat gains and losses, and interior temperature were evaluated. The lighting performance parameters examined were daylight factor, illuminance level, light distribution, and uniformity. EnergyPlus was used as the thermal analysis tool, and RADIANCE, along with a physical scale model, was used as the lighting performance analysis tool. The sky conditions tested were overcast, clear sky, and intermediate sky. Results have shown that, for locations with hot and humid climates with variable sky conditions such as Bangkok, Thailand, the roof monitors perform better than the other two systems in terms of the thermal and lighting performance. With similar cooling loads, the roof monitor provides better illuminance uniformity than the skylights and lightscoops, with adequate illuminance level (at mostly higher than 500 lux).
4

Strategic environmental assessment : a land use evaluation approach for development assistance

Warner, Michael January 1995 (has links)
No description available.
5

Low-energy Passive Solar Residence in Austin, Texas

Sau, Arunabha 2010 August 1900 (has links)
From the various studies, it can be concluded that the excessive summer heating and the humidity are one of the major problems of the hot, humid climatic region. The literature review for this study shows that natural ventilation alone cannot meet year long optimum indoor comfort in buildings. This research, through a design exercise, intends to verify whether a naturally ventilated house, in hot humid region of Austin, TX, can enhance its passive cooling potential through double‐walled wind catcher and solar chimney. In this research, a passive solar residence has been designed. Two designs have been explored on the chosen site: a basecase design without the wind catcher and solar chimney and another design with wind catcher and solar chimney. In the designcase, the placement of the wind catcher and the solar chimney has been designed so that a thermal siphon of airflow inside the building can be created. The design might show that there will be a natural airflow during the time of the year when natural wind does not flow. Moreover, the double walled wind catcher will resist the cool winter wind due to its shape and orientation. In the design, the placement of the wind catcher and the solar chimney has been done so that a thermal siphon inside the building can be created. Therefore, inside the home, there will be a natural airflow during the time of the year when natural wind does not flow. The double walled wind catcher has been designed and placed according to the orientation of the building in order to achieve the optimum wind flow throughout the year. The solar chimney has been placed in a certain part of the building where it can get maximum solar exposure. By comparing two cases, it can be clearly said that there will some kind of changed indoor comfort level. Since the potential of the design has been judged through perception, a computational fluid dynamics simulation analysis for a year is to be done.
6

An analysis of maximum residential energy-efficiency in hot and humid climates

Malhotra, Mini 12 April 2006 (has links)
Energy-efficient building design involves minimizing the energy use and optimizing the performance of individual systems and components of the building. The benefits of energyefficient design, in the residential sector, are direct and tangible, provided that design strategies with a substantial combined energy and cost-saving potential are adopted. Many studies have been performed to evaluate the energy-saving potential and the costeffectiveness of various design options, and to identify conditions for optimizing the performance of building systems and components. The results of these studies, published in various resources, were analyzed discretely using different techniques, and were reported using different bases for comparison. Considering the complex interaction of, and energy flows through various building components, it is difficult to directly compare/combine the results from various studies to determine the energy-saving potential of combination of strategies, and to select an appropriate set of strategies for making design decisions. Therefore, this thesis develops a comprehensive survey and analysis of energy-efficient design strategies and their energy-saving potential, in isolation as well as in combination, using a DOE-2 simulation model of a prototype house in the hot and humid climate of Houston, Texas. Optimized strategies that included building configuration, materials/ assembly for building envelop components, and efficient mechanical and electrical systems, equipment and appliances, were applied in combination that could minimize the annual energy use. Application of these strategies is expected to allow downsizing systems and equipment and to confirm their operation at their rated performance, resulting in additional installation and operation cost savings. The study is concluded by outlining the procedures for selecting optimized set of strategies, and by developing guidelines for achieving maximum energy-efficiency in singlefamily detached houses in hot and humid climates. Thus, this study will facilitate the selection of energy-saving measures for their individual or combined application for developing energyefficient residences in hot and humid climates.
7

Ecología y geografía de las regiones tropicales : la cuenca del Madre de Dios. De la franja pionera a la integración binacional

Novoa Goicochea, Zaniel I. 10 April 2018 (has links)
La Cuenca del Madre de Dios, es una región que está plenamente inserta en el trópico húmedo y abarca una considerable superficie del oriente peruanoboliviano. Esta región con vastas áreas naturales, empieza a mostrar cambios fundamentales en la organización de su espacio. Su ocupación si bien se reconoce es desde muy antiguo, por parte de grupos etnicos; ha visto en el presente siglo, principalmente en las tres últimas décadas, el acontecer de diferentes fases en las relaciones del hombre con su medio. El estudio para el desarrollo integral de espacios definidos por cuencas hidrográficas multinacionales como la del Madre de Dios, supone problemas técnicos y políticos. El diseño del estudio, con un enfoque amplio, debe considerar factores de tipo físico, socio-económico, político e institucional.Estas notas, resultado de la experiencia de trabajo en la región, presentan una visión sintética de la realidad de la Cuenca y ponen el acento en: La Oferta Ambiental, la Ocupación del Territorio, la Caracterización de sus Unidades Político-Administrativas y la Estrategia para el Desarrollo Integral. El ecodesarrollo, la ordenación territorial y la integración son elementos claves de una estrategia de actuación que considere a la Cuenca como marco de la planificación regional que define un contexto espacial y ambiental adecuado para las tareas del desarrollo. Por todo lo anterior, el Ecodesarrollo como estilo y la Integración Territorial Multinacional como política-, son consideradas de suma importancia para el desarrollo integral y sostenido de espacios fronterizos en las regiones tropicales como lo es la Cuenca del Madre de Dios.  The Madre de Dios Basin is a region totally inserted in the humid tropic and covers a large section of the Peruvian and Bolivian Oriente. This region with extensive natural areas has already started to show changes in its spatial organisation. Though it was settled by different ethnic groups since ancient times, it has been in the last three decades that sorne important changes have occurred in the man-environment relationships. To study binational basins such as the one of Madre de Dios, brings about many technical and political difficulties. This is because the research project design must be broadly oriented to cover topics such as physical, socioeconomic, political, and institutional. In this paper 1 present the results of a fieldwork experience in the region. They give us a synthetic view of the Madre de Dios reality, placing special attention to the environmental realm, its characterization of the political and administrative units, and a strategy to integral development. Land management, ecodevelopment and integration are key elements toward a decision-making strategy that takes the basin as a framework to regional planning.
8

Exergoeconomic Analysis of Solar Organic Rankine Cycle for Geothermal Air Conditioned Net Zero Energy Buildings

Rayegan, Rambod 12 July 2011 (has links)
This study is an attempt at achieving Net Zero Energy Building (NZEB) using a solar Organic Rankine Cycle (ORC) based on exergetic and economic measures. The working fluid, working conditions of the cycle, cycle configuration, and solar collector type are considered the optimization parameters for the solar ORC system. In the first section, a procedure is developed to compare ORC working fluids based on their molecular components, temperature-entropy diagram and fluid effects on the thermal efficiency, net power generated, vapor expansion ratio, and exergy efficiency of the Rankine cycle. Fluids with the best cycle performance are recognized in two different temperature levels within two different categories of fluids: refrigerants and non-refrigerants. Important factors that could lead to irreversibility reduction of the solar ORC are also investigated in this study. In the next section, the system requirements needed to maintain the electricity demand of a geothermal air-conditioned commercial building located in Pensacola of Florida is considered as the criteria to select the optimal components and optimal working condition of the system. The solar collector loop, building, and geothermal air conditioning system are modeled using TRNSYS. Available electricity bills of the building and the 3-week monitoring data on the performance of the geothermal system are employed to calibrate the simulation. The simulation is repeated for Miami and Houston in order to evaluate the effect of the different solar radiations on the system requirements. The final section discusses the exergoeconomic analysis of the ORC system with the optimum performance. Exergoeconomics rests on the philosophy that exergy is the only rational basis for assigning monetary costs to a system’s interactions with its surroundings and to the sources of thermodynamic inefficiencies within it. Exergoeconomic analysis of the optimal ORC system shows that the ratio Rex of the annual exergy loss to the capital cost can be considered a key parameter in optimizing a solar ORC system from the thermodynamic and economic point of view. It also shows that there is a systematic correlation between the exergy loss and capital cost for the investigated solar ORC system.
9

Using Ventilated Envelopes to Improve the Thermal Performance of Buildings in Hot-Humid Climate

Bakri, Miassar Mohammed January 2015 (has links)
Many attempts have been made to design buildings that reduce the heat gain inside the building. In hot-humid region, architects deal with many forces of nature. These forces might be Rain, Humidity, and solar heat gain. Thermal mass was been used for centuries in hot-arid region as a way to limit the dry-bulb temperature swing inside the building. However, there are some architects who agree that thermal mass materials could be used in hot-humid climate. This thesis project suggests using ventilated envelope that incorporates thermal mass in the design of the ventilated envelope. The result of the experiment shows that using ventilated envelopes with thermal mass would allow the heat gained in the cladding and in the thermal mass to be released to the air cavity and therefore releasing the heat from the building to the exterior atmosphere. The ventilated facade could be improved by adding thermal insulation and by using reflective materials on the cladding.
10

Low energy ground cooling system for buildings in hot and humid Malaysia

Sanusi, Aliyah Nur Zafirah January 2012 (has links)
This thesis presents an investigation into the viability of Low Energy Earth Pipe Cooling Technology in providing thermal comfort in Malaysia. The demand for air-conditioning in buildings in Malaysia affects the country escalating energy consumption. Therefore, this investigation was intended to seek for a passive cooling alternative to air-conditioning. By reducing the air-conditioning demand, there would be a higher chance of Malaysia government to achieve their aim in reducing CO2 emissions to 40 per cent by the year 2020, compared to 2005 levels. The passive technology, where the ground was used as a heat sink to produce cooler air, has not been investigated systematically in hot and humid countries. In this work, air and soil temperatures were measured on a test site in Kuala Lumpur. At 1m underground, the result is most significant, where the soil temperature are 6oC and 9oC lower than the maximum ambient temperature during wet and dry season, respectively. Polyethylene pipes were buried around 0.5m, 1.0m and 1.5m underground and temperature drop between inlet and outlet were compared. A significant temperature drop was found in these pipes: up to 6.4oC and 6.9oC depending on the season of the year. The results have shown the potential of Earth Pipe in providing low energy cooling in Malaysia. A parametric study on the same experiment was carried out using Energy Plus programme. Energy Plus data agreed with the field work data and therefore, this confirms Energy Plus is reliable to investigate Earth Pipe Cooling in Malaysia. Furthermore, thermal comfort of air at the Earth Pipe outlet was analyzed and the result has shown that the outlet air is within the envelope of thermal comfort conditions for hot/humid countries

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