published_or_final_version / abstract / toc / Mechanical Engineering / Master / Master of Philosophy

Call number: LD2668 .T4 1985 S64 / Master of Science

Cheng Bo-ki. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 150-153). / Abstracts in English and Chinese. / Chapter chapter 1 --- Introduction --- p.10 / Chapter chapter 2 --- Background & Literature --- p.15 / Chapter 2.1 --- Why Environmental Design? --- p.15 / Comfort and Energy --- p.15 / "Our Problems: Energy, Environment, and Health" --- p.19 / Chapter 2.2 --- Knowledge in Environmental Design --- p.27 / What is Environmental Design? --- p.27 / Current knowledge in Environmental Design: Thermal Performance --- p.30 / Thermal Studies in Hong Kong --- p.37 / Chapter 2.3 --- Summary and Propositions --- p.42 / Chapter chapter 3 --- Scale Model Study --- p.47 / Chapter 3.1 --- Test Modules Application --- p.47 / Chapter 3.2 --- Research Methodology & Experimental Setup --- p.54 / Testing Facility in CUHK --- p.54 / Solarimeter Substitute --- p.58 / Chapter 3.3 --- Experimental Series --- p.61 / Chapter 3.3.1 --- Envelope Colour --- p.61 / Chapter 3.3.2 --- Windows --- p.73 / Chapter 3.3.3 --- Shading --- p.75 / Chapter 3.3.4 --- Thermal Mass --- p.80 / Chapter 3.3.5 --- Orientations --- p.83 / Chapter 3.3.6 --- "Combined Effects ofThermal Mass, Windows and Orientations" --- p.85 / Chapter 3.3.7 --- "Combined Effects ofThermal Mass, Shading and Orientations" --- p.88 / Chapter 3.4 --- Summary of Experiments --- p.90 / Chapter 3.5 --- Predicting Indoor Air Temperature --- p.93 / Chapter 3.5.1 --- Development of Predictive Formulas --- p.93 / Chapter 3.5.2 --- Parametric Study of Envelope Colour --- p.97 / Chapter 3.5.3 --- Parametric Study of Window Shading --- p.100 / Chapter chapter 4 --- Field Study --- p.104 / Chapter 4.1 --- Description of Housing Unit: Concord-I Block --- p.104 / Chapter 4.2 --- Experimental Setup --- p.105 / Chapter 4.3 --- Result of Field Measurement --- p.108 / Chapter 4.3.1 --- Perform ance of top-most floor --- p.108 / Chapter 4.3.2 --- Performance of Individual Rooms --- p.109 / Chapter 4.3.3 --- Effect of Orientation --- p.110 / Chapter 4.3.4 --- Indoor Thermal Comfort --- p.113 / Chapter 4.4 --- Summary of Field Measurement --- p.116 / Chapter chapter 5 --- Thermal Performance Prediction --- p.118 / Chapter chapter 6 --- Conclusion --- p.126 / Appendix 1 --- p.131 / Appendix 2 --- p.133 / Appendix 3 --- p.140

Green roofs can be an effective and appealing way to increase the energy efficiency of buildings by providing active insulation. As plants in the green roof transpire, there is a reduction in heat flux that is conducted through the green roof. The R-value, or thermal resistance, of a green roof is an effective measurement of thermal performance because it can be easily included in building energy calculations applicable to many different buildings and situations. The purpose of this study was to determine if an increase in ambient temperature would cause an increase in the R-value of green roofs. Test trays containing green roof materials were tested in a low speed wind tunnel equipped to determine the R-value of the trays. Three different plant species were tested in this study, ryegrass (Lolium perenne), sedum (Sedum hispanicum), and vinca (Vinca minor). For each test in this study the relative humidity was maintained at 45% and the soil was saturated with water. The trays were tested at four different ambient temperatures, ranging from room temperature to 120ºF. The resulting R-values for sedum ranged from 1.37 to 3.28 ft²h°F/BTU, for ryegrass the R-values ranged from 2.15 to 3.62 ft²h°F/BTU, and for vinca the R-values ranged from 3.15 to 5.19 ft²h°F/BTU. The average R-value for all the tests in this study was 3.20 ft²h°F/BTU. The results showed an increase in R-value with increasing temperature. Applying an ANOVA analysis to the data, the relationship between temperature and R-value for all three plant species was found to be statistically significant.

M.S.

Mu Jun. / Thesis submitted in: December 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 181-183). / Abstracts in English and Chinese. / Chapter 1. --- Introduction --- p.1 / Chapter 2. --- Issues and Background --- p.5 / Chapter 2.1. --- Why Ecological Architecture? --- p.5 / Chapter 2.1.1. --- Fossil Fuels and Environmental Issues --- p.5 / Chapter 2.1.2. --- The Buildings' Role in the Issues --- p.9 / Chapter 2.2. --- Knowledge in Ecological Design --- p.11 / Chapter 2.2.1. --- About Ecological Architecture --- p.11 / Chapter 2.2.2. --- Thermal Study ~ A Significant Way to Ecological Architecture --- p.13 / Chapter 2.2.3. --- What is Suitable Ecological Architecture for Loess Plateau areas of China --- p.16 / Chapter 3. --- Defining the Future Ecological Architecture in Loess Plateau Areas --- p.20 / Chapter 3.1. --- Economy for Building --- p.20 / Chapter 3.1.1. --- Situation --- p.20 / Chapter 3.1.2. --- Technological Strategies towards a Cost-effective Ecological Approach --- p.22 / Chapter 3.1.3. --- Alternative-Technological Approach --- p.24 / Chapter 3.2. --- Climate --- p.25 / Chapter 3.2.1. --- Climatic Characteristics --- p.25 / Chapter 3.2.2. --- A climatically Responsive Approach ~ Selective Environmental Design --- p.32 / Chapter 3.2.3. --- Climatic Response of Thermal Design Guidelines --- p.33 / Chapter 3.2.3.1. --- Minimizing Heat loss through Building Fabrics --- p.34 / Chapter 3.2.3.2. --- Utilization of Available Natural Energy --- p.37 / Chapter 3.3. --- Benefits from Vernacular Architecture --- p.45 / Chapter 3.3.1. --- Earth ArchitecturéؤVernacular Architecture on Loess Plateau --- p.45 / Chapter 3.3.1.1. --- Classification --- p.46 / Chapter 3.3.1.2. --- Environmental Performance --- p.53 / Chapter 3.3.2. --- Literature Review of Studies on Earth Architecture --- p.58 / Chapter 3.3.2.1. --- Properties of Earth-based Materials --- p.58 / Chapter 3.3.2.2. --- Literature on Earth Architecture --- p.60 / Chapter 3.3.3. --- Issues and Development --- p.76 / Chapter 3.3.3.1. --- Limitation in Existing Earth Architecture of Loess Plateau --- p.76 / Chapter 3.3.3.2. --- Recent Research on Developing Earth Architecture in Loess Plateau Areas --- p.77 / Chapter 3.3.3.3. --- Considerations --- p.81 / Chapter 3.4. --- Conclusion --- p.82 / Chapter 4. --- Making of the Classroom as Designed for the Thermal Study --- p.84 / Chapter 4.1. --- Why a Classroom? --- p.84 / Chapter 4.2. --- The School Project and the Classroom Simulated --- p.85 / Chapter 5. --- Thermal Study by Simulating Experiments --- p.88 / Chapter 5.1. --- Research Methodology --- p.88 / Chapter 5.2. --- Program Validation --- p.89 / Chapter 5.3. --- Experimental Series of Simulation and Model Setup --- p.93 / Chapter 5.4. --- Thermal Mass and Insulation --- p.95 / Chapter 5.4.1. --- External Wall --- p.95 / Chapter 5.4.2. --- Roof Study --- p.97 / Chapter 5.4.3. --- "Windows, Doors and Glazing" --- p.100 / Chapter 5.4.4. --- Incorporated Performance --- p.103 / Chapter 5.5. --- Passive system for natural energy use --- p.106 / Chapter 5.5.1. --- Passive Solar System Study --- p.106 / Chapter 5.5.1.1. --- Wall-based Passive Solar System --- p.106 / Chapter 5.5.1.2. --- Roof-based Passive Solar System --- p.125 / Chapter 5.5.1.3. --- System Comparison in Thermal Performance --- p.135 / Chapter 5.5.2. --- Natural Ventilation System with the Heat Exchanger --- p.137 / Chapter 5.5.2.1. --- Pre-warming Effect of the Solar Space --- p.139 / Chapter 5.5.2.2. --- Effect of the Earth-air-tunnel --- p.142 / Chapter 5.5.2.3. --- Incorporation with the Chimney --- p.153 / Chapter 5.5.2.4. --- Comparison in Performance --- p.158 / Chapter 5.6. --- Summary --- p.159 / Chapter 6. --- Design Improvement and Performance Prediction --- p.162 / Chapter 6.1. --- System Incorporation and Design Improvement --- p.161 / Chapter 6.2. --- Thermal Performance Prediction --- p.167 / Chapter 7. --- Conclusion --- p.174 / Appendix --- p.179

This study describes a simulation-based approach for informing the incorporation of Phase Change Materials (PCMs) in buildings designed to the "Passive House" standard. PCMs provide a minimally invasive method of adding thermal mass to a building, thus mitigating overheating events. Phase change transition temperature, quantity, and location of PCM were all considered while incrementally adding PCM to Passive House simulation models in multiple climate zones across the United States. Whole building energy simulations were performed using EnergyPlus from the US Department of Energy. A prototypical Passive House with a 1500 Watt electric heater and no mechanical cooling was modeled. The effectiveness of the PCM was determined by comparing the zone-hours and zone-degree-hours outside the ASHRAE defined comfort zone for all PCM cases against a control simulation without PCM. Results show that adding PCM to Passive Houses can significantly increase thermal comfort so long as the house is in a dry or marine climate. The addition of PCM in moist climates will not significantly increase occupant comfort because the majority of discomfort in these climates arises due to latent load. For dry or marine climates, PCM has the most significant impact in climates with lower cooling degree-days, reducing by 93% the number of zone-hours outside of thermal comfort and by 98% the number of zone-degree-hours uncomfortable in Portland, Oregon. However, the application of PCM is not as well suited for very hot climates because the PCM becomes overcharged. Only single digit reductions in discomfort were realized when modeling PCM in a Passive House in Phoenix, Arizona. It was found that regardless of the climate PCM should be placed in the top floor, focusing on zones with large southern glazing areas. Also, selecting PCM with a melt temperature of 25°C resulted in the most significant increases in thermal comfort for the majority of climates studied.

O presente trabalho apresenta uma análise numérica do desempenho térmico de painéis construídos utilizando o sistema light steel framing (LSF) submetido a ação térmica decorrente de um incêndio. O objeto de estudo foram painéis utilizados na construção de duas casas modelo localizadas na Universidade Tecnológica Federal do Paraná campus Curitiba, construídas com materiais disponíveis comercialmente no Brasil e as análises utilizaram propriedades disponibilizadas pelos fabricantes e pela norma brasileira. A análise numérica foi realizada no software ANSYS, com base no método dos elementos finitos em análise térmica transiente. O modelo foi validado com base em comparação com análises experimentais pesquisadas na literatura. Quatro painéis obtidos das casas modelo foram analisados. Os painéis que utilizaram lã de PET para preenchimento da cavidade foram também analisados com preenchimento de lã de vidro. Um painel simples, com a cavidade preenchida por ar foi analisado para ser usado como referência. Por fim, com a utilização de coeficientes de redução da resistência ao escoamento propostos pela ABNT NBR 14323:2001, determinou-se a redução da resistência do aço do perfil de acordo com o tempo de exposição ao incendio e o tempo de resistência ao fogo dos perfis. Com base nos resultados obtidos é possível afirmar que mesmo para os paneis com pior desempenho, a proteção obtida pode ser suficiente, a depender do carregamento aplicado ao montante e do Tempo requerido de resistência ao fogo necessário. O presente trabalho apresenta informação relevante sobre o desempenho térmico em situação de incêndio do sistema LSF constituído com materiais brasileiros. / The thermal performance of light steel framing (LSF) panels was the objective of this study. The study subject was panels used in the construction of two model houses located at Federal Technology University – Parana, built with materials commercially available in Brazil. The analysis was set with material properties from the manufacturer and in compliance with the Brazilian regulation, using the finite element method for a transient thermal analysis. The model validation was based on experimental tests available in the literature. Based on the validated model, the four panels have been analyzed. Two of the panels used PET wool in the cavity for insulation and the analysis was repeated with them replacing it for glass wool. A panel with no insulation was also analyzed to be used as reference. Based on the analysis results and the resistance reduction coefficients proposed by ABNT NBR 14323:2001, the resistance decrease of the studs due to the fire exposure and the panels resistance to fire were determined. Based on the obtained results, it can be affirmed that, depending on the applied load and the required Equivalent time of fire exposure, even the less protective configuration of the panels presented can be viable. The current study presented relevant information about the performance of LSF manufactured in Brazil when exposed to fire.