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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

A Performance Analysis of Solar Chimney Passive Ventilation System in the Unt Zero Energy Lab

Talele, Suraj H. 08 1900 (has links)
The purpose of this investigation is to find out suitability of the solar chimney natural ventilation system in a Zero Energy Lab located at the University of North Texas campus, to figure out performance of the solar chimney. Reduction in the heating and ventilation and air conditioning energy consumption of the house has been also analyzed. The parameters which are considered for investigation are volumetric flow rate of outlet of chimney, the absorber wall temperature and glass wall temperatures. ANSYS FLUENT 14.0 has been employed for the 3-D modeling of the solar chimney. The dimensions of the solar chimney are 14’2” X 7’4” X 6’11”. The flow inside solar chimney is found to be laminar and the simulation results show that maximum outlet volumetric flow rate of about 0.12m3/s or 432 cfm is possible from chimney. The experimental velocity of chimney was found to be 0.21 m/s. Density Boussinesq approximation is considered for the modeling. Velocity and temperature sensors have been installed at inlet and outlet of the chimney in order to validate the modeling results. It is found that based on simulated volumetric flow rate that cooling load of 9.29 kwh can be saved and fan power of 7.85 Watts can be saved.
2

Multi-year Operation Effect of Geothermal Heat Exchanger on Soil Temperature for Unt Zero Energy Lab

Walikar, Vinayak P. 12 1900 (has links)
Ground source heat pump (GSHP) uses earth’s heat to heat or cool space. Absorbing heat from earth or rejecting heat to the earth, changes soil’s constant temperature over the multiple years. In this report we have studied about Soil temperature change over multiple years due to Ground loop heat exchanger (GLHE) for Zero Energy Research Laboratory (ZØE) which is located in Discovery Park, University of North Texas, Denton, TX. We did 2D thermal analysis GLHP at particular Depth. For simulation we have used ANSYS workbench for pre-processing and FLUENT ANYS as solver. TAC Vista is software that monitors and controls various systems in ZØE. It also monitors temperature of water inlet/outlet of GLHE. For Monitoring Ground temperatures at various depths we have thermocouples installed till 8ft from earth surface, these temperatures are measured using LabVIEW. From TAC Vista and LabVIEW Reading’s we have studied five parameters in this report using FLUENT ANSYS, they are; (1) Effect of Time on soil Temperature change over Multi-years, (2) Effect of Load on soil temperature change over Multi-years, (3) Effect of Depth on soil temperature change over Multi-years, (4) Effect of Doubling ΔT of inlet and outlet of GLHE on soil temperature change over multi-years and (5) Effect on soil temperature change for same ZØE Laboratory, if it’s in Miami, Florida. For studying effect of time on soil temperature change for multi-years, we have varied heating and cooling seasons. We have four cases they are Case A: GSHP always “ON” (1) 7 months cooling and 5 month cooling and (2) 257 days are cooling and 108 days heating. Case B: GSHP “OFF” for 2 months (1) 7 months cooling and 3 months heating and (2) 6 months cooling and 4 month heating. For Studying Effect of Load on soil temperature change over multi-years, we have considered maximum temperature difference between inlet and outlet for heating and cooling season for simulation. For studying effect of doubling ΔT of inlet and outlet of GLHE, we have doubled the temperature difference between inlet and outlet of GLHP. There will be soil temperature change over year at various depths. For studying Effect of Depth on soil temperature change for multi-years, we have consider 5 depths, they are 4ft, 6ft, 8ft, 110ft and 220ft. The Densities of soil are known from site survey report of ZØE GSHP manufacturers till depth of 13ft. For studying effect of soil temperature over multi-years for same ZØE in Miami, Florida, we have considered equivalent cooling and heating season from weather data for past one year and assuming same number of days of cooling and heating for next 20 years we have simulated for soil temperature change.
3

An analysis of market, financing, regulatory and geographic barriers to zero energy buildings

January 2013 (has links)
0 / SPK / specialcollections@tulane.edu
4

Practical path to net-zero homes

Najafi, Mike 24 May 2011 (has links)
As demand for energy is skyrocketing around the globe, environmental challenges are becoming more severe than ever before. Carbon dioxide, methane gas and other greenhouse gases are rapidly contributing to global warming and ozone depletion phenomenon. Buildings are among major contributors of greenhouse gases. They are consuming more than 40% of total energy and three quarter of the total electricity in the United States. It is to some distance the responsibility of building design professionals to address the impacts of their practice on the environment by reducing the energy consumption and carbon emission of their projects. This thesis aims to create a practical design guideline to help architects design energy-neutral homes in North America. The study's primary emphasis is on reducing building energy demand by implementing core principles of building physics into the design process throughout a case study project. What makes this process unique compared to other existing green design programs is its focus on architect's knowledge to implement core energy saving design strategies into design and evaluate their performance with a normative simulation tool. Selection and analysis of building systems, financial evaluation of cost effective systems and materials, uncertainty analysis of building systems, construction cost estimating and marketing analysis of the case study project, demonstrate simple strategies for designers to use in projects with higher sensitivity. In conclusion, the idea behind this methodology is building marketable energy-neutral homes in the current market with existing materials and none-complex technologies. The success of this design method is depends on the knowledge and skills of architects in building science, architectural design, and building construction. Despite barriers and many uncertainties embedded in this process, moving toward energy-neutral homes will have positive impacts on environment even if it could not reach the Net-Zero balance.
5

The Impact of Neighbourhood Density on the Energy Demand of Passive Houses and on Potential Energy Sources from the Waste Flows and Solar Energy

Stupka, Robert 11 January 2011 (has links)
This study demonstrates how the density of a neighbourhood affects its energy demand, metabolism (energy and material flows) and its ability to produce its own energy. Single-family detached houses and row townhouses were each modeled using passive solar housing guidelines with the DesignBuilder building energy simulation software. Energy demand is then modeled within neighbourhoods at two densities based on south facing windows fully un-shaded at 9:00 am, and 12:00 pm solar time on Dec. 21. The neighbourhood metabolisms were then calculated based on location and density. The potential energy supply was evaluated from the spatial characteristics of the neighbourhood (for solar) and the metabolism (municipal solid waste and wastewater flows.) The potential energy demand and supply are then compared for the varying building types and densities to determine the sensitivity of the energy supply and demand relationships.
6

The Impact of Neighbourhood Density on the Energy Demand of Passive Houses and on Potential Energy Sources from the Waste Flows and Solar Energy

Stupka, Robert 11 January 2011 (has links)
This study demonstrates how the density of a neighbourhood affects its energy demand, metabolism (energy and material flows) and its ability to produce its own energy. Single-family detached houses and row townhouses were each modeled using passive solar housing guidelines with the DesignBuilder building energy simulation software. Energy demand is then modeled within neighbourhoods at two densities based on south facing windows fully un-shaded at 9:00 am, and 12:00 pm solar time on Dec. 21. The neighbourhood metabolisms were then calculated based on location and density. The potential energy supply was evaluated from the spatial characteristics of the neighbourhood (for solar) and the metabolism (municipal solid waste and wastewater flows.) The potential energy demand and supply are then compared for the varying building types and densities to determine the sensitivity of the energy supply and demand relationships.
7

Zero energy buildings : theoretical investigation and applied analysis for the design of zero energy building in hot climate countries

Pittakaras, Paris January 2015 (has links)
Problem description: The buildings consume significant amounts of energy and are therefore major contributors to the overall CO2 emissions at the present time. The reduction of energy consumption in buildings is a major contribution to the overall control of global warming and to the improvement of sustainability. These reductions are essential as the world faces economic and energy crisis. An important key to the world’s energy problem is sustainable development. Taking the island of Cyprus as a case study, this thesis explores the different building categories and types, analyse building energy models and propose guidelines for the success development of Zero energy buildings in hot climates without compromising the comfort levels of the buildings. Purpose: The ultimate target is to be able to design and operate a building which requires no fossil fuel consumption – the so called “zero energy/carbon (emissions)” building. It is important for all countries to set a national goal in order to achieve zero energy consumption in the building sector and reduce the energy demands. Method: Through the theoretical research the project explored the causes of the problem of building energy, the different types of buildings, the definitions of zero energy buildings in various countries, regulations and standards concerning the buildings energy and all the available technology, methods and materials that can be used in the building sector. In this way the analysis presents the needs of the project and the point of focus during the practical part of the research with simulation of building models. The practical part of the project was the simulation of different building models in order to apply and check the theoretical findings and finally reach conclusions on the development of Zero energy buildings in hot climate countries. During the building simulation a variety of parameters such as the weather, the orientation, the shading methods, the insulation methods, the buildings materials, the glazing, the HVAC systems and building operation profiles were checked in order to find the appropriate combination of factors and achieve the zero energy building goals. Conclusions: This new approach to zero energy building, gives a new perspective to the energy consumption of the building and the indoor environment while also taking environmental impact from the building sector into account. This change in approach is a crucial part of the overall problem of how to achieve the ultimate goal of Zero Energy Buildings and how to convert buildings into “producers” of energy and help solve the world energy problem/crisis.
8

Design of a net-zero energy community: Waalwijk

Sundaram, Smitha January 2013 (has links)
No description available.
9

Feasibility study on making Van Maanenblok a near zero energy building urban neighbourhood

Krishnamurthy, Sriram January 2014 (has links)
The rapid exhaustion of the finite reserves of fossil-fuels adds to the woes on all walks of the society, and especially on the policy-makers, scientists and engineers to devise means to mitigate the consequences. Reducing energy demand and grid-dependency by decentralized energy production can help improve energy security of a nation. A holistic approach to achieve these goals in the building sector could be through a shift towards fostering near zero-energy communities. This project is an initiative taken by the residents in Van Maanenblok, an urban residential block constructed in early 1930’s and situated at the heart of North-Rotterdam, to try to achieve self-sustainability in terms of energy consumption of the block through renovation. The objective of this study is to analyze the energy consumption of the block over the past three years and using the ‘Trias Energetica’ approach, investigate the extent to which self-sustainability is possible. This study also includes an overview on financial feasibility of this initiative together with identification of innovation opportunities. Passive energy reduction measures such as insulation, LED lighting-retrofits have been explored. Active renewable energy systems (RES) like solar photovoltaic (PV) systems, micro-windmills were designed and sized. Also, energy potential from Organic Fraction of Municipal Solid Waste (OFMSW) from within the block, and use ground-source heat pump to meet thermal energy has been investigated. The aforementioned technologies have been compared over certain financial parameters like net present value (NPV), payback period (PBP), and levelised cost of energy (LCOE) based on installation costs obtained from actual figures quoted by the installers and also general indicative market figures. Results of the study indicate that nearly 54% of present gas demand and 9% of electricity demand can be reduced by passive energy reduction measures alone. It would be possible to meet 42% and 54% of reduced electricity and gas demand respectively from RES. User-behaviour plays an important role in energy consumption and social factor largely determines the metamorphosis of projects with such complex setup. Renovation projects towards near zero energy buildings opens up several innovative opportunities and extended benefits to various actors, however stimulus from government is needed on financial and technical front in order to realize such ambitious initiatives.
10

A Macroergonomics Path to Human-centered, Adaptive Buildings

Agee, Philip 26 September 2019 (has links)
Human-building relationships impact everyone in industrialized society. We spend approximately 90% of our lives in the built environment. Buildings have a large impact on the environment; consuming 20% of worldwide energy (40% of U.S. energy) annually. Buildings are complex systems, yet architecture, engineering, and construction (AEC) professionals often perform their work without considering the human factors that affect the operational performance of the building system. The AEC industry currently employs a linear design and delivery approach, lacking verified performance standards and real-time feedback once a certificate of occupancy is issued. We rely on static monthly utility bills that lag and mask occupant behavior. We rely on lawsuits and anecdotal business development trends as our feedback mechanisms for the evaluation of a complex, system-based product. The omission of human factors in the design and delivery of high performance building systems creates risk for the AEC industry. Neglecting an iterative, human-centered design approach inhibits our ability to relinquish the building industry's position as the top energy consuming sector. Therefore, this research aims to explore, identify, and propose optimizations to critical human-building relationships in the multifamily housing system. This work is grounded in Sociotechnical Systems theory (STS). STS provides the most appropriate theoretical construct for this work because 1) human-building interactions (HBI) are fundamentally, human-technology interactions, 2) understanding HBI will improve total system performance, and 3) the interrelationships among human-building subsystems and the potential for interventions to effect the dynamics of the system are not currently well understood. STS was developed in the 1940's as a result of work system design changes with coal mining in the United Kingdom. STS consists of four subsystems and provides a theoretical framework to approach the joint optimization of complex social and technical problems. In the context of this work, multidisciplinary approaches were leveraged from human factors engineering and building construction to explore relationships among the four STS subsystems. An exploratory case study transformed the work from theoretical construct toward an applied STS model. Data are gathered from each STS subsystem using a mixed-methods research design. Methods include Systematic Review (SR), a descriptive case study of zero energy housing, and the Macroergonomics Analysis and Design (MEAD) of three builder-developers. This work contributes to bridging the bodies of knowledge between human factors engineering and the AEC industry. An output of this work is a framework and work system recommendations to produce human-centered, adaptive buildings. This work specifically examined the system inputs and outputs of multifamily housing in the United States. The findings are supportive of existing scientific society, government, and industry standards and goals. Relevant standards and goals include the Human Factors and Ergonomics Society (HFES) Macroergonomics and Environmental Design Technical Groups, International Energy Agency's Energy in Buildings ANNEX 79 Occupant Behavior-Centric Building Design and Operation, the U.S. Department of Energy's Building America Research to Market Plan and zero energy building goals of the American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE). / Doctor of Philosophy / We spend approximately 90% of our lives in the built environment. Buildings have a large impact on the environment; consuming 20% of worldwide energy (40% of U.S. energy) annually. As we work to reduce energy use in buildings, new challenges have emerged. As buildings become more complex, the architecture, engineering, and construction industry (AEC) must adapt. The industry historically employs a linear design and delivery approach, lacking verified performance standards and real-time feedback once a certificate of occupancy is issued. We rely on static monthly utility bills that lag and mask occupant behavior. We rely on lawsuits and anecdotal business development trends as our feedback mechanisms for the evaluation of a complex, system-based product. The omission of human factors in the design and delivery of high-performance building systems creates risk for the industry and occupants. To better understand that risk, a comparative analysis of zero energy housing explores the relationship between humans and the buildings of the future. A second case study explores the work systems of builder-developers by using the Macroergonomic Analysis and Design method. The work reports risks and barriers in the system, as well as opportunities to create human-centered, adaptive housing. Specifically, this project enhances our understanding of 1) high performance housing, 2) their occupants, and 3) the builder-developers that produce high performance housing.

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