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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

Performance Analysis of Two Alternative Hvac Systems for the Unt Zero Energy Lab

Hasib, Naimee 08 1900 (has links)
This paper covers the simulation and comparison among three different HVAC (heating, ventilation & air conditioning)systems to achieve the goal of finding the most effective HVAC among these three in terms of human comfort, efficiency and cost considering North Texas climate. In the Zero Energy Lab at the University of North Texas, Denton, TX, the HVAC system of the building assembles with geothermal heat source. Here, water to water heat pump with radiant floor and water to air heat pump with air ducts provide heating & cooling of the building. In this paper electricity consumption, comfort, cost & efficiency analysis is done for the existing system using Energy Plus simulation software. Calibration of the simulated data of the existing system is done comparing with the actual data. Actual data is measured using 150 sensors that installed in Zero Energy Lab. After the baseline model calibration, simulation for ground source water to water heat pump, evaporative cooler with baseboard electric heater and water cooled electric chiller with baseboard electric heater (as a conventional system) is shown. Simulation results evaluate the life cycle cost (LCC) for these HVAC systems. The results of the comparison analysis among all the three HVAC systems show the most effective HVAC system among these three systems in North Texas weather. The results will make UNT Zero Energy lab a standard model towards a sustainable green future.
2

Análise do desempenho térmico em edifícios residenciais: estudo comparativo entre métodos de avaliação para a zona bioclimática 2

Bisolo, Giovani 03 June 2018 (has links)
Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2018-11-12T15:52:27Z No. of bitstreams: 1 Giovani Bisolo_.pdf: 1274897 bytes, checksum: a33f65812348a6d5c4673cc3ca5b2d40 (MD5) / Made available in DSpace on 2018-11-12T15:52:27Z (GMT). No. of bitstreams: 1 Giovani Bisolo_.pdf: 1274897 bytes, checksum: a33f65812348a6d5c4673cc3ca5b2d40 (MD5) Previous issue date: 2018-06-03 / Nenhuma / Este estudo tem como finalidade avaliar por simulação computacional a influência das caraterísticas construtivas e da orientação no seu desempenho térmico de uma unidade habitacional na Zona Bioclimática 2, pela Norma NBR 15575 e pelo método de graus hora, com o intuito de compreender como essas diretrizes tratam o desempenho da edificação. Para isso, foi pesquisado dados sobre a caracterização climática e as estratégicas construtivas para a Zona Bioclimática 2. O objeto tema deste estudo foi um projeto de edifício residencial com quatro pavimentos, com disposição que permitiu avaliar tanto o desempenho térmico dos dormitórios voltados para todas as fachadas, quanto a avaliação dos cômodos com abertura para oeste e sul, conforme exigência da NBR 15575. Para a comparação do método da NBR foram escolhidos 4 dias de verão, e 4 dias de inverno. Já para comparação de desempenho térmico pelo método de graus-hora foram utilizadas todas as horas do ano. Para esse estudo, a temperatura base para o cálculo de graus-hora de resfriamento foi de 26ªC e a temperatura base para o cálculo de graus-hora de aquecimento foi de 18ªC. Percebe-se que a temperatura no interior das unidades habitacionais foi melhor às do ambiente externo, conforme critérios da NBR 15575-1, para todos os ambientes de permanência prolongada. Sendo que, para a condição de verão foi considerado o valor máximo diário da temperatura do ar interior e para a condição de inverno, foi considerado o valor mínimo diário da temperatura do ar interior, ambos para ambientes de permanência prolongada (salas e dormitórios). Os resultados das simulações avaliados pelos critérios da NBR 15575, indicam que, as vedações verticais com blocos de concreto ou blocos cerâmicos, podem ter níveis mínimos, intermediários e superiores, ou até mesmo, não atender a norma, dependendo da escolha do dia típico para a análise. Os resultados simulados com carga térmica pelo método graus-hora, demostram que o desempenho térmico piora no verão e melhora no inverno, isso demostra que as edificações habitadas e com o uso de equipamentos, o desempenho térmico pode ser influenciado. Ao final o estudo pode concluir que a simplificação do método da norma pode alterar a classificação de desempenho térmico do edifício quando indica somente uma renovação de ar por hora ou quando não permite a inclusão de carga térmica, assim como a simplificação do tempo de simulação para apenas um dia de inverno e um dia de verão, pois não há um parâmetro de escolha para as cidades que não estão listadas na norma. Assim sendo, entende-se que a análise do desempenho térmico de um edifício precisa ser elaborado para o ano todo. / The purpose of this study was to evaluate by computational simulation the influence of the constructive characteristics and the orientation in its thermal performance of a housing unit in the Bioclimatic Zone 2, by the norm NBR 15575 and the hour degrees method, in order to understand how these guidelines deal the performance of the building. For this, data on the climatic characterization and the constructive strategies for the Bioclimatic Zone 2 were investigated. The object of this study was a residential building project with four floors, with disposition that allowed to evaluate both the thermal performance of the dormitories facing all the as regards the evaluation of the rooms with opening to the west and south, as required by NBR 15575. For the comparison of the NBR method, 4 days of summer and 4 days of winter were chosen. For comparison of thermal performance by the degree-hour method, all the hours of the year were used. For this study, the base temperature for calculating degree-hours of cooling was 26 ° C and the base temperature for calculating degree-hours of heating was 18 ° C. It can be noticed that the temperature inside the dwelling units was better than those of the external environment, according to the criteria of NBR 15575-1, for all the environments of prolonged residence. For the summer condition, the daily maximum value of the indoor air temperature and for the winter condition were considered, the minimum daily value of the indoor air temperature was considered, both for long stay environments (rooms and dormitories). The results of the simulations evaluated by the criteria of NBR 15575 indicate that vertical fences with concrete blocks or ceramic blocks may have minimum, intermediate and higher levels, or even do not meet the standard, depending on the choice of the typical day for the analysis. The simulated results with thermal load by the degree-hour method, show that thermal performance worsens in summer and winter improves, this shows that inhabited buildings and with the use of equipment, thermal performance can be influenced. At the end of the study, it can be concluded that the simplification of the method of the standard can alter the classification of thermal performance of the building when it indicates only a renewal of air per hour or when it does not allow the inclusion of thermal load, as well as the simplification of the simulation time for only a winter day and a summer day, as there is no parameter of choice for cities that are not listed in the standard. Therefore, it is understood that the analysis of the thermal performance of a building must be elaborated for the whole year.
3

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
4

A Comparison of Energy Plus and eQUEST Whole Building Energy Simulation Results for a Medium Sized Office Building

January 2010 (has links)
abstract: With the increasing interest in energy efficient building design, whole building energy simulation programs are increasingly employed in the design process to help architects and engineers determine which design alternatives save energy and are cost effective. DOE-2 is one of the most popular programs used by the building energy simulation community. eQUEST is a powerful graphic user interface for the DOE-2 engine. EnergyPlus is the newest generation simulation program under development by the U.S. Department of Energy which adds new modeling features beyond the DOE-2's capability. The new modeling capabilities of EnergyPlus make it possible to model new and complex building technologies which cannot be modeled by other whole building energy simulation programs. On the other hand, EnergyPlus models, especially with a large number of zones, run much slower than those of eQUEST. Both eQUEST and EnergyPlus offer their own set of advantages and disadvantages. The choice of which building simulation program should be used might vary in each case. The purpose of this thesis is to investigate the potential of both the programs to do the whole building energy analysis and compare the results with the actual building energy performance. For this purpose the energy simulation of a fully functional building is done in eQUEST and EnergyPlus and the results were compared with utility data of the building to identify the degree of closeness with which simulation results match with the actual heat and energy flows in building. It was observed in this study that eQUEST is easy to use and quick in producing results that would especially help in the taking critical decisions during the design phase. On the other hand EnergyPlus aids in modeling complex systems, producing more accurate results, but consumes more time. The choice of simulation program might change depending on the usability and applicability of the program to our need in different phases of a building's lifecycle. Therefore, it makes sense if a common front end is designed for both these simulation programs thereby allowing the user to select either the DOE-2.2 engine or the EnergyPlus engine based upon the need in each particular case. / Dissertation/Thesis / M.S. Architecture 2010
5

Short-Term Reduction of Peak Loads in Commercial Buildings in a Hot and Dry Climate

January 2012 (has links)
abstract: A major problem faced by electric utilities is the need to meet electric loads during certain times of peak demand. One of the widely adopted and promising programs is demand response (DR) where building owners are encouraged, by way of financial incentives, to reduce their electric loads during a few hours of the day when the electric utility is likely to encounter peak loads. In this thesis, we investigate the effect of various DR measures and their resulting indoor occupant comfort implications, on two prototype commercial buildings in the hot and dry climate of Phoenix, AZ. The focus of this study is commercial buildings during peak hours and peak days. Two types of office buildings are modeled using a detailed building energy simulation program (EnergyPlus V6.0.0): medium size office building (53,600 sq. ft.) and large size office building (498,600 sq. ft.). The two prototype buildings selected are those advocated by the Department of Energy and adopted by ASHRAE in the framework of ongoing work on ASHRAE standard 90.1 which reflect 80% of the commercial buildings in the US. After due diligence, the peak time window is selected to be 12:00-18:00 PM (6 hour window). The days when utility companies require demand reduction mostly fall during hot summer days. Therefore, two days, the summer high-peak (15th July) and the mid-peak (29th June) days are selected to perform our investigations. The impact of building thermal mass as well as several other measures such as reducing lighting levels, increasing thermostat set points, adjusting supply air temperature, resetting chilled water temperature are studied using the EnergyPlus building energy simulation program. Subsequently the simulation results are summarized in tabular form so as to provide practical guidance and recommendations of which DR measures are appropriate for different levels of DR reductions and the associated percentage values of people dissatisfied (PPD). This type of tabular recommendations is of direct usefulness to the building owners and operators contemplating DR response. The methodology can be extended to other building types and climates as needed. / Dissertation/Thesis / M.S. Architecture 2012
6

Art and Effective Altruism: Case Studies in Sustainable Practice

January 2017 (has links)
abstract: Effective Altruism (EA), a moral philosophy concerned with accomplishing the greatest possible good in one’s lifetime, sees little utilitarian and/or humanitarian value in the arts. EA suggests that amidst so much global strife, the time, energy, and finances expended to create fleeting art would be put to better, more practical use in the fight against poverty. However, EA has yet to sufficiently account for sustainable art practice — an art form deeply rooted in utilitarianism and humanitarianism — and the possibility of its accompanying aesthetics as a constituent of utilitarian/humanitarian theories. The first chapter of this thesis illustrates an intersection of EA, sustainability, and aesthetics, detailing ways in which sustainable art and EA philosophy overlap, as well as problematizing EA’s dismissal of contemporary art practice. This chapter also points to sustainable art as one possible alternative art route for practicing artists with EA interests. Chapters two and three present case studies of Danish art collective SUPERFLEX and an American non-profit called the Land Art Generator Initiative (LAGI) and how their sustainable goals fit the utilitarian and humanitarian scope through which EA functions. / Dissertation/Thesis / Masters Thesis Art History 2017
7

Phase change materials and thermal performance of buildings in Cyprus

Ozdenefe, Murat January 2013 (has links)
This work investigates the thermal performance of buildings in Cyprus and application of a particular passive technology; Phase Change Materials (PCMs) for the ultimate aim of reducing indoor air temperatures and energy supplied for the cooling season.PCMs for passive building applications are emerging technology and have not been tested for the buildings of Cyprus neither by computer simulations nor by practical applications. In this work, particular PCM end product; wallboard, having phase change temperature of 26 oC is employed together with various construction materials and simulated for buildings of Cyprus. Description of the current state in Cyprus has been carried out in terms of low energy building studies, widely used building fabric and building statistics. There is a huge gap in Cyprus in the field of energy performance and thermal comfort of buildings, which creates big room for research. Climatic design of buildings has been abandoned resulting in poor thermal comfort and increased energy consumption. There is still no regulation in place regarding the thermal performance of buildings in North Cyprus.Recent weather data of different Cyprus locations has been investigated and compared with the simulation weather data files that are employed in this work. The author has demonstrated that Finkelstein-Schafer statistics between recent weather data of Cyprus and simulation weather data files are close enough to obtain accurate results.Dynamic thermal simulations has been carried out by using Energy Plus, which is a strong and validated thermal simulation program that can model PCMs. Simulations are done for two different building geometry; “simple building” and “typical building” by employing different construction materials. Simple building is a small size box shaped building and typical building is a real existing building and selected by investigation of the building statistics.Simulation results showed that with this particular PCM product, indoor air temperatures and cooling energies supplied to simple building is reduced up to 1.2 oC and 18.64 % when heavier construction materials are used and up to 1.6 oC and 44.12 % when lighter construction materials are used. These values for typical building are found to be 0.7 oC, 3.24 % when heavier construction materials are used and 1.2 oC, 3.64 % when lighter construction materials are used. It is also found that, if thinner walls and slabs are used in the buildings the effectiveness of the PCM lining increases in significant amount.
8

The Energy+ Skyscraper: A Critical Investigation, Rethinking, and Redesign of the Sustainable Tower Typology

Thong, Paul 11 October 2016 (has links)
No description available.
9

Simulação termoenergética e proposta de melhoria em espaços de ensino e aprendizagem : estudo de caso campus Unisinos São Leopoldo

Fagundes, Suzana Fetter 05 January 2017 (has links)
Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2017-05-18T16:40:43Z No. of bitstreams: 1 Suzana Fetter Fagundes_.pdf: 5489681 bytes, checksum: 21bf7754ce6c0314a38ac237cc458c4d (MD5) / Made available in DSpace on 2017-05-18T16:40:43Z (GMT). No. of bitstreams: 1 Suzana Fetter Fagundes_.pdf: 5489681 bytes, checksum: 21bf7754ce6c0314a38ac237cc458c4d (MD5) Previous issue date: 2017-01-05 / Nenhuma / A habitabilidade do espaço construído afeta a capacidade produtiva das pessoas. Neste sentido, cabe verificar alternativas para otimizar o desempenho térmico das edificações, garantindo condições adequadas de conforto. Pesquisas realizadas no campus São Leopoldo da Universidade do Rio dos Sinos (UNISINOS), junto ao corpo discente, apontaram a necessidade de climatização das salas de aula. Este estudo se propõe a avaliar as condições atuais de temperatura dessas salas e investigar alternativas, através de simulações termoenergéticas, para aprimorar o desempenho térmico das edificações existentes. Com o uso do software Energy Plus foram analisados cenários alterando as características da envoltória da edificação com objetivo de aprimorar seu desempenho térmico e, com isso, reduzir a necessidade de sistemas artificiais de climatização. O estudo ponderou aspectos de viabilidade técnica e econômica de implantação e operação dos sistemas em um bloco de salas de aula tomado como piloto. Além disso, realizou uma comparação dos sistemas simulados com propostas técnicas obtidas no mercado. Os resultados mostram que, ao associar um sistema de climatização com a alteração da cor da cobertura para branco, é possível reduzir o consumo de energia em até 37,34%. O investimento necessário para a implantação dessa solução, pintura da cobertura e instalação de aparelhos de ar condicionado, gera um payback de 13,1 anos. / Built space habitability affects productive capacity of people. In this sense, it is necessary to search for alternatives to optimize the thermal performance of buildings, aiming to ensure adequate comfort conditions. Surveys carried out with the student body of Universidade do Vale do Rio dos Sinos (UNISINOS), at São Leopoldo campus, pointed out the need of classrooms thermal comfort enhancement. This study proposes to evaluate the current temperature conditions of those rooms and to investigate alternatives to improve thermal performance of existing buildings by means of thermoenergetic simulations. Using Energy Plus software, settings were analyzed considering possible changes on characteristics of the building envelope in order to improve its thermal performance and, therefore, reduce the need for artificial climatization systems. The study considered aspects of technical and economic feasibility of implantation and operation of the systems in a set of classrooms taken as pilot. In addition, the simulated systems were compared with technical proposals obtained in the market. The results show that combining air conditioning with changing the color of the roof the white, it is possible to reduce energy consumption by up to 37.34%. The payback for implementation of this solution, painting the roof white and installing the air conditioning equipment is 13.1 years.
10

Energisimulering av ett nordsvenskt plusenergihus med kombination av bergvärme och solceller

Henriksen, Theodor January 2020 (has links)
Energianvändningen i världen växer för varje år, vilket i sin tur bidrar med ökade mängder utsläpp av växthusgaser till atmosfären. På grund av den ökade energianvändningen blir intresset för energisnåla byggnader allt högre med tiden. I detta projekt har en nordligt placerad fastighet med en Atemp på 716 m2 i Gnarp simulerats med hjälp av IDA Indoor Climate and Energy (IDA ICE) samt WINSUN. Fastigheten har två våningar med åtta lägenheter totalt och är uppvärmd med bergvärme då fjärrvärmenätet ligger för långt ifrån området. Tanken med byggnaden är att den ska uppnå kriterierna för ett plusenergihus, vilket innebär att fastigheten ska generera mer energi än vad den gör av med via en solcellsanläggning som monteras på taket. Enligt de teoretiska resultat som simuleringen visar så kan fastigheten klassas som ett plusenergihus, då solcellsanläggningen på taket producerar mer energi än vad som används årligen. Det innebär att möjligheterna för byggnation av ett plusenergihus i nordligare områden i Sverige finns, där temperaturer varierar kraftigt under årets gång och kan gå lägre än -30°C under vintertid. Den årliga elproduktionen ligger över 26 700 kWh/år och elanvändningen hamnar på 16 400 kWh/år, där tappvarmvattnet står för den största delen använt el. Det innebär att den genererar ungefär 10 300 kWh/år i överskott relativt till inköpt el-energi. Huset är välisolerat och har smart placerade glasytor för värmeinsläpp. Det inkluderar en effektiv värmepump, ett FTX-System för värmeåtervinning via ventilationssystemet samt ett solcellssystem på taket som i sin tur bidrar till möjligheten för en energiproducering som är högre än energianvändningen, därav en plusenergihus-klassning. Under energianvändningsprocessen så har den årliga uppvärmningen, tappvarmvattnet samt fastighetselen tagits till godo i beräkningarna för bedömning av byggnadens energiprestanda. Eftersom solcellerna producerar mer energi under sommaren, vilket medföljer att överskott på elproduktionen uppstår under vissa perioder av året, så innebär det att el kan säljas via elnätet till en elhandlare. / The interest in low-energy-houses has risen in recent years as the energy usage around the globe is constantly increasing, resulting in ever-increasing amounts of greenhouse gases in the atmosphere. In this project, the energy consumption of a building in a northern area of Sweden, Gnarp, with an Atemp of 716m2 was simulated using IDA indoor Climate and Energy (IDA ICE) and WINSUN. The building has two floors and is comprised of eight apartments. It is heated using geothermal heating since it is not located close enough to a district heating area. The goal of the simulation was to determine if this building is an energy-plus-house, whereby a PV-system mounted on the rooftop allows for the energy production-value of the building to be higher than the energy-usage. The theoretical results of the simulation show that this building is indeed an energy-plus-house since the PV-system is generating more energy than the yearly usage of the building. This simulation shows that it is possible to build an energy-plus-house in northern areas of Sweden where temperatures are highly variable and can go below -30°C during winter season. It indicates a yearly electricity-production of over 26 700 kWh/year and a usage of approximately 16 400 kWh/year, where the domestic hot water accounts for the highest usage of electricity. This means that the building generates an electricity surplus of approximately 10 300 kWh/year. The building is well isolated and has well placed windows for heat generation via the sun. It includes an effective heat pump, an FTX-system, and solar panels on the roof which gives the opportunity for an energy-production that is larger than the energy-usage, which in turn gives the opportunity for an energy-plus-house classification. The heating, domestic hot water, and the building electricity were all considered when calculating the estimation of the energy-quality of the property. The PV-system generates more energy during the summer, which results in an overproduction of electricity at certain times of the year. The extra electricity produced can be sold to the electric utility.

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