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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.
41

Methodology for Rating a Building's Overall Performance based on the ASHRAE/CIBSE/USGBC Performance Measurement Protocols for Commercial Buildings

Kim, Hyojin 1981- 14 March 2013 (has links)
This study developed and applied a field test to evaluate the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)/Chartered Institute of Building Services Engineers (CIBSE)/United States Green Building Council (USGBC) Performance Measurement Protocols (PMP) for Commercial Buildings in a case-study office building in central Texas. As the first integrated protocol on building performance measurement, the ASHRAE PMP accomplished its goal of providing the standardized protocols for measuring and comparing the overall performance of a building, including energy, water, thermal comfort, Indoor Air Quality (IAQ), lighting, and acoustics. However, several areas for improvement were identified such as conflicting results from different procedures or benchmarks provided in the ASHRAE PMP; limited guidelines for performing the measurements; lack of detailed modeling techniques, graphical indices, and clear benchmarks; and some practical issues (i.e., high cost requirements and time-intensive procedures). All these observations are listed as the forty issues, including thirteen for energy, five for water, and twenty-two for Indoor Environmental Quality (IEQ). Recommendations were developed for each issue identified. For the selected high-priority issues, twelve new or modified approaches were proposed and then evaluated against the existing procedures in the ASHRAE PMP. Of these twelve new or modified approaches, the following are the most significant developments: a more accurate monthly energy use regression model including occupancy; a monthly water use regression model for a weather-normalized comparison of measured water performance; a method how to use a vertical temperature profile to evaluate room air circulation; a method how to use LCeq – LAeq difference as a low-cost alternative to estimate low frequency noise annoyance; a statistical decomposition method of time-varying distribution of indices; and a real-time wireless IEQ monitoring system for the continuous IEQ measurements. The application of the forty recommendations and the twelve new or modified approaches developed in this study to the ASHRAE PMP is expected to improve the applicability of the ASHRAE PMP, which aligns the overall purpose of this study. Finally, this study developed a new single figure-of-merit rating system based on the ASHRAE PMP procedures. The developed rating system is expected to improve the usability of the protocols.
42

Design and Development of an Intelligent Energy Controller for Home Energy Saving in Heating/Cooling System

Abaalkhail, Rana 18 January 2012 (has links)
Energy is consumed every day at home as we perform simple tasks, such as watching television, washing dishes and heating/cooling home spaces during season of extreme weather conditions, using appliances, or turning on lights. Most often, the energy resources used in residential systems are obtained from natural gas, coal and oil. Moreover, climate change has increased awareness of a need for expendable, energy resources. As a result, carbon dioxide emissions are increasing and creating a negative effect on our environment and on our health. In fact, growing energy demands and limited natural resource might have negative impacts on our future. Therefore, saving energy is becoming an important issue in our society and it is receiving more attention from the research community. This thesis introduces a intelligent energy controller algorithm based on software agent approach that reduce the energy consumption at home for both heating and cooling spaces by considering the user’s occupancy, outdoor temperature and user’s preferences as input to the system. Thus the proposed approach takes into consideration the occupant’s preferred temperature, the occupied and unoccupied spaces, as well as the time spent in each area of the home. A Java based simulator has been implemented to simulate the algorithm for saving energy in heating and cooling systems. The results from the simulator are compared to the results of using HOT2000, which is Canada’s leading residential energy analysis and rating software developed by CanmetENERGY’s Housing, Buildings, Communities and Simulation (HBCS) group. We have calculated how much energy a home modelled will use under emulated conditions. The results showed that the implementation of the proposed energy controller algorithm can save up to 50% in energy consumption in homes dedicated to heating and cooling systems compared to the results obtained by using HOT2000.
43

Energieffektiv projektering : Projektering för ett träffsäkert och energieffektivt slutresultat

Jonsson, Viktor, Lundberg, Mattias January 2010 (has links)
Byggnadssektorn uppskattas idag stå för närmare 40 % av vår totala energiförbrukning, varav nästan 60 % utgörs av uppvärmning och varmvatten. Från myndigheter såväl som allmänheten börjar högre krav ställas på energihushållning i vårt byggnadsbestånd. I media duggar informationen tätt om nya metoder för energieffektivisering, ändå visar statistiken att mycket finns kvar att göra. Frågan som bör ställas är var problemet ligger. Detta examensarbete behandlar projekteringens roll för slutresultatet med avseende på energianvändningen i flerbostadshus. Syftet är att identifiera förbättringsfaktorer för hur projekteringen kan påverka byggprocessen mot ett mer energieffektivt slutresultat. Arbetet grundar sig på tidigare studier och utnyttjar dels en fallstudie av ett 3 st. flerbostadshus i Västerås från 2000-talets början, dels en intervjustudie med fokus på upplevda svårigheter i arbetet med energifrågor bland byggbranschens aktörer. I den inledande litteraturstudien identifierades tekniska och processberoende faktorer som avgör en byggnads energianvändning. Den knyter också an till liknande studier för att tillvarata tidigare erfarenheter. Fallstudien resulterade i att uppmärksamma hur stora konsekvenserna blir av att inte beakta energianvändningen i tillräcklig omfattning. Intervjustudien resulterade i att identifiera likheter och skillnader i de olika aktörernas syn på projekteringen med avseende på byggnaders energianvändning. Bland de förbättringsfaktorer som identifierats bör framför allt en mer framträdande roll hos byggherren nämnas. En tydlig ambitionsnivå för projektet tillsammans med kravformuleringar är också en nödvändighet. Ett samarbete mellan aktörer där all tillgänglig kompetens utnyttjas redan i tidiga skeden krävs också för att kunna beakta energifrågan på allvar. Tekniska konsulter måste ges tillfälle att påverka projektet innan det låsts i alltför stor utsträckning. Fokus genom hela projekteringen bör ligga på ett betraktningssätt där hela byggnaden ses som ett sammanhängande system. Under arbetets gång har också uppmärksammats ett behov av att underlätta uppföljning av utförda byggprojekt. Uppföljning är nödvändigt för att utveckla branschen och frångå ryktet om en byggbransch oförmögen att lära av tidigare misstag. Slutligen kan nämnas att en ökad efterfrågan från samhället måste ske som incitament för byggherren att bygga mer energieffektivt. Samtidigt handlar det för byggherren om att marknadsföra fördelarna med energieffektiva alternativ till konventionella bostäder för att skapa efterfrågan.
44

Optimal väggisoleringstjocklek på hyresfastighet vid begränsad byggyta / Optimum of wall insulation in an apartment building for renting, built on a limited area

Perman, Daniel January 2011 (has links)
Miljömedvetenheten och ökat intresse för energieffektiva hus har gjort att byggnader isoleras som aldrig förr. Oftast är det på lång sikt ganska så lätt att räkna hem en ökad isoleringsmängd och det är just den ekonomiska vinsten som brukar lyftas fram som det främsta argument varför en beställare bör välja den tjockare isoleringen. För en beställare av hyresfastigheter är det oftast ekonomin som avgör ifall ett projekt ska påbörjas eller inte och denna studie ska därför vara en hjälp till att välja den mest ekonomiska isoleringstjockleken i väggar. Syftet med denna studie är att utreda var den optimala väggisoleringstjocken hamnar på en hyresfastighet med flerfamiljsbostäder som byggs på en begränsad byggyta. Inte sällan finns det krav på maximal byggyta från kommunen och då innebär det att ju tjockare isoleringen är desto mindre blir den uthyrningsbara boytan. Kvalitativa intervjuer låg till grund för att bestämma några vanligt förekommande ytterväggskonstruktioner som isoleringen sedan skulle optimeras på. Dessa ytterväggar placerades på en teoretisk referensbyggnad som därefter energiberäknades med hjälp av handberäkningar där matematiska uttryck för en varierande isoleringstjocklek användes. De teoretiska ytterväggarna kalkylerades därefter med hjälp av kalkylprogrammet Sektionsdata.  En livscykelkostnadsanalys utfördes sedan där historisk statistik på hyror, energipriser och räntor utnyttjades. Slutligen kunde en optimal isoleringstjocklek hittas för varje väggtyp. Väggkonstruktionerna som valts var två betongväggar och två träregelväggar, båda med puts respektive tegel. Optimal isoleringstjocklek för väggkonstruktionen betongstomme med tegel hamnade på 84mm. För väggkonstruktionen betongstomme med puts hamnade optimal isoleringstjocklek på 88mm. För väggkonstruktionerna med trästomme kunde en optimal isoleringstjocklek inte hittas eftersom väggarnas uppbyggnad med två respektive tre isoleringsskikt gjorde att väggarna förblev överisolerade i ett ekonomiskt perspektiv även vid minsta möjliga tjocklek på isoleringsskiktet som skulle optimeras.  Studien visar på att det med dagens byggregler ger en stor vinst att hålla nere på väggisoleringstjockleken på flerfamiljsbostäder som byggs på en begränsad byggyta. / Environmental awareness and increased interest in energy-efficient housing have made the buildings more insulated in Sweden. Usually, it is quite easy to calculate a profit from a greater amount of insulation, in the long term. This is usually the seller’s main argument to why the client should choose the thicker insulation. For a client that wants to build a rental property, it is usually the economy that determines whether a project should be started or not. Hopefully this study will be a help to choose the most economic insulation thickness in walls. The purpose of this study is to investigate where the optimum of wall insulation thickness is in an apartment building for renting which is built on a limited area. Quite often there are requirements for a maximum building area from the municipality, which means that the rentable living space will come smaller when the insulation gets thicker. Qualitative interviews were used to determinate the common wall constructions which the insulation would be optimized for. These walls were placed in a theoretical reference building in which the energy use were estimated using hand calculations where mathematical expressions of a variety of insulation thickness were used. Thereafter, the prices of the walls were calculated using a spreadsheet program called Sektionsdata. A life cycle cost analysis was performed in which the historical statistics on rents, energy prices and interest rates were used. Finally, the optimal insulation thickness was found for each wall type. The wall types chosen were a wall of concrete and brick, a wall of concrete and rendering, a wall of wood and brick and a wall of wood and rendering. Optimal insulation thickness of the wall with concrete and brick ended up at 84mm. For the wall of rendered concrete, the optimal insulation thickness ended up at 88mm. The optimal insulation thickness of the walls of wood could not be found as the wall structure with two and three insulation layers made the walls too isolated in an economic perspective even at a minimal thickness of the layer that was going to be optimized. The study shows that with current building codes in Sweden it is profitable to keep down the wall insulation thickness in an apartment building for renting, built on a limited area.
45

Development of an automated methodology for calibration of simplified air-side HVAC system models and estimation of potential savings from retrofit/commissioning measures

Baltazar Cervantes, Juan Carlos 25 April 2007 (has links)
This dissertation provides one methodology to determine potential energy savings of buildings with limited information. This methodology is based upon the simplified energy analysis procedure of HVAC systems and the control of the comfort conditions. Numerically, the algorithm is a tailored exhaustive search over all the independent variables that are commonly controlled for a specific type of HVAC system. The potential energy savings methodology has been applied in several buildings that have been retrofitted and/or commissioned previously. Results from the determined savings for the Zachry building at Texas A&M after being commissioned show a close agreement to the calculated potential energy savings (about 85%). Differences are mainly attributed to the use of simplified models. Due to the restriction of limited information about the building characteristics and operational control, the potential energy savings method requires the determination of parameters that characterize its thermal performance. Thus, a calibrated building is needed. A general procedure has been developed to carry out automated calibration of building energy use simulations. The methodology has been tested successfully on building simulations based on the simplified energy analysis procedure. The automated calibration is the minimization of the RMSE of the energy use over daily conditions. The minimization procedure is fulfilled with a non-canonical optimization algorithm, the Simulated Annealing, which mimics the Statistical Thermodynamic performance of the annealing process. That is to say, starting at a specified temperature the algorithm searches variable-space states that are steadier, while heuristically, by the Boltzmann distribution, the local minima is avoided. The process is repeated at a new lower temperature that is determined by a specific schedule until the global minimum is found. This methodology was applied to the most common air-handler units producing excellent results for ideal cases or for samples modified with a 1% white noise.
46

Life Cycle Assessment for Building Products - The significanse of the usage phase

Paulsen, Jacob January 2001 (has links)
No description available.
47

Freshwater on the island of Maui : system interactions, supply, and demand

Grubert, Emily 08 July 2011 (has links)
This work is part of a broader, multi-year investigation of Maui Island’s freshwater resources. Maui Island faces multiple resource constraints, including water, land, energy, and capital, and these resource constraints could become relevant over the next forty years. Not only does Maui face potential changes to its water and other systems due to external factors beyond its control, like anthropogenic and other climate changes, but Maui also could make developmental choices that will impact how its resource systems interact. In particular, this work looks at Maui’s freshwater systems as they relate to energy, waste, and environmental systems. This report provides a foundation for future scenario analysis on the island that will aim to characterize potential synergies and hazards of choices like increased food production, local fuel production, and increased use of renewable energies. / text
48

Emissions and Energy Use Efficiency of Household Biochar Production during Cooking in Kenya

Helander, Hanna, Larsson, Lovisa January 2014 (has links)
This project examines the efficiency of a biochar-producing stove in meeting the needs of households in rural of Kenya. The stove has been tested and evaluated by five household in Embu, Kenya and compared with two other common cooking methods. The main parameters were time consumption, fuel consumption and emissions of carbon monoxide and particulate matter. Usability and energy use efficiency have also been evaluated. Three potential feedstocks have been examined for use in the biochar-producing stove; Grevillea prunings, maize cobs and coconut husks. The biochar-producing stove was well received by the households. It has potential of saving time, it saves fuel and it has a significantly lower level of emissions than other examined stoves. Despite some challenges related to the usability and the handling of the stove, an implementation of the biochar-producing stove can contribute to an alleviation of the women’s burdens, save fuel and contribute to a healthier indoor air climate.
49

Energy use in buildings and design requirements : the energy costs and financial costs of building materials, structures and space heating, the detailed patterns of use of heating systems in dwellings, and their interactions : their implications for design

Sansam, Robert Verdon January 1981 (has links)
The primary energy costs of building materials and structures are discussed and comparisons are made between typical dwelling types. The economics of alternative wall, roof and floor constructions, providing various levels of insulationy are examined. Costs are assessed for a number of periods from 1970 to early 1980 for heating by gas and night rate electricity. The effect of price changes-on the economic attractiveness of insulation is investigated and the likely effects of future price rises are considered. It is concluded that, in certain circumstances, higher levels of insulation than those normally used in the UK have been economically attractive for the last few years and may possibly become more so. A survey of over fifty local authority houses with central heating, carried out by the author in Spring 1978, is described. Three types of houses of similar size were involved, having gas-fired 'wet' systems, and ducted warm air heating from electric storage and gas-fired units respectively. The survey was designed to determine certain aspects of occupant behaviour relevant to fuel consumption. Using regression techniques, relationships are obtained which explain more than two thirds of the variance of mean useful energy input rate between the houses of a given type in cold weather in terms of hours of use of central heating window opening habits, and for warm air heating, the closing of outlet registers. It was also revealed that for the house types with gas-fired heating the number of hours of use of the central heating was strongly influenced by household size and occupancy patterns. The implications for building design of the effects of occupant behaviour and of financial and energy costs are discussed.
50

Design and Development of an Intelligent Energy Controller for Home Energy Saving in Heating/Cooling System

Abaalkhail, Rana 18 January 2012 (has links)
Energy is consumed every day at home as we perform simple tasks, such as watching television, washing dishes and heating/cooling home spaces during season of extreme weather conditions, using appliances, or turning on lights. Most often, the energy resources used in residential systems are obtained from natural gas, coal and oil. Moreover, climate change has increased awareness of a need for expendable, energy resources. As a result, carbon dioxide emissions are increasing and creating a negative effect on our environment and on our health. In fact, growing energy demands and limited natural resource might have negative impacts on our future. Therefore, saving energy is becoming an important issue in our society and it is receiving more attention from the research community. This thesis introduces a intelligent energy controller algorithm based on software agent approach that reduce the energy consumption at home for both heating and cooling spaces by considering the user’s occupancy, outdoor temperature and user’s preferences as input to the system. Thus the proposed approach takes into consideration the occupant’s preferred temperature, the occupied and unoccupied spaces, as well as the time spent in each area of the home. A Java based simulator has been implemented to simulate the algorithm for saving energy in heating and cooling systems. The results from the simulator are compared to the results of using HOT2000, which is Canada’s leading residential energy analysis and rating software developed by CanmetENERGY’s Housing, Buildings, Communities and Simulation (HBCS) group. We have calculated how much energy a home modelled will use under emulated conditions. The results showed that the implementation of the proposed energy controller algorithm can save up to 50% in energy consumption in homes dedicated to heating and cooling systems compared to the results obtained by using HOT2000.

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