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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

An Investigation of Window and Lighting Systems using Life Cycle Cost Analysis for the Purpose of Energy Conservation in Langford Building A at Texas A&M University

Hwang, Hea Yeon 2011 May 1900 (has links)
Langford Building A forms part of the Langford Architectural Complex at Texas A & M University. Inefficient lighting fixtures and single pane windows in Langford Building A contribute to a considerable portion of the total cost of energy for this building. In the Southwestern United States, a building's windows can be responsible for a significant loss of energy. The windows and inefficient light bulbs can result in high utility costs and high labor charges from more frequent lighting maintenance than that required for efficient lighting. In Langford Building A, window system energy efficiency has not been improved since the building was constructed in 1977. This paper investigates the economic feasibility of using efficient lighting and window systems in Langford Building A. The cost for windows and new lighting tubes was analyzed and compared by using Life Cycle Cost Analysis. The payback periods, determined in this analysis, showed that more efficient lighting and window systems would reduce costs. As results of this analysis, the window film and LED lighting tube reduce building life cycle cost and short payback periods than other alternatives.
2

Dimensionamento e análise do ciclo de vida de pavimentos rodoviários: uma abordagem probabilística. / Pavement design and life cycle analysis: a probabilistic approach.

Santos, Caio Rubens Gonçalves 31 May 2011 (has links)
Frequentemente é utilizada a abordagem determinística tanto em dimensionamentos quanto em análises do ciclo de vida de pavimentos rodoviários. A variabilidade inerente aos parâmetros pertinentes à implantação e ao desempenho de um pavimento é comumente desprezada, porém sua consideração pode ser contemplada com a utilização de uma abordagem probabilística, onde cada variável é caracterizada através de uma distribuição de probabilidade adequada. Uma análise econômica de um pavimento, seja asfáltico ou rígido, deve sempre abordar todos os custos pertinentes, desde a implantação. Os custos e benefícios tanto dos usuários quanto da administração rodoviária devem ser considerados. Um dos principais objetivos da avaliação econômica de pavimentos é o de apoiar a decisão quanto à seleção de alternativas de construção ou manutenção mais viáveis, quanto ao custo, e face de determinadas condições técnicas e econômicas. Este trabalho foca a utilização da abordagem probabilística no dimensionamento e em uma análise econômica de pavimentos rodoviários, tanto asfálticos quanto rígidos. São propostos procedimentos para a determinação da confiabilidade de uma estrutura de pavimento, asfáltico ou rígido, baseados nos métodos do DNIT e da AASHTO. Para análise do ciclo de vida são propostos modelos computacionais para a execução destas análises utilizando-se a equação de desempenho da AASHTO. Os custos dos usuários não foram contemplados nos modelos. O método Monte Carlo foi utilizado em todos os modelos. O risco de falha é determinado para o dimensionamento do pavimento. Os resultados contam ainda com uma distribuição dos custos totais ao longo de um período de projeto, possibilitando uma análise de risco. Os dados de saída (resultados) revelam- se como importantes balizadores para a tomada de decisão quanto à alocação de investimentos em alternativas de pavimentação, considerando os riscos inerentes às variabilidades das parcelas do processo consideradas neste trabalho. / A deterministic approach is often used for pavement design and life cycle cost analysis, which does not consider the inherent variability of some relevant parameters. The inherent variability of relevant parameters to the construction and performance of a pavement is often overlooked, but their consideration can be addressed with the use of a probabilistic approach, where each variable is characterized by a suitable probability distribution. An economic analysis of a pavement, either asphaltic or rigid, should always include an approach that considers all relevant construction costs, since its construction. The benefit-cost for both agency and road users should be considered. Improving the decision making process to choose among all construction and maintenance alternatives is one of the main pavement economic analysis goals. This thesis focuses on the use of probabilistic approach in the pavement design and in the Life Cycle Cost Analysis of road pavements, either asphalt or rigid. Procedures are proposed for determining the reliability of a structure of pavement, based on the methods of DNIT and AASHTO. For life cycle cost analysis, models are proposed for the implementation of these computational analyses using the performance equation of AASHTO. The user costs were not included in the models. The Monte Carlo method was used in all models. The reliability (and the risk of failure) is determined for pavements design. The results also come with a distribution of total costs over an analysis period, allowing a risk analysis. The output data (results) are revealed as important indicators for decision making process regarding the allocation of investments in alternative pavements solution, considering the inherent variability of the parcels of the process considered in this work.
3

Dimensionamento e análise do ciclo de vida de pavimentos rodoviários: uma abordagem probabilística. / Pavement design and life cycle analysis: a probabilistic approach.

Caio Rubens Gonçalves Santos 31 May 2011 (has links)
Frequentemente é utilizada a abordagem determinística tanto em dimensionamentos quanto em análises do ciclo de vida de pavimentos rodoviários. A variabilidade inerente aos parâmetros pertinentes à implantação e ao desempenho de um pavimento é comumente desprezada, porém sua consideração pode ser contemplada com a utilização de uma abordagem probabilística, onde cada variável é caracterizada através de uma distribuição de probabilidade adequada. Uma análise econômica de um pavimento, seja asfáltico ou rígido, deve sempre abordar todos os custos pertinentes, desde a implantação. Os custos e benefícios tanto dos usuários quanto da administração rodoviária devem ser considerados. Um dos principais objetivos da avaliação econômica de pavimentos é o de apoiar a decisão quanto à seleção de alternativas de construção ou manutenção mais viáveis, quanto ao custo, e face de determinadas condições técnicas e econômicas. Este trabalho foca a utilização da abordagem probabilística no dimensionamento e em uma análise econômica de pavimentos rodoviários, tanto asfálticos quanto rígidos. São propostos procedimentos para a determinação da confiabilidade de uma estrutura de pavimento, asfáltico ou rígido, baseados nos métodos do DNIT e da AASHTO. Para análise do ciclo de vida são propostos modelos computacionais para a execução destas análises utilizando-se a equação de desempenho da AASHTO. Os custos dos usuários não foram contemplados nos modelos. O método Monte Carlo foi utilizado em todos os modelos. O risco de falha é determinado para o dimensionamento do pavimento. Os resultados contam ainda com uma distribuição dos custos totais ao longo de um período de projeto, possibilitando uma análise de risco. Os dados de saída (resultados) revelam- se como importantes balizadores para a tomada de decisão quanto à alocação de investimentos em alternativas de pavimentação, considerando os riscos inerentes às variabilidades das parcelas do processo consideradas neste trabalho. / A deterministic approach is often used for pavement design and life cycle cost analysis, which does not consider the inherent variability of some relevant parameters. The inherent variability of relevant parameters to the construction and performance of a pavement is often overlooked, but their consideration can be addressed with the use of a probabilistic approach, where each variable is characterized by a suitable probability distribution. An economic analysis of a pavement, either asphaltic or rigid, should always include an approach that considers all relevant construction costs, since its construction. The benefit-cost for both agency and road users should be considered. Improving the decision making process to choose among all construction and maintenance alternatives is one of the main pavement economic analysis goals. This thesis focuses on the use of probabilistic approach in the pavement design and in the Life Cycle Cost Analysis of road pavements, either asphalt or rigid. Procedures are proposed for determining the reliability of a structure of pavement, based on the methods of DNIT and AASHTO. For life cycle cost analysis, models are proposed for the implementation of these computational analyses using the performance equation of AASHTO. The user costs were not included in the models. The Monte Carlo method was used in all models. The reliability (and the risk of failure) is determined for pavements design. The results also come with a distribution of total costs over an analysis period, allowing a risk analysis. The output data (results) are revealed as important indicators for decision making process regarding the allocation of investments in alternative pavements solution, considering the inherent variability of the parcels of the process considered in this work.
4

Comparative analysis of the VRF system and conventional HVAC systems, focused on life-cycle cost

Park, Jaesuk 13 January 2014 (has links)
As concern for the environment has been dramatically raised over the recent decade, all fields have increased their efforts to reduce impact on environment. The field of construction has responded and started to develop the building performance strategies as well as regulations to reduce the impact on the environment. HVAC systems are obviously one of the key factors of building energy consumption. This study investigates the system performance and economic value of variable refrigerant flow (VRF) systems relative to conventional HVAC systems by comparing life-cycle cost of VRF systems to that of conventional HVAC systems. VRF systems consist mainly of one outdoor unit and several indoor units. The outdoor unit provides all indoor units with cooled or heated refrigerant; with these refrigerants, each indoor unit serves one zone, delivering either heating or cooling. Due to its special configuration, the VRF system can cool some zones and heat other zones simultaneously. This comparative analysis covers six building types—medium office, standalone retail, primary school, hotel, hospital, and apartment—in a eleven climate zones—1A Miami, 2A Houston, 2B Phoenix, 3A Atlanta, 3B Las Vegas, 3C San Francisco, 4A Baltimore, 4B Albuquerque, 4C Seattle, 5A Chicago, and 5B Boulder. Energy simulations conducted by EnergyPlus are done for each building type in each climate zone. Base cases for each simulation are the reference models that U.S. Department of Energy has developed, whereas the alternative case is the same building in the same location with a VRF system. The life-cycle cost analysis provides Net Savings, Savingto- Investment ratio, and payback years. The major findings are that the VRF system has an average of thirty-nine percent HVAC energy consumption savings. As for the results of the life-cycle cost analysis, the average of simple payback period is twelve years.
5

Pilot Study for Quantifying LEED Energy & Atmosphere Operational Savings in Healthcare Facilities

Daniels, Patrick Rudolph 2012 August 1900 (has links)
Owner groups and Facility Managers of health care facilities interested in reducing operation and maintenance (O&M) expenses for new facilities have often been placed in the difficult position of making cost-benefit assessments without a complete understanding of the cumulative impact of building systems selection on their internal rate of return. This is particularly true when owners are evaluating the initial cost and operational benefit (if any) of obtaining various levels of "Leadership in Energy and Environmental Design" (LEED) certifications for their buildings. Heating Ventilation and Air Conditioning, and Lighting (HVAC&L) loads comprise 51% of the total energy demand in the typical outpatient facility; however, in order to estimate the likelihood of achieving a particular LEED rating for a new building, a "Whole Building Energy Simulation" is necessary to evaluate HVAC&L system performance. The conventional of requiring a design upon which to base an analysis presents owner operators attempting to perform a Lifecycle Cost Analysis (LCCA) early in the concept phase with two unique problems - how to estimate energy use without an actual "design" to model, and how to estimate a system's first cost without knowing its performance requirements. This study outlines a process by which existing energy metrics from the Department of Energy (DOE), Commercial Building Energy Consumption Survey (CBECS), and Energy Star, can be made early during the developer's pro forma phase - without the need for a building design. Furthermore, preliminary business decisions targeted at determining the likelihood of obtaining a particular LEED rating, and specifying the corresponding building systems, can be estimated without the cost required to employ an Architect and Engineer (A&E) team, or the time necessary to develop a design. This paper concludes that regional factors can dramatically affect a building's required level of energy performance, and that the highest performing HVAC&L system, irrespective of cost, will not always provide the best return on investment. Accordingly, the national averages utilized to establish LEED EA1 thresholds do not reflect the cost particularities owners may encounter when developing in various climate zones, and therefor may be less relevant to lifecycle considerations that previously believed.
6

A model for Assessing Cost Effectiveness of Facility Layouts : A case study

Ciganovic, Renato, Tates, Mikael January 2006 (has links)
<p>The purpose of this master thesis is to develop a model for assessing cost effectiveness of facility layouts. A critical literature review of the available relevant models as well as theories was performed in accordance to this purpose. After this a model was developed in order to cover lacks in existing theories. The aim of the model is to evaluate different facility layouts, from both economical and working environmental aspects. The model as a whole is about evaluating, creating and selecting the most preferable facility layout. In this thesis a case study has been performed for testing the developed model. The case company for this testing was the Mail Terminal in Alvesta, which is a part of Posten Sweden AB. The mail terminal receives, sorts and distributes the mail further. The result of this thesis is that, by following the model the authors were able to evaluate all the layouts and also to create the most preferable one. This thesis provides a general model in a structured way, primary aimed to be used for manufacturing companies. Further researches could be to test the model on service producing companies and to define to what extent the model can be generalised.</p> / <p>Syftet med denna magisteruppsats är att utveckla en modell för att utvärdera kostnadseffektiviteten av anläggningslayouter. En kritisk litteraturundersökning av tillgängliga relevanta modeller samt teorier genomfördes i enlighet med syftet. Därefter utvecklades en modell för att täcka brister i existerande teorier. Syftet med modellen är att utvärdera olika layouter, från både ett ekonomiskt- och arbetsmiljös- perspektiv. Modellen i sin helhet handlar om att utvärdera, skapa och välja den mest fördelaktiga layouten. En fallstudie har genomförts i denna uppsats för att testa den skapade modellen. Fallföretaget för att testa modellen var Postterminalen i Alvesta, som är en del av Posten Sverige AB. Postterminal tar emot, sorterar och distribuerar posten vidare. Resultatet av denna uppsats är att genom att använda modellen lyckades författarna utvärdera alla layouter och även skapa den mest fördelaktiga layouten. Denna uppsats bidrar med en strukturerad generell model, som främst riktar sig till producerande företag. Fortsatt forskning skulle kunna vara att testa modellen på service baserade företag och att definiera till vilken omfattning man kan generalisera modellen.</p>
7

A model for Assessing Cost Effectiveness of Facility Layouts : A case study

Ciganovic, Renato, Tates, Mikael January 2006 (has links)
The purpose of this master thesis is to develop a model for assessing cost effectiveness of facility layouts. A critical literature review of the available relevant models as well as theories was performed in accordance to this purpose. After this a model was developed in order to cover lacks in existing theories. The aim of the model is to evaluate different facility layouts, from both economical and working environmental aspects. The model as a whole is about evaluating, creating and selecting the most preferable facility layout. In this thesis a case study has been performed for testing the developed model. The case company for this testing was the Mail Terminal in Alvesta, which is a part of Posten Sweden AB. The mail terminal receives, sorts and distributes the mail further. The result of this thesis is that, by following the model the authors were able to evaluate all the layouts and also to create the most preferable one. This thesis provides a general model in a structured way, primary aimed to be used for manufacturing companies. Further researches could be to test the model on service producing companies and to define to what extent the model can be generalised. / Syftet med denna magisteruppsats är att utveckla en modell för att utvärdera kostnadseffektiviteten av anläggningslayouter. En kritisk litteraturundersökning av tillgängliga relevanta modeller samt teorier genomfördes i enlighet med syftet. Därefter utvecklades en modell för att täcka brister i existerande teorier. Syftet med modellen är att utvärdera olika layouter, från både ett ekonomiskt- och arbetsmiljös- perspektiv. Modellen i sin helhet handlar om att utvärdera, skapa och välja den mest fördelaktiga layouten. En fallstudie har genomförts i denna uppsats för att testa den skapade modellen. Fallföretaget för att testa modellen var Postterminalen i Alvesta, som är en del av Posten Sverige AB. Postterminal tar emot, sorterar och distribuerar posten vidare. Resultatet av denna uppsats är att genom att använda modellen lyckades författarna utvärdera alla layouter och även skapa den mest fördelaktiga layouten. Denna uppsats bidrar med en strukturerad generell model, som främst riktar sig till producerande företag. Fortsatt forskning skulle kunna vara att testa modellen på service baserade företag och att definiera till vilken omfattning man kan generalisera modellen.
8

Sustainable Renovation and Operation of Family Houses for Improved Climate Efficiency : A Case Study

Ramírez Villegas, Ricardo January 2010 (has links)
In the developed world, the existing stock of houses will provide shelter to the majority of population in the upcoming years. Houses are physical objects that consume material and energy and need to be maintained, repaired and restructured from time to time. In order to fulfill the requirements of the Kyoto protocol and be comfortable for their inhabitants, the existing stock needs to be renovated. Strong disagreement between different parts of the scientific community and overlapping and contradictory concepts make the definition of sustainable renovation confusing. In this Thesis, therefore, an approach of renovation and operation for higher energy efficiency and lower climate impact has been the main focus. Based on a systems analysis approach, the aim of this work is to develop a manual to stimulate house owners to become role models in sustainable renovation and operation of family houses, the Thesis providing recommendations to reducing the energy consumption of their houses by evaluating cost and benefits of possible actions and choosing the most energy and cost effective approach of a series of alternatives. With the results of this analysis, a sustainable renovation and operation staircase is proposed. The work found that it is possible develop a staircase manual for sustainable renovation and operation of family houses that follows a logical step-by-step approach and could result in considerable life cycle reductions in both costs and climate impact. The work also suggests that it is possible for academic experts to develop material in a simpler form and language to reach the public in a more understandable form.
9

Soft Computing-based Life-Cycle Cost Analysis Tools for Transportation Infrastructure Management

Chen, Chen 08 August 2007 (has links)
Increasing demands, shrinking financial and human resources, and increased infrastructure deterioration have made the task of maintaining the infrastructure systems more challenging than ever before. Life-cycle cost analysis (LCCA) is an important tool for transportation infrastructure management, which is used extensively to support project level decisions, and is increasingly being applied to enhance network level analysis. However, traditional LCCA tools cannot practically and effectively utilize expert knowledge and handle ambiguous uncertainties. The main objective of this dissertation was to develop enhanced LCCA models using soft computing (mainly fuzzy logic) techniques. The proposed models use available "real-world" information to forecast life-cycle costs of competing maintenance and rehabilitation strategies and support infrastructure management decisions. A critical review of available soft computing techniques and their applications in infrastructure management suggested that these techniques provide appealing alternatives for supporting many of the infrastructure management functions. In particular, LCCA often utilizes information that is uncertain, ambiguous and incomplete, which is obtained from both existing databases and expert opinion. Consequently, fuzzy logic techniques were selected to enhance life-cycle cost analysis of transportation infrastructure investments because they provide a formal approach for the effective treatment of these types of information. The dissertation first proposes a fuzzy-logic-based decision-support model, whose inference rules can be customized according to agency's management policies and expert opinion. The feasibility and practicality of the proposed model is illustrated by its implementation in a life-cycle cost analysis algorithm for comparing and selecting pavement maintenance, rehabilitation and reconstruction (MR&R) policies. To enhance the traditional probabilistic LCCA model, the fuzzy-logic-based model is then incorporated into the risk analysis process. A fuzzy logic approach for determining the timing of pavement MR&R treatments in a probabilistic LCCA model for selecting pavement MR&R strategies is proposed. The proposed approach uses performance curves and fuzzy-logic triggering models to determine the most effective timing of pavement MR&R activities. The application of the approach in a case study demonstrates that the fuzzy-logic-based risk analysis model for LCCA can effectively produce results that are at least comparable to those of the benchmark methods while effectively considering some of the ambiguous uncertainty inherent to the process. Finally, the research establishes a systematic method to calibrate the fuzzy-logic based rehabilitation decision model using real cases extracted from the Long Term Pavement Performance (LTPP) database. By reinterpreting the model in the form of a neuro-fuzzy system, the calibration algorithm takes advantage of the learning capabilities of artificial neural networks for tuning the fuzzy membership functions and rules. The practicality of the method is demonstrated by successfully tuning the treatment selection model to distinguish between rehabilitation (light overlay) and do-nothing cases. / Ph. D.
10

Economic Performance Assessment of Three Renovated Multi-Family Houses with Different HVAC Systems

Khadra, Alaa January 2018 (has links)
Since the building sector is responsible for 40% of the energy consumption and 36% of CO2 emissions in the EU, the reduction of energy use has become a priority in this sector. The EU has adopted several policies to improve energy efficiency. One of these policies aims to achieve energy efficient renovations in at least 3% of buildings owned and occupied by governments annually. In Sweden, a large part of existing buildings was built between 1965 and 1974, a period commonly referred to as ‘miljonprogrammet’. Stora Tunabyggen AB, the public housing company in Borlänge municipality, begun a renovation project in the Tjärna Ängar neighborhood within the municipality with the greatest share of its buildings stock from this period. The pilot project started in 2015. The aim of this project was to renovate three buildings with similar measures, that is, by adding 150 mm attic insulation, replacing windows with higher performing ones (U-value 1 W/m ²K), by adding 50 mm of insulation to the infill walls and by the installation of flowreducing taps. The essential difference between the three renovation packages is the HVAC systems. The selected HVAC systems are (1) exhaust air heat pump, (2) mechanical ventilation with heat recovery and (3) exhaust ventilation. Life cycle cost analysis was conducted for the three building and sensitivity analysis for different values of discount rate and energy price escalation was performed. The study found that the house with exhaust ventilation has the lowest life cycle cost and the highest energy cost. The house with exhaust air heat pump has 3% higher life cycle cost and 18% lower energy use at 3% discount rate and 3% energy price escalation. The study found that mechanical ventilation with heat recovery is not profitable, although it saves energy. The sensitivity analysis has shown that the possible increment of price energy and lower discount rate give higher value for the future costs in life cycle cost analysis. This lead to the main finding of this thesis, which is that exhaust air heat pump is the best choice for the owner according to the available data and the assessed parameters.

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