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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.
21

Building energy retrofitting: from energy audit to renovation proposals : The case of an office building in France

Clément, Paul Francois January 2012 (has links)
Abstract The built environment is responsible for 40% of the global energy demand (1). To reduce building energy consumption, regulations are enhancing the appeal of sustainable constructions. Nevertheless, the rate of construction is low in most of developed countries. Efforts are to be made in existing buildings, namely in office buildings, which are statistically more energy-consuming than residential buildings (3). To conduct an adapted energy retrofitting, an energy audit can be realized as a pre-study. The first step is to realize an inventory of fixture of the building equipment. From that analysis, the building behavior and consumption are modeled with the help of dynamic simulation software. A comparison with the real life energy consumption guides the study to obtain a model close to reality. Energy retrofitting plans can then be created, based on this model and on the inventory of fixture phase. If technically adapted, each retrofitting solution is evaluated in terms of investment cost and energy savings. Building energy audits and recommendation phases are not unique and normalized procedures. More advanced and complex calculations and measurements can improve the result accuracy. Nevertheless, the introduced approach gives a first understanding of a building, by analyzing its strengths and its weaknesses. As a result, the proposed retrofitting solutions are suited to each specific building. This renovation plan can then be used as a first-decision making tool for the various stakeholders included in the retrofitting project. Abstract The built environment is responsible for 40% of the global energy demand (1). To reduce building energy consumption, regulations are enhancing the appeal of sustainable constructions. Nevertheless, the rate of construction is low in most of developed countries. Efforts are to be made in existing buildings, namely in office buildings, which are statistically more energy-consuming than residential buildings (3). To conduct an adapted energy retrofitting, an energy audit can be realized as a pre-study. The first step is to realize an inventory of fixture of the building equipment. From that analysis, the building behavior and consumption are modeled with the help of dynamic simulation software. A comparison with the real life energy consumption guides the study to obtain a model close to reality. Energy retrofitting plans can then be created, based on this model and on the inventory of fixture phase. If technically adapted, each retrofitting solution is evaluated in terms of investment cost and energy savings. Building energy audits and recommendation phases are not unique and normalized procedures. More advanced and complex calculations and measurements can improve the result accuracy. Nevertheless, the introduced approach gives a first understanding of a building, by analyzing its strengths and its weaknesses. As a result, the proposed retrofitting solutions are suited to each specific building. This renovation plan can then be used as a first-decision making tool for the various stakeholders included in the retrofitting project. Abstract The built environment is responsible for 40% of the global energy demand (1). To reduce building energy consumption, regulations are enhancing the appeal of sustainable constructions. Nevertheless, the rate of construction is low in most of developed countries. Efforts are to be made in existing buildings, namely in office buildings, which are statistically more energy-consuming than residential buildings (3). To conduct an adapted energy retrofitting, an energy audit can be realized as a pre-study. The first step is to realize an inventory of fixture of the building equipment. From that analysis, the building behavior and consumption are modeled with the help of dynamic simulation software. A comparison with the real life energy consumption guides the study to obtain a model close to reality. Energy retrofitting plans can then be created, based on this model and on the inventory of fixture phase. If technically adapted, each retrofitting solution is evaluated in terms of investment cost and energy savings. Building energy audits and recommendation phases are not unique and normalized procedures. More advanced and complex calculations and measurements can improve the result accuracy. Nevertheless, the introduced approach gives a first understanding of a building, by analyzing its strengths and its weaknesses. As a result, the proposed retrofitting solutions are suited to each specific building. This renovation plan can then be used as a first-decision making tool for the various stakeholders included in the retrofitting project.
22

Estimates of Transportation Energy Savings with Transportation Management Measures for Varying City Size

Edaayf, Ramadan 05 1900 (has links)
Since the early 1970's, fuel consumption in the transportation sector has been one of the major issues facing planners trying to conserve energy. Generally, fuel consumption is influenced directly by the number of vehicles, the distance travelled, the operating speed and the overall population of city. Traffic engineers spent a great deal of time solving such a problem sometimes by introducing the concept of traffic management, the different actions and strategies that reduce the fuel consumption and some other times by estimating the energy saving to evaluate the effectiveness of these actions. Despite best efforts, energy savings estimation have shown wide fluctuations. This study provides a preliminary Investigation of the impact of city size, in the medium range, on potential energy savings accrued due to implementation of Transportation Energy Management Measures (TEMM's). The data sources used includes the energy savings for each of five city size groups, subjected to 23 TEMM's. These data were rearranged and regressed over city size by using the CURFIT technique. Formulae were derived for each of the TEMM's. For the purpose of verification, the Community Benefits Analysis program (CBA) was applied to test some of the obtained results. It is thus concluded that the resulting energy savings, using the regressed equations provide a reasonable way to predict potential benefits across the medium range of city sizes. / Thesis / Master of Engineering (ME)
23

Improving DSM project implementation and sustainability through ISO standards / Mariska van Heerden

Van Heerden, Mariska January 2014 (has links)
South African industries are challenged with above inflation electricity tariffs which may affect their competitiveness within their relative markets. In order to successfully manage these rising electricity costs and ensuing top market competition, a well organised demand side management (DSM) strategy must be implemented. Energy service companies (ESCos) have been assisting Eskom, South Africa’s leading electricity utility, in managing energy projects around the country. These DSM projects have introduced remarkable electricity and cost savings. However, the need for a sustainable energy management system (EnMS) within these projects does exist. This dissertation illustrates and discusses an EnMS designed to achieve maximum possible energy savings performances. The ISO 9 001 (quality management), ISO 14 001 (environmental management) and ISO 50 001 (energy management) standards were integrated for the development and implementation of this system. It provides a framework for project engineers and industrial clients to apply before, during and after project implementation. The use of the Plan-Do-Check-Act (PDCA) cycle will be applied throughout the dissertation. The PDCA cycle follows basic steps recommended by the relevant ISO standards. This cycle emphasises the concept of continual improvement. The developed EnMS was successfully implemented on various DSM projects. This selection includes previously maintained and new implemented projects. An analysis between the implementation and post- implementation performances supports the achieved results. The results of the case studies are presented in this dissertation. This dissertation illustrates that the continual improvement of an ISO based EnMS will result in a sustainable increase in electricity savings. An overall increase in project quality can be defined and measured according to the electricity consumptions and electricity cost savings. These electricity cost savings from the selected projects resulted to nearly R18 million during project implementation. A total amount of R52 million was already saved during the maintenance phase of 2014. This cost savings only reflect the results of the eight selected projects for the first eight months in 2014. The EnMS explained in this dissertation indicates that a continually controlled framework can improve the quality of DSM project implementation and sustainability. With the flexibility of changing the system according to impulsive constraints and client demands, the system can be used with various DSM projects. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
24

Improving DSM project implementation and sustainability through ISO standards / Mariska van Heerden

Van Heerden, Mariska January 2014 (has links)
South African industries are challenged with above inflation electricity tariffs which may affect their competitiveness within their relative markets. In order to successfully manage these rising electricity costs and ensuing top market competition, a well organised demand side management (DSM) strategy must be implemented. Energy service companies (ESCos) have been assisting Eskom, South Africa’s leading electricity utility, in managing energy projects around the country. These DSM projects have introduced remarkable electricity and cost savings. However, the need for a sustainable energy management system (EnMS) within these projects does exist. This dissertation illustrates and discusses an EnMS designed to achieve maximum possible energy savings performances. The ISO 9 001 (quality management), ISO 14 001 (environmental management) and ISO 50 001 (energy management) standards were integrated for the development and implementation of this system. It provides a framework for project engineers and industrial clients to apply before, during and after project implementation. The use of the Plan-Do-Check-Act (PDCA) cycle will be applied throughout the dissertation. The PDCA cycle follows basic steps recommended by the relevant ISO standards. This cycle emphasises the concept of continual improvement. The developed EnMS was successfully implemented on various DSM projects. This selection includes previously maintained and new implemented projects. An analysis between the implementation and post- implementation performances supports the achieved results. The results of the case studies are presented in this dissertation. This dissertation illustrates that the continual improvement of an ISO based EnMS will result in a sustainable increase in electricity savings. An overall increase in project quality can be defined and measured according to the electricity consumptions and electricity cost savings. These electricity cost savings from the selected projects resulted to nearly R18 million during project implementation. A total amount of R52 million was already saved during the maintenance phase of 2014. This cost savings only reflect the results of the eight selected projects for the first eight months in 2014. The EnMS explained in this dissertation indicates that a continually controlled framework can improve the quality of DSM project implementation and sustainability. With the flexibility of changing the system according to impulsive constraints and client demands, the system can be used with various DSM projects. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
25

A study of membrane properties on air conditioning performance

Boyer, Elizabeth J. January 1900 (has links)
Master of Science / Department of Chemical Engineering / Mary E. Rezac / Mary E. Rezac / Energy consumption due to heating, ventilation, and air conditioning amounts to 10-20% of global electrical energy usage. Air conditioning alone uses one trillion kilowatt hours globally. This energy is required for the dehumidification of air in addition to its cooling. New membrane technologies have the potential to decrease air conditioning energy requirements by significant amounts. A membrane acts as a partial heat and mass exchanger in conjunction with a traditional air conditioning system to remove water content and reduce the cooling load. Membranes vary according to their properties and method of mass transport. Liquid membranes have high permeability and selectivity, dense membranes have high selectivity and low permeability, and porous membranes have low selectivity and high permeability. A theoretical model was created to observe how membrane properties affected the potential energy savings of such systems. The most influential properties were flow rate, water permeability and selectivity, membrane area and thickness, and the purge flow temperature. Other properties were determined to be minimally important such as outdoor temperature and humidity. The effect on energy savings in many cases was not a linear relationship but suggested an optimal value beyond which energy savings did not significantly increase. The best simulations showed electrical energy savings of 86-95%.
26

Financování úspor energie v ČR v porovnání s vybranými programy v zahraničí / Energy saving financing in the CR in comparison with selected programs abroad

Svobodová, Alena January 2011 (has links)
This master thesis is looking into problems of financing of energy saving arrangements in residential buildings. The paper concentrates on an analysis of all available sources of financing. After a brief characteristic of basic ways of financing, including Czech and foreign models, it introduces closer only a selection of the available programs, grant titles and commercial products. Then the attention is paid to more specific programs and products from the Czech Republic, Slovakia and Germany. This paper applies their program parameters to a model object of the residential building and assesses each and every option, using selected economical standards. Based on these parameters, it appraises an economical effectiveness of the investment in individual variations of financing from the point of view of an investor and a state, expressed with the price of a unit saved CO2 emission. By combining both preferential variations of an investor and a state, an optimal variation of financing for the model object is found.
27

Applicator Exposure to Glycol Derivatives and Total Volatile Organic Compounds during the Application of Spray Polyurethane Foam Insulation

Kaniuga, Michael Brian 31 October 2014 (has links)
There is currently high demand for new building materials which are considered "environmentally friendly" or "green" for both new construction and renovations. Spray polyurethane foam (SPUF) insulation has gained significant acceptance by both consumers and the construction industry due to its high R-value, which results into significant energy savings among other things. Despite its acceptance by consumers and the construction industry, consideration must be given to potential chemical exposures to applicators installing these products. This study sought to determine, through quantitative experimentation, if there was a release of glycol derivatives including, diethylene glycol (DEG), ethylene glycol (EG), and propylene glycol (PEG), during the application of SPUF. In addition, total volatile organic Compounds (tVOCs) and various environmental parameters were also collected during this research. This study utilized a two-component small-scale SPUF kit manufactured by the Dow Chemical Company, known as the FROTH-PAK™ kit. This specific kit is typically used by the construction industry to fill cavities, cracks, floor and wall penetrations, and expansion joints of buildings. In order to determine the presence of these glycol derivatives, personal breathing zone samples were collected during the application of the SPUF during three application trials. Glycols derivatives were measured using active sampling techniques. Supplementary parameters including tVOCs, ambient and wet-bulb temperature, relative humidity, carbon monoxide, and carbon dioxide, were measured using direct-reading techniques. During this study several modifications were made to the work area and the air sampling methodology to assist in verifying the presence of the glycols and the conditions in which they may be present in the air during the application of SPUF insulation. All samples were sent to an accredited laboratory and were analyzed by the Nation Institute of Occupational Safety and Health Method 5523. During this study, measurable amounts of diethylene glycol and propylene glycol were detected in two of the trials in which no ventilation in the work area was utilized. During one trial in which a work area ventilation system was utilized, none of the glycols were detected in the laboratory analysis above the limit of detection given the analytical method. Ethylene glycol was not detected in any of the samples submitted for analysis. The results for the tVOC measurements were inconclusive. Based on the results of the air sampling, it is likely that exposure to diethylene glycol and propylene glycol may occur under certain conditions. However, due to the limited number of samples and the variation between the samples collected in this study, a generation rate or concentration buildup estimate for comparison of the OELs was not conducted. These conditions include the quantity of ventilation used during application, the application duration, and proper operation of the SPUF application equipment. Based on the results, there is evidence that additional research may be needed in this area.
28

The effect of energy recovery on indoor climate, air quality and energy consumption using computer simulations

Fauchoux, Melanie 23 June 2006
The main objectives of this thesis are to determine if the addition of an energy wheel in an HVAC system can improve the indoor air relative humidity (RH), and perceived air quality (PAQ), as well as reduce energy consumption. An energy wheel is an air-to-air energy exchanger that transfers heat and moisture between the outdoor air entering and the exhaust air leaving a building. This thesis uses the TRNSYS computer package to model two buildings (an office and a school) in four different cities (Saskatoon, Saskatchewan; Vancouver, British Columbia; Tampa, Florida and Phoenix, Arizona).<p>The results with and without an energy wheel are compared to see if the energy wheel has a significant impact on the RH and PAQ in the buildings. The energy wheel reduces peak RH levels in Tampa, (up to 15% RH), which is a humid climate, but has a smaller effect on the indoor RH in Saskatoon (up to 4% RH) and Phoenix (up to 11% RH), which are dry climates. The energy wheel also reduces the number of people that are dissatisfied with the PAQ within the space by up to 17% in Tampa. <p>The addition of the energy wheel to the HVAC system creates a reduction in the total energy consumed by the HVAC system in Saskatoon, Phoenix and Tampa (2% in each city). There is a significant reduction in the size of the heating equipment in Saskatoon (26%) and in the size of the cooling equipment in Phoenix (18%) and Tampa (17%). A cost analysis shows that the HVAC system including an energy wheel has the least life-cycle costs in these three cities, with savings of up to 6%. In Vancouver, the energy wheel has a negligible impact on the indoor RH, PAQ and energy consumption.
29

Reducing DRAM Row Activations with Eager Writeback

Jeon, Myeongjae 06 September 2012 (has links)
This thesis describes and evaluates a new approach to optimizing DRAM performance and energy consumption that is based on eagerly writing dirty cache lines to DRAM. Under this approach, dirty cache lines that have not been recently accessed are eagerly written to DRAM when the corresponding row has been activated by an ordinary access, such as a read. This approach enables clustering of reads and writes that target the same row, resulting in a significant reduction in row activations. Specifically, for 29 applications, it reduces the number of DRAM row activations by an average of 38% and a maximum of 81%. The results from a full system simulator show that for the 29 applications, 11 have performance improvements between 10% and 20%, and 9 have improvements in excess of 20%. Furthermore, 10 consume between 10% and 20% less DRAM energy, and 10 have energy consumption reductions in excess of 20%.
30

The effect of energy recovery on indoor climate, air quality and energy consumption using computer simulations

Fauchoux, Melanie 23 June 2006 (has links)
The main objectives of this thesis are to determine if the addition of an energy wheel in an HVAC system can improve the indoor air relative humidity (RH), and perceived air quality (PAQ), as well as reduce energy consumption. An energy wheel is an air-to-air energy exchanger that transfers heat and moisture between the outdoor air entering and the exhaust air leaving a building. This thesis uses the TRNSYS computer package to model two buildings (an office and a school) in four different cities (Saskatoon, Saskatchewan; Vancouver, British Columbia; Tampa, Florida and Phoenix, Arizona).<p>The results with and without an energy wheel are compared to see if the energy wheel has a significant impact on the RH and PAQ in the buildings. The energy wheel reduces peak RH levels in Tampa, (up to 15% RH), which is a humid climate, but has a smaller effect on the indoor RH in Saskatoon (up to 4% RH) and Phoenix (up to 11% RH), which are dry climates. The energy wheel also reduces the number of people that are dissatisfied with the PAQ within the space by up to 17% in Tampa. <p>The addition of the energy wheel to the HVAC system creates a reduction in the total energy consumed by the HVAC system in Saskatoon, Phoenix and Tampa (2% in each city). There is a significant reduction in the size of the heating equipment in Saskatoon (26%) and in the size of the cooling equipment in Phoenix (18%) and Tampa (17%). A cost analysis shows that the HVAC system including an energy wheel has the least life-cycle costs in these three cities, with savings of up to 6%. In Vancouver, the energy wheel has a negligible impact on the indoor RH, PAQ and energy consumption.

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