Miljö och energianvändning blir ett mer aktuellt ämne. 40 % av landets totala energianvändning går idag till bostäder.[1] Om elpriserna stiger under den närmsta tiden kommer det med stor säkerhet leda till att människor blir mer kostnadsmedvetna och gärna hittar sätt för att minska sina energikostnader. Som ett led i detta har hustillverkare tagit fram ett energisnålt alternativ till det vanliga huset. Det benämns lågenergihus och använder mindre energi än de hus som är vanliga på marknaden idag. Det här är möjligt genom att lågenergihus byggs på ett annorlunda vis jämfört med ett ordinärt hus. Bland annat används mer isolering och bättre fönster och dörrar. Dessutom är täthet ett viktigt begrepp för att minska värmeförlusterna. Rapporten syftar till att redogöra för vad som karaktäriserar lågenergihus och ge vägledning vid byggande av dessa. Vidare ska rapporten ge svar på frågorna, vilka är problemen och vilka är fördelarna med lågenergihus? Hur ser byggprocessen ut och vad är viktigt att tänka på i de olika skedena i processen? samt, är det ekonomiskt rimligt att bygga lågenergihus? För att få svar på dessa frågor har jag använt mig av litteratur, intervjuer samt informationssökning på nätet, dessutom har jag använt mig av de kunskaper som införskaffats under studietiden. I rapporten har jag valt att endast behandla energianvändning då miljöfrågan är alltför omfattande. Vidare ger rapporten en introduktion till vad som är utmärkande för lågenergihus rent byggnadstekniskt och lotsar läsaren genom byggprocessens olika skeden samt vilka aktörer som är inblandade och vilka deras respektive ansvarsområden är. Dessutom pekar rapporten ut vad som är viktigt för dig som byggherre att tänka på under de olika skedena i byggprocessen i form av planering, utformning, konstruktion, installationer, utgifter, försäkringar, kontroller och avtal, vare sig du väljer att uppföra byggnaden i egen regi eller anlita en entreprenör. Rapporten ger exempel på lösningar gällande konstruktion, installationer och värmesystem som är lämpliga i ett lågenergihus. Dessutom görs en energiberäkning på ett lågenergihus ritat av författaren till rapporten. Beräkningen ger huset en energianvändning på 56 kWh/m2, år, vilket är ca hälften av vad lagar och föreskrifter anger som maximalt värde ett hus får ha. Idéer och tankar som legat till grund för huset beskrivs. Då detta hus ritats har även andra idéer implementerats som inte är specifika för lågenergihus, utan syftar till att huset ska ha en beredskap vid tillexempel elavbrott. I slutet av rapporten ges även tips på hur du som husägare ytterligare kan spara energi och bidra till en hållbar utveckling. [1]Gross, Holger (2008). Energismarta småhus: vägledning och råd till byggherrar, arkitekter och ingenjörer. Stockholm: Gross produktion i samarbete med Villaägarnas riksförbund / The environment and the use of energy is becoming a more present subject. Today the real estate industry accounts for more than 40% of Sweden’s total energy consumption.[1]As energy prices rise, energy-saving in buildings is becoming increasingly important to homeowners. As result of this, house manufacturers have created a new type of energy-saving house called low-energy house. This house has a different construction in comparison to an ordinary house. The theses aims to give guidance when building a low-energy house and answer the following questions, what are the problems and what are the benefits, which are the different phases of the building process, what issues are important to consider in these phases and is it economically realistic to build a low-energy house. To be able to answer these questions I have collected material from litterateur, interviews, and web searching. In addition I also have used the knowledge I have obtained during my period of studies. The thesis only concern the energy consumption as the environmental part of it is too substantial. In addition the thesis gives a presentation of the building process, who are involved and what are their field of responsibility. Furthermore it points out what you as a future owner of a house/building proprietor should be attentive to during the building process so that no mistakes are made that causes the end results not turning out as expected. Different laws, rules, contracts, norms and authorities that occurs in the building process,  are accounted for and explained in the thesis in such a way that is easy to grasp for those not familiar to the subject.   The report gives advice and example of solutions in terms of construction and installations e.g. heating distribution system that are appropriate in a low-energy house. The thesis includes a calculation of the energy use of a low-energy house, which shows that the house uses about 56 kWh/m2, year. In comparison, this is about half the maximum limit decided by the Swedish constitution BBR.    A suggestion for a low-energy house is displayed in the paper, it is the same housed used for the calculation of energy use. Ideas and thoughts regarding the house are described. This suggestion also implements a few ideas’ that perhaps contributes additionally to energy-savings and a sustainable environment.   [1] Gross, Holger (2008). Energismarta småhus: vägledning och råd till byggherrar, arkitekter och ingenjörer. Stockholm: Gross produktion i samarbete med Villaägarnas riksförbund

The use of mobile devices is increasing due to the constant development of more advanced and appealing applications and computing features. However, these new features are very power hungry leading to short battery lifetimes. Research shows that a major reason for fast battery depletion is the excessive and inefficient use of the wireless interfaces. This thesis studies how we can attempt to increase the battery lifetime of the devices without having to sacrifice the usage of these advanced features in some applications. The thesis focuses on adapting the traffic pattern characteristics of mobile communication using a widespread wireless communication technology like 3G. Traffic pattern adaptation is performed at packet level in kernel space in Android. The data transfers are scheduled with the knowledge of the energy consumption characteristics of 3G. The performed measurements indicate that our solution can provide energy savings ranging from 7% to 59%. This work confirms that 3G conscious scheduling of network traffic reduces energy consumption, and that, both applications and energy saving libraries are potential directions to be further studied.

Energy input is vital in every swine operation as it directly affects production performance and overall profitability. With the increasing trend in energy prices and feed costs, the swine industry needed to find ways to improve energy use efficiency in their operations in order to reduce overall cost of production. The goals of this study were to gather benchmark information on current energy usage in swine barns through survey and energy audit, and evaluate different energy-saving measures through building simulation.<p> The results of the survey showed that the average electricity and gas cost was $6.50/head for farrow-to-finish barns, $1.70/head for grow-finish barns, $0.59/head for nursery and $1.95/head for farrow-wean barns. Significant difference (P<0.05) in energy usage within the same type of operation was observed, implying significant opportunities to improve energy use practices in some barns to reduce overall energy costs.<p> The results of the barn monitoring showed that the average daily electricity consumption during summer for farrowing, nursery, grow-finish and gestation room was 3.79 kWh/head (16 sows); 0.12 kWh/head (226 pigs); 0.14 kWh/head (551 pigs) and 0.33 kWh/head (349 sows); respectively. During winter, the average daily electricity consumption for farrowing, nursery, grow-finish and gestation room was 3.92 kWh/head (15 sows); 0.14 kWh/head (227 pigs); 0.09 kWh/head (521 pigs) and 0.22 kWh/head (322 sows); respectively. Highly negative correlation (range from -0.6 to -0.9) was observed between the fan energy consumption and gas concentration of H2S, NH3 and CO2 during summer. This implied that reducing ventilation rate was not a sound option to reduce energy consumption.<p> A simulation model was developed using the principle of heat transfer and thermodynamics to evaluate various energy-conservation measures through building simulation. Applying energy conservation strategies to lighting, creep heating, recirculation fans, exhaust fans, feed motor and heat recovery, an average annual savings of 25,957 kWh (43 kWh/sow); 47,391 kWh (79 kWh/sow); 9,872 kWh (16 kWh/sow); 118,890 kWh (198 kWh/sow); 1,846 kWh (3 kWh/sow); and 74,952 m3 (125 m3/sow) can be achieved, respectively. The outcome of this research project will help pork producers in managing the use of energy in their operations more efficiently, thereby reducing overall energy costs. Additionally, the reduction of energy use across the industry would contribute to the reduction in greenhouse gas emissions associated with energy generation.

The central theme of this dissertation is the study of a multimedia client for pervasive wireless multimedia applications. Speech recognition is considered as one such application, where the computational demands have hindered its use on wireless mobile devices. Our analysis considers distributed speech recognition on hardware platforms with PDA-like functionality (i.e. wireless LAN networking, high-quality audio input/output, a low-power general-purpose processing core, and limited amounts of flash and working memory.) We focus on quality of service for the end-user (i.e. ASR accuracy and delay) and reduced energy consumption with increased battery lifetimes. We investigate quality of service and energy trade-offs in this context. We present software optimizations on a speech recognition front-end that can reduce the energy consumption by over 80% compared to the original implementation. A power on/off scheduling algorithm for the wireless interface is presented. This scheduling of the wireless interface can increase the battery lifetime by an order of magnitude. We study the effects of wireless networking and fading channel characteristics on distributed speech recognition using Bluetooth and IEEE 802.11b networks. When viewed as a whole, the optimized distributed speech recognition system can reduce the total energy consumption by over 95% compared to a client-side ASR implementation. We present an interleaving and loss concealment algorithm to increase the robustness of distributed speech recognition in a burst error channel. This improvement allows a decreased reliance on error protection overhead, which can provide reductions in transmit energy of up to 46% on a Bluetooth wireless network. The findings presented in this dissertation stress the importance of energy-aware design and optimization at all levels for battery-powered wireless devices.

In a water distribution system from groundwater supply, the bulk of energy consumption is expended at pump stations. These pumps pressurize the water and transport it from the aquifer to the distribution system and to elevated storage tanks. Each pump in the system has a range of possible operating conditions with varying flow rates, hydraulic head imparted, and hydraulic efficiencies. In this research, the water distribution system of a mid-sized city in a subtropical climate is modeled and optimized in order to minimize the energy usage of its fourteen pumps. A simplified model of the pipes, pumps, and storage tanks is designed using freely-available EPANET hydraulic modeling software. Physical and operational parameters of this model are calibrated against five weeks of observed data using a genetic algorithm to predict storage tank volume given a forecasted system demand. Uncertainty analysis on the calibrated parameters is performed to assess model sensitivity. Finally, the pumping schedule for the system's fourteen pumps is optimized using a genetic algorithm in order to minimize total energy use across a 24-hour period.

No description available.

Predicted cooling system performance plays an important role in choices among alternative system selections and designs. When system performance is expressed in proper indicators such as "overall system energy consumption" or "overall system efficiency", it can provide the decision makers with a quantitative measure of the extent to which a cooling system satisfies the system design requirements and objectives. Predictions of cooling system energy consumption and efficiency imply assumptions about component performance. Quantitative appraisal of the uncertainty (lack of knowledge) in these assumptions can be used by design practitioners to select and design systems, by energy contractors to guarantee future system energy cost savings, and codes and standards officials to set proper goals to conserve energy. Our lack of knowledge has different sources, notably unknown tolerances in equipment nameplate data, and unpredictable load profiles. Both cause systems to under-perform current predictions, and as a result decrease the accuracy of the outcomes of energy simulations that commonly are used to verify system performance during the design and construction stages. There can be many other causes of unpredictable system behavior, for example due to bad workmanship in the installation, occurrence of faults in the operation of certain system parts, deterioration over time and other. These uncertainties are typically much harder to quantify and their propagation into the calculated energy consumption is much harder to accomplish. In this thesis, these categories of failures are not considered, i.e. the treatment is limited to component tolerances and load variability. In this research the effects of equipment nameplate tolerances and cooling load profile variability on the overall energy consumption and efficiency of commonly used commercial cooling systems are quantified. The main target of this thesis is to present a methodology for calculating the chances that a specific cooling system could deviate from a certain efficiency level by a certain margin, and use these results to guide practitioners and energy performance contractors to select, and guarantee system performances more realistically. By doing that, the plan is to establish a systematic approach of developing expressions of risk, in commercial cooling system consumption and efficiency calculations, and thus to advocate the use of expressions of risk as design targets. This thesis makes a contribution to improving our fundamental understanding of performance risk in selecting and sizing certain HVAC design concepts.

Die immer schneller steigenden Energiepreise haben in der jüngsten Vergangenheit eine breite Diskussion über Energieeffizienz und alternative Erzeugungsverfahren ausgelöst. Von besonderer Bedeutung ist dies für den Gebäudesektor und die darin installierte Anlagentechnik, da in Deutschland ca. 30 % des Energieverbrauches hier anfallen. Eine Minderung dieses Verbrauches kann nur durch eine Vielzahl von Maßnahmen erreicht werden, die schon bei der Planung berücksichtigt werden müssen. Vor diesem Hintergrund wird in diesem Artikel die Anordnung von freien Heizflächen im Raum untersucht sowie energetische und wärmephysiologische Ergebnisse aufgezeigt. Die beschriebenen Analysen wurden für eine repräsentative Raumgeometrie vorgenommen, wodurch es möglich ist, die Aussagen auf eine Vielzahl von Räumen zu übertragen. / The steady rise in energy prices has recently triggered a broad discussion on energy efficiency and alternative methods of generation. Since approximately 30 % of the total energy consumption is attributable to HVAC installations (Heating, Ventilation and Air Conditioning), this sector is acutely relevant for the building industry and for building services. Reduction of the building energy consumption can be achieved only by applying a wide range of measures across the whole process from planning to the realisation stage. Considering the aforementioned, the influence on thermal comfort and energy consumption of different radiator positions within a room is described in the following paper. The analysis was carried out for a representative room geometry, which allows the results to be applied to a broad spectrum of real room configurations.

Thesis (Ph. D.)--Open University. BLDSC no. DX204584.

Indoor air is associated with substantial health risks and is estimated to be responsible for the loss of over 4.7 million healthy life years (years lost due to morbidity and mortality) annually in the U.S. The highest indoor air-related health benefits can be expected from policies and strategies that efficiently target pollutants having the greatest contribution to the burden of disease. This burden is caused by indoor sources as well as by outdoor pollutants transported to the indoors. The diversity of pollutants, pollutant sources, and the resulting health effects challenge the comparison of the impacts of different control strategies on energy consumption and indoor air quality. To address this challenge, this work presents a quantitative framework for reaching the optimal energy cost for the maximum achieved exposure benefits, specifically for retail buildings and their understudied energy, economic, and health risk influence. The main objectives of this dissertation are to 1) determine pollutants of concern in retail buildings that contribute the greatest to the burden of disease, and 2) determine energy-efficient, exposure-based control strategies for different retail types and locations. The research in this dissertation is divided into four specific aims that fulfill these two objectives. The first specific aim (Specific aim 1.a) addresses Objective 1 by applying available disease impact models on pollutant concentrations taken from 15 literature studies (150 stores, a total of 34 pollutants). Of those pollutants, there was little data reported on particulate matter (PM) concentrations and none on emission rates for PM, limiting our understanding of exposure to this pollutant. The second specific aim (Specific aim 1.b) also addresses Objective 1 by characterizing particulate matter (PM) concentrations, emission rates, and fate of ambient and indoor-generated particles in retail buildings. The tasks of this specific aim consisted of particulate matter and ventilation measurements in 14 retail buildings. Among the findings of Objective 1, PM2.5 and acrolein are the main contaminants of concern for which control methods should be prioritized, contributing to 160 disability-adjusted life years (DALYs; years lost due to premature mortality and disability) per 100,000 persons annually. Employees in grocery stores mainly drove this burden. An efficient indoor exposure reduction strategy should take into account all mechanisms that influence pollutant concentrations: indoor and outdoor sources (highlighting the importance of retail type and location), infiltration, ventilation, and filtration. The remaining specific aims address Objective 2 by investigating the energy and air quality impact of two commonly used exposure control scenarios, ventilation (Specific aim 2.a) and filtration (Specific aim 2.b). The tasks of Specific aim 2.a consisted of modeling the impact of multiple ventilation strategies on contaminants of concern for six major U.S. cities and two retail types. The tasks for Specific aim 2.b consisted of conducting field measurements on 15 rooftop units to determine the fan energy impacts of filter pressure drop. These results are used in combination with a large dataset of 75 filters commonly installed in commercial buildings to estimate the energy consequences of filtration. Results for Objective 2 are presented from the quantitative comparison of the impact on energy usage and DALYs lost of three main approaches: (1) adjusting ventilation only; (2) adjusting filtration only; and (3) adjusting ventilation and filtration together. All approaches were able to provide substantial reductions in the health risks (19-26% decrease in DALYs lost); the magnitude of the reductions depended on the ventilation/filtration scenario, the retail type, and the city. The magnitude of energy cost to achieve the maximum health benefits depended on the city and the retail type (for example for a 10,000 m2 grocery store, the energy cost ranged from $1,100 for the annual cost of filtration energy in Los Angeles to $24,000 for the annual cost of ventilation in Austin). The uncertainties of the estimates driving these findings are discussed throughout the results section. The finding that emerges from this analysis is the pollutant exposure control ventilation (PECV) strategy. This strategy is superior to the ventilation rate procedure (VRP; ASHRAE Standard 62.1-2010) and the indoor air quality procedure (IAQP; ASHRAE Standard 62.1-2010) as it decides on a range of ventilation rates by weighing the exposures of contaminants of concern found in retail buildings. Then, among the range of ventilation rates identified, the PECV recommends the optimal ventilation rate that leads to energy usage savings in the climate considered. Overall, the work presented here prioritizes specific contaminants of concern in retail buildings and proposes an exposure-based, energy-efficient control strategy for different retail types and locations. Policy makers, engineers, and building owners can use these results to decide amongst appropriate control strategies that will lead to minimum energy consumption and, at the same time, will not compromise occupant health. This work can be repeated for different types of buildings, notably for residences, schools, and offices where abundant information is available on both pollutant concentrations and ventilation rates, but where information is lacking on how to optimize the control strategies for better indoor air quality. / text