Academic literature on the topic 'Energy Efficiency (incl. Buildings)'

The impeding climate change challenge urges for a reduction of energy use in the built environment. Buildings account for nearly 40% of the total energy use and about 35% of the greenhouse gas emissions in Europe. EU member states are required to improve the energy efficiency of the existing building stock, for example by sharpening building regulations and developing enforcement schemes. Since energy efficiency retrofits can affect irreplaceable values in heritage buildings, heritage buildings are often excluded from mandatory demands aiming at reducing the energy use in buildings. However, saving energy have gradually become embraced by the conservation community and heritage buildings with are seen as part of the solution. This licentiate thesis discusses the methods to identify heritage significance in a building and how the underlying theory determines different scenarios in a energy retrofitting process. The choice of conservation theory and conservation approach will affect the success the energy retrofitting process and determine how much the energy use that can be reduced. This thesis therefore suggests a framework to understand the different interpretation of the impacts that one could exert either by having an Objectivistic or Relative conservation value approach.. Based on this framework, a decision-support tool is developed to further detail the impacts of such approaches for different energy measures. Other results show that a majority of reviewed research publications focused on the operational energy in a building and only a few were concerned with energy use over the entire life- cycle of a building. These analyses are used to evaluate where most energy savings can be made, and often pinpoint weak spots in the building’s envelope or technical system. If it was mentioned at all, the influence of cultural and historical factors on energy efficiency measures as applied to heritage buildings tended to be assessed only briefly. Indeed, the majority does not describe conservation principles or even mention the methodology used – if any – for assessing or defining heritage values. Instead, researchers often show an explicit (sometimes an implicit) understanding of conservation as essentially something that is not destructive of original construction material and hence the authenticity of a building. This licentiate thesis is a compilation thesis, consisting of one separate sub-study, one literature review and an extended cover essay. The study is oriented towards a Swedish and European context, especially when it comes to climate conditions and discussions on building regulations and the theory and practice of architectural conservation. It addresses the growing research field of energy efficiency in heritage buildings and the thesis aims to contribute to an increased understanding on how the process of assessment and evaluation of heritage significance in buildings affects the making of heritage buildings more energy efficient. The main research question is: How do different approaches for assessing and evaluating heritage significance in buildings affect possible technical energy saving measures in heritage buildings?<br>Klimatförändringarna driver utvecklingen mot att energianvändningen i den byggda miljön behöver minska. Byggnader står för nästan 40% av den totala energianvändningen och cirka 35% av utsläppen av växthusgaser i Europa. EUs medlemsländer är bundna att förbättra energieffektiviteten hos befintliga byggnader, till exempel genom att skärpa byggreglerna och utveckla handlingsplaner. Eftersom energieffektiviseringar kan påverka värden i kulturhurhistoriska byggnader, är dessa ofta undantagna från krav som syftar till att minska energianvändningen i byggnader. Energibesparing och resurshushållning har gradvis blivit omfamnad av kulturmiljösektorn och kulturhistoriska byggnader betraktas allt mer som en del av lösningen på klimatförändringarna. I licentiatavhandlingen diskuteras metoderna för att identifiera kulturhistoriska värden i en byggnad och hur den underliggande teorin påverkar olika scenarier i en energieffektiviseringprocess. Valet av bevarandeteori och bevarandestrategi påverkar framgångsfaktorn i energieffektivseringen och hur mycket energianvändningen i en kulturhistorisk byggnad kan minskas. I denna avhandling föreslås därför ett teoretiskt ramverk för att förstå effekterna av de olika kulturhistoriska bedömningar som kan göras, antingen genom att använda ett objektivistiskt eller en relativ syn på hur en en byggnads kulturhistoriska värden skapas och bäst bevaras. Utifrån detta teoretiska ramverk har ett stöd för beslutsfattande utvecklats för att ytterligare beskriva effekterna av de olika bevarandestrategiernas påverkan på implementeringen av olika energieffektiviserande åtgärder. Andra resultat visar att en majoritet av de granskade forskningspublikationerna fokuserade på den operativa energin i en byggnad och bara ett fåtal gällde energianvändning under hela livscykeln i en byggnad. Dessa analyser används för att utvärdera var de flesta energibesparingar kan göras och ofta identifiera svaga punkter i byggnadens klimatskal eller tekniska system. Om det nämndes alls tenderade inflytandet av kulturella och historiska faktorer på energieffektivitetsåtgärder som tillämpas på arvsbyggnader endast att bedömas kortfattat. Faktum är att majoriteten av de genomgångna publikationerna inte beskriver bevarandeprinciper och inte nämner den metod som används för att bedöma eller definiera kulturhistoriska värden. Istället används ofta en explicit (ibland en implicit) förståelse för bevarande som i huvudsak något som inte förstör ursprungligt material och därmed autenticitet i en byggnad. Denna licentiatavhandling består av en separat undersökning, en litteraturöversikt och en utökad kappa. Studien är inriktad på ett svenskt och europeiskt sammanhang, särskilt när det gäller klimatförhållanden och diskussioner om byggregler och teori och praktik för kulturhistoriskt bevarande av byggnader. Den är en del av det växande forskningsområdet energieffektivisering i kulturhistoriska byggnader och avhandlingen syftar till att bidra till en ökad förståelse för hur utvärderingen av kulturhistoriska värden i byggnader påverkar arbetet med att göra dem mer energieffektiva. Huvudforskningsfrågan är: Hur påverkar olika metoder för bedömning och utvärdering av kulturhistoriska värden energibesparande åtgärder i kulturhistoriska byggnader?

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR<br>PROGRAMA DE EXCELENCIA ACADEMICA<br>O crescente consumo de energia é preocupante, principalmente pelo uso de sistemas de condicionamento de ar e de iluminação artificial. Nas edificações modernas, os projetos arquitetônicos vêm negligenciando os fatores que proporcionam o conforto ambiental. Baseando-se nos conceitos da arquitetura sustentável, esta dissertação propõe e modela um sistema que otimiza os parâmetros da edificação que influenciarão no consumo de energia elétrica, nos custos com a construção e na emissão de poluentes pela edificação. Propõe-se um modelo de algoritmos genéticos que, juntamente com um programa de simulação de energia, EnergyPlus, constitui o modelo evolucionário desenvolvido neste trabalho. Este modelo otimiza parâmetros como: dimensionamento de aberturas e de pédireito; orientação da edificação; condicionamento do ar; disposição de árvores no entorno da edificação; etc . O modelo evolucionário tem sua ação e eficácia testados em estudo de casos - edificações desenhadas por projetista -, em que se alteram: espessura das paredes, altura de pé direito, largura de janelas, orientação quanto ao Norte geográfico, localização de elementos sombreantes (árvores), uso ou não de bloqueadores solares. Estes fatores influenciarão no conforto térmico da edificação e, consequentemente, no consumo elétrico dos sistemas de condicionamento de ar e de iluminação artificial, que por sua vez, influenciam os parâmetros que se pretende otimizar. Os resultados obtidos mostram que as otimizações feitas pelo modelo evolucionário foram efetivas, minimizando o consumo de energia pelos sistemas de condicionamento de ar e de iluminação artificial em comparação com os resultados obtidos com as edificações originais fornecidas pelo projetista.<br>The continuous rising on energy consumption is a concerning issue, especially regarding the use of air conditioning systems and artificial lighting. In modern buildings, architectural designs are neglecting the factors that provide environmental comfort in a natural way. Based on concepts of sustainable architecture, this work proposes and models a system that optimizes the parameters of a building that influence the consumption of electricity, the costs with the building itself, and the emission of pollutants by these buildings. For this purpose a genetic algorithm model is proposed, which works together with an energy simulation program called EnergyPlus, both comprising the evolutionary model developed in this work. This model is able to optimize parameters like: dimensions of windows and ceiling height; orientation of a building; air conditioning; location of trees around a building; etc. The evolutionary model has its efficiency tested in case studies - buildings originally designed by a designer -, and the following specifications provided by the designer have been changed by the evolutionary model: wall thickness, ceiling height, windows width, building orientation, location of elements that perform shading function (trees), the use (or not) of sun blockers. These factors influence the building s heat comfort and therefore the energy consumption of air conditioning systems and artificial lighting which, in turn, influence the parameters that are meant to be optimized. The results show that the optimizations made by the evolutionary model were effective, minimizing the energy consumption for air conditioning systems and artificial light in comparison with the results obtained with the original buildings provided by the designer.

The building and property sector stands for one third of the final energy usage in Sweden and this should be diminished, in order to reach goals within environmental sustainability. Glass is a poor thermal insulator but nevertheless a popular choice of material when constructing new buildings. The contradiction between need of energy efficiency and the wish for “glass buildings” led to the subject of this report. This Bachelor’s thesis examines how demands on energy efficiency is met in nine glass buildings in Stockholm. Glass buildings and the current legislation is discussed from a perspective of environmental sustainability. This was done by investigating the demands stated by Boverket from a historical perspective, executing quantitative measurements of heat transfer on elected objects, and interviewing stakeholders linked to the buildings and the Swedish legislation. The study shows that the construction of glass buildings has been possible due to a restructuring of the demands on energy efficiency and technical development. It was found, in most cases, that the shares of glass were in fact lower than apparent. A larger share of glass in the building envelope required creative measures to achieve energy solutions, within legislative demands. Nevertheless, the inlet of solar radiation heat is the greatest challenge. Despite the challenges, the desire for glass is rooted in well-being and aesthetic values, which insinuate that glass buildings will be included in the cityscape henceforth. The conclusions drawn from these results are that the energy performance of glass buildings is still weaker than conventional “solid wall buildings”. Enhancement regarding insulation abilities and improvements of excluding solar radiation must be realized to strengthen the environmental sustainability of this category of buildings.<br>Bygg- och fastighetssektorn står för en tredjedel av den slutliga energianvändningen i Sverige, vilken måste minimeras för att nå miljömässiga hållbarhetsmål. Att bygga i glas är populärt bland moderna byggnader, trots att glas har relativt låg termisk isolationsförmåga. Motsättningen mellan behovet av energieffektivitet och efterfrågan på “glashus” skapade ämnet för denna rapport. Detta kandidatexamensarbete utforskar hur energieffektivitetskrav möts i nio olika glasbyggnader i Stockholm. Glashus och nuvarande lagstiftning diskuteras ur ett miljömässigt hållbarhetsperspektiv. Detta gjordes genom undersökningar av Boverkets krav ur ett historiskt perspektiv, kvantitativa mätningar av värmeflöden, samt intervjuer med aktörer kopplade till byggnaderna och svensk bygglagstiftning. Studien visar att byggnation av glashus har blivit möjlig på grund av en omstrukturering av energieffektivitetskraven samt teknisk utveckling. Det visade sig att andelen glas i de undersökta byggnaderna oftast var lägre än det såg ut. Större andel glas i klimatskalet krävde kreativa åtgärder för att uppnå energilösningar inom lagstiftningen. Det visade sig också att solinstrålning var den största energiutmaningen för glasbyggnaderna. Trots utmaningarna finns värden anknutna till estetik och välmående som skapar en efterfrågan på glashus, och detta leder till att glashus fortfarande kommer inkluderas i stadsmiljön framöver. En slutsats från arbetet är att energiprestandan i glasbyggnader är svagare än för konventionella “tätväggsbyggnader”. Förbättringar av glaskonstruktionen gällande isolationsförmåga och utestängning av värme från solinstrålning måste realiseras för att stärka den miljömässiga hållbarheten för denna byggnadskategori.

In order to control climate change it is important to limit the atmosphericconcentration of carbon dioxide (CO2). Increased energy efficiency, as well as ashift from fossil fuels to renewable resources can reduce net CO2 emission. Theenergy required for constructing and operating buildings is significant in manycountries, and it is thus important to design energy efficient buildings and energysupply systems.Improvements in existing buildings are needed in order to achieve short-termemission reductions. The Swedish building stock expanded greatly during the1960s and 1970s. The energy efficiency of these houses was often quite low, andmany of them were built with resistance heating. In this thesis increased energyefficiency in such buildings is studied, as well as conversions from resistanceheating to other heating systems, and various technologies and fuels for theproduction of electricity and heat. The effects of these measures are analysed withrespect to primary energy use, CO2 emission and societal cost. The studies wereperformed using process-based systems analysis in a life-cycle perspective. Thesystem boundaries include energy chains from the natural resources to the usefulelectricity and heat in the houses. The results show that the choice of heatingsystem in the house has a greater effect on the primary energy use than measureson both the house envelope and the energy supply chains. District heating basedon cogeneration of heat and electricity and bedrock heat pumps were found to beenergy-efficient systems. The net emission of CO2 is dependent on the fuel and theCO2 emissions from these systems are comparable to those from a wood pelletboiler, if biomass-based supply chains are used. Conversion from resistanceheating to any of the other heating systems studied is also profitable from a societaleconomic perspective.The decision to implement energy-efficiency measures or install a new heatingsystem in a detached house is taken by the house owner. In order for successfulimplementation the alternatives must either be sufficiently attractive or incentivesor policy instruments that affects this large, inhomogeneous group must beimplemented. In this thesis, the house owners’ economic situation when changingthe heating system and implementing energy-efficiency measures on the buildingenvelope is analysed. The economic analysis includes current Swedish policyinstruments, such as an investment subsidy for heating system conversion, anincome tax deduction for replacing windows, levying a consumer electricity tax and increasing real estate tax. House owners’ perceptions of different heatingsystems are analysed through the results of comprehensive questionnaires. Societaleconomy, private economy and individuals’ perceptions are compared. Theconversion subsidy provides some incentive to house owners to act according tothe national energy policy, as does the electricity tax, which has a significantinfluence on consumer costs. The use of economic instruments seems efficient inpromoting systems in line with environmental goals since environmental factorsare ranked much lower by the home owners. However, the effect on the annualcost of most of the policy instruments studied is smaller than the price variationsbetween different energy suppliers. Energy suppliers thus have considerableopportunity to influence house owners.To achieve long-term changes in the building sector new houses should beconstructed with as low primary energy use and emission as possible, seen overtheir entire life cycle. The primary energy use is analysed for both the productionand operational phase of several types of residential buildings. When the demandfor operational primary energy decreases, due to a high energy standard orenergy-efficient supply, the relative importance of the energy required forproduction will increase. The amount of primary energy required for theproduction of a new low-energy building is significant compared with the primaryenergy required for space heating. One way of reducing both primary energy useand CO2 emission in the production phase is to use constructions with woodframes instead of concrete.The energy supply system is nevertheless still important also for low energybuildings. A new house built to passive standard, heated with fossil-fuel-basedresistance heating gives rise to higher primary energy use and CO2 emission than aconventional detached house from the 1970s that is heated with an energy-efficientbiomass-based heating system. The results thus indicate that wood-framed houseswith a high energy standard, together with efficient energy supply systems, couldbe an option for sustainable residential construction.

The main objective in this thesis is to explore if a model predictive control scheme can increase the energy efficiency in office buildings with waterborne heating systems. The number of office buildings is constantly increasing, which displays the importance of efficient control systems. Since the aim is to decrease the energy consumption, improving the control systems in existing buildings and developing smart control schemes for new buildings are equally important. That is why the vision in this thesis is to design a control scheme that theoretically can be introduced to all new and existingoffice buildings. The model predictive controller&#146;s objective is therefore to minimize the supply water temperature to the heating system, while fulfilling a set of defined indoor temperature demands.The model is the most important tool when comparing different control schemes. It is derived using an electrical analogy, and includes the most important thermodynamical relations in three rooms, a ventilation system, and a district heating system. To achieve optimal control of the supply-water temperature, a constrained optimization problem is introduced through a model predictive control scheme. Two versions of the model predictive control scheme are compared with a conventional control scheme. The first version is an ordinary formulation with some ad-hoc solutions including time-varying output constraints, while the second version is a robust formulation includingslack variables. The energy-consumption analysis imply that a 33 % - 34 % reduction potential is obtainable if a model predictive control scheme is introduced.

In recent years, energy efficiency in the built environment has been attracting considerable interest to mitigate energy consumption. A number of scientific studies indicate that rising air pollution, decreasing biodiversity, ocean acidification and other adverse effects on humans and the environment in recent decades are due to greenhouse gas emissions, and a substantial share of the emissions can be attributed to energy usage in residential buildings. Investments in energy-efficient technologies have been made to alleviate such human induced causes contributing to the emissions, but they are still far from widespread, calling for a thorough understanding of individuals' decision-making processes to promote further adoption of energy efficiency investments. Although personality has been widely recognised as an explanatory factor of behaviour, a rigorous discussion of it in the context of energy efficiency investments is missing. As such, to understand the role of personality traits in making high-cost energy efficiency investments in residential buildings, this research applies a multidisciplinary approach to derive theoretical models that are evaluated in subsequent empirical investigations using quantitative methods and data from the UK and Germany. The findings suggest three ways through which personality can influence energy efficiency investments. The first is an indirect impact of personality traits through risk preferences, in which the significance of the personality effects depends on the financial subsidy context. The second is an indirect effect of personality traits through environmental concern. The third way suggests an impact of personality traits through their importance for individuals' capability and willingness to consider peer behaviour.

The aim of this thesis work is to analyse the trends in heat use among Borlänge Energis district heating customer over the last 20 years. Several reports show that in general the buildings stock get more and more efficient, both in Sweden and other European countries, but will the same trend be seen among Borlänge Energis customer? Data of delivered heat to 324 customers, both single-family houses and multifamily houses, for the period of 1998-2018 is used in this study. The heating that is assumed for domestic hot water is calculated and the heat used for heating is temperature corrected so the heat needed for a normal year could be calculated. The investigated customers are divided into different groups representing various types of buildings with different building years. From this data it’s possible to see trends in heat usage in kWh/building, and year for various types of buildings over the period. Other studies on how trends for heating usage in buildings have report heating usage in kWh/(m2,year). It wasn’t possible in this work to get data of the size of each building, which means that it’s not possible to compare the result from this study with other studies. However, assuming that the building area have been the same and that no extensions of the buildings have been done during the period, the trend in changed heat use should be the same, unless the result is presented in kWh/m2, year and kWh/building, year. The overall results show that there is a reduction in energy use in the buildings in Borlänge during the period 1998-2018. The decrease in heat use are in the order of 0.3 – 0.4 %/year, with larger decrease in multi-family houses. This is considerably less than the decrease of heat use in the buildings stock of 0.9 – 1.2 %/year reported for the entire building stock in Sweden during approximately the same period.