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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

Prediction of Building Count and Dimensions from U.S. Census Data Using Multiple Regression

Leach, Jamison Dane 19 October 2001 (has links)
Providers of high-speed, wireless data services need to know where in their service area to place transmitters to reach potential customers. Viewshed analysis, a technique found in Geographic Information Systems (GIS) software, can be used to model propagation of the wireless signals from different locations to find the best transmitter site. To carry out viewshed analysis, digital data are required for all obstructions the signal may encounter along its path. One such obstruction, terrain, can be represented in the GIS by easily available Digital Elevation Models (DEMs). Another obstruction is buildings, which are common in populated areas, and therefore of particular concern to wireless providers. Unfortunately, digital data for buildings in U.S. cities and towns are often non-existent, difficult to obtain, or very costly. In light of the difficulties surrounding acquisition of building data for wireless propagation studies, this study used Multiple Regression analysis to construct models to predict building count and dimensions. U.S. Census Housing and Demographic data, aggregated at the Census Block level, served as the predictor variables in the regression equations. The models were built from sample data collected from four U.S. cities. For each variable to be predicted (Y), the top models were compared to find the optimum one. The model chosen for Building Count (per Block) showed quite good results, and future research in the prediction of this variable shows promise. Results for the models of Average Building Height and Average Building Footprint Area (both per Block) were not nearly as encouraging, but additional work modeling these variables may still yield insights. / Master of Science
2

Characterising space use and electricity consumption in non-domestic buildings

Liddiard, Robert January 2012 (has links)
Energy used in the operation of the United Kingdom’s non-domestic buildings contributes 18% of national carbon dioxide emissions and reducing these is government policy. The use of electrical equipment in buildings is a major contributor to overall consumption, due to both its intrinsic energy consumption and the effects of incidental internal gains resulting from its operation. Knowledge of how and where consumption and internal gains occur in buildings is important in understanding the consumption characteristics of the building stock. The overall aim of this research was to improve the prediction of energy consumption in the non-domestic stock through the inference of appliance electricity consumption and resultant heat gains, for internal space uses of premises, as identified in UK property taxation data. To achieve this, the objectives were to: 1. Develop a method for inferring space usage in premises. 2. Infer values for the electricity consumption of appliances, and hence internal gains, for space uses within premises. 3. Apply the method to a dataset at the urban scale and use a suitable model to deduce the energy consumption. 4. Compare the results with measured data. Objectives 1 and 2 were achieved through analyses of detailed energy surveys of more than 300 non-domestic premises. By excluding equipment used for heating and cooling, both intrinsic electricity consumption and internal gains from appliances have been characterised for combinations of internal space use and premises activity type. For each combination, the characteristics include the energy intensity (kWh/m2/year) for: • overall appliance use • 14 end uses of appliances (e.g. lighting, catering, computers) • 18 groups of appliance activity descriptions (e.g. sales, office work, process) These characteristics were mapped onto subdivisions of space use, within premises, listed in property taxation data for a test urban area (City of Leicester). Using only 115 descriptions of space use, appliance consumption characteristics have been inferred for 91.5% of the measured internal floor area of the test dataset; this achieved the third objective. More than 80% of the floor area was identified using standard space use descriptions utilised in real estate taxation datasets. The total estimated consumption accounted for 75% of the recorded annual electricity consumption of the test area (the fourth objective). This result is acceptable, given the known limitations of the datasets and suggests that the method constitutes an improvement to stock energy modelling, thus meeting the overall aim. By inferring appliance electricity consumption and internal gains at a finer spatial resolution than previous methods, the diversity of energy consumption characteristics of the non-domestic stock may be represented more faithfully than by values applied to entire homogenised premises or premises types. The method may be used by policy makers as part of an urban energy model and as a means of evaluating potential energy interventions in the non-domestic stock, or parts thereof.
3

Energy Use in the EU Building Stock - Case Study: UK

Arababadi, Reza January 2012 (has links)
Previous studies in building energy assessmnet have made it clear that the largest potential energy efficiency improvements are conected to the retrofitting of existing buildings. But, lack of information about the building stock and associated modelling tools is one of the barriers to assessment of energy efficiency strategies in the building stocks. Therefore, a methodology has been developed to describe any building stock by the means of archetype buildings.  The aim has been to assess the effects of energy saving measures. The model which is used for the building energy simulation is called:  Energy, Carbon and Cost Assessment for Buildings Stocks (ECCABS). This model calculated the net energy demand aggregated in heating, cooling, lighting, hotwater and appliances.   This model has already been validated using the Swedish residential stock as a test case. The present work continues the development of the methodology by focusing on the UK building stock by discribing the UK building stock trough archetype buildings and their physical properties which are used as inputs to the ECCABS. In addition, this work seekes to check the adequacy of applying the ECCABS model to the UK building stock. The outputs which are the final energy use of the entire building stock are compared to data available in national and international sources.   The UK building stoch is described by a total of 252 archetype buildings. It is determined by considering nine building typologies, four climate zones, six periods of construction and two types of heating systems. The total final energy demand calculated by ECCABS for the residential sector is 578.83 TWh for the year 2010, which is 2.6 % higher than the statistics provided by the Department of Energy and Climate Change(DECC). In the non-residential sector the total final energy demand is 77.28 TWh for the year 2009, which is about 3.2% lower than the energy demand given by DECC. Potential reasons which could have affected the acuracy of the final resualts are discussed in this master thesis.
4

Analysis Of Existing Building Stock According To Mitigation Plan Objectives

Hasdemir, Berna 01 February 2010 (has links) (PDF)
Earthquakes in Turkey, among all natural disasters claim the highest losses in terms of human lives, material and economic assets. Most of the lives are lost within the collapsed buildings, and most of the material and economic losses are again directly related to the functional capacities of the building stock. The method of risk assessment in the existing building stock is therefore an essential step in the maintenance of safer urban environments. Analysis of risks in the building stock is usually claimed to demand surveys of engineering studies. Yet risk determination studies by planners could prove not only a more comprehensive approach, but less time consuming and cheaper. As carried out by engineers, most of safety studies in the building stock are directly related with estimating the probability of collapse and damage in individual buildings. It is necessary to recognize the need for analysis of the building stock not only in terms of structural robustness, but as part of a mitigation plan, taking into consideration all sources of hazards and the urban pattern, densities, landuse, forms of ownership, social features, management capacities, and local opportunities. Risky buildings determined by a simple set of criteria within a comprehensive planning context are comparatively explored in this study to observe the level of fit with those determined by engineering surveys. The case of Fatih District in Istanbul provides an opportunity to carry out comparative analyses. It indicates that a &lsquo / perfect fit&rsquo / can not be achieved if for nothing but due to the disregard of multi-hazard areas, hazardous activities and other vulnerabilities like timber buildings other than reinforced concrete in the district by the engineering survey. Several trials indicated that there is a trade-off between ratio of fit and the total volume of relative vulnerability assumed. Ratios like 70% or more could make the planning approach a preferable method owing to its nature of least time-consuming and costly alternative in the determination of what constitutes risk in any urban area. Ultimate assessment could be made with the occurance of the earthquake itself.
5

Decarbonising the English residential sector : modelling policies, technologies and behaviour within a heterogeneous building stock

Kelly, Scott January 2013 (has links)
The residential sector in England is often identified as having the largest potential for emissions reduction at some of the lowest costs when compared against other sectors. In spite of this, decarbonisation within the residential sector has not materialised. This thesis explores the complexities of decarbonising the residential sector in England using a whole systems approach. It is only when the interaction between social, psychological, regulatory, technical, material and economic factors are considered together that the behaviour of the system emerges and the relationships between different system components can be explained giving insight into the underlying issues of decarbonisation. Building regulations, assessments and certification standards are critical for motivating and driving innovation towards decarbonising the building stock. Many existing building performance and evaluation tools are shown to be ineffective and confound different policy objectives. Not only is the existing UK SAP standard shown to be a poor predictor of dwelling level energy demand but it perversely incentivises households to increase CO2 emissions. At the dwelling level, a structural equation model is developed to quantify direct, indirect and total effects on residential energy demand. Interestingly, building efficiency is shown to have reciprocal causality with a household’s propensity to consume energy. That is, dwellings with high-energy efficiency consume less energy, but homes with a propensity to consume more energy are also more likely to have higher energy efficiency. Internal dwelling temperature is one of the most important parameters for explaining residential energy demand over a heterogeneous building stock. Yet bottom up energy demand models inadequately incorporate internal temperature as a function of human behaviour. A panel model is developed to predict daily mean internal temperatures from individual dwellings. In this model, socio-demographic, behavioural, physical and environmental variables are combined to estimate the daily fluctuations of mean internal temperature demand. The internal temperature prediction model is then incorporated in a bottom-up engineering simulation model. The residential energy demand model is then used to project decarbonisation scenarios to 2050. Under the assumption of consistent energy demand fuel share allocation, modelling results suggest that emissions from the residential sector can be reduced from 125 MtCO2 to 44 MtCO2 after all major energy efficiency measures have been applied, the power sector is decarbonised and all newly constructed dwellings are zero carbon. Meeting future climate change targets will thus not only require extensive energy efficiency upgrades to all existing dwellings but also the complete decarbonisation of end use energy demand. Such a challenge can only be met through the transformation of existing building regulations, models that properly allow for the effects of human behaviour, and flexible policies capable of maximising impact from a heterogeneous residential building stock.
6

Optimisation before growth: New property formations for a resource-efficient use of the existing building stock

Luque, Lucio January 2019 (has links)
The building industry accounts for around one third of the total energy use and GHG emissions in Sweden. Despite the implementation of energy efficiency measures focusing on new buildings, embodied impacts from material extraction, manufacturing, construction and maintenance have grown in significant proportions. While cities like Stockholm are currently experiencing a strong demographic growth and a high pressure on the supply of new spaces and facilities for new residents, national environmental goals aim to reduce energy use and GHG emissions in the coming decades. For instance, the new Climate Act in Sweden expects the country to become carbon neutral by 2045 and the European Commission urges the decarbonisation of national building stocks by 2050. The dual pressure of growth and environmental targets urges the exploration of alternatives for the supply and use of space. In fact, some sources indicate that many spaces remain unused during several hours a day/week and estimations show that most of the buildings that will be in use in 2050 have already been built today. This study explores the potential for a resource-efficient use of space in the existing building stock in Stockholm, leading to a positive impact on the reduction of energy consumption and GHG emissions. The inquiry is conducted with a mixed methods approach in three sequential steps: the identification of relevant stakeholders, instruments and initiatives; the analysis of use of space in a sample of commercial spaces at the street level; and the formulation of strategies allowing an increase in their temporal and spatial capacity. The study suggests that one way to optimise the use of space in existing buildings is to create new property rights. Specifically, it illustrates how merging commercial spaces on the street level through the constitution of 3D properties can increase the capacity to accommodate activities in space and time. Together with digitalisation and the development of new services based on sharing solutions, this opens up new possibilities for decreasing new construction and to absorb new demands for heated floor area.
7

Energy efficiency measures and energy pricing : The effect of different price schemes on energy efficiency measures

Skogfeldt, Alexander January 2017 (has links)
This project investigates the relationship between energy efficiency measures in the Swedish building stock and different price schemes based on energy prices. Data from different categories was gathered and used in a regression model. They were based on what type of pricing and fees that are behind the energy prices for electricity and district heating. These predictors were used to get an equation of the temperature corrected energy use which can be linked to how much energy efficiency measures have been implemented over the investigated time period. The result for the main equation, that includes all the studied building types, indicated that it is possible to predict energy efficiency measures with different price schemes,and therefore it is possible to increase the rate at which measures are implemented. It showed that there is a negative relationship between energy consumption and theprice of energy from district heating. If the price of district heating increases the temperature corrected energy use decreases. The other relationships between predictors and the dependent variable were positive. It also described the geographical location as a statistically significant variable, regarding all climate zones in Sweden.
8

Energieffektivisering i befintligt fastighetsbestånd : En fallstudie och dataanalys av energideklarationer i Norrbottens län

Gren, Amanda January 2020 (has links)
Bostads- och servicesektorn står för den största energianvändningen i hela Sverige på 40 %, följt av industrisektorn och transportsektorn. Sveriges riksdag har satt upp ett klimatpolitiskt ramverk från energiöverenskommelsen, bland annat med målet om att energianvändningen ska vara 50 % effektivare till år 2030 i jämförelse med år 2005, uttryckt i termer av tillförd energi i relation till BNP. Det finns stora besparingsmöjligheter att hämta i bostäder, och för att göra en skillnad måste information och kunskap spridas till både fastighetsägare och privatpersoner. Det här examensarbetet är en del av Energikontor Norrs projekt ”Stratus” som arbetar med att stötta 12 kommuner i Norrbottens län, genom att strategiskt arbeta mot att hitta en effektiv och framgångsrik väg för att nå de nationella energi- och klimatmålen anpassad till respektive kommuns förutsättningar.   Syftet med projektet har varit att kartlägga behovet/potentialen för energieffektivisering i olika befintliga byggnader hos alla de 14 kommunerna i Norrbottens län genom analys och bearbetning av data från energideklarationer, lantmäteriet och litteratur.   Byggbeståndet har kategoriserats i fyra byggnadskategorier: ”en- och tvåbostadshus”, ”flerbostadshus”, ”lokal- och specialbyggnader” och ”lokalbyggnader”. Resultatet visar ett energideklarerat byggnadsbestånd där 80 % av byggnaderna har en energiklass mellan D-G, där stor andel av beståndet är byggt under 60–80 talet, därav i behov av någon form av renovering. Byggnadsbeståndet som saknar energideklaration är främst komplementbyggnader som ofta inte behöver en energideklaration, följt av bostäder, där friliggande småhus hör till den största andelen.   Den största besparingspotentialen utifrån förslagna åtgärdsförslag finns att hämta i lokal- och specialbyggnader följt av lokalbyggnader enligt energideklarationerna. En estimerad besparingspotential för energianvändningen i hela Norrbottens län, baserat på åtgärdsförslag från energideklarationerna, visar sig vara 1,65 TWh, mest troligt mycket större än det. Exempel på vanliga förekommande åtgärdsförslag är ”isolera tak” och ”byte/installation av värmepump” för alla byggnadskategorier tillsammans.   En prognos för energiprestandan (kWh/m2 och år) fram till år 2030 visar en minskning med cirka 36 % från hur läget var år 2009 då de första energideklarationerna gjordes i Norrbottens län. Det indikerar att energiprestandan är på rätt väg och potentialen för att minska energianvändningen i våra bostäder finns där, men kommer inte utav sig själv utan det finns fortfarande stora behov av renovering och åtgärder i byggnadsbeståndet. / The housing and service sector accounts for the largest energy consumption, 40 % in Sweden followed by the industrial and transport sectors. The Swedish Parliament has established a climate policy framework from the energy agreement, including the goal of energy use being 50 % more efficient by 2030, compared to 2005, expressed in terms of energy input in relation to GDP. There are great savings opportunities to obtain in housing, and to make a difference knowledge must be disseminated to both property owners and private individuals. This project is part of the Energikontor Norr project "Stratus", which works to support 12 municipalities in Norrbotten County, by strategically working towards finding an effective and successful way to achieve the national energy and climate goals adapted to the respective municipalities' conditions.   The purpose of the project has been to identify the need / potential for energy efficiency in various existing buildings in all the 14 municipalities in Norrbotten County through analysis and processing of data from energy performance certificates (EPC’s), surveying and literature. The building stock has been categorized into four categories: “one- and two-dwelling houses”, “apartment buildings”, “local- and special buildings” and “local buildings”. The result shows an energy-declared building stock where 80 % of the buildings have an energy class between D-G, where a large proportion of the stock is built in the 60-80s, hence in need of renovation to reduce the energy consumption.   The building stock that does not have an EPC is mainly complementary buildings, that do not even need an EPC, followed by housing, where detached houses belong to the largest proportion.   The greatest savings potential based on policy proposal can be found in the “local and special buildings”, followed by “local buildings” according to the EPC’s. An estimated saving potential for energy use in the entire county of Norrbotten, based on policy proposal proposed by the EPC’s, turns out to be 1.65 TWh, most likely much larger than that. Examples of common policy proposal are "insulate roofs" and "replacement / installation of heat pump" for all building categories together.   A forecast for the energy performance (kWh/m2 and year) until 2030 shows a decrease of approximately 36% from 2009 when the first EPC’s in the Norrbotten was made. This indicates that energy performance is on the right track and the potential for reducing energy use in our homes is there, but will not come by itself, there is still a great need of renovation and policy proposal in the building stock.
9

Développement d’une approche systémique de la gestion patrimoniale d’un parc immobilier d’envergure nationale pour améliorer sa performance énergétique : une application menée sur le parc immobilier de l’État utilisé par le ministère de la défense / Development of a systemic approach to the management of major national real estates to improve their energy performance : an application conducted on the management of the Ministry of Defence's real estate

Allaire, Didier 12 December 2012 (has links)
Les politiques abordant la problématique énergétique en France dans le domaine immobilier se focalisent sur les actions à conduire à l'échelle du bâtiment. Cette vision parcellaire occulte l'existence d'autres objets immobiliers pour lesquels l'efficacité d'une démarche limitée à la seule mise en œuvre de solutions techniques est insuffisante : c'est le cas des grands patrimoines immobiliers d'envergure nationale. L'approche systémique montre que la résolution du problème soulevé par l'intégration de la nouvelle donne énergétique ne réside pas dans l'action énergétique mais dans la mutation du système de gestion patrimoniale. La compréhension énergétique d'un parc immobilier implique alors de réinterpréter l'objet immobilier lui-même pour comprendre son fonctionnement global et déterminer un processus d'amélioration continue dans lequel devra s'inscrire la maîtrise du flux énergétique. Ce travail de thèse appréhende la complexité fonctionnelle des parcs immobiliers d'envergure nationale en menant une interprétation systémique fondée sur l'établissement d'un concept de performance globale. Cette démarche, avant tout, méthodologique repose sur l'élaboration d'une cartographie des processus macroscopiques devant intervenir en gestion patrimoniale pour obtenir une évolution positive du système immobilier. L'étude menée sur le parc ministériel de la défense a permis de confronter notre démarche à une forme réelle de complexité immobilière et de la mettre en pratique dans le domaine énergétique. L'élaboration d'une stratégie ministérielle et l'établissement d'un système d'information de gestion ont notamment contribué à valider la portée opérationnelle des résultats obtenus. L'émergence d'une véritable pensée stratégique patrimoniale ouvre des perspectives d'évolution systémique fondées sur la réorganisation progressive d'un fonctionnement immobilier souvent rudimentaire / Policies addressing energy issues in France in the real estate focus on actions to be taken throughout the building. This fragmented view obscures the existence of other real estate objects for which the effectiveness of an approach limited to only implement technical solutions is insufficient: the case of nationwide real estate assets. The systemic approach shows that the resolution of the problem raised by the integration of the new energy context doesn't lie in the energy action but in the transformation of building management beyond energy. A building stock energy understanding implies to review the real estate object itself to get its overall functioning and develop an improvement process in which to integrate the control of energy flow. This thesis presents a systemic interpretation of national building stocks and an analysis of their functional complexity using a concept of global performance. This approach, above all, based on the methodological development of a macroscopic process mapping to intervene in asset management for a positive development of the real estate system. The particular study of the Defence real estate has to confront the complexity of real estate and to apply our methodological framework to the energy field. The validation of a strategic approach and the establishment of a management information system helped to validate the operational range of results. The emergence of a real estate strategic thinking reveals perspectives of systemic progression based on the gradual reorganization of real estate rudimentary operation
10

The role of biobased building materials in the climate impacts of construction : Effects of increased use of biobased materials in the Swedish building sector

Peñaloza, Diego January 2017 (has links)
A significant share of the global climate change impacts can be attributed to the construction sector. One mitigation strategy is increasing the use of biobased materials. Life cycle assessment (LCA) has been used to demonstrate the benefits of this, but forest complexities create uncertainty due to omission of key aspects. The aim of this thesis is to enhance understanding of the effects of increasing use of biobased materials in climate change mitigation of construction works with a life cycle perspective. Non-traditional LCA methodology aspects were identified and the climate impact effects of increasing the use of biobased materials while accounting for these was studied. The method applied was dynamic LCA combined with forest carbon data under multi-approach scenarios. Diverse case studies (a building, a small road bridge and the Swedish building stock) were used. Most scenarios result in impact reductions from increasing the use of biobased materials in construction. The inclusion of non-traditional aspects affected the results, but not this outcome. Results show that the climate mitigation potential is maximized by simultaneously implementing other strategies (such as increased use of low-impact concrete). Biobased building materials should not be generalised as climate neutral because it depends on case-sensitive factors. Some of these factors depend on the modelling of the forest system (timing of tree growth, spatial level approach, forest land use baseline) or LCA modelling parameters (choice of the time horizon, end-of-life assumptions, service life). To decrease uncertainty, it is recommended to use at least one metric that allows assessment of emissions based on their timing and to use long-term time horizons. Practitioners should clearly state if and how non-traditional aspects are handled, and study several methodological settings. Technological changes should be accounted for when studying long-term climate impacts of building stocks. / Irreversibel global påverkan på klimat och miljö måste undvikas och olika strategier som begränsar klimatförändringarna kan utnyttjas för att hantera denna utmaning. En betydande andel av de globala utsläppen av växthusgaser kan hänföras till byggsektorn i allmänhet och cementproduktion i synnerhet, och begränsningsstrategier söker alternativ till fossil- och mineralbaserade resurser, med mindre påverkan, som exempelvis en ökad användning av biobaserade material i byggandet. Livscykelanalys (LCA) har använts för att demonstrera klimatnyttan av denna ökning, men skogens komplexiteter i samband med biogent koldioxid skapar osäkerhet i resultaten då de som genomför LCA-studier traditionellt utelämnar viktiga nyckelaspekter. Denna avhandling syftar till att öka förståelsen för effekterna av en ökad användning av biobaserade material för begränsning av byggandets klimatpåverkan i ett livscykelperspektiv. Forskningsfrågorna formulerades med fokus på att identifiera icke-traditionell LCA-metodik, samt att bedöma miljöeffekterna av en ökad användning av biobaserade material med redovisning av dessa aspekter på olika nivåer, gällande enstaka konstruktioner och byggnadsbeståndet som helhet. Den metodik som används är dynamisk LCA i kombination med data om skogskolbalans, med analyser av flera scenarier med olika metodologiska antaganden. Fallstudier med olika kännetecken användes, nämligen en byggnad, en bilvägsbro och en uppskattning av det svenska byggnadsbeståndet på lång sikt. Resultaten bekräftar att en ökad användning av biobaserade material minskar klimatpåverkan av byggandet – en tydlig majoritet av de scenarier som analyserats för alla fallstudier resulterar i sänkt klimatpåverkan. Införandet av icke-traditionella LCA-aspekter påverkar resultatet, men förändrar inte att en ökad användning av biobaserade material resulterar i lägre långsiktig och kumulativ klimatpåverkan. Resultaten visar också att den maximala klimatbegränsningspotentialen endast nås genom att samtidigt införa andra tekniska lösningar med lägre klimatpåverkan. När det gäller LCA-metodik visar resultaten att antagandet att biobaserade byggnadsmaterial är klimatneutrala är en överförenkling eftersom deras klimatpåverkan beror på fallspecifika faktorer och därför bör inga generaliseringar göras. Några av dessa klimatpåverkande faktorer beror på modellering av skogssystemet i en dynamisk LCA; såsom när skogstillväxten antas börja i förhållande till avverkningen, den geografiska upplösningen för att analysera de biogena kolflödena dvs. som ett avverkningsbestånd eller på landskapsnivå och vad utgångsläget sätts till vid analys av skogens markanvändning. Andra faktorer beror på LCA-modellering, nämligen valet av integrerad tidshorisont för beräkning av klimatpåverkan, det antagna scenariot för avfallshantering och lagringsperioden för det biogena kolet i tillverkade produkter. För att minska osäkerheten i bedömning av klimatpåverkan av biobaserade byggmaterial rekommenderas användning av minst en mätmetod som gör det möjligt att bedöma koldioxidutsläppen baserat på tidpunkten på dessa, samt att tillämpa mätvärden med långa tidsperspektiv. Redovisning av icke-traditionella aspekter har en betydande effekt på klimatpåverkan av biobaserade byggmaterial. Utförare av analyser rekommenderas därför även att redovisa hur dessa aspekter hanteras och att ställa upp flera olika scenarier och analysera dessa med flera olika metodologiska inställningar. Slutligen rekommenderas att ta hänsyn till den tekniska utvecklingen vid analyser av långsiktig klimatpåverkan av byggnadsbeståndet som genomförs med dynamiska värden för processer som äger rum i framtiden. / Para evitar impactos irreversibles a nivel global, es necesario mitigar el cambio climático. Una parte significativa de las emisiones globales de gases efecto invernadero puede atribuirse al sector de la construcción y la producción de cemento. Entretanto, se busca implementar estrategias de mitigación de bajo impacto, tal es el caso de incrementar el uso de materiales de origen forestal. El análisis de ciclo de vida (ACV) se aplica con frecuencia para demostrar los beneficios climáticos de este incremento, pero las complejidades relacionadas con el bosque y el carbono biogénico crean incertidumbre ya que los autores normalmente omiten ciertos aspectos clave. Esta tesis busca mejorar la comprensión de los efectos de un incremento en el uso de materiales de origen forestal en la mitigación del cambio climático en el sector de la construcción, bajo una perspectiva de ciclo de vida. Para ello se han formulado preguntas de investigación centradas en la identificación de los aspectos metodológicos no tradicionales del ACV que pueden afectar el resultado, así como en la evaluación de los efectos ambientales del aumento del uso de materiales biológicos en construcciones o en la construcción en existencia, mientras se toman en cuenta dichos aspectos. Los métodos aplicados incluyen el ACV dinámico en combinación con modelos del balance de carbón en el bosque, además del análisis de múltiples escenarios con diferentes configuraciones metodológicas y asunciones. Se utilizaron casos de estudio con diferentes características y sus respectivos productos equivalentes de referencia; un edificio, un puente para carretera pequeño y la construcción en existencia en Suecia a largo plazo. Los resultados confirman que el aumento del uso de materiales de origen forestal disminuye el impacto climático de la construcción, ya que la gran mayoría de los escenarios analizados para todos los casos de estudio resultan en reducciones del impacto climático. La inclusión de aspectos no tradicionales del ACV ha influido en los resultados, sin afectar el hecho de que incrementar el uso de material biológico se traduce en menores impactos climáticos acumulados a largo plazo. Los resultados también muestran que el potencial máximo de mitigación climática sólo se alcanza mediante la implementación simultánea de otras tecnologías de bajo impacto. En cuanto a la metodología del ACV, la tesis ilustra que la hipótesis de que los biomateriales de construcción son neutrales respecto a sus impactos climáticos es una simplificación excesiva, y demuestra también que los flujos de carbono biogénico deben ser tenidos en cuenta. El balance de carbono de los materiales de construcción de origen forestal depende de factores relacionados con el sistema forestal que son sensibles las circunstancias del caso de estudio; por lo que no deberían hacerse generalizaciones. De dichos factores, algunos dependen de los modelos usados para simular el sistema forestal; tales como la contabilización del punto temporal de ocurrencia de los flujos de carbono biogénico, la perspectiva espacial para medir estos flujos y la línea de base trazada para el sistema forestal. Otros factores dependen del modelo usado para el ACV, como la elección del horizonte temporal integrado para el cálculo del impacto, el escenario de disposición final y el período de almacenamiento del carbono biogénico en los productos. Para obtener conclusiones más robustas, se recomienda que los autores de estudios utilicen al menos un método adicional al GWP que les permita evaluar las emisiones de carbono basadas en el punto temporal de su ocurrencia, así como que se apliquen horizontes temporales a largo plazo en el uso de dichos métodos. Tener en cuenta los aspectos no tradicionales estudiados en esta tesis en estudios de ACV de materiales de construcción de origen forestal puede tener una influencia significativa en su impacto climático, por lo que se recomienda que los autores expongan claramente si estos aspectos se incluyen y cómo se incluyen. También se recomienda que se analicen múltiples escenarios con una variedad de configuraciones metodológicas alternativas. Por último, se recomienda tener en cuenta los cambios tecnológicos en los análisis a largo plazo de los impactos climáticos de la construcción en existencia, utilizando factores de impacto dinámico para los procesos que trascurran en el futuro. / <p>QC 20170517</p> / EnWoBio - Engineered Wood and Biobased Building Materials Laboratory

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