1,721,005 research outputs found
Energy retrofit of a day care center for current and future weather scenarios
Full text linkMany scientific evidences have shown that Earth’s climate is rapidly changing. By 2050, European Union is aiming to
significantly reduce greenhouse gas emissions (GHG) in the building sector. Achieving this target might help the mitigation of
global warming, but the climate change seems inevitable. This means that both new and refurbished buildings should be able to
face those conditions that they are going to experience during their lifetime. Therefore, any building design should be checked
both for current and future climate scenarios. This study describes the use of a downscaling method named morphing to generate
future weather scenarios and intends to support the design process of a deep energy retrofit of a day care center in order to
improve the energy and thermal comfort performance of the building under the current and future weather scenarios. The retrofit
concept of the building also includes hybrid ventilation, automated solar shading, lighting controls and renewable energy
generation systems
Energy retrofit for a climate resilient child care centre
Full text linkClimate scientists have developed and refined climate change models on a global scale. One of the aims of these models is to predict the effects of human activities on climate, and thus the delivery of information that is useful to devise mitigation actions. Moreover, if they can be properly downscaled to a regional and local level, they might be useful to deliver support for adaptation actions. For example, they may be used as an input for the better design of the features of buildings in order to make them resilient to climate modification, e.g., able to passively control heat flows to produce comfortable indoor conditions not only in the present climate, but also in future climate conditions. Taking into account the future weather scenarios that show an increase in the global temperature and climate severity, a likely consequence on building energy use will be a substantial shift from space heating to space cooling, and potentially uncomfortable thermal conditions during the summer will became a major challenge, both for new and existing buildings. In this paper, a deep energy retrofit of a child care centre located in Milan (Italy) is analysed on the basis of future weather scenarios; the analysis aims to identify to what extent choices that are made nowadays on the basis of a typical meteorological year may succeed to provide acceptable energy and indoor environmental performance throughout the future decades. The analysis confirms that climate change might require the installation of active cooling systems to compensate for harsher summer conditions over a long-term horizon, however, in the mid-term, passive cooling strategies combined with envelope refurbishment may still guarantee thermally comfortable conditions, and they will reduce energy cooling needs when active cooling is eventually installed
Retrofit of a kindergarten targeting zero energy balance
Full text linkOld buildings that are severe energy wasters and provide low indoor environmental quality (IEQ) form a large fraction of the European building stock. These buildings represent nevertheless, an asset that should be re-evaluated in order to promote local communities development. This paper describes the study that supported the design for the zero energy retrofit of a kindergarten as part of a renovated smart district. The work will substantially reduce the energy needs for heating and cooling while improving IEQ. Prefabricated modules, including mechanical ventilation and solar shading are proposed and particular attention is given to natural, mechanical and hybrid ventilation
Climate robust buildings: towards buildings with a robust energy performance under climate change
Full text linkBuilding performance simulation (BPS) is a powerful tool allowing building designers to estimate the behavior of buildings and assess the impacts of their design decisions on their performance. BPS requires large number of input variables, of which some can be predicted during design phase with reasonable certainty such as thermal properties of materials and building dimensions, and some are difficult to be predicted, such as climate and occupancy.
Climate as an input variable in BPS is the main theme of this PhD work. Climate conditions are key input variables for BPS, but traditionally and for simplification, a typical climate condition is used to represent the most likely condition that a building will experience. Such approach results for the final designs to be sensitive to variation of climate conditions and even fail to provide expected performance when the conditions are beyond typical ranges. Such sensitivity of buildings to atypical climate conditions is becoming more critical considering that due to climate change the frequency and intensity of extreme climate conditions is increasing. This thesis provides an overview of the risks induced by climate change on the performance of buildings and provide a method for protection against future climate uncertainty.
The first step towards protection against climate uncertainty is to identify the climate conditions that a building might face during its life span. The work identifies a prospect of climate conditions for built environment as: climate normals or typical climate conditions and climate extremes. Climate extremes are distinguished into two: foreseeable extreme conditions and unforeseeable extreme events. It further discusses to which extent these conditions can be considered during the design phase of buildings. After identifying the possible climate conditions, a work was set to create a framework that conceptualise protection for buildings against all these conditions. After reviewing the concepts and definitions provided in the literature, the two concepts of «robustness» and «resilience» were found appropriate for the aimed framework. According to the defined framework, the concept of robustness is the most proper to deal with typical and foreseeable extreme climate conditions, where in this concept the main focus is on reducing the sensitivity of performance under presence of source of uncertainty. The discussion on protection against unforeseeable extreme events falls into the concept of resilience, where withstanding and recovery mechanisms should be considered and was out of scope of this thesis. Based on the framework a climate robust building is “a building that, while in operation, can provide its performance requirements with a minimum variation under typical and foreseeable extreme climate conditions“
In the second step, a total of 74 representative weather files are synthesized for city of Geneva to account for future foreseeable extreme conditions together with typical climate conditions. The aim is to investigate the impacts of these conditions on the energy performance of single buildings and their combination to create a virtual neighborhood. The results showed, depending on the type of building, the relative change of peak load for cooling demand under near future can be up to 28.5% higher for extreme conditions compared to typical conditions. Furthermore, the results for the neighborhood demonstrate the critical situation that an energy network may face due to increased peak load under extreme climatic conditions. It is concluded that only those weather files that take into consideration both typical and extreme conditions are the most reliable for providing representative boundary conditions to test the energy robustness of buildings under future climate uncertainties.
In the final step, a method is proposed in this work, in which three future weather files including typical, extreme warm and extreme cold conditions are used in a simulation-based optimization process. The method allows architects and engineers to effectively consider future climate uncertainties during the design phase and achieve solutions with robust energy performance against these uncertainties. Using only three weather files make the process feasible and computationally inexpensive. To test the effectiveness of the method, the primary energy use of an obtained optimum solution is calculated for the 74 weather files. According to the results, the performance of the optimum solution not only has 81.5% lower variation (less sensitivity to climate uncertainty) but at the same time 14.4% lower mean value of energy use in comparison to a solution that is compliant with a recent construction standard (ASHRAE 90.1-2016). Less sensitivity to climate uncertainty means better robustness against climate change and simultaneously keeping a high performance. The simplicity and the low computational demand of the process ascertain the feasibility and applicability of this method. The approach can be used at any stage of design process and can help architects and engineers to improve robustness of their design against future climate uncertainties
Ventilation strategies for the deep energy retrofit of a kindergarten
Full text linkThe scientific literature often reports example of educational buildings with extremely poor ventilation performance. An in-field investigation for the environmental and energy assessment of a kindergarten in Milano, confirmed that operable windows were not operated when the average daily temperature dropped below 14 °C, jeopardizing indoor air quality and kids learning performance. Seven different ventilation strategies were therefore simulated, in order to evaluate the one that better fitted a general project of deep energy retrofit of the building, including building envelope and systems. The best scenario resulted to be the one using hybrid ventilation at nighttime and mechanical ventilation at daytime. Both energy and thermal comfort conditions were evaluated and a tradeoff between them was established. Nighttime ventilation showed to be extremely effective in improving thermal comfort conditions, during the cooling season. It resulted much better than mechanical ventilation in the simulated case study. Simulations show that under moderate weather conditions and if the building is properly operated (ventilation, lighting and solar screening systems) the retrofitted building may perform well also without additional active cooling
From flexible building to resilient energy communities : A scalable decentralized energy management scheme based on collaborative agents
No full textExtreme conditions caused by climate change and other crises call for enhancing the resilience of buildings and urban energy systems. This paper investigates the role of collaborative decision-making to improve the performance of single buildings and the unified whole in the form of a cohesive cluster of energy consumers to enhance resilience. CIRLEM, the previously developed energy management approach, provides flexibility in energy systems through collective behavior of entities and deploying a lightweight Reinforcement Learning algorithm. This research contributes to developing a novel signal generation structure including price-and demand-based function to stimulate the cohesion attribute. Extended thermal comfort margins are introduced to broaden the flexibility potential, and reward function includes thermal zones categories. The energy management approach and extended comfort constraints is tested under an extreme cold winter in a pilot ecosystem located in Norway made of several buildings characterized by different sizes, use types, performance and energy systems. Acting individually, buildings could save 28 % and 13 % energy and cost, while acting as a collaborative cluster, energy use and cost are reduced by 42 % and 40 %. Through collaboration between buildings, high-performance buildings could help others under high energy demand periods to keep their functionality toward the cluster's goal
Machine-Learning-Based Prediction of HVAC-Driven Load Flexibility in Warehouses
Full text linkThis paper introduces a methodology for predicting a warehouse’s reduced load while offering flexibility. Physics-based energy simulations are first performed to model flexibility events, which involve adjusting cooling setpoints with controlled temperature increases to reduce the cooling load. The warehouse building encompasses office and storage spaces, and three cooling scenarios are implemented, i.e., exclusive storage area cooling, exclusive office area cooling, and cooling in both spaces, to expand the study’s potential applications. Next, the simulation data are utilized for training machine learning (ML)-based pipelines, predicting five subsequent hourly energy consumption values an hour before the setpoint adjustments, providing time to plan participation in demand response programs or prepare for charging electric vehicles. For each scenario, the performance of an Artificial Neural Network (ANN) and a tree-based ML algorithm are compared. Moreover, an expanding window scheme is utilized, gradually incorporating new data and emulating online learning. The results indicate the superior performance of the tree-based algorithm, with an average error of less than 3.5% across all cases and a maximum hourly error of 7%. The achieved accuracy confirms the method’s reliability even in dynamic scenarios where the integrated load of storage space and offices needs to be predicted
Bærekraftig analyse av Prefabrikasjon og konvensjonell
Full text linkKaihuset oppgaven handler om, ligger i Hellesylt - Stranda kommune. Denne oppgaven skal
ta for seg bærekraftig analyse av plassbygde vegger og prefabrikkerte halmmoduler, med
hensyn på klimaavtrykk. Oppgaven har som hensikt å sammenligne de metodene og avveie
Co2 utslipp av de to metodene. Hovedfokuset vil da være å gjøre en livssyklusanalyse.
Teorien er hentet fra litteraturstudie, Sintef Byggforsk, universitets biblioteker fra USA og
Sverige. I tillegg er det brukt skolebøker og kompendier. Beregning CO2 utslipp av
prefabrikkerte og konvensjonelle vegger er gjort ved bruk av OneClick LCA.
Deretter har løsningen blitt modellert i Revit. Gjennom modellen får man ut mengder
materialene som kan eksporteres til verktøyet for livssyklusanalyse, One Click LCA. Det er
tatt hensyn til produksjon og transport av materialene, riving og avfallsbehandling ved
livsløpets slutt.
Ut ifra resultatene demonstreres da at den bærekraftige bygget har 15.2% lavere utslipp
sammenlignet med det konvensjonelle bygget. Dette er positivt resultat tilsvarende
innenfor den rekkevidden som var antatt. Konvensjonelle veggen danner 3.31 ganger så
mye utslipp sammenlignet med den bærekraftige veggen, dette var mer enn forventet.Kaihuset the task is about is in Hellesylt, Stranda municipality. This task will address
sustainable analysis of conventional walls and prefabricated straw modules, considering
climate footprints. The task aims to compare the methods and weigh CO2 worn out by the
two. The focus will then be to do a life cycle analysis for the two methods. In addition, the
task deals with the dimensioning of the new solution in prefabricated ecococon wall
elements.
The theory is taken from literature study, Sintef Byggforsk, university libraries from the USA
and Sweden. In addition, schoolbooks and compendiums are used. Calculation of
prefabricated straw modules and conventional ones is done using OneClick LCA.
Then the solution has been modeled in Revit. The model extracts quantities of the various
materials that can be exported to the lifecycle analysis tool, One Click LCA. Consideration
has been given to the production and transport of the materials, demolition and waste
treatment at the end of the life cycle.
Based on the results, it is demonstrated that the sustainable building has 15.2% lower emissions
compared to the conventional building as a whole. This is a positive result corresponding to the
range assumed. Conventional wall forms 3.31 times as many emissions compared to the sustainable
wall, this was more than expecte
En empirisk studie om kunnskapsoverføring i bygge- og anleggsbransjen
No full textOverføring av kunnskap og erfaring mellom avdelinger og prosjekter hos aktører i bygge- og
anleggsbransjen er viktig for å kunne utvikle og opprettholde kunnskapsnivået. Viktige aspekter
som forståelse og kommunikasjon er med på å avgjøre om kunnskapen til enkeltindivider blir
mottatt med riktig budskap av andre.
Prosjektrapporten har som hensikt å avdekke utfordringer med overføring av kunnskap og erfaring
knyttet til innleide ressurser og prefabrikkerte løsninger. For å kunne oppnå dette tar rapporten for
seg generelle utfordringer med kunnskap og erfaring i bransjen og svarer på tre forskningsspørsmål
knyttet til rapportens problemstilling.
Arbeidet med rapporten er gjennomført ved bruk av litteratursøk og kvalitative intervju. Litteraturen
har bidratt til et godt teoretisk grunnlag for oppgaven og veiledning av metode. De kvalitative
intervjuene har bidratt til en bedre forståelse av arbeidsdagen til medarbeidere hos en entreprenør,
med tanke på overføring av kunnskap og erfaring knyttet til den generelle overføringen, samt
innleide ressurser og prefabrikkerte løsninger. Det ble totalt gjennomført seks intervjuer med sju
forskjellige personer i ulike avdelinger.
Resultatet viser at utfordringen med overføring av kunnskap og erfaring er mellom avdelinger og
forskjellige prosjekter. Det benyttes forskjellige kommunikasjonsplattformer for deling av
informasjon og erfaringer, og det viser seg at de forskjellige avdelingene har ulik erfaring med
bruken av disse. Hvordan den enkelte medarbeider tilegner seg andres kunnskap er også varierende,
og mye handler om den enkeltes fagforståelse. Samlingspunkter for deling av kunnskap med
påfølgende referater og rapporter er ofte ustrukturerte og erfaring som helhet blir ikke med fra et
prosjekt til et annet.
For å kunne bedre overføringen av kunnskap og erfaring bør rapporter og referater fra møter
struktureres slik at det blir lettere å finne informasjonen som trengs. Faste og strukturerte
kommunikasjonsplattformer bør innføres for alle parter, slik at det enkelt kan hentes ut informasjon
og erfaring fra andre. Innsyn i andre avdelinger kan også være med på å utvikle den enkeltes
forståelse for hva forskjellige oppgaver omhandler
Bærekraftig analyse av boligblokk - med hensyn på klimaavtrykk
No full textDenne oppgaven skal ta for seg en bærekraftig analyse av en boligblokk, med hensyn på klimaavtrykk. Boligblokken oppgaven omhandler ligger i Molde. Den eksisterende løsningen i betong stod klar allerede i 2018. Oppgaven har som hensikt å sammenligne bæresystemet i den eksisterende løsningen med en ny løsning i massivtre. Hovedfokuset vil være å gjøre en livssyklusanalyse for de to materialvalgene. I tillegg tar oppgaven for seg dimensjoneringen av den nye løsningen i massivtre.
Teorien er hentet fra litteraturstudier og Sintef Byggforsk. Det er blitt brukt ulike bøker og kompendier og Norsk Standard for lastberegning. Lastberegningene er gjort for hånd og dimensjoneringen av den nye løsningen i massivtre ble gjort i beregningsprogrammet Calculatis for å kontrollere spenn og dimensjoner på vegger, søyler, bjelker og etasjeskillere.
Deretter har begge løsningene blitt modellert i Revit. Ved hjelp av modellene får man ut mengder av de ulike materialene som kan eksporteres til verktøyet for livssyklusanalyse, OneClick LCA. I klimagassregnskapet er det tatt hensyn til produksjon og transport av materialer, riving og avfallsbehandling ved livsløpets slutt.
Ut ifra klimagassregnskapet, ser vi at massivtre har store miljømessige kvaliteter i forhold til betong. Den er i tillegg fornybar. Det som hindrer den store utviklingen, er hovedsakelig tilgjengelighet og kostnad. Både i form av materialpriser og ekstrakostnader på grunn av manglende kunnskap i prosjekteringen
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