Building portfolio management on campus and metropolitan scale involves decisions about energy retrofits, energy resource pooling, and investments in shared energy systems, such as district cooling, community PV and wind power, CHP systems, geothermal systems etc. There are currently no tools that help a portfolio/campus manager make these decisions by rapid comparison of variants. The research has developed an energy supply network management tool at the campus scale. The underlying network energy performance (NEP) model uses (1) an existing energy performance toolkit to quantify the energy performance of building energy consumers on hourly basis, and (2) added modules to calculate hourly average energy generation from a wide variety of energy supply systems. The NEP model supports macro decisions at the generation side (decisions about adding or retrofitting campus wide systems) and consumption side (planning of new building design and retrofit measures). It allows testing different supply topologies by inspecting which consumer nodes should connect to which local suppliers and to which global suppliers, i.e. the electricity and gas utility grids. A prototype software implementation allows a portfolio or campus manager to define the demand and supply nodes on campus scale and manipulate the connections between them through a graphical interface. The NEP model maintains the network topology which is represented by a directed graph with the supply and demand nodes as vertices and their connections as arcs. Every change in the graph automatically triggers an update of the energy generation and consumption pattern, the results of which are shown on campus wide energy performance dashboards. The dissertation shows how the NEP model supports decision making with respect to large-scale building energy system design with a case study of the Georgia Tech campus evaluating the following three assertions: 1. The normative calculations at the individual building scale are accurate enough to support the network energy performance analysis 2. The NEP model supports the study of the tradeoffs between local building retrofits and campus wide energy interventions in renewable systems, under different circumstances 3. The NEP approach is a viable basis for routine campus asset management policies.

The European Union is planning to greatly decrease energy consumption during the coming decades. The ultimate goal is to create sustainable communities that are energy neutral. One way of achieving this challenging goal may be to use efficient hydronic (water-based) heating systems supported by heat pumps. The main objective of the research reported in this work was to improve the thermal performance of wall-mounted hydronic space heaters (radiators). By improving the thermal efficiency of the radiators, their operating temperatures can be lowered without decreasing their thermal outputs. This would significantly improve efficiency of the heat pumps, and thereby most probably also reduce the emissions of greenhouse gases. Thus, by improving the efficiency of radiators, energy sustainability of our society would also increase. The objective was also to investigate how much the temperature of the supply water to the radiators could be lowered without decreasing human thermal comfort. Both numerical and analytical modeling was used to map and improve the thermal efficiency of the analyzed radiator system. Analyses have shown that it is possible to cover space heat losses at low outdoor temperatures with the proposed heating-ventilation systems using low-temperature supplies. The proposed systems were able to give the same heat output as conventional radiator systems but at considerably lower supply water temperature. Accordingly, the heat pump efficiency in the proposed systems was in the same proportion higher than in conventional radiator systems. The human thermal comfort could also be maintained at acceptable level at low-temperature supplies with the proposed systems. In order to avoid possible draught discomfort in spaces served by these systems, it was suggested to direct the pre-heated ventilation air towards cold glazed areas. By doing so the draught discomfort could be efficiently neutralized.     Results presented in this work clearly highlight the advantage of forced convection and high temperature gradients inside and alongside radiators - especially for low-temperature supplies. Thus by a proper combination of incoming air supply and existing radiators a significant decrease in supply water temperature could be achieved without decreasing the thermal output from the system. This was confirmed in several studies in this work. It was also shown that existing radiator systems could successfully be combined with efficient air heaters. This also allowed a considerable reduction in supply water temperature without lowering the heat output of the systems. Thus, by employing the proposed methods, a significant improvement of thermal efficiency of existing radiator systems could be accomplished. A wider use of such combined systems in our society would reduce the distribution heat losses from district heating networks, improve heat pump efficiency and thereby most probably also lower carbon dioxide emissions. / <p>QC 20131029</p>

Cette étude s’inscrit dans le cadre du projet "ANR-Villes Durables VegDUD : Rôle du végétal dans le développement urbain durable ; une approche par les enjeux liés à la climatologie, l’hydrologie, la maîtrise de l’énergie et les ambiances" (2010-2013). Elle traite de la modélisation et de l’expérimentation de toitures et de façades végétales, en vue de l’évaluation de leurs impacts hygrothermiques sur les bâtiments et sur les microclimats urbains. Un modèle physique a été développé pour décrire les mécanismes de transferts couplés de chaleur et de masse au sein de la paroi végétale. L’implémentation de ce modèle dans un code de simulation thermique dynamique permet de prédire l’impact de la végétalisation sur la performance énergétique des bâtiments. L’extension de cette démarche à l’échelle d’une rue-canyon permet d’inclure l’interaction microclimatique dans la simulation thermohydrique des bâtiments. Sur le plan expérimental, une maquette reconstituant une scène urbaine est mise en place pour étudier l’impact de différentes typologies de parois végétales dans plusieurs configurations microclimatiques. La confrontation des résultats expérimentaux et ceux issus de la modélisation numérique a été entreprise à l’échelle du système constitué du bâtiment et du microclimat urbain environnant. Pour cela, l’étude du comportement d’un bâtiment et d’une rue végétalisés par rapport au comportement du même bâtiment et d’une rue témoins a permis d’évaluer l’incidence des transferts thermiques, hygrométriques et radiatifs de la végétalisation. Ceci a permis d’entreprendre la validation des outils de prédiction numérique développés. Les résultats de l’étude montrent que les transferts thermiques et hydriques sont fortement couplés et que le comportement thermique des parois végétales est tributaire de l’état hydrique du substrat de culture. Pour l’été comme pour l’hiver, les simulations numériques et les données expérimentales montrent que la végétalisation permet d’améliorer la performance énergétique des bâtiments et de réduire les îlots de chaleur urbains. / This study was conducted in the framework of the National Program "ANR-VegDUD Project : Role of vegetation in sustainable urban development, an approach related to climatology, hydrology, energy management and environments" (2010 -2013). It deals with the experimental and numerical modeling of green roofs and green facades to evaluate their thermohydric effects on buildings and urban microclimates. A physical model describing the thermal and water transfer mechanisms within the vegetated building envelopes has been developed. The model’s program has been implemented in a building simulation program. Using this tool, we are able to predict the impact of green roofs and green facades on building energy performance. This approach is extended to the street canyon in order to assess the microclimatic interaction in building simulation. An experimental mockup modeling an urban scene at reduced scale is designed to study the impact of different types of green roofs and walls. The comparison of the measurements carried out on vegetated buildings and streets with the reference highlights the hygrothermal and radiative impacts of vegetated buildings envelopes. In addition, these experimental data are used to verify and validate the reliability of developed tools. The results show that thermal and water transfers are strongly coupled. Hence, the thermal behavior of green roofs and green walls depend on the water availability within the growing medium. In summer and winter, measurements and numerical simulations show that green envelopes improve the energy efficiency of buildings and reduce the urban heat island.

Aktuellt examensarbete är en fallstudie som utförts på en miljonprogramsbyggnad i Andersberg ägd av AB Galvegårdarna vilka även är uppdragsgivarna. Då miljonprogramsbyggnader är dåligt värmeisolerade och har stora värmeläckage är det idag av stort intresse att se över eventuella förbättringsåtgärder då dessa byggnader har en potential att minska energianvändningen med 50 procent. Syftet med detta projekt är att få en kalibrerad och validerad modell med hjälp av den BES-modell (Building Energy System) som kommer att tas fram i detta examensarbete. Genom litteraturstudie, platsbesök samt inhämtning av protokoll, ritningar och uppmätta data för byggnaden kunde modellen skapas och kalibreras i simuleringsprogrammet IDA Indoor Climate and Energy. Ritningar och data tillhandahölls från AB Gavlegårdarna och platsbesök gjordes för att komplettera dessa genom att göra mätningar av temperaturer i de allmänna utrymmena. På plats kunde även byggnadens mått mätas för att säkerställa att byggnaden inte hade uppdaterats sedan tilldelade ritningarna skapats. När samtlig information ansågs ha införskaffats lades all data in i IDA ICE där även en modell av byggnaden byggdes upp. För köldbryggorna användes simuleringsverktyget COMSOL Multiphysics för att ta fram de enskilda köldbryggornas psi-värden vilka därefter användes som input i byggnadsmodellen i IDA ICE. Den kalibrerade modellen framtagen i detta projekt visade sig stämma med uppmätta värden så när som på +- 10% då den ställdes mot det uppmätta energibehovet för byggnaden. Mot en nyutvecklad energisignatursmodells byggnadsförlustkoefficient blev skillnaden 19.6% vilket kan bero på att fel från simuleringsverktygen samt osäkerheter angående omätbara parametrar. Slutsastsen utav detta arbete var att ”performance gap” även inträffade på den framtagna modellen i detta arbete. Vilket verkar vara svårt att undvika. På platsbesöket upptäcktes vattensamlingar på taket på byggnaden vilket var en förvåning för författarna då det fanns dokument som sade att ytskiktet var bytt 2015 och att det fanns indikeringar på att detta kunde få omfattande konsekvenser om det inte åtgärdas vilket tas upp under diskussion Framtida arbete om varför boendes bettendemönster underskattas vore något att gå vidare med i framtida studier för att kunna minska ”performance gap” på BES modeller. / This thesis is a case study carried out on a Million Homes Program (MHP) building in Andersberg owned by AB Galvegårdarna, whom are also the clients. Since MHPbuildings are poorly insulated and have major heat leaks, it is of great interest today to investigate any improvement measures as these buildings have a potential to reduce their energy use by 50 percent. This is possible with the help of the calibrated model in a building energy performance simulation (BEPS) tool, which is the purpose of developing in this thesis. Through a literature study, visit in the building and gathering protocols, drawings and measured data, a model could be built and calibrated in IDA Indoor Climate and Energy was started. Drawings and data were provided from AB Gavlegårdarna and site visits were made to supplement these by taking measurements of temperatures in the common areas. On site, the dimensions of the building were also measured to ensure that the building had not been upgraded since the assigned drawings were created. When all the information was considered to have been obtained, all data was entered into IDA ICE where a model of the building was also built up. For the thermal bridges, the COMSOL Multiphysics simulation tool was used to generate their individual linear heat loss coefficient which were used as input in the building model of IDA ICE. The calibrated model developed in this project turned out to have a deviation of 10 % against annual district heating energy. The simulated building heat loss coefficient differed with 19.6 % compared to the one produced with a newly developed energy signature method for the corresponding year which may be caused by errors in the simulation tools and uncertainty concerning immeasurable parameters. The final conclusion of this work was that the performance gap also occurred on this model developed in this work, which seems to be hard to avoid. During the site visit, water collections on the roof of the building were discovered which was a surprise to the authors as there were documents that said that the surface layer had been changed in 2015 and that there were indications that this could have significant consequences if not addressed which is mentioned in the chapter of discussion. Future work on why residents’ behavioral patterns are underestimated would be something to continue with in future studies in order to reduce the “performance gap” in BES models.

The interlinking of enriched BIM data to Building Energy Performance Simulation (BEPS) models facilitates the data flow throughout the building life cycle. This seamless data transfer from BIM to BEPS models increases design efficiency. To investigate the interoperability between these models, this paper analyses different data transfer methodologies along with input data requirements for the simulation process. Based on the analysed knowledge, a methodology is adopted and demonstrated to identify the quality of the data transfer process. Furthermore, discussions are provided on identified efficiency gaps and future work.:Abstract Introduction and background Methodology Methodology demonstration Creation and export of BIM data Verification of OpenBIM meta-data BEPS model generation and validation Import statics Model Geometry and Orientation Construction details Thermal Profile Results and discussion Summary and future work References

Since COVID-19 was declared a pandemic by the World Health Organization(WHO) in March 2020, teleworking, or working from home, has been used to an increasing extent by companies and organisations all over the world. Evidence suggests that teleworking will become part of “the new normal”, why teleworking-related research will be of value in a long-term perspective. To estimate the potential for energy saving in relation to teleworking, and to identify possible measures to achieve such savings, a literature study and a retrospective case study of an office building in Gävle, Sweden, was conducted. The occupant presence during 2020 was mapped through conversations with representatives of the organisation using the offices. Data logs of energy usage in 2020, in the form of district heating and electricity, were provided by the energy supplier. The results showed that the number of permanent office workers had dropped by just over 40% around the middle of March 2020, and that the occupancy from November 2020 onwards was just over 20 % of that by the beginning of the year. The demand for heating, cooling, and ventilation in an office is the same regardless of the number of people present, which was believed to be the explanation of the lack of covariation between occupancy and district heating supply, as well as between occupancy and HVAC electrical loads. Earlier research has found that a common reason behind lack of impact from occupancy on plug loads and lighting is that equipment and lighting is turned on in office spaces with no one present. This was not the case in the present study. The study failed to identify the reason behind plug loads and lighting having poor correlation with occupancy. Further research of the matter is encouraged. Methods for improving energy efficiency in office buildings in relation to teleworking includes presence-based control strategies for HVAC systems and lighting, energy efficient behaviour, consolidating office space, and hotdesking. Due to the lack of reliable occupancy data, the study failed in quantifying the potential for energy saving in the building, regarding both district heating and electricity. The results give clear evidence of there being an energy saving potential, but not the extent of it. / Sedan covid-19 deklarerades som en pandemi av Världshälsoorganisationen WHO i mars 2020 har distansarbete tillämpats i allt högre grad av verksamheter världen över. Mycket tyder på att distansarbete kommer att bli en del av ”det nya normala”, varför studier på områden relaterade till distansarbete kommer att vara värdefulla ur energieffektiviseringsperspektiv på lång sikt. I syfte att ta reda på hur stor energibesparingspotential distansarbete kan medföra, och att identifiera åtgärdsförslag för att uppnå sådana besparingar, genomfördes en litteraturstudie samt en retrospektiv fallstudie av en kontorsbyggnad i Gävle. Personnärvaron under 2020 kartlades i samtal med representanter för den verksamhet som har kontor i byggnaden, medan uppgifter om energitillförseln, fördelad på fjärrvärme, fastighetsel och verksamhetsel, tillhandahölls av energileverantören. Det framkom att den fasta personnärvaron sjunkit med drygt 40 % i mitten av mars 2020, och att den från och med november 2020 utgjorde drygt 20 % av närvaron vid årets början. Inga samvariationer mellan energianvändning och personnärvaro observerades, och tillförseln av såväl fjärrvärme som fastighetsel och verksamhetsel var densamma vid årets slut som vid dess början. Behovet av uppvärmning, kylning och ventilation i ett kontor är detsamma oavsett hur många personer som befinner sig i det, vilket bedömdes vara orsaken till bristen på samvariationer mellan personnärvaro och fjärrvärme respektive fastighetsel. Tidigare studier har visat att en vanlig orsak till att personnärvaro har liten påverkan på verksamhetselkonsumtion är att utrustning och belysning är påslagna även i utrymmen där ingen uppehåller sig. Så var inte fallet i föreliggande studie. Studien kunde inte identifiera orsaken till att användning av verksamhetsel inte följde variationerna i personnärvaro, varför ytterligare forskning är nödvändig. Metoder för energieffektivisering i kontorsbyggnader vid distansarbete inkluderar närvarostyrd teknologi, energimedvetet beteende, minskning av totalt utnyttjat kontorsutrymme samt hotdesking. Då personnärvaron inte kunde kartläggas med tillfredsställande precision i föreliggande studie var det inte möjligt att kvantifiera byggnadens energieffektiviseringspotential, varken för fjärrvärme eller elektricitet. Studiens resultat visar tydligt att energibesparingspotential föreligger, men inte i vilket omfång.

This paper presents an analysis of data supplied by the US Green Buildings Council on the credits achieved by 117 LEED-certified commercial and institutional buildings. The paper quantifies several relationships, among others it explores the correlation between building energy performance, water consumption and the overall amount of points the projects has achieved. The paper also attempts to identify which credits are not usually selected by type of project, ownership, certification level and climate zone.

Baigiamajame magistro darbe nagrinėjama Lietuvos pastatų energinio naudingumo sertifikavimo metodika pagal STR 2.01.09:2005 „Pastatų energinis naudingumas. Energinio naudingumo sertifikavimas“. Ši metodika lyginama su STR 2.09.04:2002 „Pastato šildymo sistemos galia. Energijos sąnaudos šildymui“ šilumos nuostolių skaičiavimo metodika ir su faktiniu šilumos suvartojimu. Nagrinėjamos suminės energijos sąnaudos ir energinio naudingumo kvalifikacinis rodiklis esant skirtingo aukštingumo pastatams ir jo pokytis diegiant renovacijos priemones. Taip pat atliekama renovacijos priemonių ekonominio efektyvumo analizė. Sudaromas A klasės pastato modelis. Analizuojama energinio naudingumo klasės suteikimo sistema ir pateikiamos rekomendacijos energinio naudingumo sertifikavimui Lietuvoje. / In the master thesis the methodology of building energy performance by The national building regulation STR 2.01.09:2005 „Building Energy performance. Certificate of energy performance” is analysed . The methodology is compared with heat gains calculation methodology in regulation STR 2.09.04:2002 „Capacity of building heating system. Energy input for heating“ and actual heat consumption. The total energy consumption and the energy performance qualifying index is analyzed in the buildings of different height and the difference of index after renovation. The economical efficiency analysis of recommended renovation is analysed. The model of energy performance class is analised and the recomendations for energy performance certification in Lithuania are presented.

The aim of this diploma thesis is to revitalize the selected type of panel house in the selected locality in order to meet the standards of international certification for the design and sustainable construction of buildings. First, the thesis analyzes the chronological development of the panel housing estates in Brno and compares the individual structural systems that were historically used for panel construction in Brno. Furthermore, the most used certification methodologies are compared and a specific certification is selected for next simulation. The chapter called solution is focused on performing a simulated certification process for design and sustainable construction of selected panel building, in three phases of its revitalization. The hypotheses describing the individual phases of revitalization are intended to confirm or disprove the achievement of this objective, moreover to say the extent of revitalization that has to be done in order to achieve our goals.

In my master's project I design a nearly zero energy consumption house with a café in Zaječí. The 1ST part of this project deals with a structural part of the building, which has two above-ground floors and basement. On the basement are storerooms and rooms for technical equipment, on the ground floor is café and living room with kitchen, and on the second floor are bedrooms, bathrooms and cloakrooms. Footings are from cast-in-place concrete, the load bearing walls on basement are from formwork blocks with cast-in-place concrete, on above-ground floors are from ceramic blocks and every non-load bearing walls are also from ceramic blocks. On whole floor are reinforced concrete floor slab and flat green roof. The 2ND part deals with technical equipment of the building. There are gas boiler, floor heating, air conditioning, mechanical ventilation (HVAC), photovoltaics panels with energy storage, retention tank, external blinds and biodynamic lighting. The 3RD part compares several options for using solar energy in combination with different heat sources in terms of energy and economic efficiency of the building.