bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical analysis of an evacuated tube collector with built-in compound parabolic concentrator for process heat applications
Authors: Rosa Christodoulaki , Panagiotis Tsekouras , Vassiliki Drosou 
Published: January 2020

Abstract
To date, insufficient attention has been paid to the potential of renewable energy resources in industrial applications. Up to 21% of final energy demand and feedstock-use in the manufacturing industry sector could be of renewable origin by 2050. Process temperatures found in industrial processes range from low (T<100°C), medium (100°C < T < 250°C) to high (T > 250°C) temperatures. Whereas low temperature applications are already addressed by well-established collector technologies, the medium temperature applications are still in an early development stage. The aim of this study is to evaluate the optical performance of an Evacuated Tube Collector with Compound Parabolic Concentrator (ETC-CPC) used for medium temperature industrial process heat. To this end, an optical simulation model is developed in Tonatiuh ray-tracing software and is validated towards the theoretical fully developed curve. The parametric analysis performed investigates the impact of the truncation origin, the reflectivity of the CPC mirror and the absorber radius on the optical efficiency and the power production of the solar collector. It is found that the collector with the biggest truncation origin (0.025m) performs better under small Sun angles (0°-20°), but worse under greater Sun angles (40°-90°). This happens because the collector with the greatest truncation origin has the biggest mirror area and under small Sun deviations this leads to more gains and higher efficiency. The quality of the mirror plays an important role in the optical efficiency of the collector, but mainly for incident angles less than 20°. Moreover, increasing the radius of the absorber, the power production per aperture area is increased. The variation of the absorber radius shows that the radius of the base scenario compensates most of the optical errors but without being big enough to have excess heat loss. The results of this study are valuable for the design, simulation and performance analysis of ETC-CPC for delivering medium temperature heat.
New generation of theoretical models for the thermal response of geothermal heat exchangers
Authors: Hermanns Miguel 
Published: January 2020

AbstractThe efficient harnessing of geothermal energy for the heating and cooling of buildings requires extensive simulations to be carried out during the detailed design phase of a new building. These simulations, performed using semi-analytical models, serve to assess the thermal response of the geothermal heat exchanger during the building’s lifetime, that can easily excess 100 years. By using asymptotic expansion techniques, a new generation of theoretical models is being developed since 2011 that offer the flexibility and accuracy of the best performing models available nowadays, but at a fraction of their computational cost. These new models open the doors to yet untapped design and optimization possibilities.
Preliminary evaluation of operational results of RES systems integrated in students’ residences in Xanthi, Greece
Authors: Botsaris P N , Lymperopoulos K , Pechtelidis A 
Published: January 2020

Abstract
This paper discusses the techno-economic performance of installed renewable energy technologies in students’ residences of Democritus University of Thrace, in Kimmeria, Xanthi, North Greece. The students’ residences building complex includes eleven (11) buildings of total area of 14,819.09 m2 and accommodate 630 students. The RES technologies installed, include a hybrid solar thermal/biomass system for heating, cooling and domestic hot water of the students’ residences buildings and one amphitheater, a geothermal heat pumps system for heating and cooling of a restaurant, an autonomous PV system and one small vertical axis wind turbine. The above interventions were accomplished under “REUNI” project that was funded by EEA and Norway Grants program – GR03-Renewable Energy Technologies. The present study elaborates the operational results of almost two years of the RES technologies installed and highlights their techno-economic performance, through analysis of the collected operational data. The building complex of the students’ residences of DUTH in Kimmeria has managed to operate for its thermal and cooling energy demand with hundred per cent (100%) renewables throughout a year, resulting in significant energy costs and CO2 reduction. However, the operation and maintenance cost of the installed systems has been underestimated, resulting in increased number of days of unavailability. The results highlight the need to increase solar energy penetration, as well as the need for subsidy in order to compete with the fossil fuel technologies. The development of such systems that utilize renewable energy sources is considered as a priority for the increase of share of RES in the building sector. The experience from the operation of such system is valuable for the promotion of renewable energy in the built environment.
Which is the optimum option for parking in the city centre?
Authors: Alexandri Eleftheria , Lampropoulos Anastasios 
Published: January 2020

Abstract
Most contemporary Greek cities face the lack of adequate public space. This lack has a direct effect on parking space issues, turning cities’ open spaces into congested ones with parked cars. Although, according to Greek buildings’ regulations parking space must be provided within the building itself, especially in the county of Attica, where Athens, the capital, is located, the Law offers the possibility of exemption from this obligation in small building lots. Thus, in many cases, for small apartment buildings no parking space is provided within the building, forcing drivers to resort to either off-street parking or parking lots. Offstreet parking may cause more traffic jams, noise and loss of time, among other negative effects, while parking lots have turned into environmental catastrophes in many cases (Soup, 2017; Davis et al, 2010). On the other hand, the construction of a basement parking space is linked with high initial costs, while parking spaces on other floors deprive vital area from living spaces, let alone the embodied energy of constructing these spaces. In this paper Life Cycle Analysis and Multicriteria Analysis is made so as to compare which the most sustainable option is; the creation of underground and ground floor level parking spaces within a small apartment building, off-street parking or the creation of a parking lot to host these vehicles. The environmental, social and economic effects of these three cases are analysed, taking into consideration both their constructional and operational effects. A comparison is made between these three options, with criteria for environmental protection, social equity and economic growth, the three pillars of sustainability, selected from relevant indicators of sustainable development. Hierarchy of the three examined options (off-street, in a parking lot or within the building parking) is made with Multicriteria Analysis. Through this research conclusions are drawn on the policy that cities should follow, so as to face in the most sustainable way the demand for parking space and whether legislation should change in regards to the provision of parking spaces within small building lots.
The impact of building automation control systems as retrofitting measures on the energy efficiency of a typical Norwegian single-family house
Authors: Felius L C , Hamdy M , Hrynyszyn B D , Dessen F 
Published: January 2020

Abstract
In this study, the energy savings and cost-effectiveness of building automation measures in a retrofitting context are evaluated for a Norwegian single-family house. In addition, two methods for calculating savings from implementing building automation control systems (BACS) are compared: energy performance simulation and the BACS factor method proposed in EN 15232. Four retrofitting packages and four automation levels are combined to create 16 model versions. This study shows that BACS can increase energy savings and improve indoor comfort when implemented as a retrofitting measure. However, the relative impact on energy savings of building automation decreases when the delivered energy is lower. In addition, the impact of building automation on the energy savings is low compared to the effect of retrofitting the building envelope. When only BACS are implemented, savings up to 21% can be achieved, but when an integrated solution is implemented savings up to 60% can be achieved. Finally, some directions for future work are suggested.
Innovative financial schemes for buildings’ energy renovation
Authors: Polychroni Elpida , Androutsopoulos Andreas 
Published: January 2020

Abstract
Building energy renovation is a key issue to tackle the high energy consumption of the building stock. Many countries - especially the Mediterranean ones - have been strongly hit by the financial crisis of 2008 which has affected national economies and resulted in market uncertainty. On one hand, the financial resources are very limited and on the other hand, the energy efficiency policy of the European Union (EPBD recast and Energy Efficiency Directive) has become stricter with more ambitious goals in terms of energy efficiency and CO2 emissions, especially of the public building stock. Public authorities are not ready to implement them. Administrative and regulatory obstacles help to maintain an unsuitable environment for this kind of initiatives. The majority of public buildings can significantly improve their energy performance, but to mobilize these investments new financial instruments are necessary (such as Energy Performance Contracting-EPC) that will be negotiated with new market actors (Energy Services Companies-ESCOs).The current work tries to facilitate the decision to implement energy renovation measures in public buildings by the use of a tool. The Subsidy Evaluation Tool (SET) carries out an energy and financial evaluation of Energy Conservation Measures (ECMs) for buildings energy renovation and can be used for various types of public buildings. The main aim of the tool is to find innovative financing schemes that combine public resources with private investments and to create conditions for deep investments in energy efficiency actions for public buildings considered bankable by the market. The paper presents the structure of the tool, its layout, the parameters and formulas utilized, so as to provide with the most appropriate solution for energy retrofitting of buildings from a techno-economic point of view.
Mapping the deep renovation possibilities of European buildings
Authors: Androutsopoulos Andreas , Geissler Susanne , Charalambides Alexandros G. , Escudero Cristina Jareño , Kyriacou Orestis , Petran Horia 
Published: January 2020

Abstract
Energy efficiency is priority number one in the EU in the last two years and efforts to achieve it have been made in various ways: through regulations, guidelines, good practice results, education and training. The buildings sector still is the larger consumer of energy, so many policies and national energy strategies have prepared ambitious goals to significantly decrease the sector’s energy consumption. An important step for the implementation of these strategies is the detection of the potential to energy renovate the existing building stock. This is the objective of this study; to present the ENERFUND tool which displays the current energy performance of a group of buildings and pinpoints the energy renovation potential for the selected buildings. An extensive study to identify the expectations of the future users was carried out, which provided valuable feedback for the features of the tool. The tool utilizes data from publicly available Energy Performance Certificates in the form of an interactive web map and combines them with other geo-referenced data and general information to allow for a rating of deep renovation opportunities. The paper explains the various features of the tool, and presents typical examples of the tool use for targeted stakeholder interests.
High energy efficiency renovation options for a typical apartment. The case study of the SPITI project
Authors: Ampatzidis Petros , Serasidou Anna , Tsiaousi Aikaterini , Martinopoulos Georgios 
Published: January 2020

Abstract
The need for reduced energy consumption dictates a new way of thinking about the design, construction, and renovation of buildings. Proposing a repurposing retrofit of a top-floor apartment of a typical Greek multi-storey building, the International Hellenic University has qualified to the final stage of the Solar Decathlon Europe 2019 competition. The main aim of this study is to provide a solution towards the nearly (or net) zero energy buildings, paving the way for EU countries to achieve their energy conservation targets in the building sector. The solution includes the upgrade of the building envelope and its energy systems, the rearrangement of the interior space and the implementation of renewable energy sources. The assessment of the different retrofitting measures was carried out using EnergyPlus, while the System Advisory Model was employed to simulate the prototype’s solar systems. The final energy demand was reduced by approximately 88%, with the requirements for heating and cooling at 10.3 kWh/m2 and 14.1 kWh/m2, respectively. The electricity production from the photovoltaic system, namely 4,959 kWhe, can meet the annual electricity requirements leading to a 100% self-sufficient building.
Energy upgrading of existing collective housing with environmental and economic criteria: financial accessibility gap in cost-optimal energy retrofit of a ten-storey residential building in Athens, Greece.
Authors: Politis Alexandros , Andreou Eleni 
Published: January 2020

Abstract
The collective housing buildings developed during the construction boom of the 1970s and 1980s form the bulk of the contemporary urban fabric of Athens, Greece, the majority of which lack any intrinsic capacity of thermal protection. At the same time, unprecedented economic factors during the last decade depleted the disposable income of large parts of the population and threatened households’ ability to maintain conditions of thermal comfort. This original research focuses on a ten-storey collective housing unit of multiple owners, part of a larger 1972 complex, located in central Peristeri, one of the most densely populated areas at the west of the city-centre of Athens. Cost-optimality methodology was employed to compare the energy assessment of the current condition of the building and 15 energy retrofit scenarios consisting of four fundamental measures and all their possible combinations. This calculated the annual needs in primary energy and the total cost per square meter over a period of 15 years. A users’ questionnaire was employed as an additional methodological tool and a focus group of residents established their willingness to undergo a hypothetical energy retrofit of their residence and the amount of disposable income that each resident would be willing to dedicate to cover its costs. Findings demonstrate that although primary energy consumption could be reduced significantly from the current condition levels, self-funding is not sufficient to cover most of the energy retrofit scenarios’ initial investment costs, including the cost-optimal scenario, even if a common investment amount could be agreed among the multiple residents. This indicates the financial accessibility gap between sustainable retrofit of the existing collective housing stock and current household income.
Urban land cover mapping, using open satellite data. Case study of the municipality of Thessaloniki.
Authors: Tsolakidis Ioannis , Vafiadis Marios 
Published: January 2020

Abstract
The use of open satellite data has become a valuable tool for monitoring the urban environment due to high temporal, spectral and spatial resolution. Planners and stakeholders can rely on these data since they offer an alternative point of view of a very complex urban scenery. The processing of satellite images with the combined use of different types of data (statistical, in situ etc) can extract information for the present situation, in urban and suburban areas. This study use image data from the Sentinel satellite mission, in order to extract urban land cover characteristics in Thessaloniki city. The Sentinel mission started the image acquisition on 2014. The data set are freely available for downloading. The use of high resolution satellite images (e.g IKONOS) in urban studies, has been proved very useful all these years. On the other hand the use of a medium size spatial resolution satellite, as Sentinel-2, with 10m pixel size, is a very promising optical earth-observation satellite, which is tested in this study. Image processing techniques used to produce classified map of urban characteristics and land cover classes (built up areas, vegetation etc). The contribution of a radar image of Sentinel-1, in the classification process, is also tested. All the above processing is done with an automatic procedure, giving additional value to the proposed methodology. The final classified map will give planners a management tool for decision-making concerning the sustainable urban development and will be the basis for implementing hydrology studies, planning, land use change detection and other.
Investigation of Sun Protection Issues via the Active and Passive Building Integration of Active Solar Energy Systems: A Case Study of the Renovation of an Existing Building in Cyprus
Authors: Efthymiou M , Kontonis P R , Leonidou A , Kazanakis G , Vassiliades C 
Published: January 2020

Abstract
The demand for a continuous and extensive use of buildings in contemporary central business districts without proper maintenance has led to an aging building stock. The need for refurbishment and use of these buildings, based on the Energy Performance of Buildings Directive (EPBD) in Cyprus, is a challenge that all real estate asset managers need to face. This paper aims to examine whether specific building integrated active solar systems (BIPV), along with their basic operation can be used as passive shading devices as part of a double shell, as indicated in the case study for the renovation of an existing mixed-use building in Nicosia, Cyprus. The proposed research starts with an analysis of building and site geometry and an investigation into a philosophy of operation through a literature review, along with the presentation of case studies where these active solar systems are integrated on double building shells. Digital energy simulations are performed where the technologies are examined as a passive shading device, as part of the double shell of the renovated building. These simulations aim to analyse whether the system can cover the energy needs of the aforementioned building, whilst providing adequate sun protection. Consequent to the results of the digital simulation, the heating and cooling energy loads – in order to keep the interior of the simulated building within thermal comfort levels – are examined, thus affording the opportunity to compare and contrast the before and after situation. Moreover, the annual primary energy production of the integrated systems is calculated and compared with the building ‘s annual energy needs. The ultimate aim of this work is to determine the environmental sustainability of these building integration solutions for the refurbishment of existing buildings.
Embodied emission profiles of building types: guidance for emission reduction in the early phases of construction projects
Authors: Resch Eirik , Brattebø Helge , Andresen Inger 
Published: January 2020

Abstract
The embodied emissions of the construction materials in buildings are a significant contributor to climate change but have only rarely been systematically studied by statistical methods. In the early phases of a building project, empirical results of statistical emission profiles of different building types can act as useful guiding information to inform decisions regarding reduced embodied emissions from construction materials. However, engineers and architects do not have such information at disposition. In this paper, the embodied emissions from the production and transport of initial and recurring building material use in 7 Norwegian case studies of low-emission buildings are made comparable and then studied statistically to find out how the impact varies with building types. The building types studied are timber residential, concrete office, concrete school, and concrete swimming hall. Statistics are produced for each building type and are broken down by the impact contribution from different building elements and material categories. This results in embodied emission profiles and material use profiles for these four building types, which, when based on a larger dataset, can be used by architects and engineers to make informed decisions when aiming for reduced embodied emissions in the early phases of a construction project. Additionally, these profiles can be used as benchmarks by which the final building can be compared when the building is constructed. The statistical results are preliminary and based on a limited dataset, which makes them applicable only as an indication for Norwegian low-emission buildings of these four building types. Future work includes expansion of the dataset on which the profiling is based, further development of the statistical method, and applying the methodology to additional building types.
Overview of BIM integration into the Construction Sector in European Member States and European Union Acquis
Authors: Panteli C , Polycarpou K , Morsink-Georgalli F Z , Stasiuliene L , Pupeikis D , Jurelionis A , Fokaides P A 
Published: January 2020

Abstract
The amount of information involved in any construction project and the necessity of control of time, cost and waste, has established Building Information Modelling (BIM) as an integral part of construction sector towards achieving adequate communication of information among various parties involved in construction projects. Moreover, it can be considered as a valuable tool for the optimum selection of materials, systems and design decisions, regarding not only the improve of a structure’s performance, but also in terms of reducing its carbon footprint during its life cycle. The study attempts to present the integration of BIM into the national legislation of European Member States, with a special focus on the energy related aspects of BIM analysis. This study performs an overview of the introduction of BIM into different aspects and requirements of the EU Member States building practices, through a comprehensive literature and legislation review of relative legislative documents of the construction sector. According to the findings of this overview study, the concept of BIM has already been incorporated in many aspects of the Acquis of EU Member States, which is recognized as a valuable tool to be exploited by the construction sector, however there is still room for development in this area. The study has revealed that especially in the energy assessment of the built environment, BIM applications are still lacking from the European Legislation. Examples and good practices of employing BIM for the implementation of the European Energy targets in the building sector are also presented and discussed. The findings of this study aim to shed light on the needs and requirements in the field of BIM development for the construction sector, as well as to indicate gaps and weaknesses of the European Member States Acquis towards harmonizing with BIM practices.