A full coupling between a CFD code, a thermo-radiative model and a building energy simulation model enables Solenemicroclimat software to calculate both building thermal behavior and urban microclimate with the retroaction of buildings on microclimate. However, this full coupling is time consuming and it is legitimate to wonder if it is always necessary to perform such detailed simulations. In the framework of the MERUBBI project, simulations were carried out to answer this question. A set of simulations was designed to explore different kinds of configurations: three cities in France (Nantes, Paris and Strasbourg), three levels of density (from an isolated building to an implementation in the dense city center) and three kinds of buildings (an individual house in Paris, a residential building in Nantes and an office building in Strasbourg). To study the sensitivity of energy demand to the coupling detail, for each thermal flux at the external surfaces of the building, several levels of details were taken into account. For the impact of wind on convection, three modalities were considered: a constant convective heat transfer coefficient, calculated from the wind velocity at 10m; a convective heat transfer coefficient calculated from a vertical wind profile; a convective heat transfer coefficient calculated from the local wind velocity simulated with a CFD code. For the impact of air temperature on convection, two modalities are considered the use of the temperature measured at the nearest meteorological station; a local temperature calculated with the CFD simulation. For the impact of long-wave radiative exchanges, three modalities: the building exchanges with the sky without taking into account the masks of the environment and the longwave radiative exchanges with the other surfaces; the building exchanges with the sky, taking into account the mask effects but not the exchanges with the surrounding surfaces; long-wave exchanges are taken into account with all kinds of surfaces in function of view factors. For the impact of short-wave radiations, two modalities: only direct and diffuse solar fluxes are taken into account; inter-reflections are considered. The results indicate that if the calculation of air temperature and convective heat transfer coefficient have few impacts in all the cases, the way of calculating long-wave and short wave radioactive fluxes has to be carefully considered, in winter as in summer. More detailed recommendations are given according to the density of the site in which the building will be implemented. (C) 2017 Published by Elsevier B.V.
Following development and validation of the SOLENE-microclimat tool, the underlying model was used to compare the impacts of various “greening strategies” on buildings’ summer energy consumption and indoor comfort. This study distinguishes between direct and indirect impacts by successively implementing the test strategies on both the studied building and surrounding ones; it also considers insulated vs. non-insulated buildings. Findings indicate that green walls have a direct effect on indoor comfort throughout the entire building, whereas the effect of green roofs is apparently primarily confined to the upper floor. Moreover, the indirect effect of a green wall is greater, mainly due to the drop in infrared emissions resulting from a lower surface temperature. It has also been proven that the indirect effects of green walls and surrounding lawns can help reduce the loads acting on a non-insulated building.
The Energy Performance Contracting (EPC) market is still embryonic in South Europe since there are still many barriers: difficult access to financing, limited investors' confidence in EPC models, scarcity of flagship projects, lack of certification schemes and financing mechanisms, especially for the tertiary sector (hospitality, tourism, healthcare), which presents a huge potential for Energy Efficiency (EE). The Trust EPC South project, funded by Horizon 2020 Research and Innovation Programme, aims to scale up investments in EE solutions in the private tertiary sector in South Europe, by delivering a robust investment standardization and benchmarking framework and a pipeline of bankable EPC projects in 6 countries (Portugal, Spain, France, Italy, Croatia and Greece); its results will eventually be extended to the Balkan. Tailored capacity building activities will allow an easier access to third-party financing, thus unlocking the large tertiary sector EE and Renewable Energy market potential.Initially, national market analyses took place (EPC providers, beneficiaries-clients, and financial institutions) to identify the market potential. National Discussion Platforms were set up to develop the national roadmaps addressing mechanisms for mitigation of policy, legal, and especially financial barriers. An investment standardization and benchmarking framework, built upon an established real estate assessment tool (Green Rating T), is actually setting up in order to build trust amongst all parts of the EPC value chain. The methodology will be upgraded including a financial assessment model. (C) 2017 The Authors. Published by Elsevier B.V.
This study examines the temperature distribution and the flow field in a naturally ventilated room with a localized floor heat source. The room has an orthogonal form with a low and a high opening placed in opposite walls. The temperature of outdoor air is cooler than the initial indoor air temperature forming buoyancy-driven natural ventilation (with Uwind≈0). The problem is explored with computational simulation using a CFD software. A model validation is presented with experimental and computational results of previous investigation10,11 on natural ventilation including buoyancy forces. The 3D unsteady Reynolds Averaged Navier Stokes (RANS) equations are solved in conjunction with the energy equation and the turbulence RNG k-ɛmodel. The unsteady flow of natural ventilation with buoyancy forces is analyzed andthe vertical variation of temperature with respect to timeis investigated. A thermal stratification is formed which is justified by the respective indoor air movement. The upper buoyant layer is warmer than the bottom one, while the indoor air temperature of both layers increases with time. A thermal comfort exploration accompanies the outcoming results and provides useful information for similar problems. Finally, a number of conclusions are derived about the simulation process, the function of natural ventilation and the thermal comfort of the space in corresponding cases.
The proposed work aims at assessing the sustainability of the University of Western Macedonia and, more specifically, of the Departments located in the townof Florina, Northern Greece; these refer to the School of Education, School of Fine Arts and the former Department of Balkan Studies which has been recently moved to the University of Macedonia located in Thessaloniki. The assessment concerns the period of 2000-2013 and is implemented on the three pillarsof sustainability, thus considering an environmental, social and economic point of view. Each pillaris divided into categories and furthermore into indices. The analysis presented in this work focuses on environmental issues, such as the use of water and waste management, while providing special emphasis on the energy use. More specifically, the consumption per academic year of electrical energy and oil for covering the respective demand is quantified, allowing the estimation of greenhouse gases emissions. In addition, issues related with the social factor are included, mainly embracing aspects of the scientific, educational and social contribution of Florina's Departments to the local, regional and international community. Moreover, economic issues related with the expenses of the institution and potential revenues are also discussed. The analysis borrows elements from the international experience, noting that systematic research on this field is not common on a national level. Within this context, the analysis aims at establishing a baseline of data, facilitating future actions towards sustainability. After all, a sustainable character of the University would raise public awareness in the respective issues, offering the public the opportunity to become familiar with the concept of sustainability through educational and demonstration activities, while enhancing the role of the UOWM as a key factor in the socio-economic environment of the wider area.
Seismic risk assessment and loss estimation are of major importance for decision-making with respect to the reduction of earthquake-induced losses in large urban areas. However, the methodological chain of seismic risk assessment, from seismic hazard assessment to evaluation of potential losses, encompasses both aleatory and epistemic uncertainties associated with different sources. The present study aims to give an insight into epistemic uncertainties in seismic risk assessment at urban scale when applying the Capacity Spectrum Method (CSM), using the city of Thessaloniki, Greece as a case study. Quantification of uncertainties related to structural capacity and fragility curves parameters was performed using a logic tree approach. A sensitivity analysis of the computed seismic risk results was also performed in order to determine which input parameters have the greatest impact on the output. For the considered set of input parameters, it was found that the epistemic uncertainties related to damage states thresholds of the fragility curves are the most significant ones, while those associated with the capacity curve parameters may also be substantial. On the contrary, the sensitivity of computed seismic risk on CSM parameters a1, a2 and γ appears to be negligible. The results highlight the critical points to which special attention should be paid when implementing the Capacity Spectrum Method for seismic risk assessment.
In this paper, an assessment is made on a pre-fabricated timber framed hemp-based building envelope system. The hemp-lime mixture within the envelope is produced by mixing the hemp shiv with a lime formulated solution, which acts as a binder, and provides thermal insulating and moisture buffering capacity to the resulting construction.Hemp, by its natural origin, is a fixative of CO2 and can result in a negative carbon footprint helping to reduce the global impact of a building. In addition the hemp- lime layer absorbs and expels heat and humidity in relation to the environment and acts as a thermal storage by reducing the flow of energy through the wall. The presented system targets at the generation of an innovative building system focused on the expansion of the market for structural products, sustainable, ecological and low carbon footprint. As part of its development its thermal insulation and moisture buffering properties have been assessed, and case studies and outcomes of full scale experimental studies are presented. (C) 2017 The Authors. Published by Elsevier B.V.
The natural ventilation of a 7 floors office building was studied in terms of its openings’ discharge coefficient. A 2D, steady state, incompressible CFD model was developed using the FV method. The developed CFD model was validated against experimental data from wind tunnel measurements. Discharge coefficient is calculated for three elevations (ground floor, 4th and 7th floor) considering four combination of inclination angles 15o and 30o for windward and leeward openings. It was examined the dependence of discharge coefficient from: the wind velocity, the characteristics of the field where the building is situated (roughness length and atmospheric boundary layer thickness) considering four field types: a) Urban area (center and suburbs), b) Open field (classes 2 and 3). Two types of discharge coefficient was calculated, one based on the wind velocity at the opening, Cd, and one based on the wind velocity at the infinity, Cdw. The first varies between 0.54 to 0.7 but the second varies between 0.13 to 0.89 and it is considered more usable since it relates the buildings’ ventilation to the average wind velocity in the examined area, information available to the designer. Both are depended on the openings’ inclination angle, from the elevation of the examined floor, from the field roughness length around the building and from the wind turbulence intensity.
In the Mediterranean area, rural abandonment and the rapid urbanisation after the 1950' s led to complex environmental problems, such as the exploitation of natural resources, the environmental pollution, whilst the unstrained urban growth caused excessive pressure on the existing infrastructure, which affects buildings, public transportation, water quality and public health. Various studies demonstrate that the implementation of green roof technology can moderate environmental problems, through the reduction of heat flux and solar reflectivity, the minimisation of buildings' energy consumption, the air pollution removal, the storm water runoff reduction, the air cooling and the effective management of the urban heat island effect.In this framework, the aim of this study is to assess the green roof potential and the quantification of its benefits over Thessaloniki, Greece's second largest city. In order to do so, very high spatial resolution satellite image and natural colour orthoimagery were used along with a geographical object-based image analysis approach. Carbon sequestration potential, rainwater retention and energy conservation were estimated based on coefficients adopted after a comprehensive literature review and actual dynamic energy simulations. (C) 2017 The Authors. Published by Elsevier B.V.
In this paper the analysis and assessment of the existing lighting system in one of the students’ dormitories in Warsaw is presented. It is one of the first steps of the project “Thermo-modernization of two chosen public buildings according to nZEB standards”. We characterized the analyzed building focusing on the characteristics of the interiors and lighting equipment used. The study covered a detailed inventory of the lighting system as well as the measurements of illuminance distributions on task areas in the interiors. On the ground of the results the levels of the average illuminance and illuminance uniformity on task areas in the interiors were calculated, analyzed and compared with the required values for this type of facility. The levels of the lighting installed power density and normalized power density in the interiors were calculated and analyzed either. Moreover, the installed power density and total annual energy density for the lighting system in the building were calculated. On the ground of the results the lighting energy efficiency for the analyzed building was stated. The results of the lighting conditions and its energy efficiency assessment are a reference to the planned in the further studies lighting proposals to improve the quality of the luminous environment in the interiors and energy standard in the dormitory.
Wood as hygroscopic material has the capacity to absorb moisture and thus to moderate the indoor relative humidity (RH) in a building, resulting in lower ventilation demand. In addition, when moisture migrates in hygroscopic structures energy is released through latent heat phenomena. The diurnal variation of moisture content in wood hold a potential for contributing in the buildings energy balance. This study presents the theoretical energy savings in low energy buildings with interior wooden surfaces under different moisture protocols indoors. The requirements of the Norwegian Building Regulations (TEK10) are followed regarding the U-values of the envelope components. A hygrothermal simulation tool is employed to estimate the potential diurnal variations of moisture content in the wood structure. The latent heat released and absorbed is mathematically calculated for a reference building. The results show the potential of hygroscopic structures to save thermal energy by means of heat of sorption and to reduce the conductive heat losses through opaque building elements. The limitations of the phenomena are also discussed.
Nowadays, despite the plethora of existing standards and calculation methodologies, i.e. procedures assessing a building's energy efficiency, it is unfortunately common to monitor significant differences between designed and achieved energy savings in practice. This is a problem that in extremis may lead to contractual and even legal claims, but in any case sheds doubt on the whole energy efficiency approach and finally presents one of the barriers for investments in energy efficiency projects. It should therefore be addressed and in order to achieve this, one has to understand the problem: Numerous and often intertwined factors lead to the aforementioned discrepancy, based on the differences in methodological approaches and standards adopted as well as the boundary conditions they use, they will all be discussed in the paper.Furthermore, a novel building evaluation methodology will be presented; its conceptual approach addresses the different influences addressed and taken into account, as they can significantly affect the level of achieved energy savings in buildings. In that sense, the main purpose of the proposed methodology is to evaluate in advance, the difference rate between designed and achieved energy savings. This approach can be a useful decision tool in the phase where energy efficiency projects are rated and evaluated for possible investments. (C) 2017 The Authors. Published by Elsevier B.V.
Energy Audit and Planning for both existing and new-to-build buildings has been of increasing interest during the last years due to growing environmental concerns. Especially historic buildings, such Craiglockhart Primary School, which are of great importance because of their special architectural characteristics, are energy-demanding structures of incomplete and outdated technology. Improving the energy efficiency of such buildings would mean environmental and financial benefits as well as retaining of the historical heritage of Edinburgh. Additionally, integration of renewable sources in such buildings would result in a further gain from renewable heat incentives and in greener building as well. Firstly, this paper summarizes a study of possible actions for improving the energy efficiency of such buildings. Secondly, assuming that the proposed measures have been applied, possibility of renewables’ integration is assessed. Heat pumps and biomass integration is investigated and a hybrid system is finally proposed. This paper evaluates level of improvement and cost for all scenarios explored after considering possible constraints.
The Byzantine Building Codes aimed at defining in a very precise manner the way in which settlements and towns were built within the boundaries of the Byzantine Empire. Consequently, they contained rules that defined the front, side and rear distances between buildings of different uses, the number and dimensions of the windows, the depth and distances of the projections, etc. Many of these limitations and rules were mainly derived from issues of sanitation, privacy and views. Nevertheless, in many parts of the Codes, there is reference to the achievement of acceptable daylighting and ventilation conditions.This primary aim of this paper is to investigate the bioclimatic performance of the built environment, which was shaped based on these building codes, in terms of insolation, shading and daylighting, as well as air circulation and ventilation. The findings of the study will provide information concerning the bioclimatic performance of both the urban open spaces and the interior living spaces of buildings in Byzantine towns and settlements, whose form derived from Byzantine Building Codes. (C) 2017 The Authors. Published by Elsevier B.V.
In the last years, prominent large-scale "eco-city" development proposals have emerged around the globe. While the development of eco-cities is in itself not a new trend"Eco-cities" has been applied to a number of different projects that embrace a broad array of ideological and ecological goals on this basis, the paper studied the ecological city and the relationship between Green city. this papers explains the benefits and challenges of urban green spaces. The important roles played by green spaces are social, economic, cultural and environmental aspects of sustainable development. Urban green spaces can be a comprehensive tool for long term protection of environmental sustainability through improving the quality of life and air quality, increasing property value due to their amenity and aesthetic characteristics, and reducing the energy costs of cooling buildings. Urban green spaces also can provide ecosystem services in which the recreation and relaxation facilities are especially available to urban dwellers and tourists too. To confirm the multiple roles played by green spaces, certain level of qualitative improvements and distribution of green spaces within the urban area should be considered and incorporated effectively into the environmental sustainability agenda. To do this, an integrated approach regarding the planning, monitoring, designing and maintaining of urban green spaces is required for improving the environmental sustainability in cities in different countriesUrban planners, designers, and ecologists, therefore, need to focus on urban green space strategies that are 'just green enough' and that explicitly protect social as well as ecological sustainability. Hope that through this research for ecological and green city to provide a reference. (C) 2017 The Authors. Published by Elsevier B.V.
In the presence of high rates of urbanization, sustainable transportation solutions are vital. Due to its social, economic and environmental benefits, bicycle is getting more attention in fast growing and high-dens cities. This paper attempts to examine the challenges of bicycle use in Jeddah city, Saudi Arabia. A survey has been conducted to collect the data for examining the challenges that face Jeddah residents for bicycle use. Visual assessment was conducted to observe the barriers for using the bicycle in Jeddah city. In conjunction to that, questionnaire was distributed to assess the attitude toward bicycle use and the perception of obstacles for using bicycle for different age groups of Jeddah city residents.
Urbanization is one of human induced activities causing land use changes. In recent years, various land usetransformationsin Bangkok influenced the city's ecological sustainability in all means, i.e., diminishing the city's cultivated land and greenery. This study investigates lack of green spaces due to extreme urban growth in the mega city. To do so, first, land use transitions are modelled through two different images; one from Landsat 5Thematic Mapper for the year 1994, and second fromHJ-1A CCD for the year 2012. Next, theMulti-Layer Perceptron Markov Model (MLP-Markov) is applied to predict land usechange for the year 2030. The MLP neural network is trained to modelland usetransitionsthrough creating transition maps. Markov Chain predictive model is applied with sufficient accuracy to process the transition maps for the prediction process. The results indicate that 348km2of green areas are transformed into built-up areas for the period 1994-2012,witha considerable loss of greenery (42%). The MLP model predictions show 4% increase in built-up and 6% decrease in greenery for the period 2012-2030. The study highly recommends conservation of green spaces and green corridors in the city. Future research can includeanalysing greenplot ratio for suitablegreen patches in vulnerable sites. The research output will benefit urban planners to implement long term planning strategies forsecuring natural environment in mega cities.
The present paper briefly describes a methodology to evaluate the sustainability of existing steel bridges. This method applied to the case study for the restoration design of the old steel Echedoros river railway bridge. An intervention on an existing bridge characterized as sustainable if the design considerations include critical sustainability assessments. The present case study also compared to other relevant assessments of the option to construct a new steel bridge for the same total span. Assessments concern remaining fatigue life, estimation of its structural resistance for the traffic capacity, identification of the environmental impacts of the structural solutions and evaluation of the total cost of the project. In the present work, the structural analysis performed using a finite element scheme for the overall bridge. In addition, several finite element analysis models of critical details also performed and studied. The verification of the design parameters adopted, i.e. loads and resistance assessment mainly based on the ‘Sustainable Bridges’ guidelines recently published by the European Commission. The estimation of the environmental impacts of the structural solutions according to life cycle principles based on the use of known LCA tools and the cost evaluated by applying the well-known discounted cash flow technique. The approach with the individual impacts combined to produce an overall sustainability score for the design option also highlighted. This way, the proposed methodology leads to a more accurate assessment of the sustainability of an existing steel bridge.
In 2010 some people from Favara decided to initiate a process of recovery and re-appropriation of the abandoned historical centre, by establishing Farm Cultural Park, a private cultural institution. This paper aims to describe the process of sustainable design, social innovation and inclusion, triggered by the Farm Cultural Park in the historical centre of Favara which, by showing its resilience, has redefined its identity, progressing from a place of widespread, unauthorised development to a dynamic creative city.
This paper presents the design analysis of a solar heat pumpusing cool thermal storage. The integrated concept uses cool storage (sensible or ice-based) as a short-term (i.e. days, weeks) storage for solar energy in winter and cooling energy in the summer. Annual TRNSYS simulations are performed in four Canadian regions to identify the potential of ice storage and unglazed solar collectors. Results show that combiningthese two technologies can reduce mechanical system energy use by 17% - 28% compared to a cold-climate air-water heat pump. Unglazed collectors demonstrated potential in areas with milder winters.
