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.
