Overview and future challenges of nearly zero energy buildings (nZEB) design in Southern Europe

In times of great transition of the European construction sector to energy efficient and nearly zero energy buildings (nZEB), a market observation containing qualitative and quantitative indications should help to fill out some of the current gaps concerning the EU 2020 carbon targets. Next to the economic challenges, there are equally important factors that hinder renovating the existing residential building stock and adding newly constructed high performance buildings. Under these circumstances this paper summarises the findings of a cross-comparative study of the societal and technical barriers of nZEB implementation in 7 Southern European countries. The study analyses the present situation and provides an overview on future prospects for nZEB in Southern Europe. The result presents an overview of challenges and provides recommendations based on available empirical evidence to further lower those barriers in the European construction sector. The paper finds that the most Southern European countries are poorly prepared for nZEB implementation and especially to the challenge opportunity of retrofitting existing buildings. Creating a common approach to further develop nZEB targets, concepts and definitions in synergy with the climatic, societal and technical state of progress in Southern Europe is essential. The paper provides recommendations for actions to shift the identified gaps into opportunities for future development of climate adaptive high performance buildings. (C) 2017 Elsevier B.V. All rights reserved.info:eu-repo/semantics/publishedVersio

Discrete ordinates solution of coupled conductive radiative heat transfer in a two-layer slab with Fresnel interfaces subject to diffuse and obliquely collimated irradiation

International audienceThe coupled conductive radiative heat transfer in a two-layer slab with Fresnel interfaces subject to diffuse and obliquely collimated irradiation is solved. The collimated and diffuse components problems are treated separately. The solution for diffuse radiation is obtained by using a composite discrete ordinates method and includes the development of adaptive directional quadratures to overcome the difficulties usually encountered at the interfaces. The complete radiation numerical model is validated against the predictions obtained by using the Monte Carlo method

Towards a bio-inspired design of a photovoltaic facade

International audienceFacing the challenges of climate change, energy sovereignty and urban densification, operation of local resources and available areas remains an important issue. Integration of photovoltaic components on building envelope is therefore an essential solution to produce manage energy flexibility and obtain Nearly Zero Energy Building. In order to optimize permanently their electrical and thermal performances facing building needs, photovoltaic facades functionalities should adapt and evolve with weather conditions. Bio-inspired design is a breakthrough approach to provide adaptability to physical, mechanical and optical properties of photovoltaic envelope. Therefore, this paper presents the thermal modelling and numerical parametric studies in the case of a photovoltaic bifacial ventilated facade realized with the purpose to identify properties that should acquire adaptive features. Physics related to the identified parameters allow paving the way for the search and the selection of suitable biological adaptive mechanisms. The results of this study indicate that radiative and optical properties of the photovoltaic ventilated facade are the most influential and conflict-inducing parameters on both its electrical and thermal performances. Thus, to provide adaptability to those properties, biological search should be led on live species dealing with extreme heat and radiation and developing adaptive functions aiming to control solar radiation intake

Définition d'une procédure de certification de systèmes combinés pour la production de chauffage et d'eau chaude sanitaire dans les habitations

International audienc

Evaluation de l'amélioration de la photoconversion par refroidissement actif en utilisant une approche Matlab/Simulink

International audienceLes photopiles, ou cellules photovoltaïques ont atteint leur capacité maximale de production dans l'état actuel des moyens de fabrication. L'augmentation des seuils de photo-conversion passe principalement par l'adoption de nouvelles méthodes de fabrication ou par l'emploi de nouveaux matériaux. Il est également possible de jouer sur le matériau lui-même, en maintenant par un système tiers sa température de fonctionnement. L'objectif de ce travail est d'évaluer l'influence de la température interne sur la conversion photovoltaïque. Réalisé sous Matlab/Simulink ce modèle numérique comparatif permet de traiter les données récoltées sur des panneaux photovoltaïques en conditions d'ensoleillement naturel, et de quantifier l'effet du refroidissement sur le rendement de photo-conversion

Evaluation de l'amélioration de la photoconversion par refroidissement actif en utilisant une approche Matlab/Simulink

International audienceLes photopiles, ou cellules photovoltaïques ont atteint leur capacité maximale de production dans l'état actuel des moyens de fabrication. L'augmentation des seuils de photo-conversion passe principalement par l'adoption de nouvelles méthodes de fabrication ou par l'emploi de nouveaux matériaux. Il est également possible de jouer sur le matériau lui-même, en maintenant par un système tiers sa température de fonctionnement. L'objectif de ce travail est d'évaluer l'influence de la température interne sur la conversion photovoltaïque. Réalisé sous Matlab/Simulink ce modèle numérique comparatif permet de traiter les données récoltées sur des panneaux photovoltaïques en conditions d'ensoleillement naturel, et de quantifier l'effet du refroidissement sur le rendement de photo-conversion