Social housing retrofit strategies in England and France: A parametric and behavioural analysis

© 2015 Elsevier Ltd. All rights reserved.IFORE (Innovation for Renewal) is an EU Interreg funded partnership including two large housing associations, one in England, one in France, and a university from each country. The project is an exemplar large-scale retrofit, 100 houses have been retrofitted at Rushenden, on the Isle of Sheppey (Kent, England), and a similar number at Outreau, a suburb of Boulogne (Pas-de-Calais, France). This paper offers an overview of the methods used by the project team to find common solutions and to identify similarities between retrofit measures and occupant's behaviour in both countries. The cross-border nature of IFORE makes the project also original in relation to other similar national retrofit projects that have been developed prior to it. Dynamic thermal simulation was used to evaluate the thermal behaviour of the buildings refurbished. It is a valuable decision-making tool when assessing alternative retrofit measures. Initial surveys were carried out to make a classification of the housing stock which formed the context for the computer simulations. Some results from the simulations, carried out with ESP-r in England and Pleiade + Comfie in France, are presented in this paper. The comparison of the results from the two simulation tools shows great similarity between the two methods, which gave confidence for their use in evaluating alternative specifications for the works that have now been adopted for retrofit. At the same time sociological studies have characterised the populations in order to bring the most advantageous results from the retrofit works in reducing carbon emissions but also reducing fuel poverty whilst improving comfort standards

Social housing retrofit strategies in England and France: A parametric and behavioural analysis

© 2015 Elsevier Ltd. All rights reserved.IFORE (Innovation for Renewal) is an EU Interreg funded partnership including two large housing associations, one in England, one in France, and a university from each country. The project is an exemplar large-scale retrofit, 100 houses have been retrofitted at Rushenden, on the Isle of Sheppey (Kent, England), and a similar number at Outreau, a suburb of Boulogne (Pas-de-Calais, France). This paper offers an overview of the methods used by the project team to find common solutions and to identify similarities between retrofit measures and occupant's behaviour in both countries. The cross-border nature of IFORE makes the project also original in relation to other similar national retrofit projects that have been developed prior to it. Dynamic thermal simulation was used to evaluate the thermal behaviour of the buildings refurbished. It is a valuable decision-making tool when assessing alternative retrofit measures. Initial surveys were carried out to make a classification of the housing stock which formed the context for the computer simulations. Some results from the simulations, carried out with ESP-r in England and Pleiade + Comfie in France, are presented in this paper. The comparison of the results from the two simulation tools shows great similarity between the two methods, which gave confidence for their use in evaluating alternative specifications for the works that have now been adopted for retrofit. At the same time sociological studies have characterised the populations in order to bring the most advantageous results from the retrofit works in reducing carbon emissions but also reducing fuel poverty whilst improving comfort standards

Impact de la méthode de modélisation sur la simulation du comportement thermique d'un matériau contenant des microcapsules à changement de phase

ACTNational audienc

Determination of physical properties of fibrous thermal insulation

The objective of this study is to characterize both experimentally and theoretically, conductive and radiative heat transfer within polyester batting. This material is derived from recycled bottles (PET) with fibres of constant diameters. Two other mineral and plant fibrous insulation materials, (glass wool and hemp wool) are also characterized for comparative purposes. To determine the overall thermophysical properties of the tested materials, heat flux measurement are carried out using a device developed in house. The radiative properties of the material are determined by an inverse method based on measurements of transmittance and reflectance using a FTIR spectrometer and by solving the equation of radiative heat transfer. These measures are compared to results of numerical simulations

Impact of the enthalpy function on the simulation of a building with phase change material wall

International audienc

Caractérisation des matériaux à changement de phase pour la simulation thermique des bâtiments

ACTNational audienceL'objectif du projet Stock-e MICMCP, pour « Méthodes d'Inversion et de Caractérisation pour les Matériaux à Changement de Phase », est de proposer une méthode fiable d'analyse des MCP afin d'estimer leurs propriétés thermophysiques et notamment la fonction régissant l'évolution de leur enthalpie avec la température. La première étape consiste à mettre en place un protocole basé sur une méthode d'inversion s'appuyant à la fois sur un modèle numérique et sur des mesures expérimentales. On définit ainsi une fonction « objectif », en comparant le flux thermique numérique et expérimental, que l'on minimise en adaptant la valeur des coefficients thermodynamiques. Après une classique analyse de sensibilité à différents paramètres, cette méthode a été appliquée à des mesures de calorimétrie (DSC) faisant intervenir des échantillons microscopiques puis à des mesures réalisées sur des échantillons macroscopiques, plus représentatifs des conditions réelles d'utilisation des MCP. Les résultats correspondants montrent un très bon accord entre les solutions numériques et les mesures ; par ailleurs, la méthode permet de reconstruire une fonction d'état qui respecte les principes de base de la thermodynamique (notamment l'indépendance en fonction de la vitesse de chauffe/refroidissement de l'échantillon) contrairement à l'ensemble des autres méthodes couramment utilisées dans le domaine. Enfin, dans le cas d'échantillons macroscopiques, seule la présente méthode conduit à une estimation de la fonction enthalpie qui soit apte à rendre compte du caractère non symétrique de la fusion et de la cristallisation observé expérimentalement. La seconde étape du projet a consisté à mettre en exergue l'intérêt d'une détermination rigoureuse des paramètres thermophysiques des MCP dans le cadre d'une utilisation pour des simulations thermiques dynamiques de bâtiments. L'idée est donc de comparer des résultats de simulation pour lesquels la modélisation thermodynamique du MCP est basée sur la méthode présentée ci-dessus avec des résultats utilisant les procédures habituellement mises en oeuvre pour caractériser le MCP. Dans un premier temps, cette procédure a été testée sur un mur unique, incluant des MCP puis sur une maison, de type Mozart, dans laquelle on a inclut des MCP. Les résultats montrent clairement que la modélisation du comportement thermodynamique du MCP, c'est-à-dire la forme de la fonction enthalpie, impacte de manière significative les conclusions que l'on peut tirer de leur présence et de l'influence associée sur le comportement thermique d'un bâtiment. Finalement, il apparaît qu'une possible inclusion de MCP dans un bâtiment ne peut être objectivement analysée qu'à la condition de caractériser fidèlement leur comportement thermodynamique ; ce point est certainement l'une des clefs de voute pour l'utilisation future de tels matériaux dans le domaine du bâtiment

Benchmark solutions for natural convection flows in vertical channels submitted to different open boundary conditions

International audienceComparison exercises have been carried out by different research teams to study the sensitivity of the natural convection occurring in a vertical asymmetrically heated channel to four sets of open boundary conditions. The dimensionless parameters have been chosen so that a return flow exists at the outlet. On the whole, results provided by the partners are in good agreement; benchmark solutions are then defined for each of the boundary conditions. Whilst the local and average Nusselt numbers based on the entrance temperature do not depend much on conditions applied in the aperture sections, the net fluid flow rates crossing the channel and the characteristics of the recirculation cells are highly influenced. But we proved that these modifications of flow patterns do not alter significantly the fluid flow rates leaving the channel through the exit section