Joseph VIRGONE - Profile on Academia.edu (original) (raw)

Papers by Joseph VIRGONE

HAL (Le Centre pour la Communication Scientifique Directe), Jun 10, 2007

Because we spend most of our time in enclosed spaces, demand in thermal comfort of buildings rose... more Because we spend most of our time in enclosed spaces, demand in thermal comfort of buildings rose increasingly and then energy consumption correspondingly is increased, aggravating the pollution of natural environment. Integrating phase change materials (PCM) into building walls is a potential method of reducing energy consumption in passively designed buildings. A wallboard new PCM material is experimentally investigated in this paper to enhance the thermal behaviour of light weight building internal partition wall. The experiments are carried out in a full-scale test room MINIBAT (3.10m x 3.10m x 2.50m) which is completely thermally controlled. The external temperature and radiative flux from spotlights dynamically simulate a summer and mid-season repetitive days. The tests concern walls with and without PCM material under the same external conditions. The PCM allows reducing the room air temperature fluctuations, in particular when overheating occurs.

Etude expérimentale des gains de confort obtenus grâce à des matériaux à changement de phase

HAL (Le Centre pour la Communication Scientifique Directe), Nov 1, 2006

Influence des données aérauliques sur le comportement d'un bâtiment pourvu d'une façade double-peau

HAL (Le Centre pour la Communication Scientifique Directe), Jun 6, 2012

Qualité de l'air intérieur, journée TENERRDIS, Grenoble, 17/09/2009

HAL (Le Centre pour la Communication Scientifique Directe), Sep 17, 2009

HAL (Le Centre pour la Communication Scientifique Directe), May 25, 2010

Simulation of a building equipped with a PCM/air heat exchanger

HAL (Le Centre pour la Communication Scientifique Directe), Sep 29, 2010

Computer Tool to Aid Natural and Artificial Light Integration in Building Design

HAL (Le Centre pour la Communication Scientifique Directe), Nov 14, 2011

Étude Numérique Du Confort Thermique D'Un Habitat Réhabilité Équipé D'Un Échangeur-Stockeur Air/MCP

HAL (Le Centre pour la Communication Scientifique Directe), Nov 1, 2013

Prise en Compte Du Phenomene D'Hysteresis D'Un Materiau a Changement De Phase

HAL (Le Centre pour la Communication Scientifique Directe), Jun 3, 2013

Un comportement dit d'hysteresis est releve pour de nombreux materiaux a changement de phase ... more Un comportement dit d'hysteresis est releve pour de nombreux materiaux a changement de phase (MCP) dont le compose ENERGAIN® sur les courbes enthalpiques issues des mesures par calorimetrie differentielle. Quelques pistes pour prendre en compte cet effet dans la modelisation de ces materiaux utilises en thermique du bâtiment sont comparees dans la presente communication. A travers des resultats experimentaux realises dans une veine d'air controlee et l'exploitation d'un point de mesure de la temperature au coeur de la couche de MCP, ce comportement en hysteresis est analyse puis compare aux differentes possibilites de modelisation.

In order to cool a house using the freshness of the cold night air, Phase Change Materials (PCM) ... more In order to cool a house using the freshness of the cold night air, Phase Change Materials (PCM) placed in an air heat exchanger coupled with a ventilation system have been investigated. The heat exchanger is composed of a number of units with horizontal PCM sheets contained in a box beam. Air is flown between the sheets from one side to the other and exchange heat with the material by convection. At night, fresh air is used to regenerate the PCM. To analyze the behavior of such a system in a retrofitted house with the climate of 3 different French cities, simulations in different configurations have been carried on. The TRNSYS software runs the model, coupled with Matlab for the model of the PCM / air heat exchanger. Results are expressed in terms of percentage of the time when the indoor temperature reaches each temperature and comparison between the different configurations.

Applied Energy, Mar 1, 1999

Different methods of determining formation rates of 3 nm particles are compared, basing on analys... more Different methods of determining formation rates of 3 nm particles are compared, basing on analysis of simulated data, but the results are valid for analyses of experimental particle size distribution data as well, at least within the accuracy of the applied model. The study shows that the method of determining formation rates indirectly from measured number concentration data of 3-6 nm particles is generally in good agreement with the theoretical calculation with a systematic error of 0-20 %. While this accuracy is often enough, a simple modification to the approximative equation for the formation rate is recommended. A brief study on real atmospheric data implied that in some cases the accuracy gain may be significant.

Convective heat transfer coefficient between an air flow and a PCM flat plate

HAL (Le Centre pour la Communication Scientifique Directe), May 16, 2012

建築物の熱挙動予測の精度に及ぼす太陽パッチと3次元熱伝達記述の影響【Powered by NICT】

HAL (Le Centre pour la Communication Scientifique Directe), Jun 1, 2007

In order to reduce the energy consumptions, it is urgent to be focused on existing buildings. The... more In order to reduce the energy consumptions, it is urgent to be focused on existing buildings. The answer is how to determine priorities of interventions on a building to be renovated. The traditional method consists in carrying out a great number of tests and quantifying profits obtained with each solution or combinations of solutions. Our object is to optimize the number of tests to be realized by use of the method of the experimental design concepts which is applied to draw up decisional flow charts of interventions on a building built before 1975. Software Nemrod [1] is used for the experimental design concepts. This stage carried out, the plans are applied by the means of the software Trnsys [2] giving as output the requirements.

Solar Energy, May 1, 2019

Pixel counting (PxC) emerged as a powerful technique for external solar shading calculations of b... more Pixel counting (PxC) emerged as a powerful technique for external solar shading calculations of buildings, providing accurate results with great computational efficiency even for dense geometries. Motivated by this fact and because the technique can be also adapted to cope with interior surfaces without further ado, this paper aims at experimentally evaluating the PxC technique implemented in Domus software for calculating sun patch distribution within building enclosures. For the validation purpose, digital images were taken from the surfaces of an experimental house to compare with the simulation results obtained by using EnergyPlus and two PxC based tools: Domus and Shading II SketchUp plug-in. This first task has shown that the PxC presents results in good agreement with the experimental data, in terms of both location and area of the sun patch. Also, a second case study was constructed to evaluate the capability of PxC for simulating non-convex zones with perforated shading elements. The results, in general, have shown that the PxC can provide accurate results in situations where polygon clipping based algorithms cannot be applied.

Improvement of summer comfort on light framework buildings with phase change materials (PCM)

HAL (Le Centre pour la Communication Scientifique Directe), Sep 1, 2007

Etude expérimentale des performances thermiques et lumineuses d'un dispositif de store intégré

HAL (Le Centre pour la Communication Scientifique Directe), May 23, 2005

Proposal for a highly intermittent heating law for discontinuously occupied buildings

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, Feb 1, 2000

This article presents an intermittent heating controller which is designed for calculating the su... more This article presents an intermittent heating controller which is designed for calculating the supply temperature of hot-water-radiator heating systems. This controller uses a new heating law which has been obtained by inverting a simplified model for calculating the internal temperature of a building in relation to the external temperature, as well as the supply temperature of the distribution circuit and the temperature of the structure. The latter is used to determine the thermal state of the building, which is an important parameter in the evaluation of energy needs when a building is heated in an intermittent mode. During non-occupancy periods, the parameters of the model are automatically modified by a recursive least-squares routine. A second law optimizes the heating restart time during non-occupancy periods; this law also incorporates a learning mechanism. The controller's performance is analysed, and the results are compared with those of a controller using a classical heating law which does not take into account the thermal state of building. Numerical simulations demonstrate that the new heating controller leads to performances comparable with those obtained by classical methods, but for a higher degree of intermittence. This means that the comfort obtained is similar, but that the energy consumption is lower. The new heating law also proves to be advantageous in other ways; it provides faster learning, much better lower temperature control and a reduction in instances of overheating during inter-season periods, when little heating is needed.

Optimization of the energy performance of the system: trade-off between environmental and economic objectives

Analyse des systèmes multi-énergies par la méthode du " Energy Hub " au service des bâtiments à haute performance

HAL (Le Centre pour la Communication Scientifique Directe), Nov 9, 2010