Stephane LASSUE

Université d'Artois - Faculté des Sciences Appliquées · Génie Civil / Civil Engineering

Façades built with integrated passive solar systems hold great promise for improving the energy performance of buildings and achieving indoor comfort conditions. Among these techniques, solar air preheating systems with different configurations have proven their ability to reduce the energy consumption of buildings during the heating season. In thi...

Most thermal simulations of buildings do not include green walls during thermal calculations. This study integrates and evaluates the effect of extensive green walls (GWs) on the energy balance of buildings using a global code of dynamic thermal simulation of buildings under TRNSYS. The first part presents the equations integrated in the model. A d...

An experimental set-up of triple-glazed supply-air window is developed in this research in order to characterize the window’s thermal performance without solar radiation. By simultaneously measuring the local temperatures and heat fluxes with thermocouples and heat fluxmeters, the heat fluxes determination requires no longer using the correlations...

Thermal energy storage (TES), which features an innovative technology, can enhance energy efficiency in the building sector and reduce CO2 emissions. Due to their high heat storage capacity, phase change materials (PCMs) have impressed many researchers. This paper investigates the energy performance of an individual house integrating a solar Trombe...

As the heating demands of buildings drop considerably, the use of solar walls makes increasing sense. One of the obstacles to the development of such walls is their need for on-site implementation by specialized companies. On the other hand, a storage wall is generally composed of heavy materials with high inertia, which prevents prefabrication of...

The present work addresses the numerical and experimental study of natural convection inside an asymmetrically heated open double vertical facade. Two heating cases were considered independently, the constant heat flux (Neumann condition) and the constant temperature (Dirichlet condition). The double facade has been modeled using a vertical two-dim...

This article studies a composite solar wall with latent storage (TES) designed to heat rooms inside buildings during the cold season. No numerical model of the composite solar wall is currently available in the Dymola/Modelica software library. The first objective of this work is to develop one such model. The article describes the elementary compo...

This article presents the numerical simulation of the energy effect of a solar mask created by a green wall on the thermal performance of a building envelope in a temperate climate in order to integrate it into thermal calculation codes. The document describes primarily the adaptation of a simplified prediction model. The simplified model was devel...

It is well known that indoor heat distribution can affect energy consumption according to the thermal comfort of the occupants. While most work on this topic has focused on specific heaters and how they distribute heat, this paper proposes a new concept termed virtual heaters. Virtual heaters are a set of two optimized heat distributors that respec...

An experimental device was designed to perform the thermal and dynamic study of natural convection airflow in an open vertical channel. The two side walls of the vertical channel are made of Plexiglas allowing the visualization of the flow via the particle image velocimetry (PIV) method. For the two other vertical walls, one is heated at a constant...

This paper presents an optical as well as thermal characterization study of a commercial plexiglass material. The optical band gap value of about 4eV is noticed for the investigated material, which is similar to that reported in the literature. Thus, we showed that the glass transition temperature and peak temperature for plexiglas increases with h...

Material thickness exerts an influence on radiative and phonic thermal conductivity. Abstract The present study focuses on the thermal characterization of an insulation material made from recycled textile fibers for building applications, which qualifies as a semi-transparent medium. Experimental and numerical studies have been carried out to deter...

This paper presents the results of the validation of an experimental method for studying the thermal benefits of green façades. The main aim is to evaluate the impact of plants occultation on energy performance of a vertical wall in the temperate climate of the city of Lille in northern France. An experimental platform consisting of three identical...

Electric heaters are still widely used for residential heating. It is often believed that electric systems all perform equally; however, this is not the case as diffusors distribute heat in different ways. In this study, an experimental investigation of electric heating systems shows that heat distribution can indeed influence the effectiveness of...

First, this article introduces a comparison between experimental results and the results issued from a numerical model of a composite Trombe solar wall incorporating a concrete storage wall with the help of the Dymola/Modelica software. The validation of the model is realized from the comparison between simulated and measured heat flux, external an...

A l’issue de la seconde guerre mondiale, la construction de logements a été intensive en particulier dans les régions de l’est et du nord-ouest particulièrement marquées par les destructions. Il fallait également faire face dans le même temps au « Baby-boom » et à l’arrivée de travailleurs français et étrangers dans les zones urbaines, les besoins...

Recent studies concerning phase change material (PCM) characterization show that important errors occur if differential scanning calorimetry (DSC) experiments are misinterpreted. Therefore, it is important to know the influence of such misinterpretation on system modeling. The present work deals with phase change materials integrated in building st...

A numerical method is proposed to calculate earth-energy of earth-air-pipe heat exchanger during winter heating. The proposed method is based on using numerical computation developed on Scilab a free open source software. Authors showed the comparison between their simple numerical model called Heatground with the well-known Amitrano results. The c...

This work presents a study on the thermal characterization of semi-transparent polyester batting insulation material for building application. This material is consisting of recycled plastic waste based polyester fibers with constant diameters. Thus, the effective thermal conductivity of this material is determined using fluxmeter devices. The radi...

This work presents a study on the thermal characterization of semi-transparent media. The investigated insulating material is polyester batting. This material is derived from recycled bottles (PET) with fibres of constant diameters. The effective thermal conductivity is determined experimentally using fluxmeter device. The radiative properties of t...

Solar walls constitute an important green architectural feature that positively contributes to energy saving in buildings. Different configurations may be proposed, such as, solar wall with Phase Change Material (PCM), composite solar wall, photovoltaic solar wall, zigzag solar wall, and solar hybrid wall. Being environmentally friendly, these pass...

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 su...

The objective of this study is to evaluate three different phase change models used to predict the energy behaviour of a PCM cement mortar sample. Reference data are measured on large samples of composite material using a special experimental set-up. The phase change models tested are: the apparent specific capacity method, the enthalpy method assu...

The supply-air window is a passive system of heat recovery contributing to the building ventilation. It allows the air renewal to circulate between glasses before entering the inside environment. Based on this principle, a part of heat transfer through the glasses is recovered by the airflow. In order to study the thermal performance of this window...

This paper presents the results of the validation of an experimental method for studying the thermal benefits of green façades. The main aim of this study is to compare the energy performance of a reference vertical wall against two different of vegetalized walls in the temperate climate of the city of Lille in northern France. An experimental plat...

In a recent meeting of IEA's Annex 23, several members presented their conclusions on the modeling of phase change materials behavior in the context of building applications. These conclusions were in agreement with those of a vast review, involving the survey of more than 250 journal papers, undertaken earlier by the group of École de technologie...

Comparison 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 part...

The concept of a supply-air window is to allow air renewal circulating between glasses before entering inwards. Based on this principle, a part of heat transfer through the glasses is recovered by air renewal. Actually, the way to consider it in a building simulation code is not satisfactory. This article proposes a model that can be implemented ea...

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 are in the process of being retrofitted at Rushenden, on the Isle of Sheppey (England), and 100 at Outreau, a sub...

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...

Solar energy, along with the other energy resources such as wind, tidal waves, hydroelectricity, and biomass, accounts for most of the available renewable energy on earth. Due to the growing use of solar and the other renewable energy technologies, many educational institutions are developing undergraduate and graduate courses and programs in renew...

The storage of thermal energy as latent heat of fusion presents advantages over sensible heat due to its high storage density and to the isothermal nature of the storage process at melting temperature. Latent heat thermal energy storage systems find application in space craft, solar energy system, greenhouses, heating and cooling of buildings and s...

Solar walls have been studied for decades as a way of heating building from a renewable energy source. A key ingredient of these wall is their storage capacity. However, this increases their weight and volume, which limits theirs integration into existing building. To aleviate this problem, storage mass is replaced by a phase change materials. Thes...

In a recent meeting of IEA’s Annex 23, several members presented their conclusions on the modeling of phase change materials behavior in the context of building applications. These conclusions were in agreement with those of a vast review, involving the survey of more than 250 journal papers, undertaken earlier by the group of École de technologie...

The application of phase change materials (PCMs) for solar thermal-energy storage capacities has received considerable attention in recent years due to their large storage capacity and isothermal nature of the storage process. This study deals with the comparison of numerical and experimental results for a PCM conditioned in a parallelepipedic poly...

The major objective of this project is to use phase-change materials (PCMs) as integrated components in passive solar heat recovery systems. The suggested approach involves experimental investigations and characterization of the global behavior of a parallelepiped “material wrap” filled with the PCM. The experimental apparatus permits simultaneous...

This article presents selected problems used to assess the validity and usefulness of a first-order skew, positive coefficient, upwind scheme (SPCUS) applied to radiative transfer. This particular procedure could be incorporated in several discretization methods such as finite-volume, finite-element, or control-volume finite-element methods for the...

Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. For this purpose, phase-change materials are particularly attractive since they provide a high-energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. Nevertheless, th...

This work is a contribution to the characterization of the thermal efficiency of complex walls of buildings with respect to the ever increasing requirements in thermal insulation. The work specifically concerns the quantitative evaluation of heat losses by thermal bridges. The support of the study is the envelope of industrial light construction wa...

Latent heat storage systems involving phase change materials (PCMs) are becoming more and more attractive for space heating and cooling in buildings, solar applications, off-peak energy storage, and heat exchanger improvements. This paper presents an introduction to previous works on thermal energy storage with respect to these applications. It foc...

This paper presents a numerical investigation of turbulent forced convective flow in a horizontal channel. An exchanger isothermal test plate is embedded in the lower wall, in the fully developed region of the flow close to the exit of the channel. Above this isothermal plate, on the upper surface, a black coated isothermally heating resistance fac...

This article presents the first research effort of our group to formulate, implement and validate a numerical method in order to optimise the design of solar passive walls involving phase change materials (PCMs). The fusion of ice, gallium and the commercially available PCM 27 (hydrated salt), engineered by Cristopia and later embedded within an ex...

The recourse to the passive wall systems in building envelopes can significantly decrease the energy consumption in the building. This paper presents a novel concept of Trombe Walls in building envelopes for optimizing energy efficiency while improving the building environmental impacts.

Les technologies permettant une meilleure maîtrise de l’énergie dans l’habitat sont diverses. L’un des moyens les plus importants est d’intervenir au niveau de l’enveloppe du bâtiment. Parmi ces solutions, les systèmes passifs sont particulièrement intéressants et sont par principe conçus pour avoir un fonctionnement optimisé en fonction des sollic...

The final objective of the research presented here is to use PCM (hydrated salts or others) as integrated components in a dynamic or active solar wall. The suggested approach involves experimental investigations of the global behavior of a particular polyolefin container filled with phase change material (PCM) starting with simultaneous measurement...

The storage of thermal energy as latent heat of fusion has attractive features over sensible heat due to its high storage density and isothermal nature of the storage process at melting temperature. Latent heat thermal energy storage systems find application in space craft, refrigerated cargo transport, solar energy system, greenhouses, heating and...

The objective of this research is to use PCM (hydrated salts or others) as integrated components in a passive solar wall. The proposed Composite TROMBE Wall allows daily storage of the solar energy in a building envelope and restitution in the evening, with a possible control of the air flux in a ventilated air layer. In this particular application...

This paper exhaustively presents a skewed upwinding procedure for application to finite volume methods (FVMs), finite element methods (FEMs) or control volume finite element methods (CVFEMs) in the context of radiative heat transfer problems involving participating media. The proposed scheme is based on the application of sound physical arguments....

This paper presents a numerical investigation of turbulent forced convective flow in a horizontal channel filled with rectangular obstacles located on the lower surface. An exchanger isothermal test plate is embedded in the lower wall, in the fully developed region of the flow. Immediately above this plate, on the upper surface, a black coated isot...

It is very difficult to calculate and analyze with precision the thermal behavior of the walls of building envelope when coexist various modes of thermal transfer and because of the particularly random climatic phenomena. These problems are very complex in the case of special components such as passive solar wall used in “bio-climatic” architecture...

The laboratory LAMTI has worked for several years on the study and the optimization of the thermal performances of passive solar walls like solar Trombe wall. These components of the buildings envelope have very complex behaviour because they are the seat of various coupled heat transfers modes and are subjected to the random variations of the mete...

The passive solar walls use the solar energy to heat the buildings. The composite wall solar collector system consists of a glazing, a massive wall and an insulating wall. Thanks to the big thermal resistance of the insulating wall, there is little inverse thermal flux that crosses from the interior to the exterior. In this paper, the thermal perfo...

The behaviour of civil engineering works (structures, buildings, dams, etc.) in time is a current problem which is the subject of deep consideration and numerous research projects. These studies — which are aimed at adopting a better approach to repair, maintenance and reinforcement operations — have revealed a significant need for the development...

The aim of this article is to present the results of a comparative study of four different types of solar wall. These results have been obtained using a numerical simulation model. In order to validate the model, an extensive experimental study has been conducted on a composite solar wall. The first part of the article is devoted to the particular...

In this article we present solution for experimental studies in natural convection heat transfer. This work is based on the use of thermoelectric sensors conceived in our laboratory and which allowed us to measure heatflux and then convective exchange coefficient. First, we present the sensor and the calibration methods, then for experimental valid...

The objective of this paper is to present an experimental and numerical study of the thermal transfers developing inside a wall including a closed air layer (dimensions: Height = 2.5m; Width = 1.2; thickness: 25 cm). This air layer is bounded with a massive wall in plaster blocks (thickness = 7 cm) and an insulating wall (polystyrene) placed in opp...

The subject of this communication consist in the presentation of new heatflux sensors, conceived in our laboratory and particularly how they can be used for the study of natural convection heat transfer in a vertical air layer. First we present the experimental setup, the heat flux sensor and some results about the general functioning of the therma...

This paper describes a new sensor and a method to measure low velocity or fluid flow. The prominent advantage of this device is an average temperature close to the fluid temperature. Then thermal perturbations (natural convection) generated by the sensor are negligible. The measurement method involves first the use of the Peltier effect to generate...

The use of solar energy for the heating of buildings, via storage walls, has been extensively studied and several components have been developed since the Trombe works. The standard Trombe wall has two main drawbacks. During cold and cloudy winter days, it causes important heat losses and thus discomfort to the occupants. In summer it creates impor...

À partir des signaux flux et températures mesurés aux limites d'une paroi, nous pouvons déterminer les termes de la matrice de transfert caractéristique de ce système conductif. Les méthodes de traitement du signal utilisées dans le domaine fréquentiel permettent l'utilisation de signaux aléatoires, naturels, mesurésin situ. Nous nous limitons ici...

In this article we present new solutions to experimental problems in convection heat transfer. This work is based on the use of thermoelectric sensors conceived in our laboratory and which allowed us to measure heat flux and very low air velocities.

The recent scientific and technological progress in measuring heat flux has promoted new large-sized and short rise time sensors that are convenient for measurement on massive wall surfaces under unsteady-state conditions. The objective of this paper is to show the interest of measuring the energy balance on one of the massive parts of an enclosure...

The recent scientific and technological progress in measuring heat flux has promoted new large-sized and short rise time sensors that are convenient for measurement on massive wall surfaces under unsteady-state conditions. The objective of this paper is to show the interest of measuring the energy balance on one of the massive parts of an enclosure...

L’identification de l’effusivité thermique d’une paroi « in situ » est importante dans une grande diversité d’applications industrielles. La détermination de ce paramètre essentiel nécessite tout d’abord la mesure simultanée du flux thermique et de la température de surface puis l’analyse de la corrélation entre ces quantités en vue de déterminer l...

Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. For this purpose, phase change materials are particularly attractive since they provide a high energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. Nevertheless, th...

Résumé -L'objectif de cet article est de présenter une nouvelle méthode de caractérisation thermique de matériaux contenant des matériaux à changement de phase à partir de mesures fluxmétriques et de températures. Le dispositif expérimental et l'instrumentation utilisée y sont décrits. Le principal objectif de la méthode est la détermination la cha...

Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. For this purpose, phase change materials are particularly attractive since they provide a high energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. Nevertheless, th...

The storage of thermal energy as latent heat of fusion has attractive features over sensible heat due to its high storage density and isothermal nature of the storage process at melting temperature. Latent heat thermal energy storage systems find application in space craft, refrigerated cargo transport, solar energy system, greenhouses, heating and...