ER 5 – Efficacité énergétique et habitat dans son environnement urbain

The study of materials focuses on their acoustic performance and includes the production of "bio-porous" (cellulose based), a negative work allows to control pore sizes and their interconnections from 3D printing. The aim here is to offer an efficient low-frequency absorption solution, combined with a minimal space requirements. The complementarity of the numerical and experimental approaches (in laboratory and in situ) adopted allows a better understanding of the phenomena encountered. The purpose of the Ademe Aerositan project is to develop a bio-sourced insulation material from low molecular weight organic aerogel. The introduction of plant fibers will improve their mechanical strength, the optimization of the formulation will lead to improved acoustic and thermal performance. The study of air quality, ambiances and transport phenomena in interior environments is addressed through experimental and numerical approaches. The first is to measure the physical quantities that can be used to judge the quality of the ambient air. The second is based on a computational code which consists of solving the equations of mass transport, movement quantity, and energy in order to access the dynamic, thermal and mass fields in the space considered. These are designed to highlight the impact of particulate, heat and mass transport on flow and comfort for building-specific conditions. This work is based on the Interreg Texacov project, which aims to develop a textile for the depollution of indoor air. The idea of the project is to use natural nanofibers as a vector for the incorporation of photocatalytic particles to be applied on textile support to add mechanical resistance to the functionalized composite substrate.

The aspects related to the study of materials and the non-destructive control of walls present a fundamental interest. Implementation conditions, exposure to microclimatic exchanges, aging cause significant differences in properties between laboratory and in situ characteristics. The appearance of new agro-sourced materials, highly hygroscopic or recycled, whose developments are not well known, strengthens the need for research. The P2AR regional project on flax shives and the Ademe EMIBIO project on the sustainability of biosourced materials fall within this framework. The approaches are both theoretical (COMSOL®, MATLAB®) and experimental (in laboratory and in situ), they are based on regional partnerships (Soginorpa, cd2e), through the Réhafutur 2 and Renochanvre projects which deal with the rehabilitation of workers’ housing from bio-sourced products. Natural structural materials are also studied, in partnership with CTMNC - Technical Center for Natural Materials of Construction (Villa YFS). The Non-Destructive Testing approach is coupled with the characterization of materials, it allows the development of measurement methods (infra-red thermography, microwave stresses...) and data processing.

Climate change issues have an impact on the choice and performance of building materials. They must be able to adapt to random micro-climatic stresses whose dynamics are an important constraint in winter or summer comfort. Insulating or inertial performance is no longer sufficient, materials must become "intelligent". In this context, phase-changing materials (MCPs), depending on their nature and thermophysical characteristics, significantly improve the thermal behavior of traditionally used materials. The strategic choices of the theme are to collaborate with research laboratories or companies that wish to develop materials (coatings, textiles, ...), systems (exchangers) or applications (walls, floors, ceilings) incorporating MCPs. The scientific lock remains the characterization of these materials (determination of thermophysical properties) which is necessary to the creation of reliable numerical models capable of restoring thermal behavior under real conditions of use. Numerical simulations are essential to these innovative materials to prove their energy value and economic profitability. The team is interested in developing scientific identification methods and numerical models for or for study offices. The improvement of the thermal performance of building wall constituents by the integration of phase-changing materials is the subject of research carried out within the axis. Based on an ANR (Stock-E MICMCP) project, a regional project (TESTE) and several theses, advances at both the experimental and numerical levels have made it possible to better know this type of component in order to optimize its use in the walls of buildings. The expertise developed at this level is recognized through the projects and publications produced.

In absence of a return of experience in this field, the team has set up a large-scale "SunRise Smart City", demonstrator on the Lille campus as part of a broad socio-economic partnership to test and develop this new concept. The project is included in the State-Region Plan Contract : CPER 2015 – 2020 «SunRise Smart City Territoire Catalyseur d’innovation ». This project is one of the first projects undertaken to implement the concept of a smart city in a territory equivalent to a small city, covering water and energy networks and buildings. It is almost unique in the world if the experienced territory is combined with research and training activity and broad socio-economic partnership. The project is now highly visible internationally. It also aims to create a dynamic of multidisciplinary and partnership research and development on the theme of smart and sustainable cities. This topic is of increasing interest, as it concerns a major societal and environmental issue, namely the development and redeployment of innovations in the city with the aim of significantly reducing the consumption of natural resources (energy and water) and the emission of pollutants while improving the living environment of citizens. The work included the collection and digitalization of heritage data, the instrumentation of infrastructure, the analysis of data and the formulation of recommendations for improving infrastructure management. He served as a demo for the European SmartWater4Europe project (2014 - 2017) on smart networks. Building on this success, the LGCgE has been requested to support the "Smart City" approach of several partners, including Lille Metropole Habitat on social housing, ArtoisComm on an intelligent neighborhood, the city of Béthune on Smart City, and the city of Saint-Quentin on the Intelligent Territory and the Intelligent Building and the city of Lille for Smart Governance. The LGCgE was also requested for projects in Lebanon, Qatar, Morocco, Tunisia and China.

As part of the necessary reduction in energy consumption of buildings, the laboratory has developed partnerships with different building managers (housing, tertiary) for several years. This work has been carried out partly through SunRise Smart city, Réhafutur or more recently SBnodesSG projects, but also directly with local authorities, concerned with optimizing the costs of consuming buildings. Here the main difficulties are related to the implementation of instrumentation (nature of sensors, intrusiveness, type of measurements, data survey...) and the processing of massive data (Big Data). The multiplicity of sensors and dwellings, and the close-to-the-clock data surveys over long periods of time, make the analysis and processing of information quickly complex. The objective is to detect malfunctions from supervised and unsupervised statistical classification methods. This is notably the case of the partnership with the Pas-de-Calais department on the management of 117 buildings, including 90 colleges for water, electricity and gas stations, and an internal and external temperature monitoring is also being carried out. The analytical methodology is based on the development of statistical indicators, which are monitored to detect changes in the behavior or performance of the systems. Colleges are independently studied to combine decisions. Second, in similar buildings with identical operation, this helps to highlight unusual behavior and detect abnormalities in behavior. The sites made available by the partners have enabled the development of skills on the instrumentation and processing of data and above all to create a dynamic on this subject within the team, since it develops on the different poles thanks to the different teachers researchers and doctoral students (Lille, Yncrea Hauts de France (HEI) and Béthune). This scientific transversal within the team is an additional asset for the future development of this emerging theme.