Article published INCAS-PASSYS
The house for the 2020s will be... passive!
The LITEN is investing heavily in the area of design-construction for positive energy buildings. Through its INCAS and Passys platforms, it is providing industrialists with four life-size experimental houses as well as test cells .
Buildings are the primary consumer of energy in France. Each year the sector produces 25% of the total CO2emissions, compared with 28% for transport and 22% for industry. One of the keys to limiting such pollution is the construction of the so-called "positive energy" houses, i.e. houses which, over the course of a year, produce more energy than they consume. To attain such performances, this housing must be constructed in such a way as to make best possible use of all the available natural sources of heat, such as solar energy and body heat, and to provide maximum possible reductions in heat loss. Via a platform known as INCAS, the INES is working to develop these positive energy and low energy consumption dwellings which seek to improve the annual energy balance. Eventually, four experimental houses, each with a floor space of 95 m2 on two floors, will be constructed on the INES site at Bourget-du-Lac (Savoie). They will act as life-size research tools in order to improve understanding of the global approach to energy efficiency in buildings. Two of these houses will be delivered at the end of this year, the first in double walled breezeblock with integrated insulation and the second in cast concrete (poured in a formwork exhibiting various shapes) with exterior insulation. They will of course be equipped with solar panels: photovoltaics on the south facing part of the roof and thermal panels on the balcony. Inside, each house will be equipped with nearly 300 sensors measuring temperature, humidity, air speed, luminosity and pressure, not to mention energy consumption. The presence of the inhabitants, which is a crucial element in the project, will be simulated by electrical heaters and water vapour generators. Goals: to perform life size measurements of the energy flows in order to optimise, for example, the efficiency of solar thermal systems as a function of the climate, orientation and inclination of the panels, etc. Numerical models will be developed for the buildings, which will simulate consumption over a period of one year as a function of seasonal meteorological variations. Once the dwellings are completed, the simulation data will be compared with the results measured in situ, in order to optimise the operation of the installed systems and to improve the simulation software. In parallel, four Passys test cells, composed of five adiabatic surfaces and a test facade, will enable the external components and the HVAC systems (heating, ventilation and air conditioning) to be investigated. The facade test can be modularised and these cells are instrumented for energy monitoring and for evaluation of thermal and visual comfort. The goal? To study, design, develop, optimise and evaluate components, such as a complex wall consisting of an insulator, a polymer containing phase change materials and a system for emitting heat and cold. In the medium-term, these advances will make it possible to bring a product to market which is suitable to the needs of renovation of existing buildings. All of this research addresses the Grenelle objectives on the environment: to reduce annual energy consumption for heating of houses from 110 kwh currently, to 80 kwh by 2010 and to 50 kwh by 2012. The longer term goal for 2020 is that new houses will all be positive energy.
