The most innovative yet resides in what is not

At the end of summer, it is around 30 C in the suburb of Orléans. Headquarters new Wirecom Technologies Corporation, a greenhouse of glass with two long wings, shines in the Sun. Once inside this transparent mini-cathédrale surprise: the temperature is pleasant. In offices, it does not exceed 22 C, "all without spending a watt of electricity", provides Thierry Allard, the CEO and founder of the company, specializing in the technical management of buildings. His battle horse: energy savings. Completed in April, the head office is the best of the showrooms: "You want to show that we can be very efficient with conventional materials at a cost less than or equal to that of a regular building."

Effect "thermos".

Ademe and specialists of the Centre for scientific and technical building (CSTB), to determine the interest of the project in a tender on energy efficient constructions, were skeptical. Indeed, modelling software did not take into account the innovative aspect of the building, which combines traditional techniques with other very sharp. Designed by the architect Gilbert Autret, in collaboration with the CIS, and Wirecom studies Office, headquarters plays on heat transfer and uses "all that nature offers", summarizes Thierry Allard: the Earth and the Sun for calories, light for the production of electricity, air for the regulation of temperature, etc.

Thus the building, called "Ecosm", uses two Canadian wells. This traditional technique is to vacuum the outside air and the circulating underground, where the temperature is always understood between 15 and 17 C. The revolutionary idea of designers was to inject the air temperate in the walls of flags consisting of two walls in concrete air circulating also in ceilings. "A kind of thermos bottle: a budget double with air in the middle." "The walls and ceilings are thus maintained at 15 or 17 C regardless of the outside temperature", provides Thierry Allard. It is only once out of the walls that this air powered two heat pump to heat or cool offices as required. "Having circulated in the walls, the air is found in approximately 20 C." "It is at this temperature the heat pump has the best performance," said Thierry Allard. Finally, to take advantage of the glazed surfaces avoiding the disadvantages of a tropical heat, Ecosm lives to the rhythm of very light natural air currents. Openings performed at the bottom and on the roof, and large doors in the axis of the building provide natural ventilation.

Sensors communicate

This ballet is operated without human intervention. According to the temperatures inside and outside, automatisms activate glazed openings for ventilation, fly heat pumps... In each room, the user command all through a single box: doors, shutters, light, air conditioning... But the system standby and oversees everything: access control, heating, ventilation, lighting, shutters... The fixed idea is to avoid any waste. Unthinkable, for example, a desk lamp is lit at night since, knowing the party user, the system most the étourdi light. Big Brother "The user can regain control at any time," said Thierry Allard.

The most innovative yet resides in what is not. While all technical building management systems are centralized, Wirecom gambled on distributed intelligence. 300 Electronic cards, 180 sensors and actuators 310 communicate through carrier current (CPL) online and decide the strategy to adopt. "Each element, whether an actuator or sensor, has a simple task." "They exchange information on their bead: a room to another, and then, close in close, with the entire building", emphasizes Thierry Allard. Production of energy, 42 solar membranes ensuring also the seal are installed on the roof. If their performance is less good than to solar panels, they are ten times less heavy and work even with grazing light, which allows to ask with a North orientation. The objective was to achieve a consumption of 42 kWh per square metre, less than 50 payable kWh in 2012 for new constructions. After seven months of existence, Ecosm displays today a performance of... 17 kWh.

The image of Philippe Bray, of the regional delegation of the Ademe, the specialists remain yet cautious: "A after one year of operation, it will check if the building is actually positive energy." Surprisingly innovative, this type of building is yet not the panacea. The concept will be probably less suited in warmer latitudes. It is also difficult to impose this kind of architecture in the downtown, find a specialist, but wondered: "Can ask the question of why such a concept was not invented by Ademe and the scientific and technical building Centre."