ECOSM in figure :
Total surface area of the building : 1511 m2
Cost of construction : 2.1 millions euros or 1390 €/m2
42 photovoltaic membranes : 17.14 kWc
LED lighting : 786 Watts
Heat Pumps : 4 (inside the eco-sphere)
243 Wirecom technologies electronic cards
182 sensors : temperature, hygrometry, luminosity, rain, wind, pressure
Construction and insulation of walls :
The head office building is a composed of a greenhouse made of glass accommodating two long pavilions with double walls for a thermos effect.
To maintain temperature in the offices, walls have been constructed in the shape of spouts like in castles. Composed of a block of high inertia material, the spout walls accumulate sunlight during the day and restore it at night. On the other hand, the structure of the interiors rests on the principle of a thermos bottle. Double walls allow flow of air hence maintaining temperature of offices. This air flow is recycled in the hollow tiles of the first and second floor, to minimized thermal losses and internal loads.
To reinforce the efficiency of the walls, the insulation is made by the outside.
Superficial geothermal power
Two ground coupled heat exchangers insulate temperate air in walls.The air is drawn at 2 m and injected directly in the walls.
To improve the efficiency of the global system the temperature is monitored at the outlet of the earth tube. In winter if the temperature is higher in the greenhouse than in the ground the injected air is taken from the greenhouse.
The principle of ground coupled heat exchanger, often used in traditional houses has been reviewed in order to optimise its effectiveness. Traditionally chimneys placed at some thirty meters of the building draw air from the outside, temper it in underground pipes at 1-2 m and let it out in the power stations. As for the eco-construction of the ECOSM it draws tempered air directly into the walls of the building. This innovative technique makes a difference since the air thus retained is at quasi constant temperature in the walls of the offices and optimise its isolation.
Technical data for 1 system : air flow in each heat exchanger : 2000 m3/h
Maximal power recovered in winter : 4500 W
Maximal power recovered in summer : 8900 W
Four heat pumps (air/water) on the inside of the greenhouse
4 heat pumps (23 kW each) are used for heating and cooling the offices : 2 heat pumps per detached house, with one heat pump for each level of the building. They are used only to complete the building ecosystem.. The air that circulates in the double walls then goes to the heat pumps that heat up or cool the offices. Contrary to common practice, they are located on the roofs of the wings inside of the greenhouse. The COP (Coefficient of Performance) of the pump has been increased to a great extent, due to the fact that the air coming from the walls is also injected into the heat pumps.
Openings and gates to optimise air transfers
Natural air transfer have been created. Inside the greenhouse the air circulation keep the building comfortable during hot days (>25°C). Openings in the building are designed to create a “venturi effect” with an ascending air transfer. The air circulate from bottom to the top through valves and roof window. Gates opening in the front and the rear of the greenhouse contribute also to the natural ventilation system by creating an air flow from one side of the building to another.
Solar energy :
A new technology of photovoltaic membranes covers 363 m2 on the roof. The 42 membranes supply 17,14 kWc. Characterised by their elasticity, the membranes are very light compared to solar panels (weighing only 20 kg/m2). They have been selected to adapt to the roof of the building. While solar panels require an angle of incidence between the rays of the sun and the surface of the panel of approximately 45°, 4° is sufficient.
Light-emitting diodes are embed in suspended ceilings. The total power installed for lighting is 786 W for 1500 m2 building area (0,52 W/m2).
Smart Energy regulation
The whole building is equipped with a smart regulation system designed by wirecom. 243 electronic boards are linked to the building equipment and systems.183 sensors monitor temperatures and air flow. The intelligent system functions for all applications : heating, management of lights, air conditioning, maintenance, alarms.. The neural system which act like a link between the sensors is this capable of automatically adapting the lighting or the heating according to the external temperature and the light, or the number of occupants.
Offices : The regulation system handles the functioning of comfort zones, LED, rolling parts, computer and access boxes to offices involved in planning.
Green house : sensors placed under the eco-sphere record temperatures in different areas. Electronic cards independently regulate opening of valves and roof windows, as well as the front gates and those of the green house.