Bedarfsgerechte Be- und Entlüftung
The building is equipped with a unique ventilation system that is controlled based on the outside temperature. Common areas are naturally ventilated in spring and autumn, thus saving much of the energy that is used by mechanical ventilation systems in passive-energy buildings. The integration of CO2 sensors and corresponding control baffles in the ventilation system and the optimum positioning of the ventilation shafts are also crucial for minimising energy consumption. Great importance was also placed on the energy-efficient conditioning of the fresh air supplied to the building through the ventilation system. A full 90% of the total requirement can be met by the rotary heat exchangers and the heat and moisture they recover.
Optimised use of daylight and energy-efficient artificial lighting
The innovative lighting concept combines the optimised use of daylight with energy-saving artificial lighting. Floor to ceiling window constructions as well as outdoor shades designed to make use of natural light ensure that workspaces are optimally supplied with sunlight. Artificial lighting is provided throughout the building by floor lamps with occupancy and daylight sensors that significantly reduce power needs. This reduces the connected load by 50% compared with conventional floor lamps. The shading system on the building exterior is controlled by a sensor on the roof that measures the sun's position and intensity and that uses this data to automatically adjust the sun shades.
Heating and Cooling
The office spaces are heated and cooled using concrete core activation. For cooling purposes, a combination of water circulating through the structural element and the outdoor temperature level is used. This significantly reduces the amount of energy used for the site in comparison with conventional cooling technologies. The system switches automatically between the groundwater system and the free-cooling system when the outdoor temperature reaches 15° Celsius. Once this temperature is reached, the free-cooling system is more efficient; to cover peak loads, additional use is made of the district heating system.