‘With the planning by Drees & Sommer, we have been able to achieve comfort and maximum amenity value for the users in the Turmcenter Frankfurt, and at the same time to fulfill the highest standards of sustainability and economic efficiency for the operator,’ comments Georg Strassner, Principal and Head of Germany at Benson Elliot. The new energy design aims to make the best possible use of the existing energy potential and renewable energy throughout the year. It is the first office building in Germany to use the whole of its glass façade as a year-round energy collector.
In the winter and the transition seasons, the Turmcenter Frankfurt uses the building's internal energy transfer and storage system. The sun's heat from the side facing the sun is transported to the shaded side of the building, allowing the rooms to be heated naturally. In addition, excess heat from south-facing IT and conference rooms is transferred to north-facing areas. In combination with solar thermal energy, a heat pump, recycled heat from the sun and the excess heat from rooms, 90 percent of the heating is provided from regenerative sources.
Using the sun for cooling in the summer
The Turmcenter Frankfurt plays a pioneering role in Europe because 65 percent of the cooling in the building is powered by the sun.
Even in the summer, the solar radiation is upcycled via a solar thermal installation on the roof and used to produce regenerative cooling. This is achieved by an adiabatic cooling process using a DEC system which involves drying and evaporation processes.
The excess heat which arises from the cooling ceiling system is also used to generate cooling energy and for the ventilation system. Thus, the Turmcenter Frankfurt harnesses its energy and excess heat potential all year round, and it feeds this potential back into the building via energy recycling or upcycling.
More office space and room comfort due to innovative technology
‘The energy design in the Turmcenter is based on using less technical equipment, but with innovative technology that provides improved efficiency. The annual energy consumption is particularly low with this energy design. It is 40 percent below the requirement of the German Energy Saving Ordinance 2014 (Energieeinspaarverordnung – EnEV) and 15 percent below the green building standard,’ says Norbert Otten, Partner at Drees & Sommer SE. The new energy concept enhances the value of the building as a whole. The technology used reduces the energy costs to significantly below one Euro per month per square meter.
The amenity value is also enhanced by the absence of a continuous suspended ceiling, which makes the rooms higher, and by windows reaching down to the floor instead of a perforated façade. In place of an air circulation ventilation system for heating and cooling, the building uses radiation ceilings which provide a high sense of thermal comfort without overheating or draughts. Humidification in winter and dehumidification in summer as well as the optimum use of daylight are added. In the original planning, a large proportion of the roof space was taken up with sprinkler and refrigeration systems. The new concept reduced the space needed for technical installations on the roof and on the top storey of the high-rise building, which has therefore been converted into extra rental space as an exclusive penthouse office with four meter high ceilings. This was possible because the conventional sprinkler systems were replaced by a stationary low pressure water-mist fire suppression system.