No small feat for Becker-Antriebe GmbH in downtown Berlin
It is impossible to miss the DomAquarée, situated in the heart of downtown Berlin and bordered by the Museumsinsel, Berlin Cathedral and Alexanderplatz. Since opening in 2004, this highly sought-after city quarter - boasting total floor space of over 71,000 square metres - has comprised a vibrant mix of urban and working life. In addition to stylish apartments, four-star hotel rooms and flexible office space, the various shops and restaurants in the covered walkways and open spaces of this large building complex invite visitors from around the world to shop, dine and linger. A further highlight is the world’s largest free-standing aquarium filled with roughly one million litres of saltwater and containing a glass lift at its core.
However, from the outside, the unique roof construction of the DomAquarée is the real eye-catcher: Two buildings of the four building complex that face Alexanderplatz boast an extraordinary vaulted glass roof that spans the top two floors and provides a fitting finish to the five-storey facade of Spanish limestone. The large glass panes are 7.60 metre in height and integrated into the elegantly curved steel frame construction. In contrast to the straight, sharp edges of the rest of the building, the curved corners of the vaulted glass roof offer a unique stylistic signature.
Though the architecture facilitates the much desired transparency and impression of lightness, it also presented various challenges in terms of sun protection in the respective rooms. The originally installed solution – interior Venetian blinds between the panes – failed to maintain an ideal temperature in the rooms that can heat up very quickly. The top two vaulted glass floors therefore had to be extensively refurbished during several construction phases in 2011: Today, heat-reflecting, highperformance glass and jumbo-sized, aluminium-faced screens from www.Sonnenschutz.com GmbH ensure pleasant temperatures, while providing a better view to the outside and an excellent glare-free environment. The complex task of realizing a motorized solution for the extra large sun protection elements was accomplished by Becker-Antriebe GmbH, the specialist for drives and control units for roller shutters and sun protection systems.
“Since 50 percent of the entire surface is situated in a single room in the vaulted roof, it was absolutely essential that the individual sun protection screens can move at the same time and be positioned precisely,” says Harald Heck, a construction manager at sonnenschutz.com. “It must be possible to adjust the upper and lower final position just as accurately as the central intermediate position. The Becker drives offer an excellent long-term solution and position up to 20 screens perfectly in line.” Becker applied tubular drives with mechanical limit switches that can be installed quickly thanks to a simple plug system and efficiently integrated in small boxes. They are controlled centrally via the DomAquarée’s BUS system. Although Becker also equips larger buildings with its own automation solutions, it is possible to simply link the Becker SMI drives to other systems that are already in place using the KNX building automation standard – as was the case in the DomAquarée. This enables the programming and automatic realization of individual scenarios, e.g. automatic extension of roller blinds according to the intensity of the sun.
Sophisticated solution down to the very last detail
To ensure that the screens always run in parallel to the windows despite the rounded shape of the roof, the motorized roller blind system is additionally tensioned with counter-rotating steel traction cables. A spring mechanism and cable drum ensure tensile strengths of up to 10 kg when opening and closing the blinds. It therefore takes just 69 and 38 seconds to fully and effectively extend the 7.60 metre jumbo-sized roller blinds and the screens respectively. Although it was a conscious decision to select interior sun protection in order not to compromise the architecture of the DomAquarée, the required technology must be kept well out of view. Therefore, the thin wires of the cable system are perfectly adapted to the glass construction as they run almost invisibly in front of the steel window frames. The trapezoidal screens required in the curved corners of the rooms demanded exposed shafts due to their asymmetry. And these are also hidden from sight behind specially installed cladding.
In addition to correct functioning and visual appearance, sound insulation also had to be considered. “When so many screens are moved simultaneously, the transmission of mechanical noise must be reduced to a minimum. This was yet another argument in favour of Becker-Antriebe, as its low-noise motors are inaudible next to the driving noise,” explains Harald Heck, who, together with Becker field technician Thorsten Skulski, is more than satisfied with the successful cooperation. “Our motto at sonnenschutz.com is usually: The more complicated the task, the better the result. But when it comes to our partners, we demand simplicity and reliability.” This was fortunate for Becker, and particularly fortunate for the DomAquarée.