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Sustainable Architecture Das
Dusseldorfer Stadttor
by Overdiek,
Petzinka & Partner | Building | Concept | Energy Concept | Photo Gallery | Home | Case Study Index | | |
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Concept |
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The Stadttor consists of two towers, each eighty metres tall, with the top
three storeys connected together. The resulting gap between the towers
forms a 58-metres tall atrium with tenuously detailed suspended glass
curtain facades. The office walls also consist almost entirely of glass in
wooden frames. The use of this material softens the look of the
building. A second, structural. glass skin has been mounted in front
of these walls to damp the deafening traffic noise and to make natural
ventilation possible. Vanes in the ventilation space adjust to the current
wind speed, so allowing the offices to be supplied with fresh external
ventilation practically all year round. The Stadttor is cooled by the use of cold groundwater. The chilled ceiling system can be operated by the occupants. Due to legal reasons, there was a two-year delay in the construction of the Stadttor. This delay time was used to perform additional supercomputer and wind tunnel modeling. The first phase, which took seven months, increased the efficiency of the façade by 300-400% over the original design. Upon intuition, it would appear that the larger the opening from the outside into the |
| double-skin cavity, the better the airflow; this turned out to be false. With simulation on a simple design using an opening of 70 cm, it turned out that only 10% of the air would actually pass through the channel; the rest would get caught up in vortices near the entrance. Adding louvers increased efficiency to 60%. After more refined analysis on exactly what shape and location the louvers should have, the efficiency was brought up to 80%. A 3rd iteration did not provide any significant gains. The final airflow gap distance was 1.4 meters. This wide gap was chosen to give occupants the ability to walk inside the double-skin cavity for leisure and recreation. |
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