15-storey Frankfurt glass tower uses 50pc energy of conventional offices

WASHINGTON - A 15-story glass tower opened in Frankfurt this July promises to be a world-class energy miser, using half as much energy as a conventional office building in Europe and as little as a third of the U.S. average.

The Westarkade tower glows with natural light and offers windows that open, but a first-of-a-kind “pressure ring” facade and sophisticated, sensor-rich control scheme promise to consume no more than 100 kilowatt-hours of energy per square meter per year, reports Discovery News.

Horizontal Venetian blinds installed outside of the tower’s glass envelope reject unwanted summer heat, while a pane of glass installed over the blinds and ventilated at the top and bottom protects the blinds from high winds.

However, when the windows are opened, winds create a pressure differential around the tower, sending everything flying. So the firms installed 180 vertical ventilation flaps in the outer skin to manage airflows, creating what they call a pressure-ring facade.

The building’s control system takes constant feedback from a rooftop weather station and from 40 sensors deployed throughout the building that measure temperature, pressure, and sunlight.

It continually opens and closes individual flaps to maintain a ring of consistent positive pressure around the structure, preventing strong winds from entering.

And in the fall and spring, air from the open windows should eliminate the need for mechanical ventilation altogether.

Oregon architect Perepelitza cautions that the double-skin design was overhyped but is nevertheless bullish about the pressure ring’s potential. He thinks it could point the way forward for glass towers as natural ventilation and energy efficiency grow in importance.

“This building represents a new generation,” said Perepelitza. (ANI)