Deep Daylighting in Tokyo Offices

© 2012 EPFL

© 2012 EPFL

A new deep daylighting prototype for curtain-wall façades, developed at Prof. Marilyne Andersen’s former Daylighting Lab at MIT and refined at the Interdisciplinary Laboratory for Performance-Integrated Design (LIPID) at EPFL, will be installed on floors 5 to 10 of Hulic’s Head Office Building in downtown Tokyo, a real estate company. The building’s inaugural ceremony is scheduled to take place in September 2012.

The so-called Soralux system (‘Sora’ stands for ‘sky’ in Japanese) – for which a patent application has been filed – is embedded in a double-glazing unit and combines curved reflective louvers for light collection with acrylic rods and a reflective ceiling to spread out its distribution deep in the space. Its main challenge is to offer a static and well-integrated solution to up to 12 m deep office illumination, using sunlight while avoiding any risk of glare. Its development was the topic of a recent MSc thesis by Kevin Thuot conducted under Prof. Marilyne Andersen’s supervision at MIT and EPFL. A first prototype had been tested in February 2011 and a second prototype has now been installed on the 6th floor of the actual HQ building under construction, in a dedicated area specifically designed for this testing (including scaffolding removal). Prof. Andersen spent a week performing validation measurements and tests to finalize the choice of ceiling finish and confirm the expected efficiency of the system