Fraport, Frankfurt a. M.

During sunshine, 1500 - 2000 lx have been measured on desk level in 3 m room depth. During cloudy sky still 500 lx are achieved, so that an excellent daylight illumination is attained.
The lower window part up to 2 m in height redirects the daylight steep and glare-free onto the ceiling. In middle window part above 2 m the zenith light is redirected horizontally into the depth of the room.