Double light pipe: experimental analysis on reduced scale models and comparison with numerical results

Nowadays in Europe a more and more considerable use of transparent surfaces in buildings is taking place, allowing natural light to play a significant role in architecture planning. Moreover the application of light pipes for daylighting transmission is increasing. They find application in the transmission of the daylight in underground areas, but they often present some limits in integration with architectonical structure, due to their overall dimension in the intermediate rooms crossed by the pipe. In this paper an innovative device is presented, called “Double Light Pipe”. It has been designed with the purpose to resolve this problem. It consists of two concentric pipes of different diameter, which permit to introduce natural light both in the final room and in the intermediate one. The experimental analysis was carried out on reduced scale models and the results compared with numerical data by Ecotect. A good agreement is verified.