Use of Light Pipe and Electronic Heliostat for Lighting of Underground Areas in Porto Alegre.

The use of underground spaces is increasing and light pipes are an alternative to create natural lighting in these areas, but the technique should be tested locally to verify performance and viability. This study was designed to test a specific kind of this technology in the city of Porto Alegre, southern Brazil. A scale model experiment was made in three stages. In the first stage, two different reflective materials were tested. The material that performed better was used for the second stage, where light pipes of different heights were tested. In the third and final stage, an electronic heliostat was added to the system to verify how it would improve its behavior. This specific system can be used in this city to light underground areas under clear sky conditions. However, in cloudy days the performance of the system decreases. Hybrid light systems can be an alternative to deal with this. Heat loading and glare should be controlled to avoid damage and increase in energy consumption. [ABSTRACT FROM AUTHOR]