Análise teórica e experimental do desempenho de duto de luz, na cidade de São Carlos.
Abstract
Illumination electric systems are responsible by expressive consumption of
energy in buildings. Daylight, on the other hand, is abundant, free and more favorable to
health and to the efficiency of people activities. However the side-windows system,
when it is used alone, presents limitations in illuminance distribution. These limitations
can be attenuated by usage of sunlight redirecting devices, such as Light Pipes (LPs).
LPs collect daylight, conduct it by successive reflections and deliver it to an internal
ambient, providing more visual comfort and saving energy. This research is carried out
by studying the diffuser, the internal illumination and the collection, conduction and
distribution of light by LP. To analyze the diffuser that would be used on the
distribution of light, different materials were exposed to daylight and their behavior
under the sunlight was evaluated. An appropriate diffuser was not found, therefore the
milky acrylic was used as a diffuser panel. LP systems contribution in illumination was
quantified and analyzed by monitoring scale models and the results were compared to
conventional daylight systems. LP different sections (square and rectangular) with
mirror internal surfaces were analyzed to evaluate their performances and they were
compared to evaluate the influence of geometry, internal reflectance and LP orientation.
Results indicate that the LP with square section is more efficient. Also sky conditions
were analyzed and their influence in the internal illuminance. Experimental data were
compared to a theoretical analysis. At last an evaluation of potential for energy savings
by using LP was performed.