Light Pipe Configurations Based on Daylight Simulations; Straight and Elbowed Pipe Models

Abstract

Abstract Light pipes are one of the most effective ways of transmitting daylight deeper into buildings, away from facades and windowless areas. To adapt in complex building structures, one or more elbows must be used to change the direction of light, however, an elbowed pipe is known to cause more light loss than a straight pipe of equal length. This paper presents a research study on different configurations for straight and elbowed light pipes via the accurate simulation tools, which is another light transmission efficiency method. Case study is defined in three main stages: identification of the optimum model by trying different elbow models; comparison of light pipes, which are generally used straight, and the elbow model attached to bottom interface of the pipe at an angle of 45°; comparison of double elbow light pipes with 45° and 90° elbow angles. Basic software series consist with 3D-based Rhinoceros, algorithmic graphical editor Grasshopper, simulate daylight Ladybug and Honeybee plugins. The analyzed parameters are maximum and average illumination level, Daylight Factor (DF) and Daylight Autonomy (DA). According to the illumination levels, DA and DF results, in overcast sky conditions, it is possible to provide approximately 50% of the required light level for the space with daylight using light pipe systems.