Daylight in Buildings



Jayati Chhbara, Bangseh Akuchu


Michael Gamble,

Tarek Rakha


Georgia Institute of Technology


United States


Project Description

A LIGHTING SOLUTION FOR SKYSCRAPERS IN AN OVERCAST SKY With increasing populations and lack of resources like land, it can be easily assumed that by 2080, skyscrapers will be more abundant than they are now. While this can act as a boon for regions with extreme sunlight and heat by the virtue of these tall buildings that will provide shade to the streets and neighboring structures, cities like London which have an overcast sky condition might have to deal with an exaggerated issue of no natural lighting inside the buildings like offices and libraries. This can affect the physical and mental health of people significantly. Atria and light wells are thus, commonly used to cater to the above problem. Consequently, they also reduce the energy loads significantly. However, often the designed shape of the atrium or a light well does not perform to its full potential. In recent research, it has been found that if designed improperly, the use of atria can lead to increased energy loads as well as visual and thermal discomfort. Therefore, this project optimizes the shape of the atrium with the objective of achieving most areas with 500 lux of light on the bottom floors. Using a genetic algorithm-based optimization process, called Galapagos, within the visual scripting tool, Grasshopper for Rhinoceros3D CAD software, simulations for various different design scenarios were run; testing out different radii and positioning for the atria on each level. These simulations were then compared in terms of lux levels achieved by running them through a Radiance simulation engine. Additionally, comparative simulations for Spatial Daylight Autonomy (sDA), Annual Solar Exposure (ASE), and Average lux levels were run to compare different material options for the atrium.   The final design settled on a perforated aluminum mesh material as it could reflect the light deeper into the building. Further perforations are added to spread light on each floor, providing an adequate amount of light needed for daily activities.