Daylighting design with lightscoop skylights: Towards an optimization of proportion and spacing under overcast sky conditions

The main aim of this article is to determine suitable proportions for lightscoop skylights, whose main characteristic is a vertical opening oriented in the opposite direction to the solar trajectory, with a view to ensuring maximum illuminance on the area under study within a room. Lightscape 3.2 software was used to carry out the simulations, comparing the results with those obtained using DaySim 3.1. It was finally concluded that for this type of skylight a height/width ratio of approximately 4/3 is the most suitable for ensuring the highest daylight levels in a room in overcast sky conditions.

► We analyze optimum proportions of lightscoop skylights for maximum daylighting.
► To find the right ratio we vary skylight proportions using simulation software.
► Optimum ratios for height/width in a lightscoop are close to 4/3 under overcast sky.
► The 4/3 ratio is used to analyze the optimum spacing between skylights.
► The ratio for room height to skylight spacing should not exceed 4/3.