An artificial skylight compared with daylighting and LED: Subjective and objective performance measures

In the last decade, innovative systems such as Artificial Skylights (AS) have been developed to reproduce the blue-sky effect and white sunlight, giving the impression that interiors are illuminated by natural light, even when this is not available because of construction- or climate-related reasons. Given the hybrid characteristics between natural and artificial lighting, the aim of this research is to compare an AS with daylight and with artificial lighting to identify similarities and differences in performances, pointing out the most suitable indicators to describe it and to provide useful feedback for the design and integration of these systems.