AUTHOR=Klir Stefan , Babilon Sebastian , Myland Paul , Benkner Simon , Khanh Tran Quoc 

TITLE=Sky-like interior light settings: a preference study

JOURNAL=Frontiers in Built Environment

VOLUME=Volume 9 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/built-environment/articles/10.3389/fbuil.2023.1101534

DOI=10.3389/fbuil.2023.1101534

ISSN=2297-3362

ABSTRACT=This paper explores human observer preferences for various sky-like interior lighting scenarios realized by a combination of a blue-enriched indirect up-light component with a correlated color temperature (CCT) of 6,500 K up to 30,000 K and a 4,000 K or 5,500 K direct down-light component. Variations of the natural sky were mimicked by the indirect up-light component reflected from the ceiling of the experimental room. The settings for the direct lighting component, on the other hand, were selected based on the reported outcomes of previous preference studies in the field of interior lighting. The resulting lighting conditions were evaluated by a total of 29 observers, from which subjective ratings of brightness, sky-likeness, satisfaction, pleasantness, and general appeal were collected in an office workplace environment. In this experimental setting, the most preferred lighting conditions exhibited a direct to indirect lighting ratio of 50:50 with a CCT of 4,000 K in the direct and of 6,500 K, 7,500 K, and 9,000 K in the indirect component.For all examined combinations, none was rated as truly sky-like. Nonetheless, the study results showed that only the combination of a warmer CCT in the direct and a cooler, blue-enriched CCT in the indirect lighting component leads to a maximum in the subjects' preference ratings.