Subjective preferences for LED lighting in offices

Aalto University, lighting unit has built an office room with spectrally tuneable (LED) lighting systems to study the user lighting requirements and preferences of solid state lighting products. The room is illuminated with six LED luminaires. Each LED luminaire has 480 LEDs (20 different LED types and 24 of each type). In this system the observers can be completely immersed in and fully adapted to an office lighting environment. The objective of the study was to verify the results obtained from small scale booth experiments in real office environment. The small scale booth experiments showed that LED light sources with a higher value of reference based metrics (such as colour quality scale (CQS) Colour Preference Scale) and with higher value of area or volume based metrics (such as CQS Gamut Area Scale) were preferred by the observers.