Towards a user preference model for interior lighting. Part 2: Experimental results and modelling

Subjects assessed their visual impressions about scene brightness, visual clarity, colour preference and scene preference in a real room in which the horizontal illuminance, the correlated colour temperature and the level of chroma enhancement of the light source were changed systematically. The aim of the experiment is to contribute to the development of a user preference model. The concept of this model and the experimental method were described in Part 1 of this work. In Part 2, modelling equations of these four visual attributes and their validation are shown. Criterion illuminance levels for ‘good’ levels of the visual attributes were determined depending on correlated colour temperature.