Abstract

This report has been developed in the frame of the IEA SHC Task 61 Subtask A “User requirements”. The main objective was to rethink and reformulate user requirements to lighting (daylighting and electric lighting) in public buildings on the basis of a thorough literature study. The work is a joint effort of a number of scientists and represents collective knowledge in this topic. The concept of Lighting quality is the one, among many lighting concepts, which expresses the user perspective best. Lighting quality is the important goal of lighting designers and planners; however, it is difficult to define and to measure. The following definition of lighting quality has been used for many years: Lighting quality is a concept that allows excellent vision while providing high comfort. (Kruisselbrink, Dangol and Rosemann) (2018) In this recent paper, the authors try to find measures that could be directly used for describing the lighting quality: quantity, glare, spectral power distribution, distribution of light, directionality and dynamics. The overview also shows that the luminance distribution is a suitable way for at least getting useful information of the lighting quality. If spectral distribution is added to these measurements an even better description of the lighting quality is obtained. The above-mentioned definition of lighting quality focuses at humans, but it does not take into consideration aspects of light that have indirect and profound impact on human health and well-being. Those are the non-image forming aspects of light and some psychological aspects. In this report those additional aspects are included and structured in chapters as follows: 1. Perception of light 2. Visual Comfort 3. Psychological aspects of lighting (view out, perceived quality of space, privacy, etc.) 4. Non-image forming aspects of light (ipRGCs action spectrum, hormones, etc.) By using these four different basic aspects we have the possibility to define several criteria for lighting quality, both image-forming and non-image forming. We have also the possibility to compare between qualities of electric lighting and daylighting. During the last twenty years the knowledge about light and lighting has developed and at the same time the technological development has been immense. Today we are able to get much more electrical lighting with less energy than ever before, but is the light of good quality? We need to develop evaluation methods.

Citations

Authors (7)