Visual comfort in the daylit luminous environment: Structural model for evaluation

Abstract

In order to create a comfortable daylit luminous environment which can also contribute to conservation of fossil fuel, a hypothetical model structured in terms of physical quantities representing stimuli, sensory responses, and an overall evaluation is presented. This hierarchical model was tested by a pilot experiment conducted in a side-lit classroom with 147 subjects. A questionnaire was carefully prepared according to the hierarchical model, so that the overall evaluation could be expressed in terms of comfort sensation related to the sensory responses to brightness on the desk and to the veiling reflection on the sheet of paper on the desk. The brightness sensation on the desk was expressed by a function not only of the desk illuminance but also of the vertical illuminance. Deficiencies of the model on the basis of the experimental results and a modification of the model are also discussed.