Indoor Lighting Design Incorporating Human Psychology

Lighting is one of the most important building services in every building in particular, the modern commercial buildings. Without a proper lighting design, human beings cannot carry out their intended activities effectively, efficiently and comfortably. Conventionally, the horizontal illumination level, measured in lux, has been employed as the dominating factor within an overall lighting design package. However, it is the view of the authors that a lighting system not only provides adequate lumen intensity for the visual ability of occupants, but it also significantly affects the occupants' physiology and psychology. It is also felt that interior lighting design must always come with the design of the colour of wall finishes. In this paper, the relationship between lighting design criteria and human physiology and psychology is studied and a questionnaire has been prepared to investigate the psychological effects of light, in particular colour, on the activities of occupants. Here, colour refers to the colour of either the incident light directly from the luminaires or the reflected light from the wall finishes/furniture as percepted by the occupants. A list of colour finishes is recommended for different kinds of indoor environment. It is hoped that this paper will provide a reference to lighting designers of modern buildings for satisfying the user's psychology.