A fresh approach to interior lighting design: The design objective – direct flux procedure

A new lighting design procedure is proposed based on how lighting influences the appearance of indoor spaces and their contents. Exitance is the measure of the density of luminous flux (lm/m2) exiting, or emerging from, a surface, and provides an effective basis for relating the quantity and distribution of lighting to peoples' assessments of its visual effects. The procedure guides users from identifying selected lighting design objectives relating to how peoples' assessments of appearance are affected by lighting, to developing a specification for the direct flux distribution that will optimally achieve those objectives. Applications can range from basic to complex. A selection of previously published lighting concepts is reviewed in the light of recently published research, and based on these concepts, the procedure takes the form of a downloadable spreadsheet that enables users to prioritise between efficient flux utilisation and achievement of design-oriented objectives. While it is recognised that more research is needed before the procedure could be adopted for general application, the aim of this paper is to demonstrate the opportunities offered by a practical alternative to current lighting practice.