Lighting performance of virtual natural lighting solutions with a simplified image in a reference office space

The objective of this study is to describe the approach of modelling VNLS and using the Radiance lighting simulation package to compare the lighting performance of various VNLS configurations in a defined reference office space. Prior to incorporating a realistic view component in the performance assessment, a simplified image is included in the simulation. The lighting performance is described in terms of the ability to meet the space availability demand, the illuminance uniformity on the workplane, and the ability to meet visual comfort demands, e.g. to produce minimal glare at predefined observer’s positions in the given space. Space availability is defined as "the percentage of workplane (at height of 0.75 m from the floor) meeting a certain minimum illuminance criteria". The building type discussed in this study is a reference office space with dimensions of 5.4 m × 3.6 m × 2.7 m (L×W×H). There are four vertical window configurations chosen from the earlier studies of Diepens et al (2000) and LBL (2010). Each window configuration is modelled with a simplified viewed image on its surface. No real windows are present in the modelled spaces.