Reflectance distributions and atrium daylight levels: a model study

In this study parametric changes were made to the distribution of reflectances of diffuse surfaces in the well of a square atrium model that was placed inside an artificial sky. The effects of these changes on the daylight levels at the centre, edge and comer of the floor of the atrium model were investigated. The reflectance distribution variability was created by painting the atrium surfaces with alternating bands of white and black horizontal stripes Although the widths of the bands were altered for each experiment, the overall 50-50 split of white to black wall surface area was held constant. The influence of adding specular surfaces to the atrium was also examined. It was concluded from the study that atrium surfaces with wide bands of different reflectance values did affect the daylight levels at the base of the atrium. However, if these bands were narrow, the daylight levels were not significantly altered by different reflectance distributions.