ABSTRACT
The optical properties of shading devices have an impact upon the daylighting and thermal performance of a building’s perimeter spaces. This chapter presents an overview of past and current approaches in computing the optical properties of shading devices. Optical properties are determined by the different components of visible and solar transmittance, reflectance and absorptance. Emphasis is given to the three major types of shading used today: venetian blinds, roller shades/screens and draperies. Comparisons between experimental procedures and analytical and numerical modelling techniques are presented, and limitations in existing models and standards are discussed. The final section describes the latest generalized methods and models for characterizing complex fenestration/shading systems.
