Paper Conference

Proceedings of Building Simulation 2011: 12th Conference of IBPSA


Variation Of Green Building Ratings Due To Variances In Sky Definitions

James Thompson, Michael Donn, Jacob Osborne

Abstract: This paper analyses the accuracy of a Uniform sky when used for calculating daylight illuminance levels in side-lit buildings. The results of using the Uniform sky are compared against results derived from models that represent real skies in a more accurate fashion using Radiance and 3DS Max® Design. The alternative sky models studied are the CIE (Commission Internationale de l’ Éclairage) Clear, CIE Overcast (Hopkinson et al, 1966) and Perez skies (Perez et al, 1993). The results indicated that when using a more accurate sky model there was a difference in illumination levels for each building. This difference ranged from -0.2% to 17.9% for the CIE skies and 7.8% – 30.5% difference when the Uniform sky is compared to the Perez sky.
Pages: 1832 - 1839