A COMPARISON OF SIMULATIONS, PHYSICAL MODELS, AND A FULL-SCALE PROTOTYPE IN PREDICTING DAYLIGHTING PERFORMANCE OF A COMPLEX SPACE

摘要

This report compares methods of predicting daylighting in a prototype 900 square foot (84 m2) classroom designed to be fully daylit for 95% of occupied hours. Because of the classroom's complex geometry, multiple methods of evaluation were used, each with distinct advantages and disadvantages. The daylighting tools addressed in this report include rule-of-thumb formulas, scale models, the BRS protractor, and a full-scale prototype.1 Rule-of-thumb formulas are quick, but cannot predict light distribution. Scale models allow an entire space to be analyzed, but are subject to measurement inaccuracies, cannot employ actual materials, and do not necessarily reveal specific causes of testing results. The BRS protractor method permits the analysis of the sky component of any particular point, but it is cumbersome for multiple points and difficult to apply to points that are not orthogonal to the aperture. A full-scale prototype of the space was built, permitting complete analysis of daylighting, including the use of actual materials, the integration of electric lights, performance in changing sky conditions, and spatial perception. Predicted daylight factor values were generally within 1.0 daylight factors of the baseline value measured in the prototype space The prototype had more variation in daylight distribution than predicted by other methods.