Advanced Optical Materials for Daylighting in Office Buildings

The use of daylighting to supplant electric light in office buildings offers substantial energy savings and peak electrical demand reductions. The benefits from electric lighting reductions can, however, be easily offset by increased cooling loads if solar gains are not controlled. The use of advanced glazing materials having optical switching properties can facilitate solar control and, with proper design, maximize energy and cost benefits. The potential net annual performance of these materials, based on simulation studies using DOE-2.1C, are discussed in this paper. Actively and passively controlled response functions are analyzed for the cooling-load-dominated climate of Lake Charles. The effects of advanced materials on net annual energy consumption, peak electrical demand, and chiller size are compared with those of conventional materials. The results demonstrate the importance of operable solar control to achieve energy-effective daylighting design. Advanced optical materials that provide the necessary level of control are shown to minimize peak electrical demand and electricity consumption.