Evaluation of shading devices using a hybrid dynamic lighting thermal model

The thermal modelling of windows is often carried out at a high level of precision whilst irradiance anddaylight quantities are predicted using coarse approximations. This paper describes a new approach to predict the daylighting and thermal performance of buildings with shading devices using a hybrid dynamic lighting-thermal model. Irradiation and daylighting modelling is carried out using the validated Radiance lighting simulation program. The irradiance predictions coming from raytracing calculations on virtual photocells provide input to a simplified thermal response model. The new technique is applied to the problem of evaluating shading devices in terms of overall energy and visual comfort performance for multiple climate zones.