Dynamic shading device model (simple): When the dynamic simple blinds model is used, a generic blind system is modeled that transmits 25% of diffuse daylight and no direct sunlight compared to the case when the blinds are retracted. In this shading mode the blinds down scenario is simply an extrapolation of the no blinds scenario. This very basic blinds model is usually sufficient for initial design considerations when time is more crucial than precision and the type of shading device is still unspecified