Speedup Potential of Climate-Based Daylight Modelling on GPUs

Architects must consider an entire year's worth of solar positions and climate data to design buildings with adequate daylight and minimal glare. However, annual simulations are time-consuming and computationally expensive, which makes them difficult to integrate into iterative design processes. In this paper, we compare the performance of several RADIANCE-based dynamic daylighting simulation methods, DAYSIM and the threeand five-phase methods and, perhaps more importantly, the potential to speed them up using parallel implementations on graphic processors. Using a model of a generic office, we achieve speedups of ten times with DAYSIM and twenty-five times with the five-phase method. Parallel implementations of threeand five-phase methods provide better scaling to multi-GPU environments and more accurate results for complex fenestration systems than parallelized DAYSIM.