Genetic Optimization of External Fixed Shading Devices

Marco Manzan (University of Trieste)

CHALLENGE - The constant increase in summer energy consumption due to building air conditioning requires energy saving strategies in order to guarantee both healthy conditions and low environmental impact. This is true especially for buildings with extensive glazed areas in the Mediterranean region with high cooling loads because of solar irradiance. In this paper, the multiple aspects of lowering energy consumption are explored by using genetic optimization techniques.

SOLUTION - Optimization of an external shading device has been performed with the goal of minimizing the overall primary energy consumption in an office room with a south-facing window. The coupling of a shading device (a flat panel set parallel to the window and inclined by its horizontal axis) with different glazing systems have been analyzed for two climatic conditions in the Italian cities of Trieste and Rome. The two systems are one standard double glass and a high performance glazing system specifically designed to prevent high sun loads. Simulations have been performed using the energy code ESP-r and daylight simulation software, DaySim. The optimization loop has been driven by the software tool modeFRONTIER

BENEFITS -  The coupling of modeFRONTIER with DaySim proved beneficial for reaching optimal results. For each configuration a different solution was found, with a reduction of primary energy consumption of up to 19% for Trieste and 30% for Rome with respect to the unshaded window. Results show that the impact of shading devices on energy should always consider the electrical energy absorbed by the lighting system since this load affects both heating and cooling loads.