The simultaneous role of heat and light in optimizing north and south windows

Optimizing the window surface is very effective in saving energy. The natural light in the living room, a multi-purpose collective space, must meet the users’ different needs. This study aims to optimize the north and south windows’ surface in a residential building’s floors. Simulation steps have been done with simultaneous attention to thermal and lighting performance. For this purpose, window optimization based on parametric modeling has been done using Grass Hopper software to minimize thermal energy consumption with Energy Plus engine and lighting with Radiance and Daysim engine. Optimization operations have been performed for all available modes to minimize the thermal target function and maximize the lighting target function. The results show that the optimal window surface is different on each floor and face of the building. With the window optimization in the northern unit, the dynamic daylight index has increased from about 50% to more than 80%. The percentage of improvement of the dynamic light index in the southern unit floors has been between 2% to 9%. Based on results, designers can ensure optimal heating and lighting throughout the year in similar buildings while saving energy consumption.