A Mesoscale-Microscale approach for the energy analysis of buildings

This work is aimed to suggest a numerical approach able to select the most useful building orientation with respect to the local wind in complex urban areas. It is showed a mesoscale-microscale numerical approach able to predict local flow patterns for building designers. The city of Ancona was selected to analyse wind patterns over complex orography in presence of buildings. The analysed area is characterized by a densely built hilly promontory flanked by a poorly urbanized valley. Two buildings were chosen to carry out energy analyses. At first, the MM5 weather prediction model is used to assess the wind patterns and the wind occurrence distribution. The 2010 year was simulated and compared with real data from a met-mast. After, computational fluid dynamic (CFD) analyses are conducted with and without the surrounding buildings to appreciate speed and inflow e˙ects. CFD results showed great changes in the examined building area. The final step was the energy simulation, by means of EnergyPlus, of two multistoried buildings equipped with a double skin façade; results show a great impact on the energy consumption by comparing a wrong orientation with respect to the best solution derived from the mesoscale-microscale approach.