Differentiating responses of weather files and local climate change to explain variations in building thermal-energy performance simulations

Many climate datasets are currently available for predicting buildings’ thermal-energy performance indynamic simulation environment. The most used weather files are the Typical Meteorological Year(TMY) and Test Reference Year (TRY). The purpose of this research is to experimentally highlight the needfor a frequent update of such weather files used when predicting buildings performance in urban areas inorder to include microclimate phenomena such as UHI and temperature extremities. To this aim, a sta-tistical comparison between the data collected by two urban weather stations in central Italy and thedata from the TMY and TRY weather files of the same area is carried out. The results highlight a summerUHI of 5.5°C and3.5°C in the late afternoon and early morning, respectively. Additionally, the compar-ison of TMY and TRY data with those ones collected by the urban stations shows non-negligible seasonaldiscrepancies in terms of the main microclimate monitored parameters, i.e. dry bulb temperature, rela-tive humidity, solar radiation, and wind. Such inconsistencies question the reliability of traditionalweather files to be used in building dynamic simulations to accurately estimate needs and productionwithin the city energy grid