Urban climate - Impact on energy consumption and thermal comfort of buildings

Climate change and the urban heat effect is expected to have a large influence on the energy consumption and thermal comfort of buildings. However, using meteorological data which incorporates effects of climate change and characteristics of cities is not currently a standard practice in building simulation. By default, Typical Meteorological Years (TMY) based on 20-year meteorological statistics from nearby meteorological stations often outside cities are used. This may lead to important discrepancies between simulation results and actual energy consumption and/or indoor climate data for buildings in urban areas. These effects are analyzed within Building energy part of H2020 climate-fit. city project. First, adapted urban and future meteorological data modelled using the VITO UrbClim model and standard meteorological data were compared. Second, these data were included within the Meteonorm software. In a first phase, this was carried out for the cities of Bern and Vienna. In the future, this data will be included for other urban areas in Europe. In a third step the urbanized TMY data sets generated by Meteonorm were used to simulate energy consumption and indoor climate conditions with models of three typical buildings. The whole-year simulation runs were made in series for several urban locations and -as a reference scenario -with the standard TMY. First results show that meteorological data are modelled generally well; however at some sites differences are statistically significant. In some locations Meteonorm based data show lower discrepancies, in some the ERAInterim /Urbclim model based. The differences regarding building energy needs are relatively low. Heating energy consumption is 6% lower within cities and cooling energy 15% higher. The hours outside comfort levels within cities are higher, however only to a small extent. Currently, only results from Bern and Vienna have been analysed. For other cities in other climate regions, the results and conclusions may be different. Climate-fit. city is a EU project within the framework of Horizon 2020