A Comparison Among Three Whole-Building Dynamic Simulation Software and their Applicability to the Indoor Climate Modelling of Historical Buildings

Building energy simulations are important for assessing the performance of buildings and for designing solutions aimed at reducing energy consumption and carbon emissions. Many software tools perform these simulations, focusing on systems operations and energy losses and gains. When it comes to modelling historical buildings, the simulations could be also used to estimate the risk of damage and decay processes. This paper presents preliminary results based on twelve standardised exercises of increasing complexity for the comparison of microclimate simulations modelled through three whole-building hygrothermal dynamic simulation (BDS) software tools, specifically IDA ICE, WUFI PLUS and ENERGY PLUS. Different to the testing procedures already available, this research focused on the physical variables that are relevant for conservation of historical buildings (i.e., temperature (T) and relative humidity (RH)). Starting from Common Exercise 0 (CE0), seven simulations were customised to capture differences in T values. Then, five building models were specifically conceived to consider some typical features of Historical Buildings (HB0): small window size, heavyweight structures, low insulation of roofs, large volume and free-floating conditions. In the case of CE0, good agreement was found in the simulation of indoor T. In addition, detailed windows reduced the discrepancy in T results compared with the use of simplified windows. In the case of HB0, small windows slightly affected the microclimate simulations regardless of the number of transparent elements and their position. RH variability was driven only by T, as the partial water vapor pressure was affected only by infiltrations through the building. To conclude, the comparison allowed a highlighting of some critical points due to different model implementations, such as weather file timestamp interpretation, window models or irradiation calculations. HB0 models could be used for software and model comparisons, new software testing and training activities.