Comparison of overheating risk in nearly zero-energy dwelling based on three different overheating calculation methods

This study aims to inform building designers about overheating risks in nearly zero-energy dwelling and the importance of calculation methods. Three overheating risk indicators are selected and compared, comprising 1) the EPBD overheating indicator, 2) the Passive House overheating indicator, and 3) the ambient warmness degree and indoor overheating degree indicators developed by Hamdy et al. (2017) (Hamdy et al., 2017a). The third overheating calculation method represents the latest state-of-the-art method for overheating assessment. With the help of the EnergyPlus energy modeling program, a calibrated building energy model was created. Annual simulations took place for a typical meteorological year comparing overheating risk according to three calculation approaches. Results confirm a 216% difference in the overheated hours between the Energy Performance of Buildings Directive (EPBD) method and the used method of Hamdy et al. 2017. Results emphasize the need to improve the Belgian EPBD calculation method and integrate long-term thermal discomfort indicators to represent climate change and overheating risks in dwellings. Key Innovations  Overheating risk estimation is calculated based on three different calculation methods, and results are compared  One of the overheating calculation method takes into account future climate change scenarios and applies long-term thermal comfort evaluation indicators  The findings urge the call for a new standardised wat to calculate overheating within the EU Energy Performance of Buildings Directive (EPBD) Practical Implications This paper provides a basis to integrate a new overheating calculation method in the EPBD tools in Belgium and other EU member states.