This study aims to inform the building designers about hygrothermal exposure risks in nearly zero-energy schools and the importance of evaluating these risks during short-term extreme heat events. The hygrothermal exposure in the reference school was evaluated using a metric called heat index [°C], which calculates the level of hygrothermal risks using air temperature [°C] and relative humidity [%]. Using DesignBuilder, a calibrated nearly zero-energy school energy model was created by Attia et al. (2020a) and then simulated using EnergyPlus. The building model was simulated for a 7-day heat wave. The study results confirm that the reference nearly zeroenergy school from Brussels is highly susceptible to hygrothermal exposure with a risk level of caution for 98% of the occupied time during the heat wave. The study findings highlight the need to enhance the Belgian Energy Performance of Buildings Directive (EPBD) calculation methods and incorporate hygrothermal discomfort indicators to accurately depict the exposure risks due to the impacts of climate change.
Highlights• Investigated the hygrothermal risks in a reference school during heat waves. • The hygrothermal performance evaluation used a heat stress metric called heat index. • Study findings indicate a risk level of caution in the reference school during heat waves. • This can result in possible fatigue of students with physical activities and/or prolonged exposure.