Observations and retrofitting simulations of schoolrooms in Strasbourg (France): towards reducing heat stress and air pollution for children?

The thermoregulatory and cognitive abilities of schoolchildren can be severely impaired during extreme heat events, especially in cities where urban factors tend to increase outdoor/indoor air temperatures and air pollution. Current standards for building ergonomics do not usually address the specific indoor environment of schools and the schoolchildren population. Multiple exposures are also rarely studied and require comprehensive integrative assessment methods. This contribution presents the results of a one-year-long operational research project performed in a public primary school in Strasbourg metropolis (France, VESPA project). The research project combined a two-month intensive field observation campaign of indoor human heat stress, heat perception, and air quality with a system of numerical energy balance models from urban to indoor building scales for testing different retrofit strategies on the combined exposure.

 

Heat stress and air pollution intensities were qualified using 4 heat stress indices (PMV, operative temperature, heat index, WBGT) and 3 indoor air pollutant concentrations (PM2.5, VOC, CO2). These, coupled with children’s heat perception, allowed the calibration of children's sensitivity to heat and pollution compared to adults. The chosen multiscale modeling system is based on the urbanised mesoscale WRF/BEP+BEM model and the EnergyPlus©/Contam©/INCA-Indoor© computation engine, which were coupled offline. The retrofit scenarios (e.g. green roofs, mechanical ventilation system modifications) were designed in collaboration with the city stakeholders of the city of Strasbourg. They were tested under current (June-July 2024) and near-future climate conditions (August 2003 heatwave as analog).