Prospects of Improving the Indoor Air Quality in Classrooms by Reactivating Historic Ventilation Stacks

Stack ventilation systems were installed in German schools constructed around 1900 and are no longer in operation. The aim of this study was to show how reactivating these systems could improve the indoor air quality in classrooms. Ventilation stacks were reactivated in three classrooms in a school while a fourth classroom, which was naturally ventilated via openable windows, served as the reference case. All classrooms were measured for carbon dioxide levels, air temperature and relative humidity.