Exploring the potential of combining diffuse ceiling and double-skin facade for school renovations

With the aim to offer an alternative renovation concept for schools and thus contribute to a better indoor environmental quality and reduced energy consumption, a system combining diffuse ceiling and double-skin facade with an existing exhaust ventilation (I-DIFFER) was proposed in a previous work by the authors. The initial analyses of the novel system were promising, showing a potential 11% reduction in primary energy consumption compared to a traditional renovation where the facade was insulated, windows were replaced and a balanced ventilation system was installed. Consequently, this work further investigates the performance of I-DIFFER under different boundary conditions using BPS. The influence of orientation, thermal mass and reflectance of the existing classroom facade, future climate change, extreme weather conditions, and varying occupant densities are studied. The results show that I-DIFFER can compete with the traditional renovation approach for all investigated orientations but north and leads to superior results for southern orientations (SE, S, SW). It was found that a high thermal mass facade with low reflectance is favourable for the classroom facade. For forecasted future climate conditions and climates with mild winters and mild to hot summers, I-DIFFER showed superior results compared to the traditional renovation. An equal performance was seen for a varying occupant density. With this study, I-DIFFER can be confirmed as a competitive alternative to a traditional renovation and thus contributes to improving not only the energy efficiency but also the IEQ of schools.