Integrative Lighting in Classrooms: Preliminary Results from Simulations and Field Measurements

The paper presents results from a study on integrative lighting in real middle school classrooms located in a school building in Turin, Italy. The contribution of both daylighting and electric lighting was considered. Besides the existing configuration of electric lighting systems (fluorescent luminaires), a set of six possible retrofitting solutions was considered, all using LED luminaires. The research addressed two main objectives: (i) To verify if the circadian values (melanopic equivalent daylight illuminance m-EDI) in the classrooms could meet the recommended values reported in recent literature, for instance, in the WELL protocol, (ii) to assess the influence on integrative lighting (photopic and melanopic illuminances) played by the electric lighting, as a function of the different lighting systems, and by daylighting, as a function of different room orientations and sky conditions. Results showed that the existing spaces benefit from high daylighting amount, whilst the existing lighting systems provide an insufficient m-EDI. Even when last-generation LED lighting systems were ideally used for retrofitting, no solution was able to meet the three-point WELL recommendation, while two solutions only allowed the one-point recommendation to be met. Some design implications concerned with the results were critically discussed.