CIE x048-PO38 PDF

The paper presents a registration of occupancy and the use of (day)light in four buildings representing respectively offices, primary schools, universities, and industry buildings; it was done across Europe in 2020. A self-registration method was used, assisted with light technical measurements outdoors and indoors. In general, occupants consider the visual environment at the workplace when they are coming in or out of the room. It happens mainly at the beginning (adjustment of blinds and switching light on) and at the end of the working day (switching light off). In the primary school building, where users move in-out many times during the day, the adjustment happens more frequently. Also use of projector generates very low general light level; covering windows and switching off the electric light happens accordingly, but the pattern is not consistent. In general, the changes in the electrical lighting use follow the occupancy pattern, not the light levels.