Light use patterns in Portuguese school buildings: User comfort perception, behaviour and impacts on energy consumption

Abstract

In schools, light use has been consistently highlighted as a crucial factor in the performance of school buildings; the visual comfort is connected with the students' performance and artificial light is a main source of energy consumption in the case of moderate climates. Resulting from a year-long post observational study conducted at schools, this article explains the current situation regarding light-use management in Portuguese secondary school buildings, from the point of view of their facilities, user behaviour and its impacts on energy use patterns. Both natural and artificial light-use patterns are considered. Although the classroom is still the functional space where students and teachers spend most of their time, new educational paradigms also require attention to be paid to other functional spaces where informal learning takes place. The study expands knowledge about light use and management in school buildings, by linking energy use patterns to user behaviour and addressing several functional areas within the school's premises. Results showed that various factors and criteria influence behaviour patterns in different functional spaces. The main trigger factors identified in the case of user behaviour in schools were classified and grouped according to their motivational grounds. Besides users' visual comfort parameters and functional needs, light use in schools is also strongly influenced by organisational habits. The study led to the development of more environmentally sustainable design and management strategies in school buildings. Light metering revealed that favourable conditions exist for making natural light the main light source at schools. Results also showed that improvements in the design and management of circulation areas could lead to significant reductions in artificial light (and energy) use.