Case Studies: Natural Light in Interior Spaces
After having discussed in the previous chapters the non-image forming (NIF) effects of light and the methods currently available to evaluate these effects, this chapter deals with a topic of central importance for the book. Having established that natural light is the best light for a correct timing of the human circadian cycle, with all the benefits that derive from it, this chapter explores the question if the real availability of natural light, for people who live and work in interior spaces, is adequate for a correct timing of the circadian cycle as it happens outside. This topic is developed in three contexts of interior design: office spaces, residential areas and training facilities. The question is analysed based on studies conducted at the Politecnico di Milano, placing them in relation with those carried out by other research groups. We also present the survey methods used, to then conclude that only in particular cases, unfortunately limited, the natural light present in interior spaces is able to correctly stimulate the human circadian system. This therefore leads to the consideration that artificial lighting in interior spaces could have NIF effects in the daylight hours, compensating for the lack of natural light.
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