Sustainable lighting for cultural heritage: a pilot study for evaluating the exhibits' display inside historical buildings.

Lighting cultural heritage is a complex task that requires considering the conservation needs of the exhibits and visitors' visual comfort. However, these needs are often in contrast. In addition, whenever the exhibitions are displayed inside historical buildings, the task further complicates, as lighting designers must face and respect the architectural character of the host building. They have two mean of work: static and dynamic analysis. The former uses the Daylight Factor (DF) while the latter requires a prolonged and expensive measurement campaign. Both analyses present advantages and shortcomings: the DF approach is easy and fast, but it implies many oversimplifications whereas the annual approach provides accurate results but is time and money-consuming. In this paper the authors analyse a case study with both methods. The case study is the Cetacea's Gallery of the Charterhouse of Calci (PI). The findings of this research demonstrate that the annual approach is preferable, despite its costs, and that the static approach should be used just for first instances analyses. The research pointed out the necessity of a standardized procedure of evaluation that would allow lighting designers to confront possible interventions and find the most adequate to solve the conservation and comfort issues of the case in exam.