Many ancient libraries in Italy are housed in historical buildings, only a few in former churches and monasteries. Newly built libraries mostly comply with the requirements of sustainability, energy saving and renewable energy use, but this does not occur for existing ones, especially when they belong to the historical cultural heritage. Historical library buildings have good mass and thermal inertia but often have inadequate windows with low light transmission value. Lighting systems are often without control and thus cause poor lighting conditions. Our present research concerns the energy sustainability assessment of retrofit operations for lighting in an existing historical university library, focusing on lighting quality, adequate lighting conditions for visual tasks, vision ergonomics and well-being, and guaranteeing the preventive conservation and protection of heritage books. This case study is very particular, because it concerns a Florentine historical monastery which is now a university library. Our proposed method introduces an optimal toolset for lighting design solutions with the aim of sustainability. The library indoor space was procedurally decomposed into illumination volumes according to different occupant activities and visual tasks and different use areas. This method is extensible to all similar cultural heritage case, but also existing old buildings and current designs. Sustainability 2019, 11, 3145 2 of 17Today, libraries are conceived and designed as spaces that are more virtual than physical, whether they are part of recovery and retrofitting interventions or new projects: their use, reading and research practices have been transformed and, at the same time, almost all the users have replaced notebooks with laptops, occupying a larger reading station than in the past; while at the PC station, it is also possible to consult a wide variety of texts necessary for study and research. Nowadays, libraries are also an integrated service system.Of all the libraries in Italy, approximately 50% are subjected to certain limits and over 90% are grade listed [7][8][9]. Most of them were built prior to 1930. Almost all of them are totally inefficient from energy and environmental points of view [7][8][9]. Several European programs have highlighted and aimed at integrating the recommendations of the Efficiency Performance Building Directives, EPBD and EPBD2 [10,11], European Committee for Standardization (French: Comité Européèn de Normalisation, CEN [12]), then of CEN TC 346 [13] and of the EnerPHit Certified Retrofit (PHI) in historic buildings [14]. The guidelines of the Ministry of Cultural Heritage and Activities (in Italian: Ministero per i Beni e le Attività Culturali, MiBAC) on the energy efficiency of the historical heritage are very important and decisive [15]. There are significant examples of recent European projects in the field of the redevelopment of historic buildings, which were designed and financed for the application of the aforementioned directives, such as the 2009 European project...

Abstract:The aim of our research is to investigate the physical connection between light, perception, and information by means of an integrated methodological approach. The proposed method was used for sustainable lighting design aiming at light efficacy and quality, visual perception, communication, and energy saving. Three types of synergic measurement were carried out: photometric, colourimetric, and perception measurements. Starting from the results and the post-processing of photometric and colourimetric measurements on different light sources and fresco surfaces, by applying the eye-tracking technique for eye movement analysis of a people sample, entropy calculations were carried out. The results of observer perception and preferences, patterns of their visual scanning due to different LED (Light Emitting Diode) sources, were quantified by means of Shannon entropy calculation and, consequently, the information content of images that each light source can transmit. A new lighting proposal, based on the use of LED sources characterized by a spectral emission of light in strong compliance with surface colour and relevant transmission image content information was suggested and checked by transient simulations. Our proposal was based on sustainability because this concept is linked to developing perception and visual wellbeing, information, light communication, and lower energy consumption for maintenance, but especially for preventive conservation and the protection of works of art by means quality of light.

Our present research, starting from a previous study, aimed to define a methodological approach for sustainable lighting designs in a historical library, focusing on lighting quality, mainly obtained from the optimal use of natural light and its combination with the artificial one. A historical Florentine monastery, which is now a university library, was used as a pilot project. The proposed method forms an essential part of widening and deepening the recent study. Results have shown that this method will allow for adaptive lighting, based on the optimal control and use of natural light, historical–philological re-reading of the space, cultural heritage preventive protection and conservation, with the aim of building adaptive reuse, and it can be extended to similar cultural heritage cases, but also non-listed buildings and current designs. This research demonstrates how a correct natural lighting design can be a tool for sustainable refurbishment, guaranteeing cultural heritage conservation and preventive protection, and recovery of the historical, architectural and philological value of old and/or listed buildings, which have been converted to uses, often diametrically opposed to the original ones.

No abstract

This research provides an integrated methodological approach based on the combined use of spatial syntax modelling and eyetracker analysis techniques for lighting sustainability aimed to adaptive reuse of all the spaces with high historical, architectural, philological value of Cultural Heritage (CH). MosLESS (Modelling Sustainable Lighting with Eyetracker and Spatial Syntax techniques) is the proposed method, that can suggest fundamental guidelines for dynamic and static lighting in the museographic and museological areas, but also for reuse, conservation and enhancement of historical and CH buildings integrated with efficient energy management and conservation and protection needs. The National Museum of San Matteo in Pisa (Italy) was the pilot project. Particular environments were chosen for the experimental measurement campaigns carried out to assess dynamic and static visual fields, vision and perception. Methodological approach and results can be useful tools for exhibition planning with important energy, social and cultural effects. A further objective of the research will be to facilitate cultural exchanges, communication and new procedures for the digital management of the transmission or modification of museographic and exhibition projects, up to relations with public clients, as well as integrated management of information and decision-making processes.