Smart Envelope for Nearly Zero Energy Schools. The Case Study of Vallisneri Secondary School in Lucca

摘要

The research SE*NZES analyses the evolution of smart facade systems in the area of design and industrial production, in order to investigate the technological, functional and qualitative standards of dynamic facades and to evaluate the energy performance of the school building envelope as a dynamic system that interacts with the indoor and outdoor environment. The study focuses on dynamic envelopes for the refurbishment of the school buildings, analysing the evolution of facade systems in terms of building construction, energy and structural performance and durability. The research project has been developed with the aim of spreading the research topics identified by Cordis and European Directives 2010/31 and 2013/27, developing a smart facade system, achieving the reduction of the energy requirement in the building sector by 2020 and realizing zero energy public buildings. The refurbishment of the existing school building stock requires ground-breaking strategies in order to meet targets for improved indoor comfort in the classrooms and to reduce energy use and greenhouse gas emissions. One of the most important components to be addressed with an innovative approach is the building envelope, which has to develop into an active rather than a passive element, fulfilling more functions than just the separation of the outer space from the interior with insulation. The concept of the adaptable envelope is twofold. On the one hand, it has been designed to accommodate further modifications (such as future renovation or technology upgrades). On the other hand, the envelope is able to adapt to a dynamic and intricate environment by measuring and processing multisource information (e.g. outdoor and indoor environment conditions, occupancy, behaviour of users and envelope performance) in order to respond to the building occupant's instructions and evolving environmental conditions at an appropriate time and to an appropriate extent. The main topic of research has been to develop an innovative and smart facade system that will be possible to integrate in the retrofitting of existing school buildings. In this smart envelope, it will be possible to integrate (1) Advanced materials or technologies for energy generation and storage; (2) Smart and performance insulation materials; (3) Reflecting materials and cool coatings; (4) Adaptable innovative precast solutions; (5) Materials with enhanced acoustic properties; (6) Materials with improved fire resistance; (7) Automated blinds or movable sun barriers with interrelated issues of summer overheating, air-tightness and natural light use; (8) Innovative sensing systems to control and optimize the real-time performance of the envelope. In this chapter, we introduce the characteristics of smart facade for school buildings, analysing the technological solutions and the energy performance to reduce energy needs of this type of building. We will be observing, in particular, the case study of the refurbishment of one school building: the "Vallisneri Secondary School in Lucca", where we have designed and built an innovative facade system. The project focused on the adoption of a precast facade in order to control solar radiation in summer and heat loss in winter, reduce the heat losses between the opaque envelopes and increase the natural ventilation inside the school building.