• Energy Research

In the contemporary age, museums are dealing with unexpected challenges, related to the transformation of social structures, educative methods and cultural diffusion. The conversion of heritage buildings into exhibition halls and the renovation of existent exhibits involve a series of environmental risks and preservation issues. The study aims to demonstrate that conservation and human comfort are mutually compatible, when based on rational planning, interdisciplinary cooperation, and extensive knowledge of the features of buildings and collections. This study carries out an operative strategy for assessing and managing the environmental risks in museum buildings. To validate its suitability, it is applied to the Pinacoteca di Brera in Milan (Italy), an old palace completely reshaped in the 20th century following the typical design concepts of the “Modern Movement of Architecture” (e.g., rational planning, use of innovative technologies and materials, profusion of natural light integrated with artificial lighting, etc.). Several solutions adopted in these years caused both heritage decay and human discomfort. In addition, the insertion of new functions required a complete modification of the original design project. For this reason, the proposed tool supports the environmental risk management connected with these transformations, also defining clear maintenance guidelines, and planning low-engineering and low-impact solutions to satisfy, in a practical way, the daily needs of conservators, heritage authorities and designers. Furthermore, technical skills and the awareness of museum staff has been improved.

Energy flexibility in buildings is gaining momentum with the introduction of new European directives that enable buildings to manage their own energy demand and production, by storing, consuming or selling electricity according to their need. The transition towards a low-carbon energy system, through the promotion of on-site energy production and enhancement of self-consumption, can be supported by building-integrated photovoltaics (BIPV) technologies. This paper investigates the aesthetic and technological integration of hidden coloured PV modules in architecturally sensitive areas that seem to be the best possibility to favour a balance between conservation and energy issues. First, a multidisciplinary methodology for evaluating the aesthetic and technical integration of PV systems in architecturally sensitive area is proposed, referring to the technologies available on the market. Second, the experimental characterisation of the technical performance specific BIPV modules and their comparison with standard modules under standard weather condition are analysed, with the aim of acquiring useful data for comparing the modules’ integration properties and performance. For this purpose, new testbeds have been set up to investigate the aesthetic integration and the energy performances of innovative BIPV products. The paper describes the analyses carried out to define the final configuration of these experimental testbeds. Finally, the experimental characterisation at standard test conditions of two coloured BIPV modules is presented and the experimental design for the outdoor testing is outlined.

When deciding on the best historic building retrofit, energy savings and thermal comfort can be quantitatively evaluated using an energy model, whereas conservation compatibility is intrinsically qualitative and reflects the perspective of the local heritage authority. We present a methodology that permits finding and comparing optimal retrofits for historic buildings in a multi-perspective and quantitative way. We use an analytic hierarchy process to quantify conservation compatibility by distilling a conservation score from the opinions of 10 experts in the field. This score, along with energy needs for heating and cooling and thermal comfort, are the three targets of a multi-objective optimization aimed at identifying optimal retrofits for a medieval building in the north of Italy, destined to become a museum. Retrofit measures considered were different kinds of external and internal envelope insulation, improvement of airtightness, replacement of windows, and ventilative cooling. The result is a portfolio of optimal retrofits that cover the whole range of conservation compatibility. We show that in the analyzed case heritage preservation is compatible with a four-fold reduction in energy needs at a high thermal comfort level. Even higher energy savings are only achievable at the cost of heritage degradation.

Abstract The paper presents the results of an on-site survey on several historic brick masonries with different heritage values, historical ages, and internal functions. The experimental data have been compared with the results of the standard procedures normally used in Italy for assessing the thermo-physical behavior of traditional walls, in order to provide a guidance for energy audit, simulation, and labelling of historic buildings. The research methodology is based on the following steps: (i) selection of traditional building masonries; (ii) interdisciplinary assessment for materials characterization; (iii) thermal performance evaluation using different standard procedures suggested by the Italian legislation framework; (iv) comparison between the results; and (v) final performances assessment. Compared with the experimental measurements, standard and analytical procedures tend to overestimate the thermal performance of historic brick masonries. There is a correspondence between the historical ages and the λ-value of bricks. The bricks manufactured by pre-industrial techniques have lower densities than the industrial ones. This is due to the artisanship of clay, which caused the presence of sand, raw materials, and air, improving their thermal performance.

The hygrothermal behaviour of an internally insulated historic wall is still hard to predict, mainly because the physical characteristics of the materials composing the historic wall are unknown. In this study, the hygrothermal assessment of an internally thermal insulated masonry wall of an historic palace located in Ferrara, in Italy, is shown. In situ non-destructive monitoring method is combined with a hygrothermal simulation tool, aiming to better analyse and discuss future refurbishment scenarios. In this context, the original U-value of the wall (not refurbished) is decreased from 1.44 W/m2K to 0.26 W/m2K (10 cm stone wool). Under the site specific conditions of this wall, not reached by the sun or rain, it was verified that even in the absence of vapour barrier, no frost damage is likely to occur and the condensation risk is very limited. Authors proposed further discussion based on simulation. The results showed that the introduction of a second gypsum board to the studied technology compensated such absence, while the reduction of the insulation material thickness provides a reduction of RH peaks in the interstitial area by 1%; this second solution proved to be more efficient, providing a 3% RH reduction and the avoidance of further thermal losses.

Research and development of cost-effective, high-performance thermal insulation materials for the construction sector has to be focused on their final application. In particular, solutions for refurbishing historic buildings, which represent 40% of the European building stock, have to offer a good compromise between environmental quality, energy efficiency and conservation aspects. In this paper, the experimental assessment of an insulation material based on aerogel technology, recently developed in the European project EFFESUS, is presented with regard to the material's thermal performance, compatibility with historic fabric and reversibility. The overall results obtained in laboratory testing on a real-size mock-up and in a real-world case application indicate that the new material is a promising solution for retrofitting historic buildings, thanks to its thermal properties, easy application, reversibility and material compatibility.