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Over the past few years, the Covid-19 pandemic has triggered an economic crisis, impacting various sectors including building construction. Within this sector, the residential section represents one of the main causes of energy consumption and pollutant emissions. To address this challenge the European Union has devised a strategic plan aimed at promoting energy efficiency and environmental sustainability, with a special focus on revitalizing the building sector. Within this strategic framework, the tax incentive Superbonus 110% introduced in 2020 has emerged as a pivotal program, incentivizing specific energy efficiency measures for existing buildings in alignment with the EU Directives. In this regard, this study aims to analyse the retrofit intervention of two existing residential buildings subsidized through the Superbonus 110% mechanism. A critical analysis of several passive and active energy efficiency measures is performed considering energy, environmental and economic indicators, employing a dynamic simulation approach. This work demonstrates how the proposed Italian funding program can enhance the diffusion of energy efficiency interventions. However, thanks to the analysis of real case studies, the criticalities and implications that such a mechanism has brought to the construction sector were highlighted, in the perspective of future incentives.

This paper proposes a novel radiative passive system for hot and dry climates to improve outdoor thermal comfort. The solution consists in a curtain, characterized by two different finishing surfaces, one is waterproof and the other one is absorbent, immersed in a water tank by means of a mechanized system and subsequently used as a radiant surface with reduced temperature thanks to evaporative cooling effect. The effectiveness of the proposed system is verified by means of CFD simulations carried out on a sample application in outdoor space and supported by experimental measurements carried out on a small sample of curtain. The results showed that the proposed system can reduce the operative temperature up to 6°C with respect to the testing conditions (air temperature of 28.5°C and relative humidity of 50.5%) ensuring higher comfort levels and a limited water consumption to keep the curtain constantly wet (25 l/h for 130m 2 of wet curtain). [ABSTRACT FROM AUTHOR]

Historic building heating and, in particular, church heating represents a challenging task because many objectives have to be reached simultaneously, such as occupants thermal comfort and optimal internal climate suitable for the preservation of fragile building components and artworks. Moreover, current requirements for sustainability impose to make efforts, where possible, to minimize the amount of energy needed and the consequent environmental impact. Innovative solutions are currently under research and development and are mainly based on electric radiant surfaces. The present work represents actually a detailed performance analysis of a novel hydronic high-efficiency pew-based heating system coupled with a ground-source heat pump. The system was specifically developed for the above-described application field, with particular reference to the Basilica di Collemaggio (L’Aquila, Italy), a church of worldwide relevance currently under restoration. In detail, within the work a three-dimensional CFD analysis of the heating solution was carried out considering as application field a virtual test room containing two benches with three virtual sitting manikins. Heat exchanges between the human body surfaces, the room environment and the heated benches were simulated in order to assess the whole performance. The results show that the air temperature in the room is not significantly influenced by the heating system, but the heat is directly radiated to people, ensuring comfortable conditions and contributing to artworks preservation. [ABSTRACT FROM AUTHOR]

Sustainable design strategies involve complex interactions among social, economic and environmental factors those should be analyzed and solved quite differently by heterogeneous disciplines and stakeholders involved. Focusing on the cities of developing countries in tropical regions, characterized by fast urban population growth and a staggering increase in the energy consumption for building sector, it emerges that appropriate active strategies and building energy optimizations are promptly recommended. For this purpose, in the present work, energy evaluations were carried out for the designing of a residential building in Nairobi, Kenya, considering different strategies and solutions, taking into account also the affordability and considering the possibility to push local based economies through the use of built-on-site materials. This strategy may lead to a significant cost reduction and energy saving due to lower construction costs and in addition also a lower embodied energy of the building materials. Furthermore, in a region understudy, characterized by unstable economic security, the employment of local labor forces may lead to the formation of local based economies. [ABSTRACT FROM AUTHOR]

The present work is aimed at assessing the energy performances of a multi-functional integrated system designed to cover the HVAC needs using renewable energy sources (RES), with a specific focus on residential buildings. In detail, within the system design, RES are represented by building integrated photovoltaics (BIPV) and aerothermal energy. The heating, cooling and DHW demand is in fact satisfied by a reversible and high efficiency air-water heat pump with continuous power modulation, optimized for the specific purpose, directly fed in direct current (DC) from the PV. The eventual surplus of PV production can be stored in form of thermal energy thanks to a dedicated storage system for providing heating, cooling or DHW production in the periods when there is no/low solar radiation. Moreover, the system is able to minimize the peak power demand of electricity, according to the match between PV electricity generation and usable/storable thermal energy demand. The results of the energy simulations on a case study residential building demonstrate the effectiveness of the proposed system towards nZEB standards. [ABSTRACT FROM AUTHOR]

Flat plate PVT water based technology presents many advantages in terms of overall performance and space saving than the PV modules and the solar thermal collectors installed separately. However, the electrical and the thermal performances of the PVT technologies are more deeply related to different influences factors, among which: the presence or absence of the air gap formed by the transparent frontal cover, the absorber configuration and the adopted PV technology. For that reasons, the proposed research is aimed to assess, under the energy point of view, a comparison between a covered and an uncovered PVT water collectors, realized with different PV cells coupled to two aluminium roll-bond absorbers characterized also by different channel arrangements. The performance analysis is based on energy simulations carried out with two mathematical models validated on experimental data at the Test Facility of the Politecnico di Milano. [ABSTRACT FROM AUTHOR]

The present work aims to experimentally analyze daylighting performances of the LSC- Smart Window developed by a joint R&D collaboration project between Eni (the largest Italian integrated energy company) and the Politecnico di Milano. The LSC- Smart Window , designed with the aim of enhancing the use of luminescent solar concentrators in the building sector, will be analyzed in an array of different configurations, realized with LSCs of different colors (specifically: red, orange and yellow) and compared to neutral PMMA plates. Our Smart Window represents an active element in the energy performance of a building, providing a multifunctional contribution in terms of energy saving through dynamic solar control and renewable energy production. A prototype of the Smart Window has been realized and installed in one of Eni's headquarter buildings for its accurate performance analysis. [ABSTRACT FROM AUTHOR]