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The current goal of the European Commission, which aims to reduce CO2 by 90% compared to values estimated in 1980, and the ever-increasing sensitivity to environmental sustainability, fully involve the construction sector, which, according to the OECD (Organization for Economic Co-Operation and Development) is responsible for over one-third of the world’s energy requirement. In this frame, numerous researchers and companies are focusing on ecologically sustainable building materials, to be used in new and existing buildings, that are able to simultaneously fulfill the constructive function and improve the energy behavior of the building envelope. The goal of the present paper is the analysis of the energy performance of some innovative locally produced natural building materials (timber, sheep wool, rammed earth, lime-based plaster, natural fibers) used in multilayer vertical closures, compared to that of more common building materials (bricks, concrete, synthetic insulation). First, the physical-mechanical characterization of the local natural materials was carried out, then the model of a building was implemented, whose energetic performance was simulated by varying the type of stratigraphy of the walls, including the use of both innovative and common materials. The building chosen for the simulation consists of one of the BESTEST ANSI/ASHRAE reported in the 140-2017 standard using the climatic data of the Mediterranean area. The results of the simulation have been presented and discussed.

Energy and water poverty are two main challenges of the modern world. Most developing and underdeveloped countries need more efficient electricity-producing sources to overcome the problem of potable water evaporation. At the same time, the traditional way to produce energy/electricity is also responsible for polluting the environment and damaging the ecosystem. Notably, many techniques have been used around the globe, such as a photovoltaic (PV) cooling (active, passive, and combined) process to reduce the working temperature of the PV panels (up to 60 °C) to improve the system efficiency. For floating photovoltaic (FPV), water cooling is mainly responsible for reducing the panel temperature to enhance the production capacity of the PV panels, while the system efficiency can increase up to around 30%. At the same time, due to the water surface covering, the water loss due to evaporation is also minimized, and the water evaporation could be minimized by up to 60% depending on the total area covered by the water surfaces. Therefore, it could be the right choice for generating clean and green energy, with dual positive effects. The first is to improve the efficiency of the PV panels to harness more energy and minimize water evaporation. This review article focuses mainly on various PV and FPV cooling methods and the use and advantages of FPV plants, particularly covering efficiency augmentation and reduction of water evaporation due to the installation of PV systems on the water bodies.

The building sector is known to have a significant environmental impact, considering that it is the largest contributor to global greenhouse gas emissions of around 36% and is also responsible for about 40% of global energy consumption. Of this, about 50% takes place during the building operational phase, while around 10–20% is consumed in materials manufacturing, transport and building construction, maintenance, and demolition. Increasing the necessity of reducing the environmental impact of buildings has led to enhancing not only the thermal performances of building materials, but also the environmental sustainability of their production chains and waste prevention. As a consequence, novel thermo-insulating building materials or products have been developed by using both locally produced natural and waste/recycled materials that are able to provide good thermal performances while also having a lower environmental impact. In this context, the aim of this work is to provide a detailed analysis for the thermal characterization of recycled materials for building insulation. To this end, the thermal behavior of different materials representing industrial residual or wastes collected or recycled using Sardinian zero-km locally available raw materials was investigated, namely: (1) plasters with recycled materials; (2) plasters with natural fibers; and (3) building insulation materials with natural fibers. Results indicate that the investigated materials were able to improve not only the energy performances but also the environmental comfort in both new and in existing buildings. In particular, plasters and mortars with recycled materials and with natural fibers showed, respectively, values of thermal conductivity (at 20 °C) lower than 0.475 and 0.272 W/(m⋅K), while that of building materials with natural fibers was always lower than 0.162 W/(m⋅K) with lower values for compounds with recycled materials (0.107 W/(m⋅K)). Further developments are underway to analyze the mechanical properties of these materials.

Airport activities can contribute to the emission of ultrafine particles (UFPs) in the environment. The aim of our study is to assess the airborne levels of UFPs in a military airport and in the surrounding area. Four outdoor air samplings were carried out inside a military airport during flight activities, twelve nearby the military airport, five in an urban area, and one in a rural area. We used a portable Electrical Low Pressure Impactor to detect the particle number size distribution as well as the number concentration. Particles were chemically analyzed by field emission scanning electron microscopy. Inside the military airport, we observed an inverse correlation with distance from flight activities. The median UFP count ranged 3.7 × 103 –2.9 × 104 particles/cm3, and the highest UFP count was 4.0 × 106 particles/cm3 (during the taxi and take-off activities). Nearby the airport, UFP number concentrations were more elevated in the winter season and we did not observe a correlation with flight activities. Our results show a constant presence of UFPs regardless of the flight activities nearby the airport. Other anthropic sources may generate UFP concentrations significantly higher than those generated by airport activities.