Analysis of the main anthropogenic sources’ contribution to pollutant emissions in the lazio region, italy

Most cities worldwide suffer from serious air-quality problems, which have received increasing attention in the past decade. The most probable reason for the air-quality problems is the urban population growth, combined with a change in land use due to increasing urban areas. The emission of air pollutants is caused by different anthropogenic processes which can be categorized into the sources of urban traffic, industry, and domestic heating. Dispersion and dilution of air pollutants are strongly influenced by meteorological conditions, especially by wind direction, wind speed, turbulence, and atmospheric stability. With an increasing number of people living in cities, there is the need to examine the correlation between air pollution, local climate, and the effects these changes have on global climate. New interdisciplinary research studies are needed to increase our understanding of the interactions among these aspects. The aim is to analyze the pollutant condition in Rome and the other provinces of the Lazio region with qualitative and quantitative analysis, in order to understand which are the main pollutant sources and what is the correlation of habits of the population on air pollutant emissions

How Cool Pavements and Green Roof Affect Building Energy Performances

The urban heat island effect amplifies the global warming phenomenon with sensible aftermaths on the building energy consumptions. The absence of green areas, open water channels as well as the lack of free unsurfaced spaces creates a sort of urban cap and a heat reflection effect, from the bottom upwards, which persists in the early hours of the night. This heating effect exacerbates the use of air conditioners which, if on one hand helps to cool houses, on the other hand rejects outside hot air hindering the cooling effect of nighttime air. The aim of this study is to analyze the effects of urban heat island mitigation techniques on the building energy performances, such as cool pavements and green roofs. Measured temperatures were used to calibrate a model of a densely populated district in Rome by means of ENVI-met software. It was subsequently carried out an energy analysis through the use of TRNSYS in order to study the energy behavior of a reference building in its urban context in function of the variation of the boundary conditions

Retroreflective materials for building's façades: Experimental characterization and numerical simulations

The urban heat island (UHI) is one of the most studied phenomenon in the last years. Its main effect is associated with the air temperature increase in the cities compared to the rural areas. In order to reduce the air temperature difference between urban and rural areas, several mitigation techniques have been studied. One of the solutions chosen to face the UHI phenomenon consist in the adoption of innovative building envelope materials. Among them, high reflective and cool materials represent a valid solution to achieve this objective. These materials are characterized by high solar reflectance (high ability to reflect solar incident radiation) and high thermal emittance (high ability to emit heat in the infrared wavelength). In the last years, the adoption of a new kind of materials, called retro-reflective materials (RR), used as building envelope coating, is spreading with the purpose of reducing both the façades solar loads and the amount of solar radiation entrapped within the urban fabric. Retro-reflective materials have a particular surface conformation that allows to reflect the solar radiation back in the same direction of the incident radiation. In this case the temperature of the surfaces inside an urban canyon, defined as the space between building that line up continuously on both sides of the street, should have lower values compared with the case with common construction materials. Consequently, also the air temperature inside the urban canyon have low values with significant advantages on outdoor thermal comfort and on building thermal energy demands. Usually, most of the building energy simulation tools consider construction material with a constant and perfectly diffusive solar reflectance. For this reason it is very hard to simulate retro-reflective materials behaviour, since they present an angular dependence of their optical-radiative response. In this work the directional dependence of solar reflectance of a retro-reflective sample material is investigated with the main purpose to assess its impact on façades solar loads and on the building thermal energy demands. The directional reflectance was measured with an experimental setup developed at Roma Tre University. A numerical analysis was subsequently carried out to evaluate the differences in surface solar loads and in thermal energy demands for three Italian cities during cooling and heating season

Urban Overheating Mitigation Strategies Opportunities: A Case Study of a Square in Rome (Italy)

It is well-known that the occurrence of urban heat islands (UHI) is related to climate change and urbanization. Urban locations experience local overheating throughout the summer, which is uncomfortable and it has a detrimental impact on buildings ability to consume energy. In this study, a methodology was developed to assess the urban heat island effect in a localized urban area and to evaluate the effects of different kind of mitigation strategies. The numerical model was developed using the ENVI_met tool and it was calibrated with weather data and albedo measured inside the examined area and near the simulated domain. The procedure adopted overtaking the limit of the software in reproducing accurate weather conditions without calibration. Finally, combination of extensive mitigation strategies (cool pavements, greenery, grass pavers) with local strategies (shading) were investigated. An experimental and numerical investigation of a square in Rome was exanimated to evaluate the possible solution for mitigating outdoor air temperatures. Results of the paper affirm that an intervention on the pavement albedo and the increase of vegetation inside the square, lead to an improvement of the air thermal conditions. In particular, the application of the grass pavers would lead to the greatest benefits. A maximum decrease in the air temperature of 1.2 °C was obtained through the application of cool material, while the reduction reaches up to 2.88 °C when a grass paver is applied. The improve of the vegetation can bring to a maximum decrease of 1.46 °C, while the use of shading projecting roof allows a reduction up to a maximum of 2.07 °C

Retrofit Analysis of a Historical Building in an Architectural Constrained Area: A Case Study in Rome, Italy

A significant portion of Europe’s historical buildings have significant potential for energy efficiency. Social policy is typically opposed to energy retrofits because it is concerned about damaging historical or cultural sites. Contrarily, there are several approaches to energy efficiency that may be used with historic structures while also retaining the region’s architectural constraints. The findings of this study demonstrate that historical structures, which are typically not targets of energy efficiency technology because of architectural constraints on the building or in the neighbourhood, may also achieve a meaningful decrease in energy usage and GHG emissions. The significant energy-saving capability of this type of building is emphasized in the historical structure taken into consideration. The historical building object of the present study was built in the beginning of the 1900s and it was selected by the Ministry of Culture for energy efficiency improvements

Effects of urban heat island mitigation strategies in an urban square: A numerical modelling and experimental investigation

It is generally recognized that both urbanization and climate change contribute to the emergence of urban heat islands (UHI). Urban areas frequently encounter summertime local overheating, which is stressful and negatively affects a building's systems capacity to maintain the indoor air temperature setpoint. UHI has sharply increased during the last 10 years as a result of shifting land use patterns, escalating urbanization, and declining plant and water supplies. The scientific community has recently paid a lot of attention to studies on UHI mitigation techniques, including those utilizing green roofs, cool materials, vegetation, and water supplies. In this work, a square in Rome was experimentally and numerically investigated to assess a potential remedy for reducing outdoor air temperatures. A calibrated numerical model was made using the ENVI met tool, and several types of mitigation scenarios were looked at in order to lessen the area's warming and analyze the impacts of the recommended remedies on decreasing air temperature. The study's findings show that changing the pavement's albedo and adding more vegetation inside the square enhance the thermal conditions of the air. The use of grass pavers, in particular, would provide the biggest advantages

School Roofs: Hubs of New Renewable Energy Communities

Large public infrastructures, such as school buildings, have the potential to serve as vital resources for surrounding communities by incorporating photovoltaic panels on their roofs. By harnessing solar power, a school roof can become an electrical power station operating daily, with minimal environmental or architectural impact. This innovative approach can supply renewable electricity to the local community, aligning with the concept of renewable energy communities (REC). This study delves into the case of a primary school in Rome, examining strategies to distribute the generated electricity to the surrounding community. Utilizing System Advisor Model (SAM), an energy simulation was conducted to assess the performance of the photovoltaic plant. The study then analysed the energy output from the photovoltaic system in relation to streetlights and household electricity consumption. The findings underscore the effectiveness of the photovoltaic plant and the numerous benefits it offers in terms of energy efficiency, cost savings, and environmental sustainability.