Environmental Impact of Industrial Prefabricated Buildings: Carbon and Energy Footprint Analysis Based on an LCA Approach☆

Abstract The world-wide effort to reduce the environmental impact associated to the industrial sector is quickly producing an increasing feedback on national and international decision makers. In this context, the analysis of life-cycle based assessments on the main impact categories associated to the pre-production, production, assembly, use, and end-of- life phases represents a powerful tool towards a holistic interpretation of the footprint from industrial buildings. The Italian prefabricated building sector, characterized, on average, by local enterprises with regional coverage, has been investigated in order to study the Carbon and Energy Footprints. Data from a large company, running several facilities spread on the national territory, have been collected and analyzed in order to provide a parameterized evaluation of the GHG emission and the energy consumption associated to the single phases of the building life cycle as a function of the sensible design requirements. The quantification of the Carbon and the Energy footprint, associated to the prefabricated industrial building sector, is presented. The assessment procedure is performed through a parametric modeling of the building properties bases on the analysis of different sizes and designs. A detailed discussion of the outputs is presented, including the comparison of the environmental performance depending on different construction requirements

Combined thermal effect of cool roof and cool façade on a prototype building

Abstract Recently, huge efforts were made to develop new passive solutions for optimizing building summer thermal-energy behavior. While cool roofs are well investigated, a lack of knowledge is detected about the benefits deriving from the combination of cool roofs and cool facades. This work aims at determining the thermal performance of innovative cool roofing membrane and cool facade painting when applied on a prototype building, through continuous monitoring. Additionally, sensitivity analysis is performed to investigate the thermal benefits of the coupled solutions. Results showed that the combined solutions generate significant passive cooling in terms of indoor operative temperature reduction

Hybrid Vehicles as a Transition for Full E-Mobility Achievement in Positive Energy Districts: Comparative Assessment of Real-Driving Emissions

Air pollution is a major concern, particularly in developing countries. Road transport and mobile sources are considered the root causes of air pollutants. With the implementation of zero-carbon and zero-energy concepts at the district scale, cities can make great strides towards sustainable development. Urban planning schemes are moving from mere building solutions to the larger positive energy district (PED) scale. Alongside other technology systems in PEDs, increased uptake of electro-mobility solutions can play an important role in CO2 mitigation at the district level. This paper aims to quantify the exhaust emissions of six conventional and two fully hybrid vehicles using a portable emission measurement system (PEMS) in real driving conditions. The fuel consumption and exhaust pollutants of the conventional and hybrid vehicles were compared in four different urban and highway driving routes during autumn 2019 in Iran. The results showed that hybrid vehicles presented lower fuel consumption and produced relatively lower exhaust emissions. The conventional group’s fuel consumption (CO2 emissions) was 11%, 41% higher than that of the hy-brids. In addition, the hybrid vehicles showed much better fuel economy in urban routes, which is beneficial for PEDs. Micro-trip analysis showed that although conventional vehicles emitted more CO2 at lower speeds, the hybrids showed a lower amount of CO2. Moreover, in conventional vehi-cles, NOx emissions showed an increasing trend with vehicle speed, while no decisive trend was found for NOx emissions versus vehicle speed in hybrid vehicles

Assessing the Impact of Heat Mitigation Measures on Thermal Performance and Energy Demand at the Community Level: A Pathway Toward Designing Net-zero Energy Communities

In the context of escalating global energy demands, urban areas, specifically the building sector, contribute to the largest energy consumption, with urban overheating exacerbating this issue. Utilizing urban modelling for heat-mitigation and reduction of energy demand is crucial steps towards a sustainable built-environment, complementing onsite energy generation in the design and development of Net-zero Energy (NZE) Settlement, especially in the context of Australian weather conditions. Addressing a significant gap in existing literature, this study offers empirical analysis on the climate and energy efficacy of integrated heat mitigation strategies applied in 14 neighbourhood typologies located in Sydney, Australia. Examining the application of cool materials on roads, pavements, and rooftops, alongside urban vegetation enhancement, the analysis demonstrates scenario effectiveness on heat mitigation that leads to reduce ambient temperature and energy demands along with CO2 emissions within the neighbourhoods. Considering building arrangement, built-area ratio, building height, and locations, ENVI-met and CitySim are utilized to assess the heat-mitigation and the energy demand of neighbourhoods, respectively. Results indicate that mitigation measures can lead up to a 2.71 °C reduction in ambient temperature and over 25% reduction in Cooling Degree Hours, with a 34.34% reduction in cooling energy demand and overall energy savings of up to 12.49%. In addition, the annual energy-saving yields a CO2 reduction of approximately 141.12 tonnes, where additional vegetation further amplifies these reductions by enhancing CO2 absorption. This study showcases the pathway towards achieving NZE goals in climates similar to that of Australia, highlighting significant benefits in heat-mitigation, environmental impact, and energy-savings

4E Advancement of Heat Recovery During Hot Seasons for a Building Integrated Photovoltaic Thermal (BIPV/T) System

In conventional building integrated photovoltaic thermal (BIPV/T) systems, heat is only recovered during cold seasons. However, no recovery takes place in hot seasons. Therefore, this study comes up with an answer to the question “how much improvement in the amount of annual recovered heat (ANRH), average exergy efficiency (AAEE), and CO2 saving (ACDS), as well as payback period (PBP), is achieved when heat recovery is done in hot seasons?”. These are representatives of energy, exergy, environmental and economic (4E) aspects, respectively. The results show a 135.6%, 1.8% and 123.0% enhancement in the ANRH, AAEE and ACDS, respectively, while PBP decreases from 6.10 to 3.94 years

Canopy urban heat island and its association with climate conditions in Dubai, UAE

The impact that climate change and urbanization are having on the thermal-energy balance of the built environment is a major environmental concern today. Urban heat island (UHI) is another phenomenon that can raise the temperature in cities. This study aims to examine the UHI magnitude and its association with the main meteorological parameters (i.e., temperature, wind speed, and wind direction) in Dubai, United Arab Emirates. Five years of hourly weather data (2014–2018) obtained from weather stations located in an urban, suburban, and rural area, were post-processed by means of a clustering technique. Six clusters characterized by different ranges of wind directions were analyzed. The analysis reveals that UHI is affected by the synoptic weather conditions (i.e., sea breeze and hot air coming from the desert) and is larger at night. In the urban area, air temperature and night-time UHI intensity, averaged on the five year period, are 1.3 °C and 3.3 °C higher with respect to the rural area, respectively, and the UHI and air temperature are independent of each other only when the wind comes from the desert. A negative and inverse correlation was found between the UHI and wind speed for all the wind directions, except for the northern wind where no correlation was observed. In the suburban area, the UHI and both temperatures and wind speed ranged between the strong and a weak negative correlation considering all the wind directions, while a strong negative correlation was observed in the rural area. This paper concludes that UHI intensity is strongly associated with local climatic parameters and to the changes in wind direction

Size optimization of the grid-connected solar-wind hybrid system in Net Zero Energy Buildings: A case study

This study proposes a hybrid renewable energy system consisting of photovoltaic panels and a wind turbine to supply the total or part of the demand of a grid-connected residential building and presents the optimal system size using a genetic algorithm. Wind speed, solar irradiance, and electricity demand are monitored in 15 min intervals over a year. It is found that the optimal values for PV panels’ area, rated power of the wind turbine, and the tower height are 148.5 m2, 1.5 kW, and 20 m, respectively. These optimal values lead to a total system cost of EUR 42,218 over 20 years

Outdoor thermal and visual perception of natural cool materials for roof and urban paving

Given the acknowledged thermal performance of natural light color gravels applied as cool roof and cool urban paving, this work is aimed at investigating if such behavior is perceivable by pedestrians, who are questioned in this paper about their visual and thermal comfort perception. In fact, there are still related aspects to analyze, in order to optimize their application and provide a comfortable space for users, both on the thermal and the visual point of view. Therefore, the question that this work wants to answer is: given their intrinsic characteristics, do these materials create a sensitive thermally and visually more comfortable environment for pedestrians? In order to address this uninvestigated issue, users’ judgment about visual and thermal comfort of these surfaces is considered, also by comparing them with grassland and asphalt. Also, the statistical correspondence between physical properties of such materials and possible correspondence with respect to human perception with varying weather conditions is analyzed. Given the relatively high reflectance of these materials, it appears particularly important to evaluate these aspects, to consciously apply them as urban paving or roof covering by optimizing their natural passive cooling potential. In this preliminary study, users’ response to these surfaces is evaluated by mean of field surveys, both on the thermal and the visual evaluation, and contemporary in-field measurements of surface parameters. Also, human perception with respect to these high-reflectance surfaces’ is compared with the one related to grassland and asphalt, with varying weather conditions. Then, a statistical analysis is performed to investigate the differences among different gravels, grassland and asphalt, based on surveys’ results. The results show how pedestrians, questioned during summer days, prefer grassland, while asphalt is the less favorite surface both visually and thermally; there is a small difference between gravels’ types evaluation, while weather variability affect the preferences