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As the urgency to mitigate climate change intensifies, the achievement of zero carbon targets in the built environment has become a critical objective. Building retrofitting plays a vital role in reducing energy consumption and carbon emissions in existing buildings. This paper presents an approach that combines Building Information Modeling (BIM) with multiple domains to strive for zero carbon targets in building retrofit projects. The proposed approach is based on a dynamic multi-parameter analysis that integrates indoor comfort, energy savings, CO2eq reduction, and the social cost of carbon while considering investment costs. Renewable energy technologies, such as photovoltaic panels and solar thermal systems, are emphasized to achieve the desired zero-carbon outcomes. Real-time monitoring mechanisms enable continuous performance evaluation and adaptive retrofit strategies for further energy savings. This approach is validated through a case study of an existing thermal bath building, known as "Terme Lucane", located in southern Italy. The results of the study demonstrate significant reductions in energy consumption and carbon emissions, highlighting the potential of the proposed approach to achieve zero carbon targets through the integration of multi-data BIM implementation. These findings offer a promising pathway for building retrofit projects aiming for zero carbon targets through multi-data BIM modeling. [ABSTRACT FROM AUTHOR]

This study evaluated the dynamic properties of Pisa clay and Ticino sand (shear modulus and damping ratio) for a relatively wide range of consolidation pressures using the resonant column apparatus (RC), after which the results were simulated. The study aimed at the evaluation of the soil dynamic properties at very low consolidation pressure; the results of which are used for seismic response analysis of sites particularly near the ground surface where shear modulus may be more pronounced than at other depths. The results were compared to previous studies, which led to development of a modified constitutive model for evaluating the dynamic properties. The modified constitutive model mainly concerns the reference shear strain values (γr) that differently varied at low levels of consolidation stresses compared to higher levels. It was observed that reference shear strain is about 0.035% < γ < 0.1% for Ticino sand and 0.04% < γ < 0.08% for Pisa clay. The so-called "elastic threshold shear strain" was also observed in a range of 0.0005–0.001% for Ticino sand and 0.002–0.003% for Pisa clay. Case studies were conducted, whereby the above-mentioned model was integrated into a new analytical approach for site response analysis assuming a continuous variation of the shear wave velocity with soil depth. A computer program was written in a MATLAB environment based on this approach. Results were compared to those given by DEEPSOIL software. It was observed that the use of the current approach to reasonable results, while the efficiency and speeds of calculations are highly maintained by the current approach. [ABSTRACT FROM AUTHOR]

This paper regards the design and dynamic modelling of a greenhouse coupled with renewable energy technologies to obtain a hybrid renewable energy plant as an optimal solution in the green farm framework. The considered technologies are PV panels, solar thermal collectors, and a biomass auxiliary heater. The system is also coupled with a pyrogasifier, supplied by wood and agricultural waste in the framework of a biocircular economic approach. To supply the investigated user, with a "green farm" located in Castelvolturno (Naples, South of Italy) reducing the energy consumption and operating costs, all of the main components of the plant were suitably designed. The operation of the designed components was simulated by a dynamic simulation model developed by TRNSYS software and validated by means of the literature results. A comprehensive energy, economic, and environmental analysis of the greenhouse is presented. The main results suggest that the investigated renewable plant reduces the total equivalent CO2 emissions by 148.66 t/y. Considering the current high increases in energy prices as a result of the energy crisis due to the war, the system shows very significant profitability with a simple payback of only 1.7 years. [ABSTRACT FROM AUTHOR]

In Europe, the recast of Directive 2018/2001 defined Renewable Energy Communities as innovative configurations for renewable energy sharing between different end user types. In this regard, this work aims to assess the benefits following the constitution of a Renewable Energy Community in the industrial area of Benevento (South of Italy), involving a mixed-use building and an industrial wastewater treatment plant. The alternative single end users' configuration has been also examined, and both solutions have been compared with the current state where the users' electric energy requests are fully met by the power grid. The users have been equipped with a 466 kWp photovoltaic plant, modelled in HOMER Pro®, providing in input experimental meteorological data (global solar radiation and air temperature) collected by one of the weather control units in Benevento. Real data about users' electric energy demand have been gathered from their electricity bills, and when unavailable their electric load profiles on an hourly basis have been reconstructed based on the aggregated monthly data. Energy sharing has been proven to increase energy self-consumption and the users' self-sufficiency. Annually, the primary energy demand is reduced by 577 MWh (1.2 MWh/kWp), carbon dioxide emissions by 84 tCO2 and operative costs by 101 kEUR. [ABSTRACT FROM AUTHOR]

The safety assessment of existing structures in areas with a relevant seismic hazard is one of the major topics for engineers since many existing reinforced concrete structures have been realized disregarding seismic design with minimal details with respect to present practice. In this context, seismic assessment is a primary issue in order to identify the best retrofitting solution with the aim of enhancing the efficiency of existing buildings. In recent years, with the aim to enhance the seismic behavior of reinforced concrete (RC) structures (with particular care to existing ones), the system of seismic isolation adopting friction pendulum (FPS) devices proved to be among the most diffuse and effective solutions. The purpose of this paper is to explore the effectiveness of the refurbishment using FPS with single concavity devices on the performance of one irregular existing RC building placed in a highly seismic area of central Italy. First, the geometric and material characteristics of the building have been determined within the approach based on the "knowledge levels". Second, a suitable numerical model based on a fiber-modeling approach has been established using SAP2000, including relevant mechanical non-linearities. Then, a set of 21 natural seismic inputs, inclusive of 3 accelerations over vertical and horizontal directions, was adopted with the aim of performing non-linear (NL) dynamic simulations. The NL dynamic simulations have been performed considering the structural system, both inclusive and not inclusive of the FPS isolator devices. The influence of the actual distribution of infill masonry panels on the overall behavior of the structure has also been evaluated in both of the cases mentioned above. Finally, the outcomes deriving from the NL dynamic simulations were helpful in assessing the advantages of the intervention of retrofitting to improve the seismic performance of the building, highlighting the influence of masonry infills. [ABSTRACT FROM AUTHOR]

This work aims to assess the impacts of climate change on photovoltaic (PV) electricity in two Italian cities, with different latitudes and Köppen–Geiger climate classifications. This was undertaken using the recent EURO-CORDEX set of high-resolution climate projections and PV power generation models, implemented on TRNSYS software. Data for two variables (surface air temperature and solar radiation) were analysed over a long period from 1971 to 2100. For future periods, two of the Representative Concentration Pathway scenarios (RCP4.5 and RCP8.5) used in the Intergovernmental Panel on Climate Change Fifth Assessment Report were considered. In both RCP scenarios and both locations, it is estimated that the yearly PV energy produced in the future period will not undergo significant variations on average given that the rate of decrease is foreseen almost constant; instead, a slight reduction in the PV energy was detected in the past period. It can be concluded that the PV market in Italy will grow in the next years considering that the reduction in the foreseen PV purchase costs will be also supported by the slight positive effect of climate change on PV manufacturability. [ABSTRACT FROM AUTHOR]

Residential buildings account for 84 % of Italy's built environment, playing a pivotal role in the EU's aim to cut GHG emissions by 55 % through enhanced energy efficiency and climate adaptation. This necessitates comprehensive energy retrofit initiatives, especially in sectors like social housing, which has been relatively overlooked in terms of energy efficiency strategies. This study focuses on a multi-story building from the 1980s in Rome, implementing an innovative energy system proposed by the RESHeat European project. This system, aimed at standardizing energy retrofits for late 20th-century social housing, leverages the underexplored potential of water-source heat pump (WSHP) systems. The novelty of this research extends to its examination of multi-family housing, a sector that has seen less attention compared to public spaces and smaller residential buildings. Through experimental validation and annual dynamic simulations using TRNSYS and Simulink, the research compares the existing heating system with a proposed upgrade that includes a WSHP and Photovoltaic-Thermal (PVT) panels. This upgrade demonstrated a significant efficiency improvement, achieving an annual COP of 6.1 for the WSHP and a 36 % Primary Energy Savings (PES) from the PVT panels, showcasing the effectiveness of these technologies in enhancing the energy profile of multi-family residential buildings. [Display omitted] • A multi-energy system for a 1980s social housing in mild climate is presented. • A dynamic model based on a water-source HP and cooled PV panels was set. • Experimental validation of building and plant components were conducted. • Combining heat pump and PVT panels a seasonal COP of 5.4 can be achieved in heating. • Solar fraction of 0.98 ensured by PVT contributes to a Primary Energy Saving of 36 %. [ABSTRACT FROM AUTHOR]

• Novel layout to be easily adopted by existing residential districts. • The novel layout can reduce the primary energy consumption of the residential district. • A primary energy saving index of 38 % and payback period of 2.2 years is achieved. • Power to heat strategy increases the district self-consumed electricity by 15%. • The power to heat strategy is able to further exploit the excess renewable electricity. This paper aims at reducing both electricity and space heating demands of residential districts. It specifically investigates the emerging paradigm, based on renewable energy communities, for existing residential districts. In particular, a novel renewable energy community layout is analyzed. This layout integrates a district heating network and the power to heat control strategy. The proposed system is designed to prevent any major refurbishment inside the apartments, using the existing high temperature space heating system. This arrangement is compared with more conventional renewable energy community layouts. Detailed dynamic models for both the residential district and the proposed layouts are developed using the TRNSYS software. Results show that renewable energy community is an extremely profitable paradigm for promoting the use of renewables at residential buildings scale. Moreover, the layout integrating energy community, district heating network, and Power-to-Heat strategy achieves the best results with a payback period of 2.2 years and a primary energy saving of 38 %. [ABSTRACT FROM AUTHOR]

The energy needs of a Net Zero Energy Building (NZEB) are fully met by renewable energy sources. Nevertheless, the time span of the energy balance can affect the effective energy self-sufficiency of the building. The aim of this paper is to demonstrate the lack of reliability that a yearly energy balance has in characterizing an NZEB. At this scope, comparisons between two different photovoltaic systems (fixed and tracking) and two kinds of energy balance (yearly and monthly) are made for a real NZEB building located in South-Italy. The investigation was carried out through dynamic energy simulations after validating the building model. The results show that the PV surface which attains the NZEB target on yearly basis not always achieves the same objective as the monthly balance. Furthermore, considering a monthly balance, the size of the photovoltaic system with biaxial solar tracking is 50% minor than the fixed one, thanks to a steadier energy production. Also, solar tracking systems show a significantly lower reduction of operational and embodied CO 2 emissions. A final technical-economic analysis shows, however, that design solutions that satisfy NZEB target not always can meet the financial interest of the private stakeholder, showing a high discounted payback period. • The energy needs of an existing NZEB are evaluated through dynamic simulation. • Fixed and tracking PV systems are designed and compared to obtain the NZEB target. • Comparisons between yearly and monthly balance using different PV systems are made. • Yearly balance is not adequate to characterize energy self-sufficiency for an NZEB. • Tracking PVs reduce monthly withdrawal from electricity grid and CO 2 emissions. [ABSTRACT FROM AUTHOR]

Electricity from renewable energy sources represents the most promising way to decarbonize energy systems. A grid connection of car Electricity Storage Systems (ESSs) represents an opportunity to tackle issues regarding electricity production non-programmability, only if sufficiently smart bi-directional Vehicle to Grid technologies (V2G) are widely implemented. Fully Bi-directional grid capabilities are still poor and must be increased, both physically and in terms of management and billing possibilities (in the so-called smart-grid paradigm). However, some V2G technologies may be already implemented in smaller individual contexts: so-called Vehicle to Home, V2H technologies. Starting from these considerations, within the frame of an Italian publicly funded research project, the authors categorized and described many possible application contexts and developed an open-source dynamic simulation (fully available under request for the scientific community) to identify most promising conditions. To this aim, they also synthetized and tested an effective energy optimization algorithm which will soon be implemented on a prototypal wireless V2H device, built by ENEA in cooperation with Cassino University, in Italy. The performances of the system were assessed evaluating electricity auto-consumption and home auto-feeding ratios. Simulations show that very relevant performances can be obtained, up to the values 69% for electricity auto-consumption and 82% of home auto-feeding. [ABSTRACT FROM AUTHOR]

This works proposes a dynamic thermoeconomic analysis of a liquefied biomethane production plant to meet the fuel demand of a fleet of heavy duty trucks in the south of Italy. The biomethane is obtained from the upgrading of the biogas produced by means of anaerobic digestion through a plug flow reactor fed by organic fraction of municipal solid waste. The upgrading of the biogas is realized using a three-stage membrane compression process, producing a 96 % pure biomethane. The biomethane liquefaction is realized using a single-mixed refrigerant process and compared to a Linde cycle process. The whole system is assisted by solar energy to reduce the fossil energy consumption of the process and feed-in tariffs are considered as funding policy. The models for the anaerobic digestion, the biogas upgrading, and the biomethane liquefaction are in detail developed in MatLab. The anaerobic digestion model is based on the ADM1 biological model, integrated with a suitable heat transfer model. The biogas upgrading model is based on a simplified Fick model. The liquefaction model is based on an equivalent two heat-exchangers model, taking into account the transient heat transfer. All the components are then integrated in TRNSYS to perform the dynamic simulation for one operating year of the whole system. Results from the thermoeconomic analysis are outstanding in terms of profitability, showing a payback period of less than 2 years and a Net Present Value of the system of 402 M€. The great environmental impact is also confirmed by a Primary Energy Saving of 91 % and a dramatic reduction of 86 % of the CO 2 equivalent emissions. • Feasible LBM production for heavy-duty trucks. • SMR liquefaction is more efficient than Linde cycle process. • Government incentives are needed in both cases. • Incentives for waste disposal is even more effective. [ABSTRACT FROM AUTHOR]

Ensuring optimum interior lighting is a topic of great importance, as this influences not only the well-being of users but also the optimal performance of visual tasks. Lighting can be natural, but if not sufficient, it can be compensated with artificial lighting. This study highlights a methodology for designing a new lighting system that takes into account both technical and economic aspects. The method was applied to an existing school located in southern Italy, in which the electricity consumption is related to the current lighting system. The school is chosen as being representative of the construction type and layout of many local schools. In addition, the coexistence of several visual tasks with different design requisites (e.g., illuminance levels) makes the school a very complex environment. The school lighting is modelled in Google SketchUp and imported into Daysim to simulate the yearly and hourly daylight indoor contribution. Dialux Evo has been used to simulate and design artificial lighting. The results show a reduction of energy consumption of 33% with the simple replacement of fluorescent luminaires with LEDs, while the LED lamp dimming and modulation for rows of luminaires leads to a 95% reduction in energy consumption compared with the current state. [ABSTRACT FROM AUTHOR]

• Thermochromic glazing properties have been measured under variable temperature conditions with customized spectrophotometer. • Procedure for thermochromic thin film preparation has been presented. • Building energy simulation has been implemented for impact assessment. • Optimization of the thermochromic properties has been performed for different climates. • A complete procedure for thermochromic design and optimization has been described. Thermochromic (TC) glazing could provide a significant reduction of energy consumption in curtain wall buildings. However, each application requires a design tailored to building's specifications. This paper proposes a complete approach for designing TC glaze based on building energy simulation starting from the production of thin thermochromic layers and the measurements of their optical properties by means of a customized spectrophotometer. The main focus of this work is to identify the optimal TC optical response that minimises the building energy consumption. Energy simulations have been performed for a virtual mock-up set at two locations with different climates, Italy and Poland. A set of profiles, each one determining thermochromic properties in terms of switching temperature, range of solar transmittance and transition speed, have been created with a fine step of temperature (2 °C) and used to simulate different scenarios. The outcome of the optimization provided the optimal properties to achieve the right balance between cooling energy reduction and heating energy increase due to the application of the thermochromic layer, in comparison to a standard clear glass. The fine step in switching temperature allowed to accurately estimate the subtle differences for the two different climates (25 °C Italy, 24–26 °C Poland). The highest impact has been found for the Italian location with a maximum reduction of total energy consumption of 22.8%. This was achieved with a thermochromic switching at 25 °C, with fast transition and range of transmittance between 0.1 (switched state) and 0.5 (normal state), which is a not extreme behaviour. [ABSTRACT FROM AUTHOR]

A centralized solar hybrid heating and cooling system satisfying the thermal, cooling and sanitary water demands of a typical Italian small district composed of six residential buildings situated in Naples (southern Italy) is modelled, simulated and analysed through the software TRNSYS over a period of 5 years. The plant is based on the operation of solar thermal collectors coupled with seasonal borehole storage; the solar field is also composed of photovoltaic solar panels connected with electric energy storage. An adsorption chiller powered by solar energy is adopted for cooling purposes, while a condensing boiler is used as an auxiliary unit. The performance of the proposed system has been assessed from energy, environmental and economic points of view and contrasted with the operation of a typical Italian heating and cooling plant, highlighting the following main results: saving of primary energy consumption up to 40.2%; (decrease of equivalent CO2 emissions up to 38.4%; reduction of operating costs up to 40.1%; and simple pay-back period of about 20 years. [ABSTRACT FROM AUTHOR]

Numerical simulations are carried out for the dynamic rupture and wave propagation process of the 24th August 2016 ML 6.0 Amatrice, Italy, earthquake, using a boundary domain method (BDM), a hybrid method of boundary integral equation and finite difference methods. Dynamic rupture parameters of two seismogenic asperities are searched by iterative search through the comparison of the near-field ground motions. The preferred models indicate two asperities, aligned at around 4–5 km depth and separated from each other as well as from the initial rupture point. This requires a few supplementary patches connecting them, and that are less energetic than the asperities. The asperities are characterized by a radius of 2–3 km in the south (first to rupture) and of 2–4 km in the north (second to rupture), and the corresponding fracture energies of the asperities are (25.35 ± 0.63) × 1012 J and (38.05 ± 7.91) × 1012 J, respectively. These values are consistent with the scaling relation extrapolated from various analyses of large earthquakes. Although the parameter space of the search is limited due to the numerical performance of the dynamic rupture simulation, the proposed simple characterization of the earthquakes source confirms the scaling relation in fracture energy of the seismogenic asperities, which is essential for constructing mechanical earthquake source models. [ABSTRACT FROM AUTHOR]

Among the various heating technologies that can be applied to urban areas district heating is recognized to allow significant reduction in primary energy consumption, provided that the system is properly designed and operated. Thermo-fluid dynamic simulation tools can be of extreme importance in order to achieve this objective. This paper aims at presenting a thermo fluid dynamic model for the detailed simulation of large district heating network and showing how it can be usefully applied to examine options for the reduction of primary energy consumption. The model is tested using experimental data and then applied for analyzing transient operations of the Turin district heating network, which is the largest network in Italy and one of the largest in Europe. A comparison between simulations and experimental results shows that the model is able to predict the temperature in the nodes of the network with good accuracy. The thermal power required to each plant is also calculated with a good level of accuracy. The model can be used for the simulation of operational strategies, thus representing a versatile and important tool for the implementation of advanced management such as the installation of local storage units or the variation of user request schedules. • A thermo-fluid dynamic model for the detailed simulation of large DHNs is proposed. • The model receives data from the substations as the input. • The transient simulation of the Turin DHN is compared with measurements. • The model can be applied to implement advanced management strategies. [ABSTRACT FROM AUTHOR]

Featured Application: This work could contribute to evidence strengths and weaknesses of manual and automatic calibration of building dynamic simulation models leading at improving the quality of building retrofit solutions investigation. Energy reduction can benefit from the improvement of energy efficiency in buildings. For this purpose, simulation models can be used both as diagnostic and prognostic tools, reproducing the behaviour of the real building as accurately as possible. High modelling accuracy can be achieved only through calibration. Two approaches can be adopted—manual or automatic. Manual calibration consists of an iterative trial and error procedure that requires high skill and expertise of the modeler. Automatic calibration relies on mathematical and statistical methods that mostly use optimization algorithms to minimize the difference between measured and simulated data. This paper aims to compare a manual calibration procedure with an automatic calibration method developed by the authors, coupling dynamic simulation, sensitivity analysis and automatic optimization using IDA ICE, Matlab and GenOpt respectively. Differences, advantages and disadvantages are evidenced applying both methods to a dynamic simulation model of a real office building in Rome, Italy. Although both methods require high expertise from operators and showed good results in terms of accuracy, automatic calibration presents better performance and consistently helps with speeding up the procedure. [ABSTRACT FROM AUTHOR]

• Replacement of thermal generator is a simple and efficient building retrofit action. • Three generators are compared using environmental, energy and economic metrics. • A building stock energy model for Italy has been defined (4 buildings, 3 climates). • Heat pumps are preferrable for emission reduction, but lead to high operative costs. • The flexibility of hybrid heat pump allows for high savings on all the objectives. In many countries, old inefficient generators are used for heating purposes. A way to improve energy efficiency in those countries can be the choice of the most suitable heating generators to replace the current ones, without the inconveniences caused by other retrofit measures. In this context, we present a methodology to choose the most appropriate generator through dynamic simulations applied to building stock energy models. Economic, energetic, and environmental parameters guide the choice. The methodology is applied in the Italian residential building scenario, where the most widespread heating device is traditional boiler. Three options are considered: condensing boiler, heat pump, and hybrid heat pump (an alternative-working system with a condensing boiler and heat pump). For a detailed analysis, a white-box bottom-up building stock energy model is defined, through a statistical analysis, consisting of four building typologies in three different external climates. An hourly dynamic building-system simulation has been performed to obtain energy performance, emissions, and operational costs. The results have demonstrated that condensing boiler allows limited economic, environmental, and energy savings (8 - 14 %), compared to traditional boiler. The highest economic savings are obtained with the hybrid heat pump (20 %), while the heat pump alone leads to higher costs, but the highest savings in emissions and non-renewable primary energy (25 - 50 %). The flexibility offered by the hybrid heat pump allows to obtain high savings in different cost scenarios, but also to further reduce CO 2 emissions by implementing an environmental-based control strategy. [ABSTRACT FROM AUTHOR]

A wide variety of weather-data are readily available for simulating buildings energy performance by using dynamic software. However, climate change and its effects on buildings energy performance represent a critical issue, also considering the implications of climate change on human comfort. Starting from this, the present study aims at analyzing the climatic conditions in Rome and its surroundings, evaluating the occurrence of the Urban Heat Island (UHI) phenomenon. Therefore, meteorological data derived from two airports near the city and climatic data registered for two years in a central, densely-built zone of Rome were analyzed and compared. Furthermore, the differences among weather data were tested by means of a commonly used dynamic software in order to evaluate the effects of different climatic boundary conditions on building energy performance, in terms of heating and cooling energy demands. The results highlight significant differences with regard to temperature, wind velocity and relative humidity, as a result of a prevailing UHI phenomenon in central Rome throughout the year. The simulations show an average increase of cooling energy demand of about 30% and an average reduction of heating energy demand of about 11%. Such differences give the rise for the investigation of the reliability of weather-data files commonly used in building simulations, in order to properly estimate the buildings energy demand under a sustainable city perspective. [ABSTRACT FROM AUTHOR]

• A method to support investment decisions for smart shading devices is proposed. • PROMETHEE II multi-criteria is coupled to EnergyPlus to study smart building aspects. • Criteria related to energy, finance, environment, occupants' well-being are defined. • More expensive smart options are repaid through enhanced comfort and energy savings. In the framework of the current energy transition, the building sector is experiencing a smart revolution, recognizing how the adoption of advanced control strategies and smart management systems can increase buildings energy efficiency and improve occupants' comfort. As a key element for smart buildings, solar shading devices coupled with effective control systems need to be strategically assessed. The investment decision-making process for selecting the proper shading systems is influenced by the existence of potential conflicts from economic, environmental, social, and energy standpoints, thus asking to be supported by innovative methodological approaches able to include all these aspects in the decisional framework. To this purpose, the work aims to propose a multi-disciplinary methodological framework to support decision-makers in ranking a set of solar shading device and relative control strategy, integrating energy dynamic simulations with multi-criteria decision analysis techniques. The analysis focuses on office buildings, recognizing their huge impact in terms of energy consumptions and the need to guarantee proper indoor conditions to increase employees' productivity and well-being. To test the applicability of the multi-step methodology for this building category, the proposed approach is applied to an office building located in the North-West of Italy, aiming to assess and compare different alternative combinations of shadings devices and management strategies. The advanced features of building energy modelling and simulation and the application of PROMETHEE II (Preference Ranking Organization METHod for Enrichment Evaluation II) method as multi-criteria analysis allows to provide recommendations to decision-makers to identify the systems to be installed, able to guarantee the best trade-off between internal comfort, operational energy, and environmental costs for the building under investigation. [ABSTRACT FROM AUTHOR]

In the last years, the Covid-19 outbreak raised great awareness about ventilation system performance in confined spaces. Specifically, the heating, ventilation, and air conditioning system design and operating parameters, such as air change per hour, air recirculation ratio, filtration device performance, and vents location, play a crucial role in reducing the spread of viruses, moulds, bacteria, and general pollutants. Concerning the transport sector, due to the impracticability of social distancing, and the relatively loose requirements of ventilation standards, the SARS-COV-19 outbreak brought a reduction of payload (up to 50%) for different carriers. Specifically, this has been particularly severe for the railway sector, where train coaches are typically characterized by relatively elevated occupancy and high recirculation ratios. In this framework, to improve the Indoor Air Quality and reduce the Covid-19 contagion risk in railway carriages, the present paper investigates the energy, economic and environmental feasibility of diverse ventilation strategies. To do so, a novel dynamic simulation tool for the complete dynamic performance investigation of trains was developed in an OpenStudio environment. To assess the Covid-19 contagion risk connected to the investigated scenarios, the Wells-Riley model has been adopted. To prove the proposed approach's capabilities and show the Covid-19 infection risk reduction potentially achievable by varying the adopted ventilation strategies, a suitable case study related to an existing medium-distance train operating in South/Central Italy is presented. The conducted numerical simulations return interesting results providing also useful design criteria. [ABSTRACT FROM AUTHOR]

Desiccant-based air handling units can provide significant operational advantages and can use solar energy as the main heat source. Hereinafter a plant equipped with a silica-gel desiccant wheel is analyzed for two Italian locations (Benevento and Milano). A parametric study involving collectors types, surfaces, tilt angles and installation site has been performed. The proposed system has been compared with a conventional HVAC unit, through dynamic simulations. In terms of energy and environmental analysis, solar desiccant systems should always be preferred to conventional ones, even when the solar thermal energy surplus is fully dissipated. A maximum primary energy saving of about 10% and 20% with flat plat and evacuated tube collectors, respectively, occurs in both locations. The savings increase up to about 58% and 72% in Benevento and 43% and 58% in Milano, when the solar heat excess is completely used for further energy demands. One observes that systems with evacuated tube collectors are preferable where the available space for the solar field is small, instead with larger surfaces flat plate collectors are advantaged. In terms of economic analysis, the shortest payback periods are 6 and 8 years for Benevento and Milano, respectively. [ABSTRACT FROM AUTHOR]

Sustainable solutions for energy saving in buildings are assuming increasing interest both in the research and the industrial community. In this view, cool roof systems demonstrated to be interesting and effective solutions which role in energy saving for cooling and mitigating local and global warming is already acknowledged. In these recent years, several studies were carried out in order to quantify their thermal-energy effect with varying boundary conditions, while global climate analytical models were proposed with the purpose to evaluate the effect of high albedo solutions in terms of radiative forcing and CO 2eq offset. This work concerns the combined analysis of thermal-energy and environmental effect of cool roof (high albedo) clay tiles with low visual impact, specifically optimized in order to preserve traditional residential buildings. In particular, dynamic simulation models and field monitoring of a real residential village were developed and the effect of such tiles is analyzed in terms of energy saving for cooling and of CO 2eq avoided emissions due to the energy efficient intervention, coupled with the effect in climate change mitigation. This aspect is specifically considered by applying an analytical method elaborated in previous works, where the effect of high albedo surfaces in terms of CO 2eq offset is quantified with varying orientation, inclination, solar reflectance and geographical details. The combined analysis showed how an overall annual CO2 emissions’ offset is achievable by coupling single-building and global assessment methodologies. In particular, the energy saving contribution saved around 141 tonnes of CO 2eq per year, and the global warming analytical model showed that the albedo increase allowed to offset about 772 tonnes of CO 2eq per year. This prototypical study showed how local energy analysis should be coupled to global analysis in order to have an exhaustive view of building retrofit strategies’ sustainability. [ABSTRACT FROM AUTHOR]

This study presents a detailed failure analysis of seven masonry churches, which were severely damaged during the 2012 Emilia-Romagna (Italy) seismic sequence, by means of 3D FE non-linear dynamic simulations. The main aims of the numerical investigations are: (1) to carry out a sufficiently wide sensitivity study on different specific case studies to have an insight into the role played by the geometry – which is always unique for churches – and by the irregularities; (2) to validate or address the limits of applicability of the most widespread conventional static approaches recommended by Italian Code, i.e. kinematic limit and pushover analyses. Non-linear dynamic analyses are carried out assuming that masonry behaves as a non-linear material exhibiting softening and damage, frictional behavior and different strength in tension and compression. The set of case studies investigated in this work shows how conventional static approaches are still capable of roughly identifying the most critical macro-elements that usually activate a failure mechanism, but that the results (e.g. collapse acceleration, behavior factor) are affected by a level of approximation that may considerably depend on in-plan irregularity and hypotheses done on the interlocking between contiguous walls. From the comparative analyses carried out, it is authors’ opinion that it is always beneficial to perform different types of analysis in order to have a comprehensive insight into the portions of the structure that can suffer a partial collapse with high probability. Once the active mechanism is identified, non-linear dynamic analyses, with more sophisticated material models and with refined FE discretizations of the critical regions, may be useful to deepen the knowledge of the behavior of such complex structures under seismic actions. [ABSTRACT FROM AUTHOR]

Abstract: The European Energy Efficiency Building Directive 2002/91/CE, as well as other acts and funding programs, strongly promotes the adoption of passive strategies for buildings, in order to achieve indoor thermal comfort conditions above all in summer, so reducing or avoiding the use of air conditioning systems. In this paper, the energy performances achievable using an earth-to-air heat exchanger for an air-conditioned building have been evaluated for both winter and summer. By means of dynamic building energy performance simulation codes, the energy requirements of the systems have been analysed for different Italian climates, as a function of the main boundary conditions (such as the typology of soil, tube material, tube length and depth, velocity of the air crossing the tube, ventilation airflow rates, control modes). The earth-to-air heat exchanger has shown the highest efficiency for cold climates both in winter and summer. The possible coupling of this technology with other passive strategies has been also examined. Then, a technical-economic analysis has been carried out: this technology is economically acceptable (simple payback of 5–9 years) only in the cases of easy and cheap moving earth works; moreover, metallic tubes are not suitable. Finally, considering in summer a not fully air-conditioned building, only provided with diurnal ventilation coupled to an earth-to-air heat exchanger plus night-time ventilation, the possible indoor thermal comfort conditions have been evaluated. [Copyright &y& Elsevier]

Abstract: The paper investigates the energetic and economic feasibility of a solar-assisted heating and cooling system (SHC) for different types of school buildings and Italian climates. The SHC system under investigation is based on the coupling of evacuated solar collectors with a single-stage LiBr–H2O absorption chiller; auxiliary energy for both heating and cooling is supplied by an electric-driven reversible heat pump. The SHC system was coupled with different types of school buildings located in three different Italian climatic zones. The analysis is carried out by means of a zero-dimensional transient simulation model, developed using the TRNSYS software; the analysis of the dynamic behaviour of the building was also included. An economic model is proposed, in order to assess the operating and capital costs of the systems under analysis. Furthermore, a parametric analysis and a subsequent mixed heuristic-deterministic optimization algorithm was implemented, in order to determine the set of the synthesis/design variables that maximize system profitability. The results are encouraging, as for the potential of energy saving. On the contrary, the SHC economic profitability can be achieved only in case of public funding policies (e.g. feed-in tariffs), as always happens for the great majority of renewable energy systems. [Copyright &y& Elsevier]

The human-centric energy transition is required to foster efficient buildings and communities by combining users' engagement and technical solutions. In this view, the present study aims at evaluating for the first time the influence of users' holistic experience on the feasibility of Net Zero Energy (NZE) communities in laggard countries for their application. The human-centric role is analyzed from a twofold perspective: the influence of user-building interaction on the expected final energy performance and the psychological factors affecting willingness towards the exploitation of NZE communities. To this aim, different scenarios for user-building interaction, obtained varying the family typology and occupants' energy-related attitude, are assessed via validated dynamic simulation. In addition, an extended Technology Acceptance Model is examined through the submission of an extensive survey to investigate consumers' intent to live and invest in buildings within NZE communities. Findings show the clear impact of users' energy-awareness and knowledge of the potentialities of this solution on both buildings NZE performance achievement and consumers' willingness towards NZE settlements implementation. Accordingly, this study brings to light how people engagement in energy communities is of fundamental relevance to reach the expected energy transition towards peer-to-peer renewable energy market, especially in laggard countries (e.g. Italy), where these concepts are currently being exploited. • Occupants' awareness toward feasibility of Net Zero Energy communities is evaluated. • Role of user-building interaction is assessed via validated dynamic energy simulation. • Surveys investigate consumers' willingness towards human-centric NZE communities. • Social groups' behavior widely impact energy saving in high performing settlements. • Occupants' engagement is essential to meet energy targets in peer-to-peer networks. [ABSTRACT FROM AUTHOR]

The heating, ventilation, and air conditioning (HVAC) system serving the test room of the SENS i-Lab of the Department of Architecture and Industrial Design of the University of Campania Luigi Vanvitelli (Aversa, south of Italy) has been experimentally investigated through a series of tests performed during both summer and winter under both normal and faulty scenarios. In particular, five distinct typical faults have been artificially implemented in the HVAC system and analyzed during transient and steady-state operation. An optimal artificial neural network-based system model has been created in the MATLAB platform and verified by contrasting the experimental data with the predictions of twenty-two different neural network architectures. The selected artificial neural network architecture has been coupled with a dynamic simulation model developed by using the TRaNsient SYStems (TRNSYS) software platform with the main aims of (i) making available an experimental dataset characterized by labeled normal and faulty data covering a wide range of operating and climatic conditions; (ii) providing an accurate simulation tool able to generate operation data for assisting further research in fault detection and diagnosis of HVAC units; and (iii) evaluating the impact of selected faults on occupant indoor thermo-hygrometric comfort, temporal trends of key operating system parameters, and electric energy consumptions. [ABSTRACT FROM AUTHOR]

• An innovative computational performance-driven design optimization workflow is set. • Optimization of designer's control on several variables of the building is set. • The best geometry configurations are found to improve energy needs, costs and UDI. • The graphical visualization of the outputs improves the decision-making process. • An educational building is analysed setting 900 iterations of a genetic algorithm. Delaying the analysis of the building performance to the final stages of the design process can often cause the actual results to differ from the expected ones, with the issue of significant redesign costs. The aim of this work is to improve the designer's control on thermal and geometric variables of the building in the first stages of the design process, to obtain an optimized building from different points of view. An innovative computational performance-driven design optimization workflow is proposed. The integration of a parametric algorithmic modelling tool in a genetic algorithm powered performance optimization procedure allows to minimize energy need and construction cost of the building, and to optimize the natural illumination levels, affecting several geometric variables. This approach is tested on the early design stages for the new construction of an educational building located in the centre of Italy (L'Aquila). The results are post-processed in order to provide an innovative graphical visualization of the outputs to improve the decision-making process. Useful insights on the influence of different design choices on three key performance indicators can be drawn for the case study building, by comparison of the Pareto solutions: optimization results highlight the strongest influence of window-to-wall ratio, among the other variables, on energy need and useful daylight illuminance. [ABSTRACT FROM AUTHOR]

In recent times, the inter-building effect has been deeply investigated because it can highly affect building energy performance. Thus, reliable energy simulations of a single building can require to model the effects of surrounding buildings. This can imply complex models, and consequently high computational burden. The study aims at investigating such phenomena with suitable simplifications by keeping high reliability. Two typical buildings of European cities, located in South Italy, are investigated with building models developed using DesignBuilder® and EnergyPlus. Dynamic energy simulations are performed by using different modeling approaches: detailed modeling, different shading systems, different shading setpoints, no shading, no inter-building effect and the combination no shading and no inter-building effect (simplest model). For each approach different simulation timesteps are considered. The coupling between EnergyPlus and MATLAB® is implemented for a comprehensive comparison of the performance indicators provided by the different approaches. The main goal is to identify the models that ensure the best tradeoff between accuracy and computational burden as well as to verify if these latter can reliably replace the most detailed model. The tradeoff models provide – compared to the most detailed one – mean bias error around 2% and reductions in simulation times around 46%, which can be considered an excellent tradeoff. Finally, the study proposes insights into building modeling to answer the question: Is it fundamental to model the inter-building effect for reliable energy simulations? Image 1 • Accurate building energy simulation can imply complex, time-expensive models. • Different modeling approaches are compared to trade-off accuracy and complexity. • Inter-building effect, shading type and use, simulation time steps are explored. • DesignBuilder®, EnergyPlus and MATLAB® are used as simulation/processing tools. • The approaches ensuring the best tradeoff accuracy-computational burden are found. [ABSTRACT FROM AUTHOR]

• Deep refurbishment of buildings to nZEB standards is an open challenge. • Design optimization is a resource intensive process requiring appropriate training. • A gap between simulated and measured performance is frequently found in high performance buildings. • HEART project platform aims to address relevant issues, from design to operation. • Parametric performance analysis and model calibration are integrated in this study. Building performance analysis changed the way in which buildings are designed and operated. The evaluation of different design and operation options is becoming more resource intensive than ever before. Although building dynamic simulation tools are potentially a suitable way for assessing energy performance of buildings accurately, they require adequate training and a careful evaluation of model input data. In Europe, the majority of buildings were constructed before 1990 and are in urgent need for a significant energy efficiency improvement, through deep renovation. In this respect, advanced renovation solutions are available, but costly and lengthy renovation processes and technical complexities hinder the achievement of a large scale impact. Energy refurbishment of buildings is an open challenge and essentially requires the adoption of a valid methodological approach to link design and operational performance analysis transparently, in order to address the potential gap between simulated and measured results. The HEART project, funded in the EU Horizon 2020 program, aims to address the increasing need for deep retrofit interventions and to develop systemic strategies leading to high performance and cost effective solutions. The research for the cloud platform used in the project is based on two fundamental tools: parametric simulation to produce a large spectrum of possible building energy performance outcomes (considering realistically the impact of the user behaviour and variable operating conditions from the very beginning), and model calibration employing simple, robust and scalable techniques. In this paper we present the preliminary development and testing of the computational processes that will be implemented in the cloud platform, employing the first pilot case study of HEART Project in Italy, currently under refurbishment. [ABSTRACT FROM AUTHOR]

This paper presents a thermodynamic, economic, and environmental analysis of a renewable polygeneration system connected to a district heating and cooling network. The system, fed by geothermal energy, provides thermal energy for heating and cooling, and domestic hot water for a residential district located in the metropolitan city of Naples (South of Italy). The produced electricity is partly used for auxiliaries of the thermal district and partly sold to the power grid. A calibration control strategy was implemented by considering manufacturer data matching the appropriate operating temperature levels in each component. The cooling and thermal demands of the connected users were calculated using suitable building dynamic simulation models. An energy network dedicated to heating and cooling loads was designed and simulated by considering the variable ground temperature throughout the year, as well as the accurate heat transfer coefficients and pressure losses of the network pipes. The results were based on a 1-year dynamic simulation and were analyzed on a daily, monthly, and yearly basis. The performance was evaluated by means of the main economic and environmental aspects. Two parametric analyses were performed by varying geothermal well depth, to consider the uncertainty in the geofluid temperature as a function of the depth, and by varying the time of operation of the district heating and cooling network. Additionally, the economic analysis was performed by considering two different scenarios with and without feed-in tariffs. Based on the assumptions made, the system is economically feasible only if feed-in tariffs are considered: the minimum Simple Pay Back period is 7.00 years, corresponding to a Discounted Pay Back period of 8.84 years, and the maximum Net Present Value is 6.11 M€, corresponding to a Profit Index of 77.9% and a maximum Internal Rate of Return of 13.0%. The system allows avoiding exploitation of 27.2 GWh of primary energy yearly, corresponding to 5.49∙103 tons of CO2 avoided emissions. The increase of the time of the operation increases the economic profitability. [ABSTRACT FROM AUTHOR]

Nowadays, due also to high hygrothermal comfort requirements, the energy consumption for heating/cooling of modern trains can reach 30% of the related overall electricity demand. Energy-saving of train Heating, Ventilation and Air Conditioning systems can be suitably assessed through dynamic simulation approaches. Specifically, the weather solicitation has to be dynamically accounted for by considering the actual moving train location and orientation. Through such methodology different innovative actions for energy efficiency, environmental impact reduction and comfort enhancement can be analysed by also assessing their economic feasibility. In this paper, a novel simulation tool for the complete performance analysis of trains was developed in TRNSYS environment. To show the capabilities of the considered approach, a novel case study referred to an existing medium-distance train operating in South Italy is presented. Heating/cooling loads and demands, and the related electricity requirements, are dynamically assessed for the standard and revamped train. Several energy saving actions are considered for the coupling between the envelope and the Heating, Ventilation and Air Conditioning systems enhancement. The obtained results return significant benefits in terms of energy saving, avoided CO 2 emissions and comfort. Paybacks depend on operating conditions. Useful design and operating criteria for trains manufacturers and users are provided. • Dynamic simulation for train HVAC system energy performance analyses using TRNSYS. • Customized weather data files for accounting real train locations and orientations. • Innovative energy efficiency solutions for trains with saving up to 6.0 MWh e /y. • Economic feasibility of energy efficiency solutions for trains. • Reduction up to 50% of the train environmental impact. [ABSTRACT FROM AUTHOR]

The paper deals with the multi-objective optimization of the HVAC control in museums. Scientific literature, technical standards and museums stakeholders mainly focus on the single-objective of artefacts conservation. However, a major attention should be paid at visitors' comfort and energy consumption, without compromizing artwork integrity. In this work, we propose and apply a methodology to find the best control of the air-handling unit to concurrently optimize the three objectives. The proposed methodology is based on the achievement function method and finds the Pareto-optimal value of the HVAC control variables over the operational period. The priority given to each objective can be customized by changing the reference point of the achievement function. The method is applied to a museum in Italy hosting paper artworks during summer. Both exhibition room and HVAC system are simulated through an in-house dynamic model. The results show that all three objectives are improved with respect to typical fixed setpoint values (i.e., T = 23 °C and RH = 50%). Depending on the reference point, different profiles of indoor hygrothermal parameters are found; in any case, improvements of each of the objective functions indexes (equivalent lifetime multiplier for artwork preservation, predicted percentage of dissatisfied, and energy consumption) are obtained with respect to fixed setpoint strategy. The multi-objective optimization of museums with paper artworks in summer periods encourages low indoor temperatures. This would lead to slightly increased energy consumptions, which can be limited, by reducing the ventilation rate to 3–3.5 1/h instead of the typical 4–5 1/h. • The multi-objective methodology optimizes museums HVAC control in each timestep. • Objective functions are artwork preservation, visitors' comfort, and energy saving. • Objectives priority is chosen by changing the optimization reference point. • All objectives are concurrently improved with respect to fixed-setpoint strategies. • A case study compares different control strategies and objectives priorities. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The Italian building stock consists of buildings mainly constructed until the mid-20th century using pre-industrial construction techniques. These buildings require energy refurbishment that takes into account the preservation of their architectural heritage. In this view, this work studies an innovative integrated modelling and simulation framework consisting of the implementation of Historical Building Information Modeling (HBIM) for the energy retrofit of historical buildings with renewable geothermal HVAC system. To this aim, the field case study is part of a medieval complex in Central Italy (Perugia), as representative ancient rural offshore architecture in the European countryside. The system involves of a ground source heat pump, a water tank for thermal-energy storage connected to a low-temperature radiant system, and an air-handling unit. The building heating energy performance, typically influenced by thermal inertia in historical buildings, when coupled to the novel HVAC system, is comparatively assessed against a traditional scenario implementing a natural-gas boiler, and made inter-operative within the HBIM ad hoc platform. Results show that the innovative renewable energy system provides relevant benefits while preserving minor visual and architectural impact within the historical complex, and also in terms of both energy saving, CO2 emissions offset, and operation costs compared to the traditional existing system. The integrated HBIM approach may effectively drive the path toward regeneration and re-functioning of heritage in Europe. [ABSTRACT FROM AUTHOR]

• Modelling and simulation of the proposed novel V2B2 energy schemes. • Use of electric vehicles and renewable energy technologies in clusters of buildings. • Analysis of the electricity transfer among buildings through electric vehicles. • Comprehensive parametric analysis for the energy and economic optimization. • Energy and economic performance guidelines for design and operating settings. This paper focuses on the energy and economic analysis of the Building To Vehicle To Building (V2B2) concept, conducted through a comprehensive parametric and sensitivity analysis. The idea behind this novel vehicle to building energy management is to exploit the use of electric vehicles as energy vectors to exchange electricity among buildings with the aim to accelerate the development of a novel zero energy paradigm, while promoting the deployment of renewable energy sources, accelerating the widespread usage of electric vehicles, and streamlining the regulation of charging stations in our future communities. In order to evaluate the potentials of the proposed schemes, a comprehensive parametric analysis is conducted to size the design and operating parameters which maximize the self-production and self-consumption of building integrated renewable energy technologies at a cluster level. The paper investigates the energy and economic performance of different V2B2 energy management schemes including a residential building, an office building, and an electric vehicle, which feature a basic cluster of human-linked energy consumers. The study is conducted by means of a novel in-house developed dynamic simulation tool, suitably enhanced to model the system operation. Numerical results, obtained for a representative weather zone (Mediterranean climate of Naples, South-Italy), show that through the V2B2 scheme, a remarkable exploitation of off-site renewable energy production is achieved, producing a significant reduction of fossil fuel consumption from the grid. [ABSTRACT FROM AUTHOR]

Natural materials, such as straw bale and earth, have substantially less embodied energy than processed materials, so that their use in building construction can give a valuable contribution to sustainability. This paper presents a natural multi-sheet wall package (named straw wall, SW) consisting of straw bale layer and innovative natural plasters, giving a rational evaluation of its potential of use in the sustainable building construction. The new building component was investigated by analyzing its environmental impact through the Life Cycle Assessment (LCA) from "Cradle to Gate" and its energy performance using dynamic simulation of a building case study; the energy saving potential of SW was assessed in different climate conditions in Italy. The innovative package highlighted excellent energy performance with respect to the NZEB reference, as prescribed by the Italian regulation, for all climates. Considering only the production and construction phases, the Embodied Energy associated to the innovative wall system is about the half of the value related to a traditional wall package and the CO 2 equivalent emissions differ by more than 40%(Pescara site). [ABSTRACT FROM AUTHOR]