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In this paper the results of a wide investigation on a geothermal-integrated air HVAC system are reported: in the first part, the energy performances of an Earth to Air Heat eXchanger (EAHX) operating in Pomezia (a locality of the area of Rome, Italy) are carried out through a comprehensive numerical two-dimensional model based on the finite element method and the system is forced under real time-changing weather conditions over 1 year. The model is able to reproduce the time- and space- dependent thermo-fluid-dynamic behavior of the EAHX system, the humid air flux and the surrounding soil, as well as to account for the mass of condensed water in the tubes. In the second part of the investigation, the EAHX is coupled to an air handling unit of a company building for office use and tested while operating both in cooling and heating mode. The hourly results, in terms of power savings and energy consumption were reported for representative days of all the months belonging to the cooling or the heating working seasons, monthly and seasonal assessment. The convenience in terms of seasonal energy savings is +40.8% in cooling mode and +44.1% in heating mode. Then, the economic impact in terms of payback time and net present value was investigated through a cost analysis to examine the return of the economic investment under two possible soil morphologies and different prices of electrical energy in Italy. The simple payback with the real price of energy in Italy (0.50 €/kWh) is 3.3 years for the tufa-soil and 5.8 years for soft rock-soil; the economic return in terms of net present value is around 500 k€ for both the morphologies (560 k€ for the tufa; 446 k€ for the soft rock), per effect of the energy saving and, consequently, for a reduced expense of electrical energy. Therefore, in all the considered cases the installation of EAHX systems in support of traditional systems would generate both energy and economic advantages. [ABSTRACT FROM AUTHOR]

This paper describes the results of experimental tests and computer simulation modelling aimed at evaluating the performance of an electrochromic (EC) window with respect to solar radiation control and the relative impact on the energy consumption of buildings of the residential type for two typical Italian climates. The research is carried out by a test-cell equipped with a small area EC double glazing unit and by a simulation program of buildings’ energy behaviour in transient regime. The experimental results show that EC devices which modulate solar radiation mainly by absorption, like the one investigated in this paper, generate secondary solar heat gains which entails a 20% decrease of the maximum potential energy flux reduction. Also, this effect could rise the temperature of the internal glass pane of the glazing to levels for which risk of thermal discomfort for the occupants may occur. The computer simulation modelling involves a residential building unoccupied during a large fraction of daytime in weekdays. The savings potential of the investigated EC window are calculated relative to a conventional clear float double glazing unit. Results show that the EC glazing may lead to a considerable decrease of the cooling energy demand (and of the total building energy consumption) in cooling dominated climates. The energy saving benefits become less marked in heating dominated climates and, for low values of the window-to-wall ratio, can be overcame by the increase in lighting and heating energy requirements that results in an increase of the total building energy demand. [ABSTRACT FROM AUTHOR]

Energy efficiency is one of the main pillars of the European energy strategy and it involves all the economic sectors. The present study proposes an analysis of the energy saving opportunities available in the Italian hotel sector, which has a relevant importance in the national context. The paper introduces a comprehensive model of the Italian hotel sector developed in the LEAP (Long-range Energy Alternatives Planning) environment. The first aim is to estimate the baseline of the consumption, then to evaluate the maximum potential energy saving and, finally, to assess the implementation of a realistic energy efficiency scenario. The paper demonstrates that it may be possible to achieve primary energy savings of 1.6 TWh (13%) in 2030 by implementing financially sustainable energy efficiency measures. [ABSTRACT FROM AUTHOR]

The present paper illustrates the Italian pilot action of the EASEE project (Envelope Approach to improve Sustainability and Energy Efficiency in existing multi-storey multi owner residential buildings), focusing on the analysis of energy refurbishment trends of the Lombardy region residential building stock. More than 60% of the existing building stock in Lombardy region has been built before the 70 s and it is among the main responsible causes of final energy absorption and corresponding CO 2 emissions with a mean primary energy index for heating of about 202.0 kWh/m 2 y. The promotion of renovation measures for such buildings, also through innovative solutions, is becoming increasingly important for both containing the greenhouse gas emissions and supporting the growth of the construction sector. To this topic, the work presents the energy renovation of a residential building in the Province of Milan through the application of innovative prefabricated composite panels that integrate both thermal insulation and exterior finishing with textile reinforced mortar. In detail, the paper describes, on one hand, the main design strategies following the preliminary analysis and, on the other hand, the whole installation process; besides, the performance of the retrofitted envelope is documented by the results of the monitoring campaign. [ABSTRACT FROM AUTHOR]

Highlights • The impact of new Italian weather data on building simulation was analysed. • Two simulations were carried out with a dated and an up-dated dataset, for 52 locations. • Italian representative multifamily house models were used. • For each model, two cases were studied: uninsulated and insulated constructions. • The results highlight great differences in ideal energy. Abstract Dynamic thermal simulation is attracting the interest of designers thanks to the availability of numerical codes. However, one of the main problems facing the potential users is hourly-weather data availability. In Italy, the main source for the data is drawn upon the IGDG database. It is provided by the EnergyPlus weather site and the related measurements were collected between 1951 and 1970. A new set of files, gathered between 1989 and 2014, has recently become available. Nevertheless, it needs additional work to be directly implemented in energy simulation codes, which can lead users to download and apply the already available IGDG database files. In order to evaluate the ensuing effects, 52 Italian weather file locations were selected, and two simulations were carried out on seven multifamily-house models considering the difference between the results obtained using the old and new weather data. Since the locations of the two databases do not coincide, a matching method was implemented. This paper compares the simulation results arising from the choice of the weather file pertaining to the two databases. The weather files were selected within a 50 km range and 50 m elevation difference, to minimize misrepresentative results due to different climatic conditions. The models are typical of the most widespread building typology of the Italian building stock. For each model, two building fabric types were considered, the former was poorly insulated, the latter was well insulated thanks to an advanced refurbishment activity. Simulations were carried out with the EnergyPlus software. [ABSTRACT FROM AUTHOR]

The cost-optimal analysis represents a useful tool to stimulate the refurbishment of existing buildings, highlighting the minimal global cost that private or public users have to sustain in order to attain appreciable energy savings in the building life span. The identification of precise interventions on the building-plant system could steer legislators to the emanation of appropriate financial incentives in order to make the refurbishment of existing edifices more attractive. However, the cost-optimal solutions cannot be generalized as they are strongly influenced by the initial conditions and by the climatic context. In this paper, a traditional social housing unit, realized in Italy during the 1970s, largely widespread and strongly energy-consuming, was analysed in two different climatic zones belonging to the Italian territory. Suitable interventions were identified for the reduction of energy requirements for heating, cooling and domestic hot water production. These analyses were carried out by using the same simulation tool for energy and economic performances, highlighting the deviances among the cost-optimal solutions, the n-ZEB target and the minimal interventions for the containment of energy consumptions imposed by the current Italian legislation for buildings subjected to refurbishment. [ABSTRACT FROM AUTHOR]

To promote energy saving in the residential sector Directive 2012/27/EU has set the obligation for buildings supplied by central heating sources to install individual heat metering and accounting systems. However, in social housing, bills based exclusively on individual consumption should be unfair due to some unfavourable situations, such as first and top floors, presence of unheated common spaces, north oriented dwellings. Nevertheless, fair heat accounting rules should be introduced especially in social housing buildings, which are often thermally underperforming with inefficient heating plants and tenants are commonly low-income people and elderly. On the other hand, common regulations for heat accounting providing compensation to avoid inequalities among tenants have not been set and different approaches on this topic are present among EU Member States. In this paper the authors present a new heat accounting method for social housing based on the estimation of extra-consumptions due to building inefficiencies. According to this method, extra-consumptions are charged to all tenants in order to encourage energy efficient retrofit interventions. Finally, the new method has been experimented in a typical social housing building in Italy and compared to other methods applicable in EU, evidencing some advantages and weaknesses. [ABSTRACT FROM AUTHOR]

Historic buildings constitute a large amount of the European building stock and their preservation is of paramount importance for cultural, economic and also environmental reasons, as their conservation is regarded as more sustainable with respect to demolition and reconstruction. However, historic buildings require frequent repair and conservation works, whose environmental impact is still to be evaluated. In the present paper the sustainability of conservation intervention is evaluated by the LCA analysis method, focusing in particular on cleaning materials and technologies, with reference to conservation sites located in Bologna, Italy. After identifying the most used cleaning materials and technologies, the time necessary for achieving an equal cleaning effectiveness was selected as functional unit and the LCA analysis was carried out, along with a quantitative evaluation of some other key aspects of the different methods (workers’ health, acoustic impact and waste produced in the building site). The results highlight that the different technologies involve remarkably different environmental impacts, but that in some cases their impact could be easily reduced by substituting some secondary materials in the cleaning process, without affecting the effectiveness of cleaning. The results also show that the methods involving the lowest environmental impact are not necessarily the best ones in terms of safety and waste production in the building site. [ABSTRACT FROM AUTHOR]

• Data about DHW in residential buildings were collected by survey in Southern Italy. • Contextual and personal factors influencing DHW usage were considered. • Descriptive statistics were performed to characterize DHW by climatic zone. • Inferential statistics were conducted to discover DHW usage patterns. • Four clusters of dwellings were identified considering DHW daily usage hours. In European efficient buildings, the share of energy use for DHW is a significant percentage of the heat requirement. The evaluation of DHW energy demand and consumption patterns has been neglected in the past and studies are located in Northern countries. This paper presents a survey conducted in Southern Italy. Descriptive statistics were performed to characterize DHW production by climatic zone. Inferential statistics were conducted to discover significant contextual and personal variables and identify usage groups. The most used energy source was biomass (49.3%), followed by methane gas (37.7%). Fireplaces were installed in the coldest zone, in detached houses, more in small municipalities (36%), and low-income families (32%). Solar systems were in 8% of dwellings having income higher than 28000€. Four clusters of dwellings were identified considering the daily usage hours. The eldest and less numerous households fell into the cluster with the lowest usage (3.5 h). Households with a percentage <25% of unemployed components had more probability to belong to clusters with more DHW usages. The paper contributes to fill the investigation in the Mediterranean area and provides a systematic approach to expand the limited knowledge about the influencing factors on the DHW production and usage. [ABSTRACT FROM AUTHOR]

• An integrated energy-economic analysis of Net ZEB office buildings was proposed. • A thorough discussion on the energy balance was provided for Italian climate zones. • Energy grid integrations, self-consumption, storage and losses were analyzed. • The cost assessment of office buildings was performed and compared to state-of-art. • The energy-economic benefit of a new Net ZEB office in Italy was demonstrated. Recently, the built environment has become one of the leading sectors in the challenge of decarbonization and energy consumption reduction. Because of the specific use and the complexity of the typological, architectural, and technical characteristics, non-residential buildings represent a challenge to overcome the nearly Zero Energy Building standard and to achieve the objective of Zero or Net Zero Energy Buildings. It is desirable that the energy produced in situ from renewable sources totally covers the energy demand (ZEB); alternatively, the amount of energy self-produced and dispatched into the grid must be greater than (or equal to) the energy withdrawn from the grid (Net ZEB). At the same time, it is necessary not to neglect the economic aspects. The aim of this work is to propose an integrated energy-economic analysis to demonstrate the actual feasibility of new Net ZEB offices in different Italian climate zones. Thus, the energy analysis of a reference building, based on consolidated and cost-effective envelope and HVAC systems, has been carried out through dynamic simulations. The photovoltaic field located on the roof provides the energy needed for lighting, appliances, and HVAC. The obtained results are the energy demand and the energy production from renewable sources for the case study in each Italian climate zone. Moreover, the paper discusses the complexity of the annual energy balance, considering contributions such as grid integrations, self-consumption, energy stored and losses. Finally, the cost assessment of the proposed building has been carried out and compared to the state-of-art, pointing out the economic feasibility of the Net ZEB. [ABSTRACT FROM AUTHOR]

Consistent climate data and reliable sizing methods are fundamental for designing Technical Building Systems. This paper addresses both these aspects with reference to the Italian context analyzing 108 different locations. Regarding the climate data, a quality analysis through the application of rules and filters was performed on the locations. The results showed good data quality, with most sites having high percentages of usable material, although highlighting recursive criticalities in the detection of humidity and wind speed parameters. Regarding the sizing methods, a sensitivity analysis was carried on for the European standard EN ISO 15927-2 to evaluate its performances in selecting the Cooling Design Days in the 108 locations. The analysis highlighted great differences in terms of chosen Design Days when using different climatic parameters, showing at the same time a negligible influence of the wind speed on the selection process. Furthermore, a sizing process for a test building applied to the 108 locations was carried on by using the Cooling Design Days. The results highlighted that the Design Days obtained through the EN ISO method often give counterintuitive sizing outputs, even obtaining higher required powers for lower risk levels, the opposite of how it should be. This implies that a designer should be very careful in evaluating which parameters to use in the Design Day selection and if the output sizing powers obtained through them are reliable for its particular sizing process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dynamic evaluation of economic and energy benefits due to thermostatic valve installation. • Dynamic evaluation of economic and energy benefits due to heat metering installation. • The adoption of both thermostatic valves and heat metering least to a payback period lower than 2 years. • Analysis carried out considering several shapes of typical building. The aim of this paper is to propose a novel approach in order to accurately calculate the energy and economic savings due to the use of heat metering and thermostatic valves in residential buildings. The paper aims at proving that the present simplified approaches used in European Legislation may lead to significantly underestimate the profitability of this technology. The study is developed for four different typologies of buildings located in the city of Naples (South of Italy), including their geometrical and thermophysical properties. The buildings are first modelled in Google Sketchup and subsequently linked to the TRNSYS environment, which also includes a detailed model of the piping systems. The models allow one to evaluate, for every period of the year, energy demand, energy supplied by radiators, heat gains, transmission, etc. The developed models are used to calculate energy demands for three scenarios for each type of building: centralized heating systems not equipped with heat metering; thermostatic valves without heat metering; heat metering and thermostatic valves. The possible savings related to thermostatic valves and heat metering are estimated using the developed model. The results are compared with the ones provided by the Italian Standards. Results show that the thermostatic valves adoption leads to a significant reduction, up to 50%, of the thermal energy demand of the residential buildings and that all the proposed systems exhibit a remarkable economic profitability, with a payback period lower than 1.7 years. [ABSTRACT FROM AUTHOR]

Non-residential buildings like healthcare ones contribute to energy consumption and cause a negative environmental impact. This is mainly due to the age of the buildings, their poor level of energy efficiency and the implementation of only a basic maintenance plan. Owing to the very limited budget available for public administrators, Energy Performance Contracting (EPC), that entails the involvement of an Energy Service Company (ESCo), can provide the entire or part of the capital needed for investments aimed at progressively increasing energy efficiency over their service life. In this paper, three acute hospitals and two community clinics built in Italy are analysed, in order to assess the economic feasibility of several energy renovation actions that can be included within EPC contracts. To this purpose, the outcomes of energy audits carried out in 2014 about these buildings are reported, which involved analyses of consumption measured over the previous three years and assessment of use profiles for the development of models to break down the overall consumption and to estimate potential savings. Diverse improvement strategies were assessed, consisting in either isolated or combined renovation actions and tested on the five buildings, whose comparison was carried out in terms of energy saving, pollution reduction and economic feasibility. As a result, the best combined renovation actions per each hospital were recommended, that included – but were not limited to – the improvement of the control and regulation of existing sub-systems without replacement, partial replacement of other sub-systems and integration of renewables. Finally, each scenario was evaluated through the payback period and other economic performance indexes in order to assess the feasibility of the EPC framework when applied to this case study. [ABSTRACT FROM AUTHOR]

The application of retrofit actions to existing building stocks can improve the energy performance of the residential sector. In this context, particular attention should be given to historical buildings, which represent a large part of the Italian building stock. To improve the energy performance of them, adequate retrofit actions must be applied. Many studies and regulations have focused on identifying the best refurbishment measures. However, the selection of these measures is difficult due to restrictive regulations, which are dictated by the Ministry of Cultural Heritage and Activities, high retrofit costs, and variable climate zones. Thus, energy renovations in Italian buildings are not simple, and it is very difficult to find generic solutions that can be applied to buildings across the entire territory. In this paper, the authors investigated the most common retrofit solutions used in Italy, focusing in particular on the energy performance of historical building envelopes. First, energy performance analyses were conducted for two typical base cases in four different Italian cities using TRNSYS software, and some common retrofit measures were analysed. In some cases, the results showed Primary Energy saving of 44.6% (sample A) and 56.7% (sample B). Furthermore, these were used to identify different energy and economic impacts associated with the same refurbishment measures in different climatic contexts, highlighting the non-existence of a generic solution suitable for all regions or countries. [ABSTRACT FROM AUTHOR]

Abstract: An understanding of the energy performance in buildings in an entire municipality or an entire district is important for sustainable energy planning strategies that accelerate the energy renovation process in existing buildings that are not energy efficient. The methodology described in this paper is largely based on information that is already available on building stock (i.e., cartographic documentation, thematic maps, geometric data and others). Data regarding the energy performance of buildings are collected using energy audits on sample buildings, which are selected using a statistical approach. Using the tools in a GIS platform, the integration of two data sources allows for a low cost, comprehensive framework of the energy performance of buildings. This methodology was tested in a medium sized town in the Lombardy region (Italy), and the results are discussed in this paper. [Copyright &y& Elsevier]

[Display omitted] • A research topic relatively new but with an increase interest in the last five years. • The largest scientific contribution from China, Australia and Italy. • The main journals in the field Building and Environment and Energy and Buildings. • Three main direction of research: thermal energy performance of buildings, ecological benefits and reducing the urban heat. • The main limitation of using green walls is the high cost of installing and maintenance. The continuous state of development of the human society imply a big effort and demand to generate and use more and more energy to power our lifestyle. The impact of human activity has negative effects on the environment and thus solutions to maintain or increase our development rate but in the same time to decrease the pressure on the environment must be developed. In this context, the purpose of this paper is to investigate if the use of green walls systems can be a solution to decrease the energy demands in buildings. The investigation include a bibliometric literature research, a scientometric analysis and an in-depth discussion. The data used for the research were obtained by interrogating the ISI Web of Science and Scopus databases, were selected using the guidelines of the PRISMA method and processed with the help of VOSviewer and Bibliometrix software. The research results indicate an increase interest in this topic in the last five years and that the use of vegetation in the constructed grey areas can bring a lot of benefits especially from environmental point of view. Green walls can be a solution to decrease the temperature on the wall surface in hot summer days and to prevent heat loses in the winter time, and thus have beneficial effects on the amount of energy required to maintain a proper interior temperature. The main limitation of using green walls is given by higher costs of installing and maintain the vegetation on walls, thus, finding new more economical, systems of green walls must be developed in the future. Considering all of this it can be state that green wall systems have the potential to become good solutions not just to improve the energy efficiency of buildings but also to create more sustainable urban areas. [ABSTRACT FROM AUTHOR]

• The resilience of a building designed to be nearly zero energy is evaluated in Mediterranean climate. • Weather file defined with monitored data are used for a short-term analysis. • Projections of climate changes are considered in the construction of weather files. • The net primary energy will decrease (–23%) and the in-situ renewable adoption will increase (85%). • Overheating will occur in the intermediate months with the need to turned on the cooling system. The paper is focused on the evaluation of how the climate changes can influence the performance of buildings designed to be nearly zero energy (nZEB) and on the evaluation of the resilience in term of energy balance. A real case study is used; it is named BNZEB, a single-storey dwelling built in Benevento (South Italy, Mediterranean climate). With five-years monitored meteorological data, both a short-term and medium-term analysis is developed; the first one consists in the evaluation of the energy behavior compared to the first operating year. Then, the energy performance is evaluated considering the medium-term climate projections generated using the CCWorldWeatherGen tool. This analysis, with reference to the case study, suggests to designers and researchers that, in a typical Mediterranean climate, the reduction of the heating demand could compensate the increment in the cooling request. In the worst climatic scenario, the net primary energy could change from 25.4 kWh/m2 year (first year of life, 2017) to 19.5 kWh/m2 year (projection to 2050) with a rate of self-consumption of 85% (80% for 2017). However, a critical point is the operating period of the cooling system. Indeed, an indoor overheating problem could occur during the spring with operative temperature higher than 30 °C; this indicates that in future, the occupants will require higher number of operating hours with most frequent switch off. This could change the results of the energy balance, reducing, for instance, the imbalance between production and consumption that currently occurs in the intermediate periods. [ABSTRACT FROM AUTHOR]

The high cost of energy, along with an urgent need to reduce global worming causing emissions, has contributed to the rethinking of contemporary design and building techniques. It also brought to the forefront the need to increase the energy performance of heritage buildings. Italy's Abruzzo region has many small towns with old structures. The earthquake that struck the area in 2009 caused significant destruction to many communities and buildings. The need to rebuild led to a series of interventions aiming not only at reconstructing, but also at increasing the structure's energy performance. This paper describes a study of Abruzzo's historic buildings and proposes interventions to improve their energy-efficiency. The authors developed a methodology based on an on-site investigation and the study of compatible possible solutions. The first phase includes a series of thermal measurements, using both indirect and qualitative methods such as thermography and direct and quantitative methods. With the information gathered, it was possible to verify the energy performance of each solution based on the level of invasiveness of the proposed intervention. The proposed methodology serves as a guide to recovery design, using a “case by case” approach to identify the method of intervention in each value context. [ABSTRACT FROM AUTHOR]

Abstract: The paper presents an energy and environmental extended input–output model combined with the life cycle assessment, applied to assess the energy and environmental benefits arising from the Italian policy of tax deduction for energy retrofit actions of buildings. The study allowed to assess the advantages due to the above policy, taking into account both direct and indirect energy saving and avoided CO2 emissions obtained with the retrofit actions and indirect energy consumption and related CO2 emissions due to the realization of the above actions. Moreover, the authors defined an original model to assess the indirect rebound effect caused by the energy saving actions. The obtained results showed that a reliable evaluation of the benefits arising from sustainable policies strongly depends on the indirect rate of the energy consumption and energy saving, that in the examined case study has the same order of magnitude of the direct one, and on the rebound effect, that can partially avoid the obtained benefits. The study represents one of the first Italian experiences aimed at assessing the effectiveness of sustainable production and consumption strategies. It can be used to support decision-makers in the selection of policies aimed at reducing energy and environmental impacts caused by final consumptions. [Copyright &y& Elsevier]

Abstract: The paper presents a methodology that has been developed and implemented for the simulation of electricity use (kWh) as well as electricity pricing (c€/kWh) in buildings. In the simulation, electricity pricing has been treated as dependent on electricity use as energy pricing tariffs usually discriminate between specific electricity consumption zones, time periods, etc. Pricing and electricity use, together, may then provide an estimation of the building electric energy cost (€). The simulation runs on an hourly resolution allowing to highlight some potential wasteful and costly practices in energy use and management and providing insight to user behavior, which has been a key driver for its development. The key aspects of the simulation approach are presented and its use is demonstrated in two different buildings in Greece and Italy. The methodology is now adapted to allow for neural network based, real time training, which will also be briefly introduced. [Copyright &y& Elsevier]

Abstract: The energy policy about energy performance of buildings, including minimum energy requirements and energy performance certificate (EPC), is applied to new and existing buildings, especially in the case of energy retrofit. Among existing buildings, heritage buildings are a special case. Another problem is finding an evaluation and measurement tool for town energy consumption which is related to the age and the characteristics of existing buildings. This problem concerns both urban planning discipline and heritage buildings discipline. The introduction of EPC database in Emilia-Romagna legislation (a region located in the North-East of Italy) is an opportunity to perform studies and simulation, in addition to GIS networking elaboration. This paper deals with the case of Ferrara, an old town, in order to debate: [-] number and energy incidence of heritage buildings; [-] influence of typology factor for energy saving in heritage buildings; [-] use of GIS tools to refer EPC, energy class in order to suggest a zone energy indicator (ZEI) for measuring the city and the old town. [Copyright &y& Elsevier]

Abstract: This paper introduces a comparison of different measuring methods of buildings fabric thermal resistance, including the test wall measuring points arrangements and measurement results, conducted in a test chamber in Cagliari (Italy) in summer 2009. Two methods and their measurement uncertainties are presented and compared by the compatibility of measurement study. The non-destructive method involves the heat-flow rate measurement through the test wall and its surface temperatures. The reliability of this method depends on the temperatures difference between the two environments separated by the building envelope. Thus two measurement series with different temperatures were carried out on the test wall. The destructive method instead foresees the acquisition of a sample by the use of a hollow drill, the building envelope layers thickness measurement and the thermal properties assignment to each different material. The wall R-value is the sum of each layer thermal resistance. The comparison shows that the R-values measured by the non-destructive method with a temperature difference of 10°C and 7°C and the one calculated from the destructive method obey the compatibility of measurement principle. [Copyright &y& Elsevier]

Abstract: In this paper the thermal behaviour of a rainscreen ventilated façade has been investigated both experimentally and numerically. Field measurements were performed during the 2009/10 winter season in a test building located in San Mauro Pascoli (Italy) having a squared base of internal dimension of 2.89m and a total internal height of 7.75m. The external walls of this tower are rainscreen ventilated façades with a 24cm air cavity and an external side composed of stoneware with open joints. Ventilation grills are located at the top and at the bottom of the tower. In this work the modelling of the test building using a dynamic thermal simulation program (ESP-r) is presented and the main results discussed. In order to study the rainscreen ventilated façade three different multi-zone models were defined and the comparison with the experimental results has been used in order to select the best ESP-r air flow network for the modelling of this kind of envelope component. The thermal analysis of this envelope component evidenced that the ventilated façade is able to reverse the direction of the heat flux through the envelope in regions characterized by large solar irradiation during the winter and moderate wind velocity, when the indoor–outdoor air temperature difference is small, thereby reducing the energy consumption required for indoor heating. [Copyright &y& Elsevier]

Abstract: The energy policy in Europe regarding buildings and the energy efficiency sector are regulated by two directives: 2002/91/CE – EPBD and 2006/32/CE – EEESD . The CEN has elaborated a standard to revise all European normatives about building energy performance and HVAC plants. The “CEN Umbrella” CEN/TR 15615 includes a new version of EN ISO 13790:2008 and a new standard about heating plant, use and contributions of renewable energy sources. Furthermore, the CEN Standard provides a software version for technicians. In this paper we present a Round Robin Test between a selection of softwares applied to an Italian case study. The selected calculation methodologies, range from research packages to extra-simplified software. Furthermore, the Italian procedure described in UNI TS 11300 has been analyzed and considered as the reference for all other calculation methodologies. The results of the Round Robin Test show the relationship between thoroughness of data input and energy evaluation accurancy. The more the input data is affected by uncertainty, the less precise is the energy efficiency calculation. On the other hand the energy performance of building evaluation accurancy depends on the aim of the simulation: the energy audit, the energy design or the energy labeling (certification). [ABSTRACT FROM AUTHOR]

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]

This paper reports on a study on the evolutionary impact of vegetation in a newly built square in Milan designed by V. Gregotti. The aim of the work is to evaluate the impact of vegetation growth on users’ comfort. The methodology adopted involves: sets of field measures (air and radiant temperature, wind velocity and relative humidity); a simplified thermal comfort evaluation with the energy budget method COMFA; and a scenario for the vegetation growth. When trees become adult we can observe different phenomena. The shading effect under an aged tree canopy clearly shows a reduction of the absorbed radiation by users, generating an energy budget very close to comfort (under 50 W/m2) even with a high air temperature. In the case of points exposed to direct sunlight all day long, tree growth reveals two phenomena of the global radiation absorbed by a user: (1) reduction, by the tree screening effect, of absorption of the diffuse solar global radiation, and (2) increase, by the elevation of the objects viewed in the sky hemisphere, in absorption of the terrestrial radiation. [Copyright &y& Elsevier]

This paper presents an energy analysis of the school buildings of a province in central Italy. The analysis is aimed at calculating the main thermal and electric energy consumption indexes to determine the status of energy consumption and the possible intervention to save energy in the school sector. Two applications of energy auditing to school buildings are also presented.It is also shown that if the optimal energy consumption indexes could be valid for all the school buildings, thermal energy savings could reach 38% and electric energy consumptions could be reduced by over 46%. [Copyright &y& Elsevier]

• University buildings must be safe, secure and suitable for an "in-presence" education. • Architectural and technological retrofits are necessary to face the COVID-19. • HVAC-related measures anti-contagion need studies in both time and space domains. • A numerical model of a University building, calibrated against measurements, is proposed. • The design of refurbishment is performed by coupled numerical methods, BES and CFD. The proposed investigation is aimed at providing useful suggestions and guidelines for the renovation of educational buildings, in order to do University classrooms safe and sustainable indoor places, with respect to the 2020 SARS-CoV-2 global pandemic. Classrooms and common spaces have to be thought again, for a new "in-presence" life, after the recent worldwide emergency following the spring 2020 pandemic diffusion of COVID-19. In this paper, starting from a real case study, and thus the architectural and technological refurbishment of an Italian University building (Campobasso, South Italy, cold climate), with the aims of improving the classrooms' quality and safety, a comprehensive approach for the retrofit design is proposed. By taking into account the necessary come back to classrooms starting, hopefully, from the next months (Autumn 2020), experimental studies (monitoring and investigations of the current energy performances) are followed by the coupling of different numerical methods of investigations, and thus building performance simulations, under transient conditions of heat transfer, and computational fluid dynamics studies, to evidence criticalities and potentialities to designers involved in the re-thinking of indoor spaces hosting multiple persons, with quite high occupancy patterns. Both energy impacts, in terms of monthly and annual increase of energy demands due to higher mechanical ventilation, and indoor distribution of microclimatic parameters (i.e., temperature, airspeed, age of air) are here investigated, by proposing new scenarios and evidencing the usefulness of HVAC systems, equipment (e.g., sensible heat recovery, without flows' contamination) and suitability of some strategies for the air distribution systems (ceiling squared and linear slot diffusers) compared to traditional ones. [ABSTRACT FROM AUTHOR]

In the energy simulation of buildings there has been little focus on their impact on the microclimate; simulation tools have usually dealt either with building or with outdoor simulation, and only recently these aspects are being interconnected. Within this framework, the paper describes a novel simulation workflow developed in the Grasshopper environment, where the Ladybug Tools are used to model the mutual relations amongst urban microclimate, building energy performance and outdoor thermal comfort. With reference to an urban canyon located in Catania, Southern Italy, the workflow – by coupling the indoor and the outdoor thermal field – provides both the dynamic thermal load of the buildings overlooking the canyon and the parameters needed to measure the outdoor comfort perceived by pedestrians. In comparison to other existing approaches, this workflow offers significant flexibility and makes it possible to perform a parametric investigation of the effects of different design solutions on both the indoor and the outdoor environment. The outdoor Mean Radiant Temperature calculated through the model is compared to on-site measurements performed with a black globe thermometer during two different days in the summer. The comparison suggests good agreement in the shaded areas of the canyon, but a non-negligible overestimation in sunlit areas. These results have driven the authors to a critical insight into the algorithms implanted in the Ladybug Tools, and have helped to highlight some critical issues that will be further investigated in upcoming research. [ABSTRACT FROM AUTHOR]

• Investigating the impact of different materials adjacent to the air cavities of ventilated facades. • Experimental evaluation on three prototypes in summer and winter. • The thermal mass in the outer side of the gap enhanced the stack effect. • The thermal mass in the inner side of the gap increased the heat transfer towards the indoor. In this paper we have investigated how different materials and thermal masses impact on the performance of ventilated facades with narrow cavities, by measuring the variation in terms of heat flows and ventilation efficiency. While geometry has been widely explored, the role of wall composition has received much less attention. To bridge the gap, three real-scale prototypes of ventilated facades were built and tested all over the year on a mock-up in Central Italy: (i) L, with a lightweight external enclosure, as a baseline reference, (ii) IM, with a massive layer enclosed in the gap and (iii) EM, with an external massive cladding. The results demonstrated that the EM solution more effectively mitigated the average surface temperatures (both external and internal), with values of –2 °C and –1 °C in summer and of –3 °C and –0.5 °C in winter, when compared to the L solution. Moreover, in the EM case, the ventilated cavity reduced both the incoming and outgoing heat fluxes, since the outer mass operated as a thermal buffer between the outdoor and the ventilation chamber. Conversely, the presence of an internal mass determined an increase of the heat transfer towards the indoor environment. The position of the thermal mass in the outer layer also increased the air velocity in the gap thus enhancing the stack effect. [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]