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Zero-energy and zero-carbon buildings would be a huge opportunity for contrasting the climatic changes and, more in general, the deterioration of the microclimate inside and around cities. About it, a question appears compulsory: are zero-energy and zero-carbon concepts applicable at urban scale? This paper tries to answer to this question, by discussing the possible effects of the application of appropriate city planning techniques when a new settlement is designed. An integrated approach to urban planning is applied to a case study, for promoting the design of buildings with very low (or zero) energy needs, characterized by high indoor comfort conditions, by taking into consideration whole city areas, with different kinds of services. Passive heating, cooling and daylighting techniques have been combined, as well as the integration of renewable sources, in order to minimize the energy demand and environmental impact, for having a sustainable 'urban balance' and in general, a sustainable urban growth. As real case study, the design of the holiday village 'Olympiad' is presented; it should be built in an unstructured seaside area in Greece. Several indexes are introduced to evaluate the global sustainability of the settlement, through the application of the definition of 'on-grid ZEB' with reference to each building as well as for the entire village. This kind of research could help city planners for a growth inspired to general goals of urban sustainability. [ABSTRACT FROM AUTHOR]

Technology transfer, scientific research and education could have a key role in Mediterranean regions, in order to reduce the environmental impact of the building sector. Recently, the Department of Engineering of University of Sannio has developed a laboratory suitable for performing researches on the dynamic interactions between building envelope components, indoor environment and mechanical systems for a typical climate of south of Italy. The work described within this paper is a part of this large-scale project. Its goals are: (a) to design, test and validate a poly-equipped test room, (b) to perform transient tests to determine performances of common and innovative building components and alternative HVAC systems. More in detail, this paper focuses on the first goal, with the aim to generalize the design approach, requirements and capabilities of calibrated outdoor test facilities, specifically thought for Mediterranean climate. The facility has undergone a substantial amount of characterization tests, aimed at determining its response under yearly operations. The primary conclusions are that the new test facility is usable for a wide range of environmental and indoor conditions, it is functional and has been validated through characterization and preliminary investigations of the behavior of the thermal envelope. Moreover, some experimental results are here analyzed, by evidencing the potentialities of vacuum insulation panels for improving the performances of the thermal envelope, for what concerns both winter and summer seasons. Then, some numerical analyses have been carried out. A 3D CFD model has been calibrated for studying the real distribution of temperatures and water vapor partial pressures within VIP panels. Furthermore, a dynamic energy model of the test cell has been developed by means of Energy Plus, with the aim to use its capability to compare potential configurations that would be installed in future researches, or to evaluate energy, environmental and economic issues. [ABSTRACT FROM AUTHOR]

COVID-19 pandemic has caused an economic crisis, and also the building sector has suffered consequences. Indeed, an increase in the building energy consumption, mainly in the residential sub-sector, was registered, due to higher energy use. European Union has enacted a strategic plan to combat this crisis by promoting environmental sustainability and giving a key role to the building sector. This study provides an overview of the implementation state from EU countries, of the European policies in terms of building energy efficiency and draws attention to the adopted financial programs and incentives to promote an energy-efficient built environment. It is shown that more than 70% of Member States have transposed the EU Energy Performance of Building Directives and all of them have activated plans or programs to finance the building energy renovation, mainly in the residential sector. A focus is made on the Italian case, by considering the recently introduced tax deduction of 110% (divided into a number of annual rates) that promotes specific energy efficiency measures for existing buildings, in the vein of new requirements provided by the Directive EU 844/2018. In this investigation, three residential buildings are selected, and, by employing both semi-stationary and dynamic approaches, a critical analysis of several passive and active energy efficiency measures is performed. The variability of climatic conditions and building markets are considered in energy and economic evaluations: the building case studies are located in different Italian climatic regions and have different construction ages. Considering the energy, environmental and economic indicators, it is shown how the new Italian funding program can boost the diffusion of energy efficiency interventions which imply the best energy performance, and not the best cost/benefit ratio. The study points out achieved goals, criticalities, and new perspectives after years of energy policies in Europe. [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]

• A deep up-to-date review of the literature concerning rating systems is proposed • The review classifies papers in the matter of rating systems into four categories • Papers comparing the various building rating systems are the most common • LEED rating system is the most investigated in current scientific literature • Health and wellbeing should get a strong weight in the rating systems An up-to-date review of more than 100 research papers about green building rating tools is proposed, with a view to what is changed or must be changed, also following the new requirements due to the recent pandemic. The review organizes current literature in the matter of rating systems in four different groups: rating systems' comparison papers, case studies, the proposition of new rating systems, possible integration of rating systems into other design tools for buildings. The research papers have been analyzed to underline the main investigated aspects in rating systems, how to improve the rating systems for enlarging the sustainability assessment, and how much the level of certification reflects the green, sustainable, healthiness, and indoor environmental quality features of buildings. Moreover, possible improvements of the weighting systems are here showed, in the rating systems' method, and some new aspects for the sustainability assessment are suggested. As regards the pillars of sustainability, the main neglected points are structural safety, vulnerability to calamitous events, compatibility with local culture and history. Moreover, the indoor environmental quality and the flexibility/adaptability of livable environments are underestimated in the current rating systems. These issues have emerged strongly during the COVID-19 pandemic and have become a priority. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel analysis approach for the energy retrofit planning of districts/neighborhoods is proposed. • The stochasticity of the occupant behavior together with the global warming are considered. • The energy, the financial and the environmental benefits are maximized. • Different energy retrofit combinations are examined. • The methodology is applied to an existing neighborhood ubicated in Naples (Italy). Buildings are responsible for around 40% of energy consumption and CO 2 -eq emissions at the European Union (EU) level, thus, it is widely recognized that the pathway towards sustainability should pass through an important renovation of the building stock. This study proposes a novel approach for planning the energy retrofit of neighborhoods of buildings. The main novelties introduced are: 1) considering the stochastic human behavior that deeply affects energy demand, by setting the usage profiles according to normal distributions; 2) considering the effects of global warming on energy retrofit measures (ERMs), by assuming different Representative Concentration Pathways (RCPs) as boundary conditions. The proposed approach is based on the coupling between EnergyPlus, used as dynamic energy simulator, and MATLAB®, used as postprocessing engine. The year 2035 is considered as the reference year of the analysis, because it is a mid-term time horizon. As case study, an existing neighborhood in Naples (Italy) has been investigated, with the aim to determine the ERMs combination that minimizes primary energy consumption (PEC), running cost (RC) and CO2-eq emissions. Three different RCPs have been considered: RCP 4.5 50% warming, RCP 8.5 50% warming and RCP 8.5 95% warming. For each of them, six different scenarios have been investigated – i.e., neighborhood as built and five retrofit combinations. Results show that for all the RCPs the retrofit combination that includes all ERMs – i.e., measures on the envelopes and on the primary energy systems – produces the highest reductions of PEC, RC and CO 2 -eq emissions. [ABSTRACT FROM AUTHOR]

Developments, trends, business climate, conditions, factors influencing the efficiency and results of mergers and acquisitions (M&A) in the energy sector are explored in this research. PESTLE (political, economic, social, technological, legal, environmental) analysis was performed in order to determine the driving forces of M&As in the energy industry. Considering the motivation and main questions of the study, a sample of global M&A deals that have occurred during the period 1995–2020 has been analyzed. DataStream 5.1 database by Thomson Reuters was employed to identify the sample of global energy companies that took over another company in the period 1995–2020. According to the research, while the role and presence of M&As in the energy industry are increasing, the purpose of the M&A deals has changed remarkably. During 1995–2010, most M&A events were conducted in order to explore synergies and benefit from cost reduction. Since the last decade, firms are pursuing M&As in the search of growth opportunities, ensuring supply and reflecting demand for green development of ecological environment and ongoing changes in the nature of energy. [ABSTRACT FROM AUTHOR]

BIM (building information modeling) is a kind of technology that has great potential to enhance the level of automation in architecture, engineering, and construction (AEC) projects. The created virtual model of the facility allows coordinating all industries during the entire life cycle of the building. The possibility to save the data related to the given facility in one place, namely in the BIM model, enables control and management of the AEC projects at every stage. During the design and implementation phase, BIM models facilitate the optimization of time, costs, and quality, and in the operational phase, they support effective management of the facility. The use of BIM for building energy modeling (BEM) is the next step of evolution in architecture and engineering design practice. The benefits of using the BIM approach are widely discussed in the literature; however, they may be hard to achieve if appropriate attention is not directed to minimizing the barriers to the implementation of this technology. Observing Europe, one can notice that western and northern countries successfully use BIM for their needs, while the countries of the Eastern Bloc, including Poland, introduce it at a slower pace. In the present paper, the authors conducted a cause-and-effect analysis of the identified barriers to the implementation of BIM technology in the construction process. For this purpose, the authors applied the Ishikawa diagram, which is a tool that helps to recognize the actual or potential causes of failure. The analysis conducted showed that one of the weakest links in the successful BIM implementation is people and, in particular, their lack of knowledge and reluctance to change. The authors indicated the need to introduce and strengthen preventive actions, mainly through education: training, courses, and studies focused on BIM technology. [ABSTRACT FROM AUTHOR]

Near-wall microenvironment of a building refers to parameters such as wind speed, temperature, relative humidity, solar radiation near the building's façade, etc. The distribution of these parameters on the building façade shows a certain variation based on changes in height. As a technology of passive heating and ventilation, the effectiveness of this application on heat collection wall is significantly affected by the near-wall microclimate, which is manifested by the differences, and rules of the thermal process of the components present at different elevations. To explore the feasibility and specificity of this application of heat collection wall in high-rise buildings, this study uses three typical high-rise buildings from Zhengzhou, China, as research buildings. Periodic measurements of the near-wall microclimate during winter and summer were carried out, and the changing rules of vertical and horizontal microclimate were discussed in detail. Later, by combining these measured data with numerical method, thermal process and performance of heat collection wall based on increasing altitude were quantitatively analyzed through numerical calculations, and the optimum scheme for heat collection wall components was summarized to provide a theoretical basis for the structural design of heat-collecting wall in high-rise buildings. [ABSTRACT FROM AUTHOR]

Windows, which have a U-value that is governed by an insulating glass unit (IGU) U-value, must be a building's only enclosure element, which has no design value concept. The declared U-value, which is calculated or measured with 0 °C of external ambient temperature, is used instead of the design value. For most of a building's elements, its thermal transmittance with a decrease in the external temperature diminishes a little, i.e., improves. However, for modern window IGUs with Low-E coatings, it is the opposite: the thermal transmittance with a lowering external temperature increases. Therefore, for calculating the peak power for the heating of buildings it is necessary to pay attention to this phenomenon and, therefore, it would be wise to introduce the concept of design U-value for windows, recalculation rules, or affix their declared U-values. This is especially the case in modern times with the prevailing architectural tendencies for enlargement of transparent building elements. For IGUs with Low-E coatings and inert gas fillers, the thermal transmittance depends on the temperature difference between warm and cold environments. When the external temperature is −30 °C instead of 0 °C, the thermal transmittance of the IGU can increase by up to 35%. This study presents the thermal properties of windows' IGUs depending on the changes in outdoor temperatures by using guarded a hot box climate chamber and presents the proposed simplified methodology for determining the thermal properties of windows' glass units. The accuracy of the composed simplified methods, comparing the calculated thermal transmittances of IGUs with those measured in the "hot box", were up to 1.25%. [ABSTRACT FROM AUTHOR]

Due to the recent growth of the Internet and the rapid development of information and communications technology, the number of data centers and the amount of power consumed are expected to increase rapidly. However, these data centers consume large amounts of electric power throughout the year, regardless of working days or holidays; hence, measures to save energy at these facilities are urgently required. A numerical analysis was conducted in this study by changing various variables to examine the effects of various design and operating conditions on outdoor air-cooling systems and to derive some operating plans to minimize electric power consumption through the introduction of outside air into the computer room. When designing the system, it is desirable to select airflow considering various factors, such as the heat generated by the computer equipment, the efficiency of the fan, and the performance of the refrigerator, rather than the theoretical maximum outdoor airflow. As a result, the optimal design air volume was calculated according to the equipment load. Consequently, the optimal design air volume of the modeled computer system was obtained as 26,200 m3/h. The application of this optimal design air volume is expected to yield an annual energy-saving effect of 56.1% compared with the power consumption in the air-conditioning period during which the application of outdoor air cooling is impossible. [ABSTRACT FROM AUTHOR]

We investigate data-driven, simple-to-implement residential environmental models that can serve as the basis for energy saving algorithms in both retrofits and new designs of residential buildings. Despite the nonlinearity of the underlying dynamics, using Koopman operator theory framework in this study we show that a linear second order model embedding, that captures the physics that occur inside a single or multi zone space does well when compared with data simulated using EnergyPlus. This class of models has low complexity. We show that their parameters have physical significance for the large-scale dynamics of a building and are correlated to concepts such as the thermal mass. We investigate consequences of changing the thermal mass on the energy behavior of a building system and provide best practice design suggestions. [ABSTRACT FROM AUTHOR]

The global increase in energy needs and environmental awareness for a more efficient energy use have boosted building rehabilitation to decrease energy consumption. The installation of solar control films (SCFs) in buildings with large glazing façades makes it possible to reduce excessive solar gains through the glazing. The main purpose of the work is to assess, with field experimental data, the thermal and luminous performances of double-glazing units with SCFs installed in office rooms, in Lisbon. An experimental campaign was carried out simultaneously in three adjacent offices: one with a highly reflective SCF (external installation), one with a reflective SCF (internal installation) and one without an SCF. The exterior SCF showed the best thermal performance with reductions in the peak indoor air temperature of up to 6.9 and 2.3 °C during the representative days of the heating and cooling periods, respectively, increasing thermal comfort mainly during the cooling period. The interior SCF had a poorer thermal performance since it contributed to solar radiation absorption that is then emitted as heat into the indoor environment, increasing the greenhouse effect of the office. The presence of SCFs reduced the indoor illuminance levels, having a positive impact on thermal comfort and glare reduction in the cooling period. [ABSTRACT FROM AUTHOR]

The building sector is the largest consumer of energy, but there are still major scientific challenges in this field. The façade, being the interface between the exterior and interior space, plays a key role in the energy efficiency of a building. In this context, this paper focuses on a ventilated bioclimatic wall for nearly zero-energy buildings (NZEB). The aim of this study is to investigate an experimental setup based on a hot box for the characterization of the thermal performances of the ventilated wall. A specific ventilated prototype and an original thermal metrology are developed. This paper presents the ventilated prototype, the experimental setup, and the experimental results on the thermal performances of the ventilated wall. The influence of the air space thickness and the air flow rate on the thermal performances of the ventilated wall is studied. [ABSTRACT FROM AUTHOR]

• Aim: energy modeling and retrofit optimization of districts/neighborhoods. • Energy consumption and global cost are minimized exploring sundry retrofit levels. • Two opposite perspectives are satisfied: the public one and the private one. • The most sustainable and the cost-optimal solutions are provided. • A part of an existing neighborhood in Naples (Italy) is addressed as case study. Buildings account for about 36% of CO 2 emissions and 40% of energy consumption at EU level. Thus, a deep renovation of the building stock is fundamental to achieve the sustainability targets established worldwide. Accordingly, the study proposes an integrated approach for energy modeling and retrofit planning of districts/neighborhoods of buildings. A Geographic Information System (GIS) tool is coupled with SketchUp® to generate accurate geometrical models, while the thermophysical definition of the building envelopes is performed under DesignBuilder®. Then, EnergyPlus is used as dynamic energy simulator, while MATLAB® is the external post-processing engine. In detail, two phases are identified: 1) development of the energy model; 2) energy retrofit optimization. The approach is relevant to different scale-levels simultaneously, from a single apartment to the whole district/neighborhood as an entity. Furthemore, the use of EnergyPlus ensures high accuracy in energy predictions, while modeling the energy systems directly under MATLAB® environment strongly reduces the computational burden without affecting the results' reliability. As a case study, part of an existing neighborhood located in Naples (Italy) and representative of the Southern Italy building stock is modeled, and its retrofit is optimized. According to the Italian laws, three retrofit levels are investigated to compare their effects on selected energy, financial and environmental indicators. Finally, two optimal solutions are selected: the "nZEB" (nearly Zero-Energy Building) and the "cost-optimal" ones. The former is the one that minimizes the neighborhood's primary energy consumption, which passes from 116.9 kWh/m2a to 72.3 kWh/m2a, while the latter minimizes the global cost, which passes from 184.4 €/m2 to 129.6 €/m2. [ABSTRACT FROM AUTHOR]

Calculating Repeating Thermal Bridges (RTBs) for Timber Frame (TF) closed panels that could occur in Offsite Manufactured (OSM) Modern Methods of Construction (MMC), such as exterior walls for nearly-to-zero operational energy dwellings to be constructed in Wales, United Kingdom (UK) is discussed in this paper. Detailed calculations for linear RTBs due to the TF components are often neglected when evaluating thermal transmittance (known as U-values hereafter). The use of standard TF fractions does not allow the designer to perceive their detrimental impact on RTBs and consequent U-values for exterior walls. With the increase of the thermal performance of exterior walls and as such lower U-values due to ever-tightening Building Regulations, specifically related to the energy use and carbon emissions from the space heating of dwellings, then the impacts of RTBs requires more investigation. By not calculating the potential of linear RTB at the design stage could lead to a performance gap where assumed U-values for exterior walls differ from manufacture to onsite. A TF detail from the Welsh manufacture has been chosen as a case study, to develop and apply a methodology using manufacturing drawings to evaluate TF fraction and their effect on the thermal performance. [ABSTRACT FROM AUTHOR]

Heat demand of buildings and related CO2 emissions caused by energy supply contribute to global climate change. Spatial data-based heat planning enables municipalities to reorganize local heating sectors towards efficient use of regional renewable energy resources. Here, annual heat demand of residential buildings is modeled and mapped for a German federal state to provide regional basic data. Using a 3D building stock model and standard values of building-type-specific heat demand from a regional building typology in a Geographic Information Systems (GIS)-based bottom-up approach, a first base reference is modeled. Two spatial data sets with information on the construction period of residential buildings, aggregated on municipality sections and hectare grid cells, are used to show how census-based spatial data sets can enhance the approach. Partial results from all three models are validated against reported regional data on heat demand as well as against gas consumption of a municipality. All three models overestimate reported heat demand on regional levels by 16% to 19%, but underestimate demand by up to 8% on city levels. Using the hectare grid cells data set leads to best prediction accuracy values at municipality section level, showing the benefit of integrating this high detailed spatial data set on building age. [ABSTRACT FROM AUTHOR]

Latent heat stored in phase change materials (PCM) can greatly improve energy efficiency in indoor heating/cooling applications. This study presents the materials and methods for the formation and characterization of a PCM layer for a latent heat thermal energy storage (LHTES) application. Four commercially available PCMs comprising the classes of organic paraffins and organic non-paraffins were selected for thermal storage application. Pure organic PCM and PCM in water emulsions were experimentally investigated. PCM electrospun microfibers were produced by a co-axial electrospinning technique, where solutions of Polycaprolactone (PCL) 9% w/v and 12% w/v in dichloromethane (DCM) were used as the fiber shell materials. PCM emulsified with sodium dodecyl sulfate (SDS), and Polyvinylalcohol 10% w/v (PVA) constituted the core of the fibers. The thermal behavior of the PCM, PCM emulsions, and PCM electrospun fibers were analyzed with differential scanning calorimetry (DSC). A commercial organic paraffin with a phase change temperature of 18 °C (RT 18) in its pure and emulsified forms was found to be a suitable PCM candidate for LHTES. The PVA-PCM electrospun fiber matrix of the organic paraffin RT18 with a PCL concentration of 12% w/v showed the most promising results leading to an encapsulation efficiency of 67%. [ABSTRACT FROM AUTHOR]

In Korea apartment buildings, most energy is consumed as heating energy. In order to reduce heating energy in apartment buildings, it is required to reduce the amount of energy used in heating systems. Energy saving in heating systems can be achieved through operation and control based on efficient operation plans. The efficient operation plan of the heating system should be based on the predicted heating load. Thus, various methods have been developed for predicting heating loads. Recently, artificial intelligence techniques (e.g., ANN: artificial neural network) have been used to predict heating loads. The process for determination of input data variables is necessary to obtain the accuracy of predicted results using an ANN model. However, there is a lack of studies to evaluate the accuracy level of the predicted results caused by the selection and combination of input variables. There is a need to evaluate the performance of an ANN model for prediction of residential heating loads. Therefore, the purpose of this study is, for a residential building, to evaluate the accuracy levels of predicted heating loads using an ANN model with various combinations of input variables. To achieve the study purpose, each case was classified according to the combination of the input variables and the prediction results were analyzed. Through this, the worst, mean, and best were selected according to the predicted performance. In addition, an actual case was selected consisting of variables that can be measured in an actual building. The derived cv(RMSE) of each case resulted in a percentage value of 38.2% for the worst, 7.3% for the mean, 3.0% for the best, and 5.4% for the actual. The largest difference between the best and worst resulted in 33.2%, and thus the precision of the predicted heating loads was highly affected by the selection and combination of the input variables used for the ANN model. [ABSTRACT FROM AUTHOR]

Fouling is a permanent problem in process technology and is estimated to cost 0.25% of the gross national product. Evaporative cooling systems are especially susceptible to air-side fouling: as they work with untreated outside air, they are exposed to both natural (e.g., pollen) and human-made (e.g., industrial dust) contaminants. In addition, suspended solid particles and dissolved salts in the spray water are an issue. In this study we analyzed an approach for fouling detection based on a semi-physical (grey-box) cooling tower model which we calibrated with measurement data. A test series with reliable laboratory data indicates good applicability of the model. In three datasets, the performance decreases due to fouling (scaling, which was provoked intentionally) in the range of 5–11% were clearly detected. When applied to measurement data of two cooling towers in real applications, the model also proved to be well calibratable with relatively little data (two to four operating days). For two data sets, the model yielded reasonable results when applied to long term data: a cooling tower cleaning could be retraced and nominal operation was verified during the remaining time. During the analysis of a third data set a temporary performance deviation was found, which could not be explained with the recorded data. Thus, the approach turned out to be generally applicable but requires further verification and refinement in order to increase the robustness. If successful, it can be transferred to a commercial product for need-oriented maintenance in order to reduce cooling tower operating costs and environmental impact. [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]

• The performance of "Benevento" Nearly Zero Energy Building is discussed. • The dynamic behaviour of the walls and the comfort conditions are measured. • The optimal management of the internal and external shades is evaluated. • The effectiveness of pre-treatment of ventilation air by means of geothermal probes is studied. • The hourly energy balance is analyzed with some new indexes. The paper discusses the results of a monitoring campaign performed during the spring and autumn with the purpose to evaluate the operational energy performance of an existing nearly zero energy building (nZEB). It is located in Benevento, a middle-size city of South Italy with typical Mediterranean climate. A methodology for real-time nZEB performance analysis is proposed by taking into consideration the implications of the continuous interplay between external conditions and indoor occupant requirements as well as between on-site generation and the building loads with the resulting interaction with the energy grid. It takes into account the inertial properties of building envelope and the occupant perception in term of thermo-hygrometric and visual comfort as well as of indoor air quality. Compilation and assessment of appropriate quantitative indicators are proposed basing on data with hourly time step for finding the optimal management of the internal and external shades and the ventilation system. Moreover it is discussed how daily variations can influence the efficiency of the whole building-HVAC system with particular attention to the pre-handling system based on an earth-water heat exchanger. [ABSTRACT FROM AUTHOR]

About 40% of global energy consumption is due to buildings. For this reason, many countries have established strict limits with regard to building energy performance. In fact, the minimization of energy consumption and related polluting emissions is undertaken in the public perspective with the main aim of fighting climate change. On the other hand, it is crucial to achieve financial benefits and proper levels of thermal comfort, which are the principal aims of the private perspective. In this paper, a multi-objective multi-stage approach is proposed to optimize building energy design by addressing the aforementioned public and private aims. The first stage implements a genetic algorithm by coupling MATLAB® and EnergyPlus pursuing the minimization of energy demands for space conditioning and of discomfort hours. In the second stage, a smart exhaustive sampling is conducted under MATLAB® environment with the aim of finding constrained cost-optimal solutions that ensure a drastic reduction of global costs as well as of greenhouse gas (GHG) emissions. Furthermore, the impact of such solutions on heat emissions into the external environment is investigated because these emissions highly affect urban overheating, external human comfort and the livability of our cities. The main novelty of this approach is the possibility to properly conjugate the public perspective (minimization of GHG emissions) and the private one (minimization of global costs). The focus on the reduction of heat emissions, in addition to the assessment of energy demands and GHG emissions, is novel too for investigations concerning building energy efficiency. The approach is applied to optimize the retrofit of a reference building related to the Italian office stock of the 1970s. [ABSTRACT FROM AUTHOR]

• Control strategy of the heating of an all-air system in an educational building is optimized. • A nearly zero energy educational building in Belgium is used as case study. • Winter monitoring campaign is analysed and a building energy simulation is calibrated. • Climatic control of the boiler causes a decrease of comfort hours up to 23%. • Climatic control of the storage tank determines energy saving until up to 47%. The optimal control of the HVAC system in the nearly zero energy buildings (nZEBs) can be considered as a challenge. Indeed, the lack of data given by monitored data does not allow understanding what are the implications of different strategies on thermal comfort and energy consumptions. This paper determines an approach for the evaluation of the management of the heating system in an existing educational nZEB. The aim is to understand how the energy efficiency of the heating system is sensitive to controls strategies and the important role played by the control systems. The test lecture rooms on KU Leuven Ghent Technology Campus (Belgium) have been chosen as case study. A deep analysis, starting from an in-field monitoring, was carried out during the winter period of 2019, in order to assess the actual operation and the energy use of building systems under real conditions. Then, a building energy simulation (BES) model of the building and its systems was developed and calibrated against the real monitoring data. Control strategies of the heating system are simulated and compared to the current configuration. The simulation results show that strategies based on a definition of a heating curve for the boiler can reduce the comfortable time (−23%). Controlling the temperature inside the storage tank as a function of the outdoor temperature together with the control on the activation of the air handling unit result in an energy savings from 32% to 46%, with a correspondent increase of comfort time in the period from 0.6% to 3.4% compared to the baseline scenario, depending to the relationship between the external temperature and water temperature inside the water storage tank. [ABSTRACT FROM AUTHOR]