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The global need to reduce energy demand has led European governments to accelerate their endeavors to achieve their targets regarding nearly zero-energy buildings. Despite the implementation of funding initiatives for the energy upgrading of buildings in EU member states and other European countries, research has shown that the absorption rates of the offered funds remain low. This research aims to assess the significance of the barriers to improving the energy efficiency of Greece's building stock. This is achieved by ranking the identified barriers using the best-worst method (BWM). The innovation provided by this study is that the data obtained are based on the experience of three categories of stakeholders, including professionals in the field, i.e., engineers and skilled workers, and homeowners. The results show that all three groups are discouraged from performing the energy upgrading of buildings due to economic barriers but also technological barriers related to a lack of training in the use of and slow development of related new technologies. [ABSTRACT FROM AUTHOR]

Energy efficiency is a cornerstone of climate change mitigation. For buildings, facility management is an essential part of achieving efficient energy use while keeping tenants satisfied. This interview study explores success factors and barriers for facility management in maintaining energy efficiency over time in four approximately 10-year-old non-residential premises built as so-called nearly zero-energy buildings (nZEB) in Sweden. The study highlights the importance of functional digital tools, benchmarks, and building professionals' involvement in ensuring energy efficiency. It also emphasizes the need for involvement communication and strategies to engage facility management in energy efficiency efforts. The study suggests that in-house and public policies can play a crucial role in sustaining high ambitions for energy efficiency. Access to professional support that is self-evident to use is identified as a critical success factor. Additionally, the research presents an analytic model that can be used in future studies to assess facility management organizations' potential for maintaining energy performance in buildings over time. [ABSTRACT FROM AUTHOR]

In recent years, the promotion of nearly zero-energy buildings (NZEBs) in China has emerged as a crucial step for the building industry in shifting towards a green and low-carbon future. Starting from scratch, the development of NZEBs in China has included the application and fundamental research, the compilation of national and local standards, and the rapid emergence of projects encompassing 23.89 million square meters nationwide. These efforts have yielded preliminary results in national standards, technology systems, technical roadmaps, and large-scale project demonstrations. However, challenges, including further reducing incremental costs, developing industries for retrofitting existing buildings into NZEBs, and expanding the range of policy incentives, remain to be addressed. This article provides an overview of the last decade’s progress in NZEBs in China, covering key technological research, policy development, engineering demonstrations, and the current industrial development status. Finally, the prospects of the NZEB industry are discussed.

Energy efficiency is a cornerstone of climate change mitigation. For buildings, facility management is an essential part of achieving efficient energy use while keeping tenants satisfied. This interview study explores success factors and barriers for facility management in maintaining energy efficiency over time in four approximately 10-year-old non-residential premises built as so-called nearly zero-energy buildings (nZEB) in Sweden. The study highlights the importance of functional digital tools, benchmarks, and building professionals’ involvement in ensuring energy efficiency. It also emphasizes the need for involvement communication and strategies to engage facility management in energy efficiency efforts. The study suggests that in-house and public policies can play a crucial role in sustaining high ambitions for energy efficiency. Access to professional support that is self-evident to use is identified as a critical success factor. Additionally, the research presents an analytic model that can be used in future studies to assess facility management organizations’ potential for maintaining energy performance in buildings over time.

At the energy consumption level, buildings are currently the largest sector, therefore, the energy efficiency of these structures, assumes a priority role in refurbishing projects. The “building automation” as well as the redesign of the electrical and thermal system of a structure can offer significant contributions in terms of energy saving, comfort, and functionality. Recent policies introduced the nearly zero-energy building (nZEB) qualification. The challenge we are facing is to work on the refurbishment of existing buildings by identifying a model that on the one hand allows nZEB qualification and on the other hand applies to existing buildings with all the technical and economic constraints. The goal of this article is to present possible redevelopment projects, thanks to the use of software, applicable to the historical university department located in the center of Rome to compare the parameters and reference indices for calculating the performance of an nZEB included in the ministerial decree (DM) June 26, 2015. The building automation and the redesign of the thermal electrical system of the structure is one of the most important aspects to obtain nZEB evaluation but it is also important to change opaque vertical and horizontal structures and transparent envelopes. [ABSTRACT FROM AUTHOR]

The energy performance of buildings and energy-saving measures have been widely investigated in recent years. However, little attention has been paid to buildings located in rural areas. The aim of this study is to assess the energy performance of two-story residential buildings located in the mountainous village of Palangan in Iran and to evaluate the impact of multiple parameters, namely building orientation, window-to-wall ratio (WWR), glazing type, shading devices, and insulation, on its energy performance. To attain a nearly zero energy building design in rural areas, the building is equipped with photovoltaic modules. The proposed building design is then economically evaluated to ensure its viability. The findings indicate that an energy saving of 29% can be achieved compared to conventional buildings, and over 22 MWh of electricity can be produced on an annual basis. The payback period is assessed at 21.7 years. However, energy subsidies are projected to be eliminated in the near future, which in turn may reduce the payback period.

The test lecture rooms on Katholieke Universiteit Leuven (KU Leuven) Ghent Technology Campus (Belgium) are a demonstration case of Annex 62: Ventilative Cooling of the International Energy Agency’s Energy in Buildings and Communities programme (IEA EBC). The building is cooled by natural night ventilation and indirect evaporative cooling (IEC). Thermal comfort and the performances of ventilative cooling are evaluated. Long-term measurements of internal temperatures, occupancy, opening of windows and IEC were carried out in the cooling season of 2017. The airflow rates through the windows in cross- and single-sided ventilation mode were measured by both tracer gas concentration decay and air velocity measurements. In addition, the air flow pattern is visualized by measuring air temperatures in the room. The results show that good thermal summer comfort was measured except during heat waves and/or periods with high occupancy. Both nighttime ventilation and IEC operate very well. IEC can lower the supply temperature by day significantly compared to the outdoor temperature. The Air Changes Rates (ACR) of the night ventilation greatly depends on wind direction and velocity. The air temperature profile showed that the air is cooled down in the whole lecture but more in the upper zone. The extensive data monitoring system was important to detect malfunctions and to optimize the whole building performance.

Heating, cooling and domestic hot water (DHW) are responsible for the largest share of energy use in residential buildings in Spain and play an important role in the implementation of nearly zero-energy buildings (NZEB). Building Information Modelling (BIM) is expected to promote more efficient buildings through evaluation of different design options. BIM can be used as a platform from which to gather information that can be conveyed to energy efficiency simulation tools. The objective of this paper was to implement the model of a reversible air-to-water heat pump in EnergyPlus 8.9. This model was employed to analyze the performance of an aerothermal heat pump system (B) in a residential building under different Spanish climates compared to a conventional Heating, Ventilating and Air Conditioning (HVAC) system (A). Significant primary energy savings were achieved with system B compared to system A. These energy savings were higher in climates with a significant heating demand such as Madrid (27.4%) and Burgos (33.6%), and in cities with a mild climate such as Barcelona (37%). The residential building studied in this work was classified as Class A according to the CO2 emissions scale when using the aerothermal heat pump system, and as Class B when using the conventional HVAC system.

• 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]

The energy performance of buildings and energy-saving measures have been widely investigated in recent years. However, little attention has been paid to buildings located in rural areas. The aim of this study is to assess the energy performance of two-story residential buildings located in the mountainous village of Palangan in Iran and to evaluate the impact of multiple parameters, namely building orientation, window-to-wall ratio (WWR), glazing type, shading devices, and insulation, on its energy performance. To attain a nearly zero energy building design in rural areas, the building is equipped with photovoltaic modules. The proposed building design is then economically evaluated to ensure its viability. The findings indicate that an energy saving of 29% can be achieved compared to conventional buildings, and over 22 MWh of electricity can be produced on an annual basis. The payback period is assessed at 21.7 years. However, energy subsidies are projected to be eliminated in the near future, which in turn may reduce the payback period. [ABSTRACT FROM AUTHOR]

Heating, cooling and domestic hot water (DHW) are responsible for the largest share of energy use in residential buildings in Spain and play an important role in the implementation of nearly zero-energy buildings (NZEB). Building Information Modelling (BIM) is expected to promote more efficient buildings through evaluation of different design options. BIM can be used as a platform from which to gather information that can be conveyed to energy efficiency simulation tools. The objective of this paper was to implement the model of a reversible air-to-water heat pump in EnergyPlus 8.9. This model was employed to analyze the performance of an aerothermal heat pump system (B) in a residential building under different Spanish climates compared to a conventional Heating, Ventilating and Air Conditioning (HVAC) system (A). Significant primary energy savings were achieved with system B compared to system A. These energy savings were higher in climates with a significant heating demand such as Madrid (27.4%) and Burgos (33.6%), and in cities with a mild climate such as Barcelona (37%). The residential building studied in this work was classified as Class A according to the CO2 emissions scale when using the aerothermal heat pump system, and as Class B when using the conventional HVAC system. [ABSTRACT FROM AUTHOR]

The main part of Italian building stock was built before the energy and seismic regulations, so most of buildings need comprehensive refurbishment to achieve the performance required by laws that are in force. This paper presents an experimental study for an energy and structural upgrade methodology, applied to an existing school building in the north-east of Italy. The methodology is based on the International Energy Agency–Energy in Buildings and Communities Programme (IEA–EBC) Annex 56 project guidelines. For the energy retrofit, a set of interventions is defined concerning the building envelope and systems. Among these interventions, the optimal cost is identified: this minimizes the energy demand and the CO2 emissions, and reduces the financial commitment. The analysis of the seismic retrofit is developed using innovative techniques of intervention and high-performance materials. The proposed interventions are evaluated in terms of efficacy and cost. The results show that it is possible to identify a comprehensive energy retrofit at optimal cost, thanks to high energy saving and subsidies. For the seismic retrofit, the intervention with the higher cost-effectiveness ratio is determined, but the related investment does not have a payback time. The union of the two retrofits permits the combination of benefits and has a payback time for both the interventions. It is possible to state that the cost of a combined intervention is lower than the costs of two different interventions; therefore, when a single retrofit is needed, the possibility of a combined intervention should be evaluated. [ABSTRACT FROM AUTHOR]