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In this study, for the first time, an off-grid zero-energy building with hydrogen energy storage integrated with two hydrogen cars is simulated and analyzed transiently. Regarding the novelties, for the first time, two types of wind turbines are compared as an energy supplier of the building, and all human living requirements are considered. Therefore, the study can fill in the gap of a comprehensive analysis of such off-grid hydrogen-integrated zero energy building by considering two types of wind turbines as its energy supplier. The mentioned wind turbines are compared in terms of total capital cost, and the cheapest one is specified. The fuel consumption of two typical hydrogen cars is considered. An occupant's thermal comfort level and domestic hot water usage are considered. Trnsys software is employed to examine the building's annual transient performance. Electrical split heat pumps and humidifiers are used to keep the residents warm. A solar collector heats a hot water storage tank for residential water heating. When renewable energy sources are unavailable, energy is stored and used through a hydrogen energy system. This way, electricity will be transformed by utilizing an alkaline electrolyzer into hydrogen and stored in a tank. Using fuel cells, stored hydrogen converts to electricity. Waste heat from fuel cells and electrolyzers is also an additional heating source for a hot water storage tank. Results demonstrate that five vertical-axis or seven horizontal-axis wind turbines are required to supply the energy needs of a typical 150 m2 building in Boston. Both of them have 2 kW rated power. The cheapest case is horizontal-axis wind turbines. The given number of wind turbines meets the building's energy requirements for two hydrogen cars. The monthly expected discontent percentage is below 9% when using a suitable split electrical heat pump and humidifier, and the predicted mean vote is in the range of − 0.4 and 0.4. An evacuated tube solar collector can meet four building residents' hot water needs. Typical buildings can be transformed into off-grid zero energy for windy cities like Boston by mounting all required energy suppliers, including solar collectors and wind turbines, on the rooftop. [ABSTRACT FROM AUTHOR]

Trombe wall is a passive strategy that reduces the energy consumption in buildings and helps for sustainable development of the residential sector. Applying these walls is very important in areas that need heating load in winter. This study evaluates a set of Trombe walls for the energy management of a residential building under real conditions in Binalood region with a cold and dry climate. In order to study the potentials of the Trombe wall, four different designs, including cubic Trombe wall with rectangular structure and three-sided glass, Trombe wall with trapezoidal structure and three-sided glass, Trombe wall with trapezoidal structure and four-sided glass, and Trombe wall with thicker storage wall, trapezoidal structure, and three-sided glass, for Trombe wall are considered. Trombe walls of all four suggested designs are exposed to outdoor conditions and installed at 17 places on the southern walls of the residential building. The results show that the most optimal design, i.e., Trombe wall with thicker storage wall, trapezoidal structure, and three-sided glass, leads to the greatest decrease (1637 kWh) in heating load in January. In addition, this design of the Trombe wall has the greatest effect in increasing the indoor air temperature among other Trombe walls investigated in this study. The Trombe wall with thicker storage wall, trapezoidal structure, and three-sided glass with a storage wall thickness of 40 cm is able to reduce the heating load of the building by 5.59 MWh in 5 months. This plan reduces the energy demand of the building by 8% more than the conventional structure of Trombe wall. [ABSTRACT FROM AUTHOR]

The production and consumption of non-renewable energy resources have disrupted the environment's biodiversity cycle. Global climate change, including worldwide warming, has made human life both now and in the future. The construction industry in the world has a significant share in the demand for energy consumption in these challenges. Therefore, the primary purpose of this paper is to implement standards to save and prevent energy loss to control and limit the demand for energy requested from the power network. Constructing a building with self-sufficient energy production that meets its energy needs by producing clean energy becomes more important. It also sells the excess energy to the grid, known as zero energy buildings. In the present paper, the issue is a constrained optimization problem that aims to minimize the total annual cost, including the initial investment cost for PV and batteries and their maintenance costs, as well as the cost of network exchanges. Among the limitations, the proposed model can mention the restrictions governing the battery, such as the limitations of the battery state of charge (SoC). The problem under optimization is a mixed integers nonlinear programming (MINLP) that will be solved by a particle swarm optimization (PSO) algorithm considering the total cost minimization. [ABSTRACT FROM AUTHOR]

Indoor dehumidification is usually achieved by mechanical cooling resulting in significant consumption of high-grade energy resources such as electricity. Conventional rotary dehumidification systems also require the use of high-grade energy to heat the desiccant and regenerate it. Utilization of renewable energy for indoor dehumidification is highly of concern. Ventilated roof desiccant bed system is a novel dehumidification method which can regenerate itself automatically with low-grade energy usage by taking advantage of solar energy and natural ventilation directly. Using renewable energy as an alternative, it can reduce the building energy consumption, which is beneficial to achieve nearly zero energy building (nZEB) target. This study establishes the heat and moisture transfer model of the ventilated roof desiccant bed while the moisture transfer model is validated by using the reference data. The flow-field characteristics in the airflow channels are numerically analyzed, and the regeneration process of the desiccant bed in a typical day is also simulated. Results show that both the temperature and air velocity in the channel are increasing from the inlet to the outlet. The air velocity increment can reach 0.5 m/s, and the temperature can rise about 6 °C under the same boundaries. On a typical day, the regeneration process of the ventilated roof desiccant bed lasts for approximately 3 h, and 80 g of water is desorped per unit. It means that about 18 units are sufficient to remove the moisture produced in 8 h by a man. The research results can provide data reference for the design of the system, and thus facilitates the realization of engineering application. • A ventilated roof desiccant bed system using natural energy for dehumidification is proposed. • A coupled heat and moisture transfer model of the desiccant bed is established and validated. • The flow-field characteristics in the airflow channels are numerically analyzed. • The dehumidification and regeneration characteristics of the desiccant bed are analyzed. [ABSTRACT FROM AUTHOR]

The need for efficient buildings to contribute to sustainable development has led to the proposal of goals and regulations in different countries linked to net zero energy objectives, following approaches specific to their regions. Such regulations are not yet developed in a developing country such as Panama. Thus, this study develops the first framework for Zero Energy Districts (ZED) in Panama based on passive and active solutions through dynamic simulation. For this, an existing urbanization area consisting of 34 residential buildings, called the existing case (EC), was studied. After undergoing a design based on the bioclimatic methodology, a redesigned case (RC) is proposed to maintain thermal comfort and reduce energy consumption. Key redesign factors are the buildings' shape, orientation, glazing, the use of shadows, material of the walls, and the air conditioning configuration. Results showed energy consumption decreases by 37.5% when considering all buildings with natural ventilation, reaching ranges of positive net energy (+356.50 kWh/m2y). In the case of nearly ZED in Panama, the ranges could be considered between 14 and 180 kWh/m2y. This balance indicates that there is potential on site to develop zero energy districts. [ABSTRACT FROM AUTHOR]

Given the notable consumption of fossil fuels, buildings prioritize their energy utilization. This paper's aim is to explore the primary strategies in attaining zero-energy and zero-carbon buildings. The investigation employs two specialized software programs: Design Builder, which analyzes energy usage, and PV Syst, which evaluates renewable energy requirements. The study is conducted in Fort Myers, USA, and Dubai, UAE, leveraging diverse regional and climate discrepancies, and real-world data on zero-energy and carbon constructions for comparison and validation. Within the Design Builder software, the research examines four strategies, with the first serving as the realistic baseline. By implementing the second strategy, utilizing internal shading devices such as Shade Roll, a reduction of 376 kWh in Fort Myers and 591 kWh in Dubai is achieved. The third strategy encompasses the deployment of blind-type internal shading systems, resulting in reductions of 212 kWh in Fort Myers and 348 kWh in Dubai. The fourth strategy involves integrating renewable energy via photovoltaic panels, injecting 323.5 kWh in Fort Myers and 2237 kWh in Dubai into the power grid for lighting purposes. Furthermore, 3200.5 kWh and 4722 kWh of energy are respectively injected into the grid for heating in Fort Myers and Dubai. Cooling, however, necessitates additional energy from the grid, amounting to 2243.94 kWh in Fort Myers and 9211.64 kWh in Dubai. In the pursuit of zero-carbon goals, the implementation of suitable low-carbon recycled materials, in place of primary building materials, reduces carbon dioxide emissions from 79 tons to 7.315 tons in Fort Myers and 7.038 tons in Dubai. By employing appropriate materials, the zero-carbon objective is attained. [ABSTRACT FROM AUTHOR]

The decarbonisation strategy of the building sector, which accounts for 24% of national greenhouse gas (GHG) emissions, is important to achieve climate neutrality in Korea by 2050. In this study, a bottom-up model and four scenarios were developed for examining scenarios for the decarbonisation of the residential building by 2050. A comparative analysis of energy consumption, GHG emissions, and investment cost was performed. The result showed that building energy performance improvement and heating fuel electrification are key measures for decarbonisation. We concluded that an investment of KRW 6.2 trillion per year would be required to achieve the 2050 decarbonisation scenario. Policy strategies were proposed for increasing investment in accelerating building retrofit, mandating zero-energy building (ZEB), and prohibiting gas boilers. [ABSTRACT FROM AUTHOR]

Building Information Modeling (BIM), as an auxiliary design platform, is increasingly adopted in construction projects. However, it is not widely applied in the collaborative design of zero energy buildings (ZEBs), due to the cross-discipline and complex features of ZEB projects and lack of research on the procedure and method of collaborative design in this field. This paper introduces a BIM-based collaborative design method for ZEBs. From the perspective of the technical requirements of ZEBs, the study elaborates the application of a BIM-based collaborative design method among specialists from different disciplines in passive design, renewable energy utilization and active design. The feasibility of this method is verified by the actual design and construction of the T&A House in Solar Decathlon China (SDC) competition. The research results show that the BIM-based collaborative design method can facilitate the completion of a construction project and achieve the expected goal of zero energy consumption in ZEBs. [ABSTRACT FROM AUTHOR]

In this study, zero energy building (ZEB) with four occupants in the capital and most populated city of Iran as one of the biggest greenhouse gas producers is simulated and designed to reduce Iran's greenhouse emissions. Due to the benefits of hydrogen energy and its usages, it is used as the primary energy storage of this building. Also, the thermal comfort of occupants is evaluated using the Fanger model, and domestic hot water consumption is supplied. Using hydrogen energy as energy storage of an off-grid zero energy building in Iran by considering occupant thermal comfort using the fanger model has been presented for the first time in this study. The contribution of electrolyzer and fuel cell in supplying domestic hot water is shown. For this simulation, Trnsys software is used. Using Trnsys software, the transient performance of mentioned ZEB is evaluated in a year. PV panels are used for supplying electricity consumption of the building. Excess produced electricity is converted to hydrogen and stored in the hydrogen tank when a lack of sunrays exists and electricity is required. An evacuated tube solar collector is used to produce hot water. The produced hot water will be stored in the hot water tank. For supplying the cooling load, hot water fired water-cooled absorption chiller is used. Also, a fan coil with hot water circulation and humidifier are used for heating and humidifying the building. Domestic hot water consumption of the occupants is supplied using stored hot water and rejected heat of fuel cell and the electrolyzer. The thermal comfort of occupants is evaluated using the Fanger model with MATLAB software. Results show that using 64 m2 PV panel power consumption of the building is supplied without a power outage, and final hydrogen pressure tank will be higher than its initial and building will be zero energy. Required hot water of the building is provided with 75 m2 evacuated tube solar collector. The HVAC system of the building provided thermal comfort during a year. The monthly average of occupant predicted mean vote (PMV) is between −0.4 and 0.4. Their predicted percentage of dissatisfaction (PPD) is lower than 13%. Also, supplied domestic hot water (DHW) always has a temperature of 50 °C, which is a setpoint temperature of DHW. Finally, it can be concluded that using the building's rooftop area can be transformed to ZEB and reduce a significant amount of greenhouse emissions of Iran. Also, it can be concluded that fuel cell rejected heat, unlike electrolyzer, can significantly contribute to supplying domestic hot water requirements. Rejected heat of electrolyzer for heating domestic water can be ignored. • Off-grid zero energy building with hydrogen energy storage is designed for the capital of Iran as a case study. • Designed building supplies the human living requirement of 4 occupants. • Solar collectors and PV panels are used as energy suppliers. Absorption chiller and fan coils are used. • The thermal comfort of occupants is analyzed using the Fanger model. • For making solar collectors smaller, rejected heat of fuel cell is used for heating domestic water. [ABSTRACT FROM AUTHOR]

Considering that a significant portion of the share of energy consumption among consumer sectors is in the home and commercial sectors and this share is still increasing, there is a need for research in energy consumption management and evaluation of effective indicators in the building industry. Building the country is vital to optimizing energy consumption. One of the most appropriate ways to optimize fuel consumption in the building and housing sector is the implementation of zero energy buildings which is considered as the main solution in the world. In this research, after analyzing the population and statistical sample, data were collected to evaluate effective criteria and options related to energy consumption management. First, fuzzy Delphi method was used to evaluate the sub-criteria and select the main options of each. At first level the criterion is discussed and at the second level the data analysis and research model is analyzed through paired comparisons using fuzzy hierarchical analysis technique. Finally, the most important indicators and criteria are obtained using fuzzy hierarchical analysis. According to the research findings, among the energy consumption optimization management indices investigated by the FAHP method, the economic, construction and utilities indices with 0.333, 0. 201 and 0.176 have the highest management priority, respectively. Energy-efficient optimization has a zero-energy building approach.

Over the last decades, Australia has taken several measures to tackle the increasing trend of energy use in residential buildings. Recently, the Trajectory for Low Energy Buildings has been endorsed aiming to reduce energy usage in residential buildings. However, the primary focus of this trajectory is on decreasing operational energy without considering the embodied energy of the building and systems. This paper aims to address one primary question; 'can the continued exclusion of embodied energy from the energy efficiency regulations effectively lead to reducing energy consumption in Australian residential buildings?'. The findings indicate that embodied energy becomes a dominating factor as buildings' thermal performances increase according to the Australian energy efficiency regulations. In transitioning from a standard 6.0-star building to a highly energy-efficient 8.7-star building, the proportion of embodied energy significantly increases from 20–40% to 50–75%. This study recommends establishing minimum mandatory requirements for buildings' embodied performance. [ABSTRACT FROM AUTHOR]

Summary: Buildings across the globe consume a prodigious amount of total energy generation and are held responsible for challenging the competing urge of the energy trilemma (ET). The available space for rooftop photovoltaic (PV) modules is often not adequate to cater to the entire energy demand of the buildings in an urban environment. Therefore, this article proposes a semi‐transparent building integrated photovoltaic (BIPV) module at the vertical part of the building facade for on‐site clean energy generation. The amount of incident solar irradiation at the surface of the BIPV placed at vertical tilt angles is estimated by using the solar transposition model, and the performance of the BIPV is evaluated on the indexes of ET. A coupled analysis of energy generated by the BIPV with the building energy demand is presented to analyze the reliability index ET. Economic parameters viz. cost of energy (COE) and levelized cost of energy (LCOE) are proposed to evaluate and compare the affordability index of ET associated with the BIPV and existing rooftop PV module. Further, the environmental sustainability (elimination of greenhouse gas (GHG) emissions) of the proposed BIPV module for the building is presented. [ABSTRACT FROM AUTHOR]

Building energy efficiency, as a traditional field which has been existing for decades performs a prosperous needs with diversity of corresponding methods. In the flow of artificial intelligence (AI) background, where does the building energy efficiency advance and how does it emphasize? This question seems to become more significant with the blueprints of zero energy building implementation issued by many countries. The major objective of this research is to review, analyze and identify the performance of AI based applications in buildings, especially for building energy efficiency and zero energy building. Based on the present research trends, the possible changes AI based approach brings to related laws, regulations and standards are firstly analyzed. The main aspects of the AI based approach infrastructure in buildings is thoroughly reviewed and compared. IoT based sensor applications for thermal comfort, platforms and algorithms for building multi energies control, and forecasting methods for building load, subsystem performance and structure safety are summarized. To provide more optimal references for zero energy building solutions, the AI based approach in zero energy building is then predicted in detail, with particular analysis of occupant presence and behaviors. Finally, the future directions of the research on AI based applications for zero energy building implementation are summarized. [ABSTRACT FROM AUTHOR]

This work gives a precise review of the researches completed on the energy conservation characteristics of liquid flow glazing. Its energy saving and environmental benefits under various design and operation conditions, contributions with renewable energy utilization, as well as application in zero energy buildings are timely explored and summarized. Its advantages lie in the reduction of thermal transmission between the indoor and outdoor environments, the beneficial thermal collection, and the tactful utilization of renewable energy. The optical and thermal properties, as well as the energy performance of liquid flow glazing were found much affected by the glazing and fluid properties, the window configuration, and the operating conditions. These are consequently linked to the degree of electricity saving, the decrease in atmospheric CO 2 emission, and the shortened life cycle payback time. The integrated use of solar and geothermal energy in liquid flow glazing systems is also addressed. This leads to more practical studies on the applications in zero energy buildings, such as control, real-time monitoring, and energy management strategies of liquid flow glazing system. In essence, the development of an evaluation platform or database, with systemic classification of liquid flow glazing categories plus the corresponding graded energy saving characteristics, is deemed helpful to the building professionals in meeting the zero energy buildings development targets. [Display omitted] • Liquid flow glazing/window. • Enhanced thermal insulation, thermal collection and thermal comfort. • Energy, environment and economic benefits. • Improved energy efficiency with renewable energy application. • Modularization, Monitor and Control, plus energy management toward ZEB. [ABSTRACT FROM AUTHOR]

This study proposes the novel concept of waste upcycling-driven zero energy building (W-ZEB). W-ZEB aims to accelerate the development of zero-energy buildings by incorporating waste upcycling processes (e.g., waste-to-energy (WtE), insulation material recovery, and biochar used in green roofs), ultimately advancing towards plus-energy building. W-ZEB includes three approaches: (1) generating additional energy through WtE, (2) enhancing building energy efficiency by utilizing advanced building materials recovered from waste, and (3) maintaining all elements and assets of W-ZEB using earnings obtained or saved from waste upcycling and management. To implement W-ZEB effectively, a building energy and waste management system (BEWMS) is suggested to coordinate and optimize energy demand, waste generation, and utilization, contributing to a net zero energy status and zero solid waste to landfills throughout building life cycle. Practical insights and research directions for unlocking the untapped potential of waste upcycling strategies to achieve zero-energy buildings are also provided. [Display omitted] • The concept of waste upcycling-driven zero energy buildings (W-ZEB) is proposed. • W-ZEB includes energy-based and material-based approaches. • A building energy & waste management system (BEWMS) is suggested to implement W-ZEB. • A literature review provides practical insights and research directions. [ABSTRACT FROM AUTHOR]

• This paper describes a community level approach to achieve zero energy objectives. • An agent-based model is developed to study renewable energy adoption by consumers. • Multiple renewable energy options are modeled simultaneously to study adoption. • The results highlight the importance of community solar to increase adoption. • Social interactions among consumers significantly affect their adoption decisions. As zero energy buildings take on an increasingly prominent role in overall efforts to reduce energy consumption, it is necessary to identify effective policies for their design and implementation. However, current zero energy building (ZEB) policies focus mainly on new buildings, primarily through on-site renewable energy generation, such as rooftop photovoltaic (PV) systems. Having a few high performing buildings will have limited impact if the community as a whole is not net zero. A more practical approach to achieve zero energy goals is to extend the zero energy boundaries beyond an individual building and have a group of buildings evaluated together as a community, such that the community in itself becomes a zero-energy community (ZEC). Successful ZEC implementation requires that community members actively participate in renewable energy and energy efficiency programs and collectively support the goal of zero energy. Hence, a consumer-oriented analysis is needed to support effective ZEC design decisions and promotion efforts. This paper describes a conceptual agent-based model for an urban neighborhood in Des Moines, Iowa, to predict household level renewable energy adoption behaviors in presence of multiple options. Specifically, the level of consumer participation before and after introducing a community solar option for the neighborhood is evaluated via experimentation with the model. Simulation results demonstrate that introducing a community solar program increases household level adoption as well as the proportion of community level electricity consumption met through renewable sources. The amount of increase in adoption, however, depends on the choice of design parameters, such as premium that households must pay to participate. The results also show that timeliness of achieving ZEC goals depends upon the frequency of social interactions in the neighborhood, indicating the importance of community events in the successful creation of a ZEC. [ABSTRACT FROM AUTHOR]

The construction of Net Zero Energy Buildings (NZEB) is one of the objectives in the road to the low-carbon economy by 2050. NZEB design includes a reduction of current energy demands and the balance between consumption and on-site energy generation without compromising indoor comfort conditions. Building designers are using building information modeling (BIM) and building energy simulation (BES) tools to validate design decisions and to evaluate energy balance in buildings. However, the flow of information between BIM software and BES tools has not been solved yet. This work proposes a method to address the decision-making process at three different stages of the building design. Initially, the use of BIM over the architectural design process helps architects to make meaningful decisions related to the passive solar heat gains and envelop materials. Secondly, a more advanced BES is used to analyze the strategies of ventilation and the influence of heating ventilation and air conditioning (HVAC) systems. Finally, a new method to integrate water flow glazing (WFG) is implemented to increase the comfort in those areas of the building with a large area of glass. Applying the right strategy for natural ventilation can reduce the thermal loads by 45% in Summer. Using WFG minimizes the gap between indoor air temperature and operative temperature according to the results. [ABSTRACT FROM AUTHOR]

In order to move toward net zero energy buildings, use of new and renewable energy resources parallel with development of high performance energy storage systems is necessary to maximize energy absorption and reduce energy losses with subsequent improvement in the energy performance of systems. In this research, two separate energy storage systems for supplying electricity and hot water for 500 residential buildings in Beijing have been designed and compared based on their performance. 1500 solar panels provide the required power for buildings. The first system is compressed air energy storage (CAES), while the second system is hydrogen energy storage (HES). Simulation has been done in TRNSYS and EES software. Energy and exergy analyses have been done for both systems. In case of the loss of hot water produced by the systems, the annual average energy efficiency of CAES and HES is about 44 % and 42 %, respectively. The energy efficiency of the first system decreases in the hot months of the year and reaches about 42 %, but the efficiency of the HES system is constant throughout the year. If the hot water produced by the systems is used for consumption in residential buildings, the energy efficiency of CAES and HES reaches 93 % and 64 %, respectively. The most exergy destruction in the CAES is related to combustion chambers (41 % of the total exergy destruction) and in the HES, it is related to electrolyzers (71 % of the total exergy destruction). The exergy efficiency of the first system is about 56 %, while for the second system this value is about 34 %. • Compressed air energy storage (CAES) and hydrogen energy storage (HES) are used. • Energy storage systems are used in parallel to provide electricity and water for buildings. • TRNSYS and EES used to perform energy and exergy analyses. • Energy efficiency of CAES and HES reaches 93 % and 64 % when using hot water in buildings. • Highest exergy destruction of CAES & HES are in combustion chambers (41 %) & electrolyzers (71 %). [ABSTRACT FROM AUTHOR]

Ground heat exchanger takes the soil underground as heat source or sink to supply cooling or heating. It has been widely used in building heating and cooling systems due to high efficiency and environmental friendliness. This paper reviews the latest research on ground heat exchangers from several new perspectives and demonstrates their potentials in achieving zero energy buildings. Firstly, ground heat exchangers are classified into water-based and air-based ones based on the heat transfer medium. They can be used in a passive or active approach. Associated research and projects for each approach are introduced and analysed. Then the integration of ground heat exchangers with various cooling and heating technologies and related studies are reviewed. These technologies include solar thermal collectors, cooling towers, nocturnal radiative cooling technology, solar chimney, etc. Finally, a technical route for ground heat exchangers to help realize zero energy buildings is presented, which provides a promising solution to improve energy efficiency of buildings. [ABSTRACT FROM AUTHOR]

Highlights • A system sizing method is proposed for nearly/net ZEBs under uncertainty. • Response surface models are developed to evaluate performance of each design option. • Number of Monte Carlo simulations is reduced by order(s) of magnitude. • Proposed method robustly sorts out top 1.1% design option in expectation. Abstract Properly treating uncertainty is critical for robust system sizing of nearly/net zero energy buildings (ZEBs). To treat uncertainty, the conventional method conducts Monte Carlo simulations for thousands of possible design options, which inevitably leads to computation load that is heavy or even impossible to handle. In order to reduce the number of Monte Carlo simulations, this study proposes a response-surface-model-based system sizing method. The response surface models of design criteria (i.e., the annual energy match ratio, self-consumption ratio and initial investment) are established based on Monte Carlo simulations for 29 specific design points which are determined by Box-Behnken design. With the response surface models, the overall performances (i.e., the weighted performance of the design criteria) of all design options (i.e., sizing combinations of photovoltaic, wind turbine and electric storage) are evaluated, and the design option with the maximal overall performance is finally selected. Cases studies with 1331 design options have validated the proposed method for 10,000 randomly produced decision scenarios (i.e., users’ preferences to the design criteria). The results show that the established response surface models reasonably predict the design criteria with errors no greater than 3.5% at a cumulative probability of 95%. The proposed method reduces the number of Monte Carlos simulations by 97.8%, and robustly sorts out top 1.1% design options in expectation. With the largely reduced Monte Carlo simulations and high overall performance of the selected design option, the proposed method provides a practical and efficient means for system sizing of nearly/net ZEBs under uncertainty. [ABSTRACT FROM AUTHOR]

Zero energy building design could be realized by passive design. Having energy conservation concepts and active mechanical renewable energy generation systems could be considered as passive technique. This concept becomes a very interesting technique in countries that consume a lot of energy for their domestic sector. The purpose of the recent paper is to investigate the effect of hybrid construction material that merges phase change material, PCM walls for heat load minimization and transparent solar cells, and TSC in the windows for electricity generation for the purpose of illumination in such typical design. PCMs could be used for storing thermal energy and utilizing this energy during different annual seasons by absorption or release mechanisms to keep the building's inside temperature at thermal comfort state. While TSC,s are substances that allow partial Sun light penetration for illumination during day and use the other part for electricity generation at night. The paper introduce a typical architectural design for residential building that utilizes such type of constructional material for energy saving and analyzes thermal effectiveness of using PCM and power production effectiveness of using TSC as passive technique integrated with the zero-energy building envelope. Proper modeling tool has been used to investigate the impact of these materials on the thermal comfort perceived by the occupants. Results show that using such type of hybrid materials reduces annual energy consumption. It has been concluded that the passive structural heat isolation and power production material is a very effective manner in countries like Iraq which has severe temperature differences between summer and winter seasons. [ABSTRACT FROM AUTHOR]

In the context of environmental policy, the EU has launched a series of initiatives aimed at increasing the use of energy efficiency, as it has pledged to reduce energy consumption by 20%, compared with projected levels of growth of CO 2 emissions into the atmosphere by 2020. In Greece CO 2 emission levels in the atmosphere have risen significantly over the past two decades [1] . For the year 2011, CO 2 emissions per person in Greece correspond to 7.56 t. According to the data, this increase in emissions is reflected to a 151.2% above from the levels of 1980 and a 756% increase from 1960 levels. The building sector consumes the largest amount of energy in Greece, therefore constitutes the most important source of CO 2 emissions. The energy upgrade of the building sector produces multiple benefits such as reduced energy consumption, which is consistent with the reduction of air pollution. Additionally, there is a significant improvement at the interior comfort conditions of the building, which promotes productivity and occupant health. Moreover, because of the large number of educational buildings in the country, the energy consumption of them present a significant amount of the country's total energy consumption and simultaneously has the effect of increasing the costs paid by the state budget for the operation and maintenance of public buildings. The investigation of alternative methods to reduce energy consumption in educational buildings is an important approach for sustainability and economic development of the country over time. The purpose of this paper is to study and evaluate the energy saving methods of a university building in Mediterranean climate with significant energy consumption. Additionally, through Building Information Modeling (BIM) and Computational Fluid Dynamics (CFD) software, studies considering the contribution of passive heating and cooling techniques were conducted, in order to minimize energy consumption in pursuit of desirable interior thermal comfort conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new configuration of HVAC systems for an office as zero energy building. • This model is simulated in six major climate regions in ten cities of Iran. • The evaporating cooler integrated with the ground is used as the main cooling facility. • Cooling energy demand scale in comparison with other systems' energy tends to zero. • PV cells and ground heat pump generate electricity and heating, respectively. • The LCC value for this article model system is lower than the 50 %of value in comparison with usual systems. This paper presents a new configuration of heating and cooling systems for a net zero energy building (NZEB). In this paper, one design for Net Zero Energy Building(NZEB) systems is simulated, which can provide cooling and heating needs in a wide variety of climates. This current model benefits from direct evaporating cooling (DEC) which is coupled with the ground instead of the chiller in order to reduce the consumption of energy, water usage, and humidity of indoor air. The PV cells and heat pump that are connected to the ground generate electricity and heating energy, respectively in the building besides domestic hot water is provided by solar collectors. This model is simulated in ten cities of Iran as a multi climate country with six various major climates. The Life Cycle Cost (LCC)is calculated for all of these cities and the value is compared with the usual systems. The results show the possibility of an NZEB in various dry weather in Iran, furthermore the thermal comfort situation is confirmed. The cooling energy demand proportion to other energy usage tends to be zero. The LCC value will be able to reduce to 50% of the usual systems. [ABSTRACT FROM AUTHOR]

Led by the European Union (EU), several countries have announced carbon-neutral goals and introduced related legislations. For example, the Korean government has recently announced a roadmap for the introduction of mandatory zero-energy buildings (ZEBs), because the building sector is a major contributor to carbon emissions. To evaluate the feasibility of achieving carbon neutrality through the legislation of mandatory ZEBs, we analyzed the energy-saving potential of residential buildings and determined whether ZEB standards could be strengthened further. The energy consumption of residential apartments was calculated, and the possibility of additional energy savings beyond those dictated by ZEB certification standards was evaluated by assessing the energy performance of individual element technologies. It was observed that, to achieve carbon neutrality, there were limits to regulating individual element technologies alone, and a comprehensive approach was required. In addition, after the introduction of mandatory ZEBs, the degree to which the hot water and plug loads are affected by user behavior increases; therefore, it is also necessary to design a policy to encourage users to exhibit energy-saving behavior. This study can be used as a reference for the design of building energy policies after the introduction of mandatory ZEBs. • Residential energy use under the mandatory zero-energy building policy is assessed. • More energy savings are possible by strengthening zero-energy building standards. • Domestic hot water and plug load use needs to be reduced in zero-energy buildings. • Energy-saving actions by the occupants are required for carbon neutrality. [ABSTRACT FROM AUTHOR]

Energy crisis and global warming have become more and more serious with the social development. Since buildings account for a significant proportion of the total energy consumption and carbon emissions, it is very necessary and urgent to decrease building energy consumption. Minimizing the need for energy use in buildings through energy-efficient measures and adopting renewable energy are the basic strategies. Zero energy buildings, which only consume solar energy and other renewable energies, have been considered as one solution and have drawn more and more attention in recent years. Solar thermoelectric cooling technologies can be powered directly by a photovoltaic (PV) and cause no harm to the environment, which fully fulfill the demand of ZEBs. This paper reviews solar thermoelectric cooling technologies and proposes a technical route of solar thermoelectric cooling technologies for use in zero energy buildings. It can be seen that solar thermoelectric cooling systems can minimize the energy demands, increase energy effectiveness and reduce fossil energy consumption in buildings. With the thermoelectric and PV industry's development along with the advent of new materials, the solar thermoelectric cooling technologies for use in zero energy buildings are promising. [ABSTRACT FROM AUTHOR]

Considering the amount of existing buildings, decarbonizing the building stock requires new buildings designed to reach the highest performance. The nearly-Zero Energy Buildings (nZEB) standard needs to be overtaken by Plus Energy Buildings (PEB) that presents the potential to produce more energy than the consumption over a specific period. Several studies investigated the potential of a building to achieve a plus energy balance, however, there is still a lack of a comprehensive and shared framework for designing and assessing the performance of a PEB. To cope with this issue, the authors identified a series of key aspects that needs to be stated in a consistent framework for PEB, and in particular: i) the balance contributions, ii) the physical boundaries, iii) the time span for the balance assessment, iv) the metrics for evaluating PEBs, v) the approach for evaluating load matching and grid interaction, vi) Indoor Environmental Quality and user satisfaction as added values of a PEB. The authors performed a comprehensive review identifying 82 papers dealing with PEB and deducing how the key aspects have been addressed. The literature overview provides the background for proposing an approach for the PEB definition and to introduce an operational assessment focused on providing the main statements focusing on PEB performance evaluation both during the design and operative phase. [ABSTRACT FROM AUTHOR]

Abstract: This paper takes an overall energy system approach to analysing the mismatch problem of zero energy and zero emission buildings (ZEBs). The mismatch arises from hourly differences in energy production and consumption at the building level and results in the need for exchange of electricity via the public grid even though the building has an annual net-exchange of zero. This paper argues that, when looked upon from the viewpoint of the overall electricity supply system, a mismatch can be both negative and positive. Moreover, there are often both an element of levelling out mismatches between individual buildings and an element of economy of scale. For these three reasons mismatches should be dealt with at the aggregated level and not at the individual level of each building. Instead, this paper suggests to compensate the mismatch of a building by increasing (or decreasing) the capacity of the energy production unit. Based on historical data for the electricity supply area in western Denmark, this paper makes a first attempt to quantify mismatch compensation factors. The results indicate that such compensation factors are a little below one for buildings with photovoltaics (PV) and a little above one for buildings with wind turbines. [Copyright &y& Elsevier]

Abstract: There are various definitions of ‘zero energy’ and ‘net-zero’ energy building. In most cases, the definitions refer only to the energy that is used in the operation of the building, ignoring the aspects of energy use related to the construction and delivery of the building and its components. On the other hand the concept of ‘net energy’ as used in the field of ecological economics, which does take into account the energy used during the production process of a commodity, is widely applied in fields such as renewable energy assessment. In this paper the concept of ‘net energy’ is introduced and applied within the built environment, based on a methodology accounting for the embodied energy of building components together with energy use in operation. A definition of life cycle zero energy buildings (LC-ZEB) is proposed, as well as the use of the net energy ratio (NER) as a factor to aid in building design with a life cycle perspective. [Copyright &y& Elsevier]

Abstract: Possible solutions for zero energy building design in UK are discussed in this paper. Simulation software (EnergyPlus and TRNSYS 16) are employed in this study, where EnergyPlus simulations are applied to enable facade design studies considering building materials, window sizes and orientations and TRNSYS is used for the investigation of the feasibility of zero energy houses with renewable electricity, solar hot water system and energy efficient heating systems under Cardiff weather conditions. Various design methods are compared and optimal design strategies for typical homes and energy systems are provided. [Copyright &y& Elsevier]

The concept of zero energy buildings (ZEBs) has recently been actively introduced in the building sector, globally, to reduce energy consumption and carbon emissions. For the implementation of ZEBs, renewable energy systems, such as solar collectors, photovoltaic (PV) systems, and ground source heat pump (GSHP) systems, have been used. The system performance of solar collectors and PV systems are dependent on the weather conditions. A GSHP system requires a large area for boring machines and mud pump machines. Therefore, inhabitants of an existing small-scale buildings hesitate to introduce GSHP systems due to the difficulties in installation and limited construction area. This study proposes an integrate photovoltaic-thermal (PVT) and air source heat pump (ASHP) system for realizing ZEB in an existing small-scale building. In order to evaluate the applicability of the integrated PVT-ASHP system, a dynamic simulation model that combines the PVT-ASHP system model and the building load model based on actual building conditions was constructed. The heating and cooling performances of the system for one year were analyzed using the dynamic simulation model. As the simulation analysis results, the average coefficient of performance (COP) for heating season was 5.3, and the average COP for cooling season was 16.3., respectively. From April to June, the electrical produced by the PVT module was higher than the power consumption of the system and could realize ZEB. [ABSTRACT FROM AUTHOR]

This study examines strategies for energy efficiency in public buildings in Korea and the implementation of certification systems. It also identifies the actual plan status and discusses improvements at the institutional level. The target is the national sports centers, where the discussion on energy efficiency has been assiduous, as they have recently expanded regionally in Korea. Among the 541 national sports centers in Korea, 90 facilities for which a preliminary review was performed on the plan by the National Public Building Center were analyzed. The energy efficiency plan is realized through Building Energy Efficiency, Zero Energy Building, and Green Standard for Energy and Environmental Design certifications. As a result of analyzing the plan status, omissions or errors in certification were confirmed in about 10% of each, even though more than 80% of the facilities were subject to mandatory application. In Korea's condition, to revitalize the practice of the system, it is necessary to expand the government's publicity and support initiatives, use differential application of evaluation items, and strengthen incentives. This study provides meaningful results and suggestions for implementing an energy efficiency system at the national level under similar conditions in the future. [ABSTRACT FROM AUTHOR]

Building energy consumption in the Asia-Pacific region continues to rise. It is important to understand the energy use and future trends of 21 members of Asia-Pacific Economic Cooperation (APEC) and to find more effective ways to achieve APEC's dual goals of reducing energy intensity by 45% of 2005 levels by 2035 and doubling the share of renewable energy in the energy mix between 2010 and 2030. Recently, promoting building toward ultra-low energy, nearly zero energy and zero energy is becoming a consensus trend. This paper aims to explore how zero energy building promotion could influence the total energy demand in the mid to long term. An EUPP (Economic, Urbanization, Population and Purchasing power parity) model was established to show the relationship between building energy consumption and its influencing factors, and the potential development path of building energy consumption in APEC was predicted by using the model. The results show that in the Business As Usual (BAU) model, building energy demand will increase from 1387.4 Mtoe in 2016 to 2456.8 Mtoe in 2050 while in the CAP model, building energy demand will be constrained to under 2000 Mtoe before 2050. In the ZEB promotion model, 897.8 to 1945.3 Mtoe could be saved separately. The share of end demand supplied by onsite renewable energy production could reach 11%–54%. The building sector has the potential to become the largest contributor to achieve the APEC energy goal and thus to the climate change goal. • A long-term building energy intensity prediction model is established. • Building demand in APEC region will reach 2456.8 Mtoe in 2050 in BAU Model. • 897.8 to 1945.3 Mtoe could be saved separately under various ZEB scenarios. • Energy consumption decreases only if more than 40% of buildings are nearly Zero. [ABSTRACT FROM AUTHOR]

One important opportunity to reduce energy waste and global warming is renovation, retrofit, and refurbishment of existing buildings. Adding a multi-layer internal insulation is an efficient way to upgrade an existing housing into a nearly zero-energy buildings, NZEB. There is a vast variety of products and solutions for the building envelope with different environmental impacts. In this paper a methodology is presented to establish a two-criteria framework to rank thermal insulation materials to be used in the envelope. The objective was to design an optimal insulation system based on a multi-objective approach to maximize the energy saving and minimize the environmental impact. Using twelve typical insulation materials with different thicknesses, a four-layer insulation system was developed and applied to a Case study, a typical multi-story apartment building located in a hot summer and cold winter zone. Results revealed there are several optimum solutions to significantly reduce the building energy consumption, with important differences in their environmental impacts. For the case study, eight Pareto-optimal solutions were derived using the two-objective optimization offering more than 70% reduction in the energy demand, and a global warming potential range of 192–1500 kgCo2 eq. [ABSTRACT FROM AUTHOR]

The paper aims to examine the possibility of adapting an existing school building to the standard of a zero energy building. The school building is a specific case of a building in which the energy consumption is periodic, except for the months with the most sunshine. Therefore, it is necessary to look for a solution that will allow storing the energy obtained, for example, from solar collectors. Based on the analysis of the literature, it was concluded that the use of borehole thermal energy storage might be the right solution to the problem. The article presents the energy balance of the building with and without the use of renewable energy sources and the benefits of using an energy storage system. [ABSTRACT FROM AUTHOR]

The existing calculation and evaluation methods for photovoltaic directly driven air conditioners (PVAC) are often based on a long timescale without considering the short-term rapid fluctuations of environmental parameters. This study proposes a comprehensive method for evaluating real-time zero energy potentials of PVACs. Firstly, an optimal determination method for PV size from the timely energy matching perspective was discussed. Then, the energy generation and consumption based on different time scales in different climate regions were simulated and analyzed. Finally, the zero-energy potentials of PVACs with the optimal PV size in different climate regions were investigated. The potentials were evaluated based on the indices of hourly self-sufficiency, hourly self-consumption, zero energy probability, and PV generation utilization. Besides these indicators, a graphical approach was also provided to enable the visualization of the real-time energy matching performance of PVACs. The results showed that different climatic conditions had significant effects on energy matching performance. Under the premise that the total PV generation can fully meet the electricity consumption of air conditioner, the number of hours that PVAC, without assistance, can realize real-time zero energy consumption only accounts for 26.40% of the whole year in Shenyang and 37.17% in Shanghai. To summarize, the method and indicators for optimizing PV capacity and evaluating dynamic energy matching for different climate zones were proposed from the perspective of achieving real-time zero energy. [ABSTRACT FROM AUTHOR]

The Indoor Environmental Quality (IEQ) is a basic requirement for the design of energy-efficient buildings since it affects the occupants' well-being and health inside buildings. Over the years, the issue of IEQ has been widely investigated under different perspectives: from the first experiments aimed at assessing the physiological response of individuals it has become a human-centric concept. In recent years, new paradigms have influenced buildings design towards sustainable and highly efficient constructions. Zero-Energy Buildings (ZEBs) are the current challenge which should be appropriately addressed with a holistic approach to achieve excellent IEQ and energy efficiency levels. Thermal, visual and acoustic comfort and indoor air quality are the most important Indoor Environmental Factors (IEF) characterizing the overall environmental condition of indoor spaces. However, there is no standard method to calculate the overall IEQ level of a building by monitoring and aggregating all individual aspects of comfort. This article aims to bridge this gap, proposing a method to define weighting factors of IEFs. A survey was carried on 100 participants out in a fully monitored Zero-Energy full-scale test building to collect and analyse the answers of the sample about their evaluation of IEFs. The collected data of questionnaire-based IEQ responses were treated with a multiple linear regression model. The results prove that IEQ is affected mostly by IAQ during the test. The proposed weighting factors were applied to rank the monitoring-based IEFs. The comparison between objective (monitoring-based) and subjective (questionnaire-based) analyses shows how the former underestimates IEQ with respect to the latter. • A questionnaire-based survey on IEQ is carried out involving 100 participants. • Weighting factors are proposed to classify the indoor comfort of ZEB. • An IEQ design-based index calculated through an aggregation of IEF is proposed. • The objective and subjective comparison suggests that the former underestimates IEQ. • The consistency of the proposed design quantities and their limit values are discussed. [ABSTRACT FROM AUTHOR]