Search

This position paper aims to pave the way for a debate on a few under-explored, at least, perhaps even neglected, challenges we face when trying to improve building overall performance. Specifically, we suggest focusing on how the efforts to increase building energy efficiency, building safety, the home and workplace healthiness, and the comfort perceived by the users can be impaired by budget constraints, especially while operating in critical scenarios. On the one hand, restraints on capital expenditures by property owners and other investors affect the decision-making processes for the construction of new buildings or the renovation of existing ones. More beyond, rapidly developing demographic and other anthropological changes, as well as frequently occurred natural disasters, pose extra burdens on the players in the building industry and the real estate market. It has been a fact that the need to adapt to both budget constraints and challenging situations is seldom fully embedded in the studies focusing on improving building performance. Therefore, we call for attentions in research and publications to advocate for complementing the need. [ABSTRACT FROM AUTHOR]

This research paper examines how multi-angled façade systems improve and optimise energy performance compared to a flat façade and meet sustainability targets for lower energy use to align with UN SDGs 3, 11, 12, and 13. The multi-angled façade system does not tilt up and down. Instead, it employs two different window orientations on a vertical axis (left and right). The large portion orients more to the north to allow more daylight to penetrate inside the room, and the small part is oriented more to the south to provide passive solar heating. The investigations in this research paper were carried out using version 4.8 of the IDA ICE software, and the researchers evaluated the energy consumption, the energy action through the façade, and the building's inside operative temperature. The results of this paper present the simulation findings for primary energy consumption in different scenarios. For example, the researchers explain that one can save 6.3 kWh/(m2·year) when using a multi-angled façade system compared to a flat façade. This is in addition to improving the thermal indoor climate that results from using the façades. The conclusions of the research show that the façade with multiple angles maximises using daylight and optimises solar power, thus avoiding overheating issues. [ABSTRACT FROM AUTHOR]

Energy efficiency in the context of building design is a significant concern in Morocco. This paper offers a comprehensive analysis of how various design variables can impact both energy consumption and thermal comfort in the Moroccan context. Rather than isolating individual design variables, we investigate synergistic combinations of these variables. To achieve this, we develop multiple building design scenarios, each employing different combinations of design options, focusing on building orientation, window-to-wall ratio, building envelope construction, and window shading. We use EnergyPlus to conduct energy simulations for all scenarios under the hypothesis of air-conditioned houses and free-running houses with and without natural ventilation. Our results reveal that building design has the potential to significantly enhance energy efficiency and thermal comfort, but not for the same design strategies. In comparison to the most energy-efficient design scenario, the least favorable design scenario can lead to an increase in energy consumption between 237% in Agadir and 130% in Ifrane. Meanwhile, design scenarios favoring comfort can increase the number of comfortable hours by 85% in Agadir and 59% in Ifrane. We identify optimal building design scenarios that simultaneously offer the highest comfort levels with the lowest energy requirements. The findings provide valuable guidance for architects, allowing them to design high-performance buildings in all climate zones in Morocco. [ABSTRACT FROM AUTHOR]

The paper describes specific usage scenarios of an innovative platform, interfacing users, monitoring, and simulations for building energy simulations and the computation of key performance indicators to support, in an interoperable and open vision, design and management choices exploiting the enabling capabilities of ICT in architecture. The modularity of the proposed solution allows the development of pre-defined usage scenarios for professionals: impact of modifications in technological design choices, model calibration, and performance gap between simulated and monitored building data. The paper faces some new architectural usage scenarios of the tool, considering its enabling capabilities, and focuses on the tool's components developed and tested in the EU H2020 E-DYCE project. [ABSTRACT FROM AUTHOR]

One-third of all greenhouse gas emissions come from the world's building stock while accounting for 40% of global energy use. There is no way to combat global warming or attain energy independence without addressing the inefficiency of the building sector. This sector is the second consumer of electricity after the industrial sector in Morocco and is ranked third emitter after the energy sector and transportation sector. Using Ifrane as a case study, this paper examines and reviews the city's energy use and the initiatives taken to improve building efficiency. The findings showed that, during the analyzed period, i.e., from 2014 to 2022, Ifrane's annual electricity consumption climbed steadily from 35 to 43 GWh. The government of Morocco has implemented effective laws, guidelines and regulations, as well as publicized ways to reduce energy consumption and increase energy efficiency. However, gathered data and survey results revealed opportunities and challenges for enhancing Ifrane's efficient energy use. The study also evaluates government programs, codes/standards and related actions for the improvement of household energy efficiency. As part of the review, the available literature was analyzed to assess the effectiveness of energy behavior and awareness, the impact of an economical and sustainable building envelope, the impact of building retrofitting programs, the importance of energy-performing devices and appliances, the adoption of smart home energy management systems, the integration of renewable energies for on-site clean energy generation and the role of policies and governance in the building sector in Ifrane. A benchmark evaluation and potential ideas are offered to guide energy policies and improve energy efficiency in Ifrane and other cities within the same climate zone. [ABSTRACT FROM AUTHOR]

Fabricated building construction is an effective way to improve construction process, productivity, quality and cost-effectiveness. However, many developers cannot actively respond to the existing policies, so giving full play to the government's guiding role and stimulating market enthusiasm is the key to the development of prefabricated buildings. Based on fairness theory, this paper constructs an evolutionary game model between the government and prefabricated building developers. It analyses the energy-saving and emission-reduction behaviour of developers. The results show that the government should combine positive and negative incentives. Most importantly, incentives and fees should be set taking into account the developer's fairness preferences and profitability. Finally, based on the research results, this paper provides suggestions for the government to improve targeted incentive policies and contributes to the promotion of prefabricated buildings. [ABSTRACT FROM AUTHOR]

The Renovation Wave for Europe highlighted the role of the public building stock for which Directive 2012/27/EU has set an annual renewal rate of 3%, which should rise to reach the goal of decarbonization by 2050. In this paper, the energy retrofit of an educational building—at the academic level—in Southern Italy was investigated. The aim was to evaluate the incentive share, which could accelerate the energy efficiency process, to achieve a cost-effective nZEB. The results show that the highest incentive rate is required for interventions on the opaque building envelope, which are also those that allow the least energy savings. An incentive rate of about 45% for the energy efficiency of the transparent envelope is necessary to reduce the payback time by about 7 years. The efficiency of the plants and the installation of a PV system are energetically and economically convenient even without forms of economic incentive. Finally, if the building is brought to high energy standards—a primary energy saving of 46% and energy class A3—an incentive rate of 40% is required to repay the intervention in about 10 years. [ABSTRACT FROM AUTHOR]

The heat exchanger can use shallow geothermal energy to provide regional heating and cooling demand in winter and summer. In this paper, a large-scale public building is taken as the example, and the energy system in the building is taken as the research object. Firstly, through the collection of geothermal drilling geographic information and geothermal data, the geothermal reserves and geothermal recoverable resources are evaluated. Secondly, the cooling and heating demand of the building is calculated by using HVAC simulation software. Then, the heat transfer capacity of a single pile is evaluated and the lay-out scheme of the underground heat exchange pile foundation of the building is given. The actual heating effect of the heat exchange pile foundation system is explored, and the heat transfer characteristics of heat exchange pile foundation under different working conditions are compared and analyzed. Finally, reasonable suggestions for the arrangement of heat exchange pile foundation are given. [ABSTRACT FROM AUTHOR]

This paper aims to explore the feasibility of the silicon aluminum (Al–Si) alloy for usage as a thermoelectric tile on building roofs. Through the simulation of the heat conduction characteristics and temperature field distribution of the step-shaped Al–Si alloy sample, the effects of the thickness, material, and shape of the Al–Si alloy sample on its thermal conversion efficiency and temperature field distribution characteristics of continuous solar irradiation were studied. The energy conversion characteristics of the Al–Si alloy sample combined with a thermoelectric generator (TEG) were investigated by numerical analysis and experiment. The results show that the Al–Si alloy sample with a thickness of 10 mm had a good heat storage efficiency. Also, the Al–Si alloy tile with a plane shaped solar irradiation surface and the back-sun surface with a certain number of bosses has a better heat transfer efficiency. Through experiment and calculation demonstrate that an Al–Si alloy tile with 500 mm × 500 mm area could generate 1.64 W electric power. [ABSTRACT FROM AUTHOR]

In this paper, an artificial neural network (ANN) based system-level model predictive control framework is established for a variable air volume (VAV) system to improve its robustness and energy efficiency. The VAV system consists of three processes: the zone temperature process, the damper process and the supply air volume process of the air handling unit connecting the ductwork for all of the boxes. An ANN-based predictive controller is designed for the zone temperature process, and a PI controller is used for the damper process; they operate in a cascaded manner. Another ANN predictive controller tracks the total supply air volume subject to the cooling load constraints from the lower level VAV boxes and minimizes the fan energy consumption. The ANN controllers are optimized online by the Lagrange variational approach (LVA) to minimize the system cost function and implement a feedback receding horizon optimal control. With the LVA based gradient descent training algorithm, the weight convergence of the ANN predictive controllers and stability of the control system is obtained with small computational and storage needs. The modeling methodology, based on ANNs for the above processes, is developed and calibrated with actual data measured from a site. All of the data processing and control strategy implementations are based on extensive measurements collected from a laboratory building located in the campus of Beijing University of Civil Engineering and Architecture , Beijing , China. The experimental results show that an additional 6.12% energy savings is achieved. This is accomplished by introducing the fan control signal into the system cost function as the performance index of energy consumption with a 0.2 penalty coefficient. In the presence of un-modeled disturbances and modeling errors, the framework also reduces the temperature oscillation at least by approximately 60% compared with PI control. • A neural network-based predictive control strategy for VAV systems is designed. • Cascade predictive control is implemented for zone temperature and air flow rate. • The duct air volume process achieves total airflow predictive control with savings in fan energy consumption. • The predictive controller using neural network implementation, easy to achieve nonlinear system optimization. • The control strategy is robust to un-modeled disturbances and modeling errors. [ABSTRACT FROM AUTHOR]

This paper introduces an innovative method for making cement-based composites from corn straw plants, and investigates the strength, thermal conductivity, and hydration characteristics of the composites. Corn straw is a natural, renewable, and breathable thermal insulation composite that contains cellular sealed pores. Corn straw contains a large amount of soluble cellulosic sugar, which hinders the hydration reaction of Portland cement and affects the use of corn straw as a building material. In this study, a 3 wt.% siliceous solution was used for surface treatment of corn straw particles to prevent cellulosic sugar from affecting the hydration performance of Portland cement. The composition of added cement-based composite materials with treated corn straw at the dosage of 11–20 wt.% was investigated. The test results showed that the corn straw cement-based composite (CSCC) had an optimal thermal conductivity of 0.102–0.112 (W/(m·K)) and a minimum compressive strength of above 1 MPa. The hydration performance of four typical CSCCs was examined using XRD, SEM, and EDS. The experimental results of this study may help to increase the comprehensive utilization of corn straw. The manufacturing method of the composite materials is simple, effective, and convenient for popularization and application, and it provides a new important technical measure to solve the problem of high energy consumption in rural houses. [ABSTRACT FROM AUTHOR]

Understanding transient heat transfer in building assemblies is important for improving the energy efficiency of the built environment. This paper describes an inverse analysis to evaluate the field energy performance of a multilayer prefabricated wall. The purpose is to estimate the heat flux through the internal surface of a wall in an occupied lightweight house in Quebec City (Canada). The inverse problem modeling was based on one-year on-site temperature measurements which convey the in-use thermal behavior of the wall assembly. The inner surface experienced an outward heat flux for most of the year. The greatest heat loss was around 5.5 W m−2 in winter and the greatest heat gain was around 1.0 W m−2 in summer. In the heating period, the indoor environment lost about 18 kW h m−2 (6.5 × 107 J m−2) of thermal energy. There was a total thermal gain of around 1 kW h m−2 (3.5 × 106 J m−2) during the free cooling period. Based on the heat flux estimations, the effective thermal resistance of the assembly was found to be 6% lower than its theoretical value, but still in compliance with Canadian building standards. • The inner wall surface experienced heat losses for most of the year monitored. • Heat loss and heat gain peaks were around 5.5 W m−2 and 1.0 W m−2, respectively. • 18 kW h m−2 of thermal energy left indoors across the wall in the heating period. • 1 kW h m−2 of thermal energy entered indoors across the wall in the cooling period. • Effective R -value is 6% lower than the theoretical one and complies with the norms. [ABSTRACT FROM AUTHOR]

The 2023 revision of the Energy Performance of Building Directive underlines the need to consider the whole life cycle emissions for buildings. The decarbonization targets could not be achieved if reduction of energy demand in the operational phase is accompanied by a high energy resource use in the whole life. This paper proposes a novel investigation of an energy renovation project, involving both building envelope components and space heating system. The adopted method is based on the life cycle assessment, in the variant cradle-to-gate with options, to analyze and compare the design data achieved through an analysis of product (embodied) and use (operational) stages. Different solutions for energy improvement of the building performance are identified, and the scenario with the lowest embodied energy was found to be more energy efficient globally. The most effective scenario, with energy and CO 2 savings of 39% and 40% is characterized by a weight of embodied energy and emissions of 6.5% and 6.9%, respectively. Given the rise of the weight of the embodied energy in the whole life cycle of future buildings, the life cycle assessment will become crucial for sustainable design and in the transition to an energy-efficiency built environment. [Display omitted] • The impact of life cycle analysis in the process of energy efficiency is investigated. • The "cradle-to-gate" with options approach is implemented. • The efficiency of walls and windows involves the greater use of energy resources. • The most energy-efficient scenarios from an operational and non-operational point of view are different. • The scenario identified in the analysis of A1-A4 phases allows a higher total energy saving. [ABSTRACT FROM AUTHOR]

The problem addressed in this work is the enhancement of energy efficiency in buildings, primarily focused on heating control. The paper highlights the importance of addressing this challenge, given that HVAC systems are responsible for over 60% of total energy consumption in buildings, making them the largest energy consumers in both the residential and nonresidential sectors. This paper presents a methodology for developing a model predictive control (MPC) system based on artificial neural network (ANN) models, with the aim of improving the energy efficiency of buildings. This approach involves the creation of a training dataset using dynamic thermal simulation tools, enabling the learning of the ANN model that is responsible for predicting future states within an MPC optimization loop. Additionally, the implementation leverages advanced technologies such as Field-Programmable Gate Arrays (FPGAs), specifically the PYNQ board, Wi-Fi modules, and MQTT communication to enhance scalability, deployment, and adaptability. The study evaluates the proposed Neural Network Model Predictive Control (NNMPC) strategy implemented on the PYNQ, reporting a substantial reduction of 38.53% in heating energy consumption in buildings compared to a basic On/Off control approach for 24-hour simulation. This outcome underscores the solutions significant potential for energy savings in building heating systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • The paper reviews 43 articles defining methodologies for climate classification. • The paper provides overview of climate classification and validation methods. • Need of standard methodology or nomenclature for climate classification. • The optimal approach for conducting climate zoning remains a topic of debate. Climate classification simplifies the representation of expected climate conditions by eliminating the need to describe each climatic parameter. Climate classification is frequently used as a basis for recommendations through codes and standards for buildings because a given climate has nearly similar design conditions. Furthermore, building energy efficiency programmes are designed based on the climatic classification to determine appropriate design strategies to eliminate the under-design or over-design of buildings for similar climatic regions. This necessitates the use of realistic and reliable climate classifications. Over the past two decades, numerous research studies have proposed climate classification methods. However, there is a lack of universal acceptance of climate classification methodology to balance complexity and accuracy. This research provides an overview of various climate classification methods and indicators used to assess the significance of climatic conditions. Moreover, this study highlights pressing issues, proposes a feasible climate classification methodology, and offers substantial possibilities for future study. This study organizes and evaluates the various classification and validation methods used by researchers, variables, and the granularity of data used for the classification. The usual criteria for defining a climate are temperature, relative humidity, cooling-degree days, heating-degree days, and solar radiation. About eighty-five percent of the classified climates are using at most three variables. The number and characteristics of climate zones vary with changes in the resolution of climate data, classification methods, and the inclusion of different sets of parameters. Clustering methods are becoming more important for climate classification as these methods can handle multiple variables more accurately. To tackle the complex relationship between climate and building thermal design, it is recommended to use climate variables with cluster analysis and validation based on thermal loads. This paper will give researchers an aerial perspective of the scope and direction of ongoing research in this field. [ABSTRACT FROM AUTHOR]

Due to the higher practicability and annual utilization, the dual-use heat pump systems are more popular in practical demonstrations. Although there are various kinds of designs for such system, most of them focus on the performance enhancement in heating mode and pay little attention to the cooling capacity. The proposed three-dimensional composite heat exchanger structure based on a concentrator plus fins could not only improve the total output in heating mode but also lower the condensing temperature by shading the solar energy with the concentrator to improve the cooling COP. Different from previous study, this paper focus on the improvement potential in cooling mode of the novel system. Experiments are carried out and used for the validation of mathematical model. By analyzing the physical state of the refrigerant during the cycle, the mechanism is revealed in detail and depth. Results show that the dryness decrease at evaporator inlet caused by the condensing temperature drop is the main reason for capacity improvement, while the mass flow rate also has crucial impact. With high mass flow rate, the mean cooling COP of proposed system could be as high as 3.1, 0.16 higher than the system without concentrator shading. • The paper presents the improvement impact in the cooling cycle. • Experiments are carried out for the validation of distributed parametric model. • The decreased dryness at the evaporator inlet explains for the increased cooling. • Lower condensing temperature may cause lower cooling energy with fixed throttling. • Proposed system could get a mean cooling COP of 3.1, 0.16 higher than irradiated system. [ABSTRACT FROM AUTHOR]

Building Performance Simulation (BPS) is an effective tool for informed decision making and providing feedback in all stages of building lifetime due to their ability to evaluate the effects of multiple parameters per multiple evaluation criteria. The energy, exergy, economy, environment, and occupant comfort (thermal and visual) are evaluation criteria in high performance building design. The decision variables or multiple parameters include architectural parameters, building materials traits, indoor and outdoor conditions, economic and ecological indicators, the characteristics of building services. Yet state-of-the-art BPS tools still need to overcome challenges to become more user friendly, improve simulation capabilities and tool interoperability. This paper surveys BPS tools by investigating their key features and limitations to help guide experts from all domains with energy efficient building design. Tool categorization based on multiple criteria is done and key findings are summarized in tables. Future development opportunities are elaborated. [ABSTRACT FROM AUTHOR]

The membrane enthalpy exchanger (MEE) is a viable energy recovery device to alleviate building energy consumption. In this paper, a quasi-counter-flow MEE's energy-saving effect and frost risk under severe cold conditions is investigated experimentally and numerically. The experimental results demonstrate that frost occurs when the outdoor air temperature falls below −14 °C. At an outdoor temperature of −26 °C, the enthalpy effectiveness decreases from 63.8% to 43.3% after one hour of frosting, accompanied by a significant increase in the exhaust air's pressure drop by 2.7 times. Furthermore, the simulation results reveal that the lower latent effectiveness compared to sensible effectiveness contributes to the highest risk of saturation near the exhaust air outlet. Moreover, this study analyzes the influence of MEE's geometrical and physical characteristics on its recovery effectiveness and frost risk. The findings indicate that increasing the membrane spacing can prolong MEE's operation duration at the expense of recovery effectiveness. Specifically, the MEE's total energy recovery during the whole heating season in Shenyang, China, increases by 18% when the membrane spacing is extended from 2 mm to 5 mm with a membrane thickness of 70 μm. This study provides insights into the MEE design. • Membrane enthalpy exchanger has impressive total effectiveness higher than 60%. • Frost occurs in the exchanger when the outdoor air temperature is below −14 °C. • Frost formation causes surge of pressure drop and attenuation of effectiveness. • Higher resistance to moisture transfer than heat transfer aggravates the frost risk. • Optimizations of geometric and physical characteristics are discussed. [ABSTRACT FROM AUTHOR]

The commonly-used in-situ test method of heat transfer coefficient of building envelope and its existing problems are introduced briefly in the paper. Through theoretical derivation based on the one-dimensional steady-state heat transfer, the mathematical relation between heat transfer coefficient of building envelope and its one side surface temperature is given in the paper. A method for conveniently and rapidly detecting heat transfer coefficient of building envelope with infrared radiation temperature measuring technology is proposed. Lastly, according to the principle and method of detecting heat transfer coefficient of building envelope with infrared radiation temperature, a kind of in-suit detector of heat transfer coefficient of portable building envelope is designed. It is hoped that this design will provide economic, high-efficient, and rapid detecting means for in-suit detection of heat transfer coefficient of building envelope. [ABSTRACT FROM AUTHOR]

Energy consumption and indoor environment of buildings are proved to be largely influenced by the presence and behaviors of occupants. The uncertainty caused by occupant behaviors accounts for a significant discrepancy between the predicted and actual energy usage. In a real world, building system operations and control will be directly affected by occupant behavior, which may lead to over thirty percent waste against building's designed performance. Therefore, the capability to seamlessly integrate occupant behavior in energy simulation tools and building management systems in the future is clearly important to optimize building energy use while maintaining the same level of services. However, research has not reached the phase that occupant behaviors could be effectively modeled. Thus, the traditional schedule based approach is not adequate to satisfy the needs of building efficiency. In this paper, a thorough survey of occupant behavior modeling and simulation state-of-the-art technologies and methodologies for building energy efficiency is conducted. The paper first identifies and discusses the significance and application scale of building occupant behavior model. Based on the information collected, some recent data acquisition technologies for behavior-related research and occupant behavior modeling approaches are summarized. The advantages and limitations of these modeling methods are compared and analyzed, as well as appropriate recommendations are made for the future research. The paper finally outlines the findings and potential development areas in the field of occupant behavior modeling for energy efficient buildings. [ABSTRACT FROM AUTHOR]

Housing conditions are addressed by climate policy in retrofitting buildings and by social policy in providing affordable and adequate housing. Aim This paper illustrates intersections between both policy spheres in Austria and argues that disjunct policies undermine efforts at alleviating energy poverty. We identify conditions under which housing in Austria may lead to reduction in carbon emissions and inequality. Methods A concurrent triangulation design combines secondary data analysis, semi-structured expert interviews, and an in-depth analysis of legal documents. Results Energy poor and generally poor similarly live in low-quality and inefficient housing. Climate and social policy suffer from fragmented jurisdictions lacking inter-sectoral integration and do not accurately target the energy poor. Structural investments and the provision of affordable, adequate housing conflict due to the tenant/landlord dilemma. Implications Socio-economic conditions and housing market structures need to be incorporated in policy design. Inter-ministerial collaboration may mainstream the integration of climate and social policy. [ABSTRACT FROM AUTHOR]

Abstract Semi-transparent photovoltaic (STPV) windows, which can not only generate electricity in situ, but also effectively reduce solar heat gain while utilizing natural daylight, have gained increasing popularity due to their energy and environmental benefits. However, the poor thermal insulation performance of single-glazed STPV windows has restricted their application in cold climate regions. PV insulated glass unit (IGU) is an alternative for STPV window applications. This paper presents a comprehensive assessment on overall energy performance of PV-IGUs with different PV glazing transmittance and rear glasses in comparison with conventional IGUs in five different climate zones in China. The results show that PV-IGUs can achieve energy savings in all the representative cities. The largest energy savings are observed in Kunming where heating and cooling demands are low but annual solar radiation level is high. In cold climate regions like Harbin, the PV-IGU with higher transmittance and rear low-e glass consumes less net source energy in comparison with that with lower transmittance and rear clear glass. Although the lighting energy demand of PV-IGU is larger than conventional IGU, the daylight quality of the room with PV-IGU is better due to the higher useful daylight illuminance (UDI) and lower daylight glare probability (DGP). Highlights • An integrated thermal, daylighting and PV power generation building energy model is developed. • Energy saving potential of PV-IGU is evaluated in comparison with conventional IGU. • Daylight analysis is conducted using daylight metrics – DA, UDI and DGP. • The optimum design of PV-IGU under different climate conditions is achieved. [ABSTRACT FROM AUTHOR]

Abstract In recent years, with the rapid development of economy and the acceleration of urbanization process, building energy consumption has become an urgent problem to be solved. Its total energy consumption shows a trend of sustained growth, and the growth rate is faster and faster, so the requirements of building energy efficiency detection technology are higher and higher. Aiming at the problems of time-consuming and difficult detection of traditional detection methods, this paper introduces infrared image processing technology and proposes an energy-saving detection method for buildings based on image processing. The air tightness and heat transfer coefficient are studied respectively. Firstly, the feasibility of infrared method to detect air tightness is theoretically analyzed, and the corresponding technical scheme and detection process are given. Secondly, the infrared image is grayed and filtered to eliminate the influence of thermal defect area on the calculation of heat transfer coefficient after eliminating interference noise. Finally, based on the one-dimensional steady heat transfer theory, the principle of quantitative detection of heat transfer coefficient in infrared image is given by studying the heat transfer process of the wall, and the related correction method is designed. The feasibility and superiority of this method are illustrated by an example. Therefore, this method has good application prospects in building energy-saving detection. [ABSTRACT FROM AUTHOR]

Abstract China has launched the energy efficiency project (EEP) for its civil building sector beginning in the mid-1980s; however, its implementation has not been effective. To better promote the EEP for the Chinese civil building sector, the Chinese government issued the China Act on the Energy Efficiency of Civil Buildings in 2008. This is the first paper to present a review of this act's implementation over the past decade. Based on China Database of Building Energy Consumption and Carbon Emissions and official documents, the achievements of this act are assessed by examining a variety of indicators. The success of the act can be attributed to the following factors: 1) a strong and sustained government commitment to top policies of building energy efficiency (BEE); 2) extensive efforts to apply the BEE standards to newly built civil buildings; 3) various incentive schemes involving energy efficiency retrofitting for existing civil buildings; 4) the increasing adoption of renewable energy to the civil building sector and of systems and platforms of energy efficiency supervision to commercial buildings; and 5) the rapid development of green buildings. Nevertheless, the revised act must address several challenges in the upcoming phase. These challenges mainly include the following: 1) the "double-control" strategy for the civil building sector; 2) the substantial development of the EEP in rural China; 3) the further development of green buildings for the low-carbon civil buildings; 4) the improvement of official statistical data systems on energy consumption and carbon emissions for civil buildings; and 5) building industrialization and informatization. It's expected that our efforts as constituting significant guidance for evaluating the EEP in the Chinese civil building sector, and the efforts will also be treated as an example for other developing countries to evaluate and revise their BEE acts. Graphical abstract Energy-saving value assessment of the Chinese civil building sector based on an IPAT-LMDI approach. Unlabelled Image Highlights • Presented a decennial review of the act for the first time. • Proposed a decadal retrospection of building energy efficiency project in China. • Building energy savings in 2011–2015: 183 million tons of standard coal equivalent. • Means of revising the act were proposed. [ABSTRACT FROM AUTHOR]

Abstract A new analysis framework is developed and applied to assess the benefits of building energy efficiency policies and programs. One of the main advantages of the new energy productivity analysis is that it accounts for both economic and energy performances of energy efficiency actions using only one metric. Specifically, the approach applies the concept of energy productivity to the building sector and accounts for both value added and energy savings of energy efficiency measures. Moreover, the proposed analysis accounts for all quantifiable benefits of energy efficiency programs including economic, environmental, and social. In this paper, the general guidelines for the energy productivity analysis are first described. Then, the analysis is applied to evaluate energy efficiency renewable energy programs for both existing and new buildings in the Gulf Cooperation Council (GCC) countries. The analysis results indicate that retrofitting the existing building stock can provide significant benefits and can improve the energy productivity of the building sector in all GCC countries and free up large energy volumes and investment potentials to the development of other economic sectors. In particular, the analysis indicates that reduction in energy consumption, peak demand, and carbon emissions due to deep retrofit programs for the existing building stock can double the energy productivity of the GCC region. Highlights • A new analysis approach is presented to evaluate building energy efficiency policies. • The analysis is used to assess energy efficiency programs for new and existing GCC building stocks. • Retrofit of the existing building stocks can double the energy productivity in all GCC countries. [ABSTRACT FROM AUTHOR]

Background: Green infrastructure is a strategic network of green spaces designed to deliver ecosystem services to human communities. Green infrastructure is a convenient concept for urban policy makers, but the term is used too generically and with limited understanding of the relative values or benefits of different types of green space and how these complement one another. At a finer scale/more practical level, little consideration is given to the composition of the plant communities, yet this is what ultimately defines the extent of service provision. This paper calls for greater attention to be paid to urban plantings with respect to ecosystem service delivery and for plant science to engage more fully in identifying those plants that promote various services. Scope: Many urban plantings are designed based on aesthetics alone, with limited thought on how plant choice/ composition provides other ecosystem services. Research is beginning to demonstrate, however, that landscape plants provide a range of important services, such as helping mitigate floods and alleviating heat islands, but that not all species are equally effective. The paper reviews a number of important services and demonstrates how genotype choice radically affects service delivery. Conclusions: Although research is in its infancy, data are being generated that relate plant traits to specific services, thereby helping identify genotypes that optimize service delivery. The urban environment, however, will become exceedingly bland if future planting is simply restricted to monocultures of a few 'functional' genotypes. Therefore, further information is required on how to design plant communities where the plants identified (1) provide more than a single benefit (multifunctionality), (B) complement each other in maximizing the range of benefits that can be delivered in one location, and (3) continue to maintain public acceptance through diversity. The identification/ development of functional landscape plants is an exciting and potentially high-impact arena for plant science. [ABSTRACT FROM AUTHOR]

Facility management has become increasingly challenging due to complex building systems that generate more diverse and complex maintenance issues. Facility managers and staff must deal with many daily maintenance requests despite various limitations, such as limited budgets and staff, which can cause delay in responding to some maintenance requests. A scheduling framework is proposed in this paper to assist in improving facility management. In practice, maintenance work is scheduled according to various priorities. For example, facility managers first consider the impact of each problem in terms of system failure and safety. In addition to those two factors, the framework proposed in this paper considers both energy efficiency and occupant satisfaction. It first quantified occupant satisfaction with data from current building maintenance work. An empirical study on occupant satisfaction was done based on classical disconfirmation theory and referenced post-occupancy evaluation (POE) research. A survey was designed to collect data to quantify occupant satisfaction. Based on the disconfirmation theory, an agent-based model was then developed to prioritize maintenance work to achieve maximum occupant satisfaction. Subsequently, a building energy model was simulated in EnergyPlus to quantify the impact of different aspects of a faulty HVAC system on energy consumption. Finally, the framework was tested through simulation and the results showed that occupant satisfaction level and building energy efficiency were improved by 30 and 97%, respectively, when using the framework. [ABSTRACT FROM AUTHOR]

Building Energy Efficiency Retrofit (BEER) is considered as a valuable way to improve energy efficiency of high-energy-consumption buildings. Sustainable BEER helps integrate sustainable development strategy into existing buildings and retrofit projects. To ensure BEER projects that can fulfill the sustainable development strategy, Energy Performance Contracting (EPC) is one possible market mechanism to deliver energy efficiency projects. Sustainable BEER under the EPC mechanism is a comprehensive system which involves the various demands of sustainable dimensions, performance criteria and groups of project success factors, making multi-criteria decisions become a challenging problem for decision makers. This paper aims to examine the interrelationships of sustainable BEER by focusing on an existing hotel building. EPC mechanism is applied in the case study and an effective Analytic Network Process (ANP) approach is also employed in the research. The result indicates that sustainable BEER in hotel buildings under the EPC mechanism is mainly determined by project control mechanism, available technology, organizing capacity of the team leader, trust, accurate Measurement and Verification (M&V), and team workers' technical skills. Decision makers should dedicate more attention to these aspects. From the research findings, several policy implications are proposed in this paper. [ABSTRACT FROM AUTHOR]

In the early stage of building design, typical meteorological year (TMY) used for building energy consumption simulation which mainly representing average conditions, cannot reflect the building energy consumption under extreme weather conditions. Intensified climate change leads to global warming and frequent extreme events, therefore, generating meteorological years for simulating building energy consumption under extreme weather conditions is desperately needed. In this paper, a new method for generating extreme weather years—An extreme building energy year (EBEY) is proposed, which not only considers the influence of various meteorological parameters on building energy consumption, but also calculates the extreme intensity and occurrence time of multiple parameters using dynamic thresholds. The results show that the accuracy of using EBEY to simulate building energy consumption under extreme weather conditions is better than that of temperature-only extreme years, radiation-only extreme years, extreme meteorological years (EMY), typical cold years (TCY) and typical hot years (THY). In addition, this study verifies that combining TMY and EBEY data reduces the number of simulations without losing the accuracy of the simulation results. • The intensity and duration of extreme weather and many parameters are considered. • Use dynamic thresholds in determining the occurrence of extreme weather. • The combination of TMY and EBEY improves the accuracy of simulation results. [ABSTRACT FROM AUTHOR]

Optimizing efficiency in the operation of the HVAC system of existing buildings requires the construction of a thermal dynamic model of the building, which may be challenging because architectural metadata may be missing or obsolete. Based on a suitable set of measured data, this paper presents a novel practical methodology to create and automatically derive thermal models of existing buildings in high-fidelity simulators for energy management. To this end, the philosophy of grey-box strategies is followed to simplify the modeling and avoid the requirement of architectural metadata, facilitating and expediting the process. First, a building model with a highly reduced number of parameters is constructed by exploiting the existing similarities in the materials of the buildings and simplifying their elements to a simple one-layer parameterization. Then, the parameters of the derived model are iteratively updated while minimizing the error between the real temperature evolution and that generated by the model being identified. For this purpose, data of the room air temperature, estimated occupancy, weather conditions, and variables of the HVAC system are assumed to be available in suitable zones of the building to apply the creation and identification processes of the model, allowing that a whole digital twin of the building is constructed. The methodology is presented by its application to a real case study: the Nimbus Research Centre building at Munster Technological University, located in Cork (Ireland). The high-fidelity simulator software TRNSYS is used for the modeling task, together with the GenOpt optimization program. The results demonstrate that the proposed methodology yields a highly accurate model of the building, capable of representing reality with RMSE values consistently below 0.6 C ∘ during open-loop validation periods of up to four days. The findings suggest that this methodology may outperform other modeling techniques reported in the literature. Importantly, the proposed technique is less complex and time-consuming to implement than many of the alternatives. • Thermal modeling of existing buildings avoiding the use of architectural metadata. • Novel integration of grey-box modeling methods with high-fidelity simulators. • The proposed method copes with the drawbacks of the models found in the literature. • Methodology validated with experimental data from the Nimbus Centre (Ireland). • Results show high accuracy of greatly simplified models—RMSE<0.6 °C in 4-day horizons. [ABSTRACT FROM AUTHOR]

High-rise buildings consume more energy and have greater environmental impacts, emphasising the need to adopt best practices during the design stage concerning BIM employment. However, despite strong support from the literature, little is known about the applications of BIM in high-rise buildings at the early design stage. Therefore, this paper aims to provide a holistic understanding of the current applications of BIM in high-rise buildings by analysing 60 studies. The findings identified seven research themes, including studies that used BIM for i) optimising building energy efficiency design; ii) collaborative design and planning; iii) life-cycle assessment; iv) designing net-zero energy buildings; v) integrating BIM with smart technologies for designing high-rise buildings; vi) cost analysis, and vii) structural design of high-rise buildings. Furthermore, this study highlights a number of challenges hindering the widespread application of BIM, alongside providing potential directions for the future development of BIM employment in high-rise buildings. [Display omitted] • A systematic review of BIM applications in high-rise buildings was conducted • Seven domains of BIM applications were identified • Challenges hindering widespread use of BIM in high-rise buildings were highlighted • Directions for future development of this research area were recommended [ABSTRACT FROM AUTHOR]

Purpose -- Building energy efficiency is an inescapable part of the solution to Africa's sustainable development; its implementation can result in cost effective ways that can contribute to economic and social development as well as environmental sustainability. Despite this, a number of factors including financial barriers and market barriers are perceived by policy makers and building designers to influence the efficient use of energy in buildings. The purpose of this paper is to investigate the perceptions of architects in relation to the challenges of building energy efficiency in Ghana. Design/methodology/approach -- From a review of pertinent literature 18 factors were identified as challenging. Empirical investigation was carried out using survey questionnaire. The consideration of overlapping aspects of the study largely motivated the use of factor analysis to analyse the data which made it possible to make scientific deductions and built explanations from the results. Findings -- The study derives five brands of uncorrelated variables that better explains challenges faced in implementing building energy efficiency in Ghana. These variables include financial barriers, information barrier, private sector participation, behavioural barriers and production barrier. The study provides insight on the contextual provision of realities faced in implementing building energy efficiency in Ghana. Originality/value -- Key contribution of the paper to the body of knowledge is manifested in the use of the principal component analysis. This has rigorously provided understanding into the complex structure and the relationship between the various knowledge areas of building energy efficiency barriers in Ghana. [ABSTRACT FROM AUTHOR]

China consumes more energy and emits more carbon dioxide than any other country. The building sector accounts for nearly 1/3 of the total national energy consumption in China; thus, it is critical to find a solution for improving buildings’ energy efficiency. Under the market-oriented mechanism, constrained by the energy performance contracting (EPC) mode, energy service companies (ESCOs) play an important role in improving energy efficiency for high-energy-consumption industries, including the building sector. The aim of this study is to determine the strategy for boosting the building ESCO industry. By conducting a strength, weakness, opportunity, and threat (SWOT) analysis, this paper presented the status of the building ESCO industry in China and proposed alternative strategies. By utilizing a conventional multi-criteria decision-making method, namely, the Analytic Network Process (ANP), this study provides a quantitative basis to analytically determine the ranking of the factors in SWOT analysis and select the best strategy to promote the development of the building ESCO industry. The results showed that the ANP-SWOT is a viable and highly capable methodology that provides invaluable insights for strategic management decisions in the building ESCO industry, and a set of strategies for promoting ESCO development in the building sector were proposed based on this approach. [ABSTRACT FROM AUTHOR]

Highlights • Balance of cooling energy saving and heating energy penalty for solar reflective coating. • Calculated and tested equivalent thermal resistance of solar reflective coating. • Quantitative design method for solar reflective thermal insulation hybrid system. • Achievement was accepted by building energy efficiency design standard of Shanghai. Abstract Solar reflective coating applied on roof/wall surface is becoming an important passive cooling technology for building energy efficiency. Shanghai is located in the climate of hot summer and cold winter, so the hybrid system of solar reflective coating combined with thermal insulation materials on roof/wall should be an efficient way for building energy saving. In this paper, the thermal performance and design method of the hybrid system was discussed. Equivalent thermal resistance for solar reflective coating was put forward for thermal performance evaluation and energy efficiency design for the hybrid system. Equivalent thermal resistance considers not only reflectance of the material, but also the weather conditions, demand for indoor comfort, orientation and thermal performance of base wall/roof. Equivalent thermal resistance in typical summer day and winter day of Shanghai were theoretically calculated and tested. Annual equivalent thermal resistance which integrated the benefit in summer and the penalty in winter was achieved by linear regression algorithm of simulated energy, and the results were 0.07–0.40 m2·KW−1 for wall and 0.18–1.07 m2·KW−1 for roof. This means solar reflective coating is energy saving equivalent and replaceable with 7–23 mm thermal insulation layer on wall, and 14–107 mm on roof. This method was useful and accepted in the energy efficiency design standard of Shanghai. [ABSTRACT FROM AUTHOR]

Occupants are integral elements of a building ecosystem and their behavior can have a substantial impact on energy consumption in buildings. A wide range of energy feedback programs have been developed to make energy consumption more visible and interpretable to occupants and help them learn how to control and save energy. In this paper, we conduct a critical review of the literature related to energy feedback and identify four key methodological approaches to designing and studying energy feedback programs: experiments, analytics, surveys and simulation. Our meta-analysis reveals five research gaps and opportunities for future methodological fusion at the intersection between such approaches, including the analytics-survey, experiments-analytics, experiments-analytics-surveys, simulation-experiments and analytics-simulation interfaces. Future research at these crucial interfaces could provide the deeper understanding necessary to develop energy feedback programs that yield substantial and persistent energy savings. [ABSTRACT FROM AUTHOR]

In this paper a techno-economic evaluation method for deep renovation of buildings is introduced. We study the validation of an integrated design methodology based upon the creation of additional volume on existing buildings (Add-Ons) intended as roof-top or aside extensions, enclosures, parasites or façade transformations. Energy price uncertainty is modelled through a mean-reverting stochastic process, which well fits the data for natural gas prices, and the proposed evaluation method is based on real-option theory, which is an advancement of standard cost-benefit analysis, to be employed whenever uncertainty has a significant impact on the investment option. The new method to evaluate the economical feasibility of the Add-ons strategy for Deep Energy Renovation is tested through design experiments on a real case study of social housing in Reggio Emilia (Italy). [ABSTRACT FROM AUTHOR]

Climatic zoning for building energy efficiency applications is an important element in building energy policy and regulations. There are several methodologies available to conduct climatic zoning, providing significantly different results. Currently, there are no procedures to assess the validity of a proposed climatic zoning, hindering the decision to use one particular climatic zoning methodology instead of another. This paper introduces a quality index and a procedure to support the validation of climatic zoning. The procedure is based on building performance simulation results concerning the building stock that is targeted in the climatic zoning policy or program. Simulation results are used to calculate a new index, the Mean Percentage of Misclassified Areas (MPMA), which assesses the quality of the zoning under analysis. The capabilities of this procedure were demonstrated by the evaluation of four alternatives for the climatic zoning of Nicaragua, obtained using different methodologies and previously reported in the literature. The building stock used in this case study is composed of a few archetypes based on typical naturally ventilated dwellings in this country. Simulations were conducted using the program EnergyPlus for a total of 328 locations in Nicaragua. Degree-hours of discomfort based on the adaptive model of ASHRAE Standard 55 were used as a performance indicator. Results indicate that zoning obtained using cluster analysis and cooling degree-days may misclassify 1 out of 5 areas in Nicaragua (MPMA around 18–20%). This study concludes that the validation procedure and proposed index are useful for highlighting qualities and deficiencies of existing climatic zoning methods, particularly when these methods are used in less conventional applications, such as for policy making targeting naturally ventilated dwellings in tropical climates. The application of this procedure in more than 50 countries which adopt climatic zoning is foreseen as the next step in his area, substantially affecting the prescription of building materials and components worldwide. [ABSTRACT FROM AUTHOR]

Building operations account for the largest proportion of energy use throughout the building life cycle. The energy saving potential is considerable taking into account the existence of a wide variety of building operation deficiencies. The advancement in information technologies has made modern buildings to be not only energy-intensive, but also information-intensive. Massive amounts of building operational data, which are in essence the reflection of actual building operating conditions, are available for knowledge discovery. It is very promising to extract potentially useful insights from big building operational data, based on which actionable measures for energy efficiency enhancement are devised. Data mining is an advanced technology for analyzing big data. It consists of two main types of data analytics, i.e., supervised and unsupervised analytics. Despite of the power of supervised analytics in predictive modeling, unsupervised analytics are more practical and promising in discovering novel knowledge given limited prior knowledge. This paper provides a comprehensive review on the current utilization of unsupervised data analytics in mining massive building operational data. The commonly used unsupervised analytics are summarized according to their knowledge representations and applications. The challenges and opportunities are elaborated as guidance for future research in this multi-disciplinary field. [ABSTRACT FROM AUTHOR]

Abstract: The energy use in the world is increasing significantly owing to increase in per capita consumption of energy and growing population. Due to increased energy demand and the depletion of existing fossil fuel based sources, it is required to use the energy more efficient. Researches show that, hospitals represent approximately 6% of total energy consumption in the utility buildings sector. Heating, Ventilation and Air Conditioning (HVAC) systems are the major part of electrical energy consumption at the hospitals. In this paper, the research papers and practical studies on energy efficiency and energy saving potentials on HVAC systems at the hospitals are presented. Under the following sections, the latest literatures including research articles, conferences, e-books, handbooks and company reports interested in energy efficiency, energy saving and energy management HVAC systems are summarized. Variant Refrigerant Flow (VRF) technology enables greater energy efficiency and cost savings compared with traditional HVAC systems is also introduced. This detailed review also focuses on the payback periods of some projects on HVAC including the installation of cogeneration, trigeneration, chiller, new burners, heat exchangers and steam trap systems. [Copyright &y& Elsevier]

In this paper, a representative office building zone with an electrochromic (EC) glazed façade was simulated in TRNSYS and Radiance/Daysim for a large number of different combinations of design parameters (i.e. location, façade orientation, window control, window-to-wall ratio, internal gains, thermal mass and envelope air tightness). Results of energy consumption, peak energy demand, useful daylight index (UDI) and predicted percentage of persons dissatisfied (PPD) for a total of 7680 scenarios were obtained and used in a sensitivity analysis considering the Main effect of the building parameters. The relative influence of the parameters is presented and the different designs improving the outputs are determined. Results have shown that the greatest total energy savings considering EC windows are for warmer climates with higher solar radiation exposures. The presence of an EC window mostly influences the cooling peak load and acts as an alternative solution to thermal mass from the perspective of peak reductions. While the choice of the specific window control strategy is having a limited impact on the energy savings and peak load reductions, the analysis revealed that this parameter has a larger impact on the visual comfort (UDI). The use of smart window does not appear to greatly influence the thermal comfort within the zone (small impact on the PPD). [ABSTRACT FROM AUTHOR]

Power engineers are expected to play a pivotal role in transforming buildings into smart and energy-efficient structures, which is necessary since buildings are responsible for a considerable amount of the total energy consumption. To fulfil this role, a holistic approach in education is required, tackling subjects traditionally related to other engineering disciplines. In this context, USE Efficiency is an inter-institutional and interdisciplinary educational programme implemented in nine European Universities targeting energy efficiency in buildings. The educational programme effectively links professors, students, engineers and industry experts, creating a unique learning environment. The scope of the paper is to present the methodology and the general framework followed in the USE Efficiency programme. The proposed methodology can be adopted for the design and implementation of educational programmes on energy efficiency and sustainable development in higher education. End-of-course survey results showed positive feedback from the participating students, indicating the success of the programme. [ABSTRACT FROM AUTHOR]

Building sector accounts for significant portion of total final energy use in most countries. One way to reduce significantly building energy consumption is to adopt energy efficiency technologies and strategies. Due to environmental concerns and high cost of energy in current years there has been a renewed interest in building energy efficiency. Advanced control strategies provide a more efficient way of minimizing energy demand of buildings and maintaining indoor environmental quality in accordance with global principle of sustainability, which has also proven reliable for diverse applications such as Heating, Ventilation and Air Conditioning (HVAC) control and thermal comfort control etc. The objective of this paper is to review the control strategies in buildings, particularly focusing on low energy buildings (LEB), in recent 10 years. Present work consists of why to use control strategies in buildings, categories of control strategies, research literature for building performance affected by diverse control strategies from the perspective of theoretical modelling, physical experimental study and numerical simulation investigation. Following that, more than 20 parameters affecting control performance have been analyzed and evaluated. The literature has illustrated that the best overall performance of control strategy is proportional integral derivative control-model predictive control (PID-MPC); the effects of those parameters on control performance are completely different, depending on which exact initial conditions and the interaction between different factors. [ABSTRACT FROM AUTHOR]

Climatic zoning for building energy efficiency applications is a key element in many programs and policies to improve thermal performance of buildings. In spite of its importance, there is no consensus about the appropriate methodology for climatic zoning. Previous studies indicate a large variety of methods and parameters are currently used for climatic zoning: degree-days, cluster analysis and administrative divisions are some of the most widely used. This study reports and reviews results obtained with these three methodologies for Nicaragua, a small country in Latin America. Results indicate a high level of agreement between the different methodologies, but they also disagree on the appropriate classification of a significant proportion of the country (37% of Nicaragua’s territory). The three methodologies have strengths and weaknesses, and at present it is impossible to conclude which one is the most appropriate to support building energy efficiency programs and policies. Results of this paper highlight the need for procedures and performance indicators to assess the validity of climatic zoning (which shall be addressed by future studies). [ABSTRACT FROM AUTHOR]

Building-integrated photovoltaic (BIPV) windows provide the benefits of generating electricity, reducing building cooling and heating energy consumption, and efficiently utilizing daylight simultaneously. In this paper, the overall energy performance of a PV double skin façade (PV-DSF) and a PV insulating glass unit (PV-IGU) is studied through comparative experiments on a test rig in Hong Kong. The PV-DSF means ventilated PV-DSF by default, if not special mentioned. It is found that the average solar heat gain coefficients (SHGCs) of the PV-DSF and the PV-IGU are 0.152 and 0.238, while the U-values are 2.535 W/m 2 K and 2.281 W/m 2 K. The results indicate that the PV-DSF has better performance than PV-IGU in reducing solar heat gains, while it has worse performance regarding thermal insulation. With a lower PV module temperature, the energy conversion efficiency of PV-DSF is 1.8% better than PV-IGU. Simulation models for the PV-DSF and the PV-IGU are developed and validated against experimental data. Using the validated models, the overall energy performances of PV-DSF and PV-IGU in five different climates of China are investigated. The results show that the average energy saving potential of the PV-DSF and the PV-IGU are 28.4% and 30%, respectively, compared to the commonly used insulating glass window in five different climates. On average, the performance of PV-IGU was 2% better performance than the ventilated PV-DSF in the five representative cities. However, if an appropriate ventilation control scheme was adopted, PV-DSF can have a much better performance than the PV-IGU. The models developed in this study can be used for selecting suitable PV windows in the design process, and the results achieved can be used as a guideline for utilizing PV windows in different climates. [ABSTRACT FROM AUTHOR]

The potential to reduce energy consumption in buildings is high. The design phase of the building is very important. In addition, it is vital to understand how to measure the energy efficiency in the building operation phase in order to encourage the right efficiency efforts. In understanding the building energy efficiency, it is important to comprehend the interplay of building occupancy, space efficiency, and energy efficiency. Recent studies found in the literature concerning energy efficiency in office buildings have concentrated heavily on the technical characteristics of the buildings or technical systems. The most commonly used engineering indicator for building energy efficiency is the specific energy consumption (SEC), commonly measured in kWh/m2 per annum. While the SEC is a sound way to measure the technical properties of a building and to guide its design, it obviously omits the issues of building occupancy and space efficiency. This paper studies existing energy efficiency indicators and introduces a new indicator for building energy efficiency which takes into account both space and occupancy efficiency. [ABSTRACT FROM AUTHOR]

Passivhaus technology is gradually applied in kinds of projects around the world because of excellent energy-saving effect since it was invented. It is becoming a new tendency of the development of building energy efficiency. In this paper, the concept contents, and evaluation criteria of Passivhaus technology system are introduced, and the latest domestic and foreign cases using Passivhaus technology system are analyzed. It is concluded that building designers should focus on their profession in the Passivhaus technology system in order to achieve the goal of improving indoor environment quality and building energy efficiency. [ABSTRACT FROM AUTHOR]

Real-time energy management within the concepts of home Microgrids (H-MG) systems is crucial for H-MG operational reliability and safe functionality, regardless of simultaneously emanated variations in generation and load demand transients. In this paper, an experimental design and validation of a real-time mutli-period artificial bee colony (MABC) topology type central energy management system (CEMS) for H-MGs in islanding mode is proposed to maximize operational efficiency and minimize operational cost of the H-MG with full degree of freedom in automatically adapt the management problem under variations in the generation and storage resources in real-time as well, suitable for different size and types of generation resources and storage devices with plug-and-play structure, is presented. A self-adapting CEMS offers a control box capability of adapting and optimally operating with any H-MGs structure and integrated types of generation and storage technologies, using a two-way communication between each asset, being a unique inherent feature. This CEMS framework utilizes feature like day-ahead scheduling (DAS) integrated with real-time scheduling (RTS) units, and local energy market (LEM) structure based on Single Side Auction (SSA) to regulate the price of energy in real-time. The proposed system operates based on the data parameterization such as: the available power from renewable energy resources, the amount of non-responsive load demand, and the wholesale offers from generation units and time-wise scheduling for a range of integrated generation and demand units. Experimental validation shows the effectiveness of our proposed EMS with minimum cost margins and plug-and-play capabilities for a H-MG in real-time islanding mode that can be envisioned for hybrid multi-functional smart grid supply chain energy systems with a revolutionary architectures. The better performance of the proposed algorithm is shown in comparison with the mixed integer non-linear programming (MINLP) algorithm, and its effectiveness is experimentally validated over a microgrid test bed. The obtained results show convergence speed increase and the remarkable improvement of efficiency and accuracy under different condition. [ABSTRACT FROM AUTHOR]

In a central heating, ventilation, and air conditioning (HVAC) system, the set-points for several local control loops have a significant influence on the overall energy performance of the system. Real-time optimization (RtOpt) of those set-points has therefore been widely studied. However, due to the nonlinear dynamics of the HVAC system as well as the constraints associated with the system operation, real-time optimization always suffers from a heavy on-line computational load when those set-points are optimized simultaneously. To overcome this problem, multiplexed real-time optimization (MRtOpt) has been developed, which optimizes only one set-point at a time but with a faster optimization frequency. Because frequently resetting the set-points introduces artificial disturbances into the local control loops and may deteriorate the system stability, this paper presents a study to enhance the system stability of the multiplexed real-time optimization by integrating a degree of freedom (DOF) based set-point reset to renew the set-points instead of the conventional step-change set-point reset. The control performance of the integrated strategy was investigated using case studies. The results showed that around 10% of the energy saving was achieved by the proposed method compared with a method without real-time optimization. When compared with the conventional real-time optimization method, the proposed method resulted in around 70% computational load reduction, and over 26% reduction in the tracking errors of the local control loops. [ABSTRACT FROM AUTHOR]

Retrofitting existing buildings has emerged as a primary strategy for reducing energy use and carbon emissions, both nationally and in cities. Despite the increasing awareness of retrofitting opportunities and a growing portfolio of successful case studies, little is known about the decision-making processes of building owners and asset managers with respect to energy efficiency investments. Specifically, the research presented here examines the effects of ownership type, tenant demand, and real estate market location on building energy retrofit decisions in the commercial office sector. This paper uses an original, detailed survey of asset managers of 763 office buildings in nineteen cities sampled from the CBRE, Inc. portfolio. Controlling for various building characteristics, the results demonstrate that ownership type and local market do, in fact, influence the retrofit decision. Overall, this analysis provides new evidence for the importance of understanding ownership type and the varying motivations of differing types of owners in building energy efficiency investment decisions. The findings of both the survey analysis and the predictive model demonstrate additional support for the targeting of energy efficiency incentives and outreach based on ownership entity, local market conditions, and specific physical building characteristics. [ABSTRACT FROM AUTHOR]