Low Energy Buildings Research Articles

Scientometric analysis of building integrated photovoltaics research: development, themes, and main trends

ABSTRACT Building-integrated photovoltaics (BIPV), a significant technological tool to reduce carbon emissions from buildings, have attracted extensive research attention worldwide as the call for “carbon neutrality” in the building sector continues to rise. Existing studies lack a comprehensive compendium of global BIPV-related research, and articles on the latest advances in the last five years are particularly scarce. Consequently, this study conducted a scientometric review of BIPV research to systematically and visually analyse the cutting-edge BIPV literature. Through multiple rounds of searching and screening, this study collected 467 BIPV-related studies between 2019 and 2023. It utilised CiteSpace to analyse the development of BIPV literature, summarise the themes, and predict the trends. The review reveals that the cross-disciplinary nature of the discipline dynamically shapes the focus of BIPV research. Based on the findings of scientometrics, three major themes are outlined and critically analysed: science and technology, market products, and implementation impediments. By comprehensively summarising and analysing the most recent BIPV literature, this study proposes a series of research trends in the field. This study provides policymakers, architects, and researchers in the field of low-carbon buildings with a detailed compendium of the current status and trends of BIPV. It offers specific insights and sources of reference for in-depth research and the promotion of the application of BIPV technology in the building industry.

Distributed Low-Carbon Energy Management of Urban Campus for Renewable Energy Consumption

In order to solve the mismatch between renewable energy and load in urban building microgrids, that is, the problem of renewable energy consumption in building microgrid clusters, while preserving the privacy of each user, this paper proposes a distributed low-carbon energy management method for urban building microgrid clusters. First, a low-carbon energy management method for the urban building microgrid is proposed in order to coordinate the power sharing of various subjects to minimize the total economic cost, unleash the consumption potential of low-carbon building clusters for renewable energy, and reduce carbon emissions on the spatial and time scale. Second, an ADMM-based distributed optimal energy management method is proposed to meet user energy needs while preserving local privacy; this includes energy storage systems, renewable energy generation, and the loads within each urban building microgrid. Finally, simulation experiments are conducted based on actual data from a certain area in Hangzhou, China, and the results verify the effectiveness of the model.

Towards codification of thermal resilience upgrades in midrise residential buildings: a Canadian archetype energy model approach

Extreme weather events are predicted to continue increasing in intensity and frequency, raising a serious concern about the thermal resilience and adaption of buildings to these events. A single residential archetype building will be chosen as the case study and evaluated in three locations across Canada (Vancouver, Ottawa, Charlottetown) using three historical extreme weather events. Two upgrade scenarios will be considered, a code-compliant (NECB 2020) and a high-performance building option, to compare thermal performance through hot/cold weather outages. By using a variety of outage events in cold-climate zones for an archetype building, this paper’s methodology offers a useful framework for building practitioners to assess the effects of building upgrades on performance metrics and improve building resilience. This research could eventually contribute to the development of codes by providing upgrade packages to create infrastructure that both mitigates and adapts to future climate change extreme weather.

Deactivated Ca-based sorbent derived from calcium looping CO2 capture as a partial substitute for cement to obtain low-carbon cementitious building materials

Calcium looping CO2 capture is a highly promising technology for carbon capture, utilization, and storage. Nevertheless, the disposal of deactivated calcium-based sorbents following cyclic carbonation and calcination processes presents an unresolved challenge. Concurrently, the development of low-carbon cement products is also a critical priority. Given the calcium-rich composition and carbon-negative nature of the calcium-based sorbent, it is proposed that the deactivated sorbent could be utilized as a partial substitute for cement in the production of building materials. This paper explored the potential of using two types of deactivated calcium sorbent (DPC/DGC) to partial substitute cement for low-carbon cementitious materials production. The effects of partial substitution of cement materials on volume stability, compressive/flexural strength, hydration kinetics, and carbon emission of the composite cementitious materials were investigated. The results indicate that a 5% and 10% replacement of cement with DPC/DGC has modest impact on volumetric stability and compressive strength. The composite cement with 5% DPC replacement achieves a 28-day compressive strength of 48.1MPa, representing a 0.4% increase compared to the 47.9MPa observed in the reference sample. Specimens with 15% DPC/DGC substitution exhibit inferior volume stability and mechanical performance than the control sample. The total hydration heat releases decrease with the increasing substitution ratio due to the dilution effect by the introduction of DPC/DGC. Additionally, substituting cement with Ca-based sorbents significantly reduced the carbon footprint of construction materials. The net carbon footprints for the building materials that containing 1 ton of binder (substitued with 10wt% DPC and DGC) were 152.5kg and 43.5kg, corresponding to reductions of 79.6% and 94.2% compared to reference cement mortar. These carbon footprints are projected to further decrease to -108.5kg and -375.5kg when DPC and DGC were obtained after 100 CO2 capture cycles. A novel technological route combining the high-temperature calcium looping CO2 capture and CO2 mineralization curing was proposed, and the associated challenges of this method were also discussed.

Aerated Concrete Made of MSW Incineration Ash: Effect of Blending Materials and CO2 Curing Condition

Municipal solid waste (MSW) incineration ash is used to produce aerated concrete blocks (ACB). To reduce cement usage and improve ACB quality, steel slag and blast-furnace slag were tested as cement substitutes, and CO2 mineralization technology was applied to cure ACB. The effect of steel blending ratios (MSW incineration ash, cement substitutes, water, aluminum powder) and CO2 curing conditions (temperature, pressure) on ACB properties was investigated. Under different conditions, the compressive strength, CO2 uptake and microstructure of ACB were determined. Higher fly ash content in ACB increases CO2 uptake but reduces compressive strength; ACB shows better mechanical properties when the cement is completely replaced by blast-furnace slag, but steel slag will cause ACB to fail to form; the optimal water-to-solid ratio enhances carbonation rate and compressive strength, and reducing aluminum powder content improves compressive strength. As the CO2 curing temperature increases from 25 to 105ºC, the carbonation rate and compressive strength of the ACB initially increase and then decrease, with the maximum CO2 uptake ratio of 20.0% and peak compressive strength occurring at 65ºC. When CO2 pressure increases from 0.2MPa to 1MPa, the carbonation rate rises to 23.4%, and the compressive strength first increases and then decreases, reaching 1.86MPa at a curing pressure of 0.6MPa, meeting the GB/T 11968-2020 B03 A1.5 grade standard. Approximately 0.58 tons of CO2 emissions can be reduced for every ton of ACB produced. This study established an innovative method to produce an environmentally friendly, low-carbon building material.

One step resource utilization treatment of solid waste: Preparation of high-performance building bricks from calcium carbide slag by ultra-high mechanical pressure

Calcium carbide slag (CCS), a bulk solid waste byproduct of the energy industry. This paper introduced an innovative ultra-high pressure contact forming technology that utilizes 100% CCS under high pressure conditions ranging from 100 to 400 MPa. investigated the effects of pressing pressure and curing conditions on the comprehensive performance of the resulting bricks. The findings reveal that bricks subjected to autoclave curing for a duration of 3 days exhibit optimal mechanical and waterproof properties. The bricks demonstrated the compressive and flexural strength of 37 MPa and 4.3 MPa, and a softening coefficient of 0.89. Furthermore, the bricks' dry density, wet density, and porosity index were measured at 1200 kg/m3, 1600 kg/m3, and 1.3, respectively. Notably, the leaching concentrations of toxic and harmful elements within the bricks are in compliance with environmental standards. This research delineates a viable avenue for the future resourceful utilization of solid waste.

Construction of stable triazine porous organic polymer nanofiltration membrane for selective separation: The role of substrate on the membrane formation and separation performance

Porous organic polymers (POPs) have been regarded as potential candidates for high-performance membrane building blocks ascribed to their robust structure, tunable pore size, and high surface area. Normally, the POPs membrane possesses a POPs selective layer on the porous substrate for its real application. Numerous efforts have been paid to manipulate the POPs selective layer to enhance the separation performance, however, except from providing mechanical strength, the role of substrates in the formation and separation performance of POPs membrane receives less attention. In this work, we employed a systematic study to reveal the role of substrates in the governing POPs membrane formation by choosing substrates with diverse properties. The relationship between the properties of substrate (e.g., pore size, porosity, roughness, hydrophilicity, and surface functional groups) and the assembly structure of POPs membranes was in-detail analyzed. We found that the hydrolyzed polyacrylonitrile substrate induced a better assembly of POPs nanoparticles. Its rough surface and carboxylic functional groups created Van der Waals interactions and hydrogen bonding interactions to reinforce interfacial adhesion between the substrate and POPs selective layer, which facilitated the formation of intact and defect-free POPs membranes. The resulting POPs membrane displayed a high water permeance of 121.3 L m-2h−1 bar−1 with a congo red rejection of 98.9 %. Moreover, benefiting from the robust interfacial interactions between POPs selective layer and the substrate, the POPs membrane enabled itself to maintain structure stability under harsh environments, such as acidic, alkaline, and organic solvents. This work gives new insights to producing robust and high-performance POPs membranes.

Influence of fiber type on the mechanical performance and fracture mechanism of fiber reinforced concrete under coupled static-dynamic compression

As a high-performance building material, fiber-reinforced concrete (FRC) has attracted garnered significant interest in practical engineering construction. However, the effect of coupled static-dynamic loading on the dynamic response of FRC remains far from understood, which seriously limits its wide application. In this study, a series of coupled static-dynamic loading tests are conducted on four types of FRC specimens using the modified split Hopkinson pressure bar (SHPB) system, and the influences of static pre-stress and strain rate on the mechanical performance of FRC under coupled static-dynamic loading are systematically analyzed. The experimental results indicate that static pre-stress generally reduces the dynamic strength and energy dissipation density, but increases the total strength and fragmentation degree of FRC. As the pre-stress ratio increases from 0 to 0.6, the dynamic strength of FRC decreases ranging from 12 to 25 %, and the total strength increases ranging from 12 to 34 %. The failure features of FRC specimens changes from tensile failure mechanism to tensile-shear mixed mechanism with increasing the static pre-stress. Combining the scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP) techniques, the microscopic structure and fracture mechanisms of FRC specimens are revealed, and the underlying influencing mechanisms of the static pre-stress, strain rate and fibers are further discussed. The axial pre-stress exerts a dual effect on FRC: enhancement by compacting primary voids as well as attenuation by stimulating secondary microcracks. The strain rate dominates the mechanical performance of FRC under coupled static-dynamic loading, and the influence of pre-stress is diminished by higher strain rates. In addition, the fiber incorporation strengthens the concrete pore structure by bridging action and crack inhibition, resulting in superior mechanical performance compared to normal concrete under coupled static-dynamic loading conditions.

Simulation of dynamic heat dissipation energy optimization based on IoT and image recognition in low carbon building VR design process

With the global emphasis on low-carbon buildings, how to effectively optimize the thermal management of buildings has become a research hotspot. This article constructs a three-dimensional model of low-carbon buildings and implements real-time heat dissipation detection of buildings through image recognition to evaluate their heat dissipation performance. Then a heat load prediction model was proposed, which obtained the heat load prediction results of buildings under different environmental conditions through data analysis. Thus, it lays the foundation for the subsequent optimization of dynamic heat dissipation energy. The core of the research is to establish a dynamic heat dissipation optimization strategy. This article provides a detailed introduction to the principle of dynamic heat dissipation synergy, combined with the thermal network temperature compensation model and dynamic adjustment model, to achieve the expected energy efficiency improvement. Finally, the construction of a dynamic heat dissipation energy optimization control system based on the Internet of Things has strengthened the collection and analysis of real-time temperature data, and its effectiveness and reliability in practical applications have been verified through system testing.

Preliminary Analysis and Possibilities of Reducing the Carbon Footprint of Embedded Materials on the Example of Innovative Systemic Railway Stations (ISS)

The paper presents a comprehensive analysis of the environmental impact of building materials used in the construction of railway stations. It analyses two examples of innovative railway stations built in Poland in recent years and examines the impact of the choice of building materials on the Global Warming Potential (GWP) of the stations. The analysis found significant differences in GWP between the two stations, with structural steel being the largest contributor for one station, accounting for 48% of the total GWP. Replacing traditional materials with low-emission alternatives was shown to reduce the total GWP for both stations by around 60%. The research highlights the importance of analysing the GWP of all building materials, even in small quantities, as some materials, such as high-pressure laminates, can have a disproportionate impact on carbon emissions. The study also shows that the correct use of low-carbon building materials in the construction of the station can lead to a significant reduction in the carbon footprint of the building. Collaboration between designers, investors and contractors is essential to achieve sustainable building designs that minimise the environmental impact of construction.

Research on Low-Carbon Retrofitting Technology for Existing Rural Buildings in Southern Henan Based on DeST

The development of low-carbon technology in urban construction is rapid, whereas in rural and other economically underdeveloped areas, the development of low-carbon buildings is relatively lagging behind. Achieving the low-carbon retrofitting of rural buildings is crucial for reaching the "dual carbon" strategic goals. This study conducted an in-depth investigation into the current situation, energy consumption levels, and factors affecting carbon emissions of rural buildings in Nanyang City. Using DeST simulation software, the energy consumption of a rural building in Wolong District of Nanyang City was simulated and analyzed, examining the impact of factors such as building exterior walls, roofs, external windows, orientation, and window-to-wall ratio on building energy efficiency.

Loading mechanism of timber screw–adhesive composite joint

The impact of carbon emission and other pollution generated by the construction industry on the natural environment and ecosystems is immeasurable. Wood, as a renewable building material with excellent performance, is a practical solution for future low-carbon buildings. Current screwed wood connections have good ductility, but the initial stiffness is relatively low. In this paper, composite wood connections with screw and adhesive were proposed and investigated. Static loading tests were conducted to screwed connections and composite connection specimens. The failure modes of different connection types, as well as the effects of adhesive type and adhesive connection area on the joint bearing capacity are discussed. The results show that the yield load and ultimate load of the composite joint made with the existing adhesive increased by up to 169% and 222%, respectively, compared with the screw connection. At the same time, the influence of curing time and bonding should also be taken into consideration. This study provides a foundation for wood joint design and promotes the sustainable development of the building industry.

Optimization of environmental thermal energy transfer based on virtual reality simulation in low-energy building interior design simulation

Optimization of environmental thermal energy transfer based on virtual reality simulation in low-energy building interior design simulation

Post occupancy evaluation of the relocatable modular construction method for temporary educational facilities

PurposeThis study aims to evaluate user satisfaction and perceptions of the relocatable modular school (RMS) system in South Korea. It seeks to identify key factors for improvement to enhance the performance of this innovative construction method, particularly in the temporary educational sector.Design/methodology/approachA comprehensive post occupancy evaluation (POE) was conducted, considering functional spaces, aesthetics, indoor environmental quality and technical aspects. This study also includes a comparative analysis with conventional school buildings to provide insights into the efficiency and potential of RMS.FindingsRelocatable modular schools can achieve the equivalent quality of building performance and user satisfaction as those built using traditional construction methods. The satisfaction performance of both methods falls within the “satisfied” level, with mean scores ranging from 3.35 to 3.90. Notably, when compared to ES, RMS exhibits a marginally lower satisfaction level in functional performance but a higher satisfaction level in the areas of aesthetics, IEQ and technical performance. Key factors identified for enhancement include optimizing classroom shape, balancing the window-to-wall ratio, enhancing natural ventilation and addressing floor noise and vibration concerns.Originality/valueThis research is pioneering in evaluating user satisfaction and perceptions of RMS in South Korea, a relatively unexplored area. By taking a holistic approach and incorporating comparative analysis with traditional school buildings, the study provides valuable insights into the practical application and potential of modular construction in educational facilities. The results contribute significantly to the advancement of high-performance modular educational buildings, informing practitioners and stakeholders of user demands and guiding future developments in the field.

A Review on Research of Prefabricated Building Costs: Exploring Collaborations, Intellectual Basis, and Research Trends

This analysis provides a comprehensive overview of current research regarding prefabricated construction costs, explained under three main categories: collaboration, intellectual basis, and research trends. The collaboration network covers country, institution, and journal distribution. Intellectual basis includes a cited journal, cited reference, and cited author, while research trends cover research category, keyword and keyword cluster analysis, and cited reference cluster. Through bibliometric analysis, we find that this field has garnered significant attention in the academic community and has developed rapidly. China dominates the field of prefabricated construction, with Curtin University, Chongqing University, and Deakin University being the leading research institutions, while Automation in Construction is the most cited journal. Although technology integration is widely regarded as a key means of cost optimization, its high implementation costs and complexity have limited its widespread application. The challenges of technology integration lie in the need to address high capital costs, complex management practices, and the demand for advanced technology integration, which have become significant barriers to the promotion of prefabricated construction. Moreover, current research also focuses on how to enhance risk control and management practices in cost management to promote sustainable development. Future research will focus on green and sustainable technologies, multidisciplinary engineering, energy and fuel, construction technologies to optimize prefabricated construction techniques, advance low-carbon building practices, and improve decision analysis and risk management. The key factors influencing costs include technological factor, policy factors, market and environmental factors, and organizational management. By systematically controlling these factors, cost pressures can be effectively alleviated, construction efficiency improved, and the sustainability of prefabricated buildings enhanced. This study not only provides a comprehensive analysis of the current state and trends in research on the costs of prefabricated construction but also highlights the critical role of technological innovation, policy optimization, and interdisciplinary collaboration in promoting the sustainable development of prefabricated construction globally.

Historical Evolution and Current Developments in Building Thermal Insulation Materials—A Review

The European Climate Law mandates a 55% reduction in CO2 emissions by 2030, intending to achieve climate neutrality by 2050. To meet these targets, there is a strong focus on reducing energy consumption in buildings, particularly for heating and cooling, which are the primary drivers of energy use and greenhouse gas emissions. As a result, the demand for energy-efficient and sustainable buildings is increasing, and thermal insulation plays a crucial role in minimizing energy consumption for both winter heating and summer cooling. This review explores the historical development of thermal insulation materials, beginning with natural options such as straw, wool, and clay, progressing to materials like cork, asbestos, and mineral wool, and culminating in synthetic insulators such as fiberglass and polystyrene. The review also examines innovative materials like polyurethane foam, vacuum insulation panels, and cement foams enhanced with phase change materials. Additionally, it highlights the renewed interest in environmentally friendly materials like cellulose, hemp, and sheep wool. The current challenges in developing sustainable, high-performance building solutions are discussed, including the implementation of the 6R principles for insulating materials. Finally, the review not only traces the historical evolution of insulation materials but also provides various classifications and summarizes emerging aspects in the field.

Risk assessment of mold growth on engineered bamboo and its application

Engineered bamboo, as a low-carbon biomass building material, is more prone to mold growth than traditional building materials. Mold not only threatens the structural integrity of buildings but also poses health risks to occupants. Current mold prediction models cannot accurately assess the risk of mold growth on engineered bamboo. This research first examined mold growth on three commonly used types of engineered bamboo under 20 different operational conditions. A prediction model was then developed and validated specifically for engineered bamboo. Results showed that bamboo surfaces became fully covered in mold at high relative humidity (RH ≥ 85%). When RH was reduced from 95% to 75%, mold germination was delayed by about 70 days. A relative humidity of 60% at temperatures between 15°C and 35°C was identified as a safe range for all engineered bamboo types. Additionally, the prediction model demonstrated high accuracy in forecasting mold risk. The findings also indicated that raising the air conditioning heating setpoint from 18°C to 20°C is more effective in reducing mold risk than lowering the cooling setpoint from 28°C to 26°C. This research offers a method to quantify indoor mold growth risks in engineered bamboo buildings under various climates, helping to optimize their design and operation.

Examining the challenges impeding the utilization of construction materials with lower embodied carbon in the construction sector

ABSTRACT This paper aimed at determining the barriers preventing the extensive utilization of innovative materials in the construction sector. As a way of providing clear understanding of the complex interrelationship between the barriers, the literature review was supplemented by an expert-based survey to determine the barriers, whereas the hierarchical structure between the barriers was analyzed using the interpretive structural modelling (ISM) approach. Based on the outcome of the level partitioning of the ISM approach, it was found out that “reluctance to take responsibility for embodied carbon reduction (B14) was partitioned at the 8th level indicating that it is the most highly prioritized barrier considered to be the most crucial in preventing the use of low-carbon building materials in the construction industry. The paper produces vital knowledge and evidence that could be applied to encourage more sustainable construction practices by the wide adoption of alternative construction materials with lower embodied carbon in the construction sector. The implications inferred based on the findings of this paper seek to suggest remedies, strategies, and actions that could help to overcome the undesirable impact of the barriers that affect the utilization of low-carbon building materials, particularly amongst prominent stakeholders of construction projects.

Research on the sustainable assessment of ecological low-carbon buildings with integrated sandstone energy storage systems

Abstract Addressing resource scarcity and climate change, enhancing building energy efficiency, and safeguarding ecological environments can effectively promote socially sustainable development. This paper employs an eco-low-carbon energy method and explores the sustainability analysis of a building system through the integration of modular energy storage units. The research results indicate that the integration of emergy storage units has significantly improved the sustainability of the building system by 56.9%, preliminarily verifying the feasibility of coupling energy storage units with the building system. The preliminary validation of sensitivity also ensures the accuracy of the analysis, providing a new model for the design of novel green building projects.

Research on 3D Model Calculation of Green and low-carbon New Buildings

Due to the widespread use of solid clay bricks in building houses in China, the annual destruction of farmland by burning bricks amounts to about 100000 acres. Faced with these problems, China has an extremely urgent demand for green and low-carbon buildings. Therefore, this article conducts computational research on the 3D model of a new type of green and low-carbon building. Due to the significant differences in the geometric form and texture representation of a large number of green and low-carbonl new buildings, it is difficult to uniformly quantify their level of detail. This article considers the usefulness and accessibility of 3D model calculation data separately. The shadow length is generally the distance from the selected building's facade roof to the end of the shadow, which can avoid the influence of building shape on its length. The determination of these two points and the calculation of the distance between them will directly affect the accuracy of shadow length calculation. Therefore, when users need to add an application subsystem to the system, they must add information such as the input and output data structures of the subsystem to the module. The height information calculation method uses the building and shadow imaging geometric modeling to calculate the building height by establishing the relationship between the shadow length and the corresponding building height.