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Phase change energy storage materials have advantages such as high energy storage density, stable performance, recyclability and environmental friendliness, making them promising for wide applications in the field of construction. This paper focuses on the research of palm oil methyl ester-lauric acid eutectic phase change materials with white carbon black and dodecanol as stabilizers and SEBS as supporting materials. It investigates the influence of different material ratios on the phase transition temperature and latent heat of the phase change materials. Additionally, microencapsulation technology is employed to combine the palm oil methyl ester-lauric acid eutectic phase change materials with gypsum building materials, creating a phase change simulation room to explore its feasibility in the construction field. The research results show that when m (methyl palmitate) ∶m (lauric acid) =6∶4, the phase transition temperature is 24. 5~28. 5 ℃ and the latent heat of phase transition is 172. 0 kJ/kg, both of which are suitable for the construction field; The original enthalpy of phase change during the melting process of phase change materials is 172. 0 kJ/kg, which changes to 167. 3 kJ/kg after 200 cycles, and the thermal conductivity is 0. 256 W/ (m·K) ; The simulated room without adding phase change materials heats up and cools down faster under simulated sunlight from infrared lamps than the simulated room with organic eutectic phase change materials. The addition of phase change energy storage materials has a significant regulating effect on indoor temperature in buildings. [ABSTRACT FROM AUTHOR]

In this paper, a morphologically stable composite phase change material (CPCM) suitable for use in the field of building energy conservation was developed using Na2HPO4∙12H2O (DHPD) as the phase change material, Na2SiO3∙9H2O (SSNH) as the nucleating agent, and silica aerogel (SA) as the carrier. The results showed that the incorporation of 25 wt% SA resulted in the as-prepared DHPD-SSNH/SA CPCM with a phase change temperature of 30.4 °C, an enthalpy of 163.4 J/g, and a low supercooling degree of 1.3 °C, which also solved the corrosion problem of reinforcing bars caused by the hydrated salt PCM. Meanwhile, DHPD-SSNH/SA CPCM had good shape stability and low thermal conductivity (0.1507 W/(m·K)). The phase change temperature was basically unchanged, and the enthalpy only decreased by 4.8% after 200 cold-heat cycles. In addition, the thermal performance evaluation of CPCM showed that the indoor thermal comfort time of the testing system loaded with PCM board accounted for 50.75%, which was 43.38% higher than that of the one without PCM board (7.37%). The results suggest that the obtained CPCM had a good energy saving effect and great potential in the field of building energy conservation. [ABSTRACT FROM AUTHOR]

Mastering building thermal science is essential for architectural professionals, as it supports the design of energy-efficient and thermally optimized buildings, which are critical for addressing the growing demands of sustainable architecture. However, traditional teaching methods often disconnect theoretical instruction from practical application, limiting students' ability to apply core concepts in real-world scenarios. This study introduces a pedagogical reform that integrates design-oriented and inquiry-based experiments, hands-on physical activities, and field-based testing into the teaching of building thermal science. The revised curriculum focuses on applying theoretical principles in real architectural contexts, allowing students to directly design and experience thermal phenomena such as heat transfer and thermal resistance in building envelope structures. To evaluate the effectiveness of this reform, a control group using traditional confirmatory experiments (following predetermined instructions to complete experiments and validate the results) was compared to a reform group engaged in inquiry-based experimental learning. Over the course of three cohorts (2019, 2020, 2021), the reform group consistently outperformed the control group, with statistically significant improvements in average course grades. Specifically, the reform group had mean grade differences of 7.21 points higher in 2019, 4.55 points higher in 2020, and 5.83 points higher in 2021, as demonstrated by t-test results (p < 0.05). The reform group also exhibited more concentrated grade distributions, reflecting enhanced comprehension and retention of key thermal concepts. In addition to improved academic performance, students in the reform group demonstrated superior problem-solving abilities and a heightened awareness of energy conservation and sustainable design practices. This approach not only deepened their understanding of theoretical knowledge but also fostered a greater commitment to integrating sustainability into their architectural projects. [ABSTRACT FROM AUTHOR]

In recent years, energy conservation became a strategic goal to preserve the environment, foster sustainability, and preserve valuable natural resources. The building sector is considered one of the largest energy consumers globally. Therefore, insulation plays a vital role in mitigating the energy consumption of the building sector. This study provides an overview of various organic and inorganic insulation materials, recent trends in insulation systems, and their applications, advantages, and disadvantages, particularly those suitable for extreme climates. Moreover, natural and composite materials that can be used as a low-cost, thermally efficient, and sustainable option for thermal insulation are discussed along with their thermal properties-associated problems, and potential solutions that could be adopted to utilize natural and sustainable options. Finally, the paper highlights factors affecting thermal performance and essential considerations for choosing a particular insulation system for a particular region. It is concluded that the most commonly used insulation materials are found to have several associated problems and there is a strong need to utilize sustainable materials along with advanced materials such as aerogels to develop novel composite insulation materials to overcome these deficiencies. [ABSTRACT FROM AUTHOR]

Based on the coupling characteristics of photovoltaic power generation and phase change heat storage, a photovoltaic phase change composite building envelope structure was proposed and the effect of phase change heat storage on the performance of the composite building envelope was further analyzed. Firstly, the heat flow transfer model of photovoltaic phase change composite envelope structure was constructed, and then the influence of phase change layer structure position, phase change temperature and phase change thickness on its power generation capacity and thermal insulation effect was explored. On this basis, by comparing the thermal characteristics of traditional envelope structure and composite envelope structure, the indoor environmental load regulation and energy saving potential of composite envelope structure were expounded. The research shows that the phase change heat storage has a great influence on the power generation and thermal insulation performance of the photovoltaic phase change composite envelope structure. The closer the phase change material is to the room, the better the thermal insulation effect is; and the indoor temperature shows a tendency to approach the phase change temperature. The phase change material close to the photovoltaic panel means that the heat can be stored more fully, and the photovoltaic power generation is higher. When the phase change material is close to the photovoltaic panel, the power generation is 1 263.06 J, which is significantly improved compared with the photovoltaic envelope structure. At the same time, when the thickness of the phase change material is 40 mm, the power generation reaches the maximum value, which is 0.55% higher than the working condition of 10 mm. In addition, within one operating cycle, the photovoltaic phase change composite envelope structure significantly reduces the building's cooling load, showing good heat insulation and energy saving effects. [ABSTRACT FROM AUTHOR]

With the global energy crisis and environmental issues becoming increasingly severe, building energy efficiency has emerged as a key societal concern. Phase change energy storage materials (PCMs) are gaining prominence in the field of building energy conservation due to their ability to absorb and release large amounts of latent heat during temperature fluctuations, thereby achieving a self-regulating temperature effect. Although numerous studies have explored the properties of PCMs and their applications in buildings, most have focused on optimizing material performance and conducting tests in laboratory settings, often overlooking the complex thermal dynamics in real-world building environments. This study establishes a mathematical model of PCMs in building walls, defines the initial and boundary conditions, and conducts error analysis to systematically investigate the self-regulating temperature mechanism and the energy-saving effects of these materials. The findings of this research will provide new theoretical support and practical references for the advancement of building energy-saving technologies. [ABSTRACT FROM AUTHOR]

Curtain wall systems stand out as a pivotal domain within the construction sector's endeavors towards energy efficiency and carbon mitigation. To refine the evaluation framework for carbon emissions within this industry, this paper explores the calculation and assessment method for building curtain walls. The article first reviews the current research status regarding carbon emissions from materials and the impact of curtain walls on buildings in the operational stage. Based on lifecycle theory, the carbon emissions from building curtain walls are divided into six stages: material acquisition, processing and production, installation and construction, transportation, use and maintenance, and dismantling. On this basis, this paper proposes a method for calculating carbon emissions from building curtain walls. Following that, a case study is conducted using a specific glass curtain wall project for illustrative analysis. The results indicate that the carbon emissions from the material acquisition stage constitute approximately 90% of the total, serving as the primary source of carbon emissions for glass curtain walls. Furthermore, the scientific application of photovoltaics can significantly reduce the carbon emission levels of building curtain walls. Finally, an analysis was conducted on the current issues existing in the evaluation of carbon emissions. [ABSTRACT FROM AUTHOR]

Mastering building thermal science is essential for architectural professionals, as it supports the design of energy-efficient and thermally optimized buildings, which are critical for addressing the growing demands of sustainable architecture. However, traditional teaching methods often disconnect theoretical instruction from practical application, limiting students’ ability to apply core concepts in real-world scenarios. This study introduces a pedagogical reform that integrates design-oriented and inquiry-based experiments, hands-on physical activities, and field-based testing into the teaching of building thermal science. The revised curriculum focuses on applying theoretical principles in real architectural contexts, allowing students to directly design and experience thermal phenomena such as heat transfer and thermal resistance in building envelope structures. To evaluate the effectiveness of this reform, a control group using traditional confirmatory experiments (following predetermined instructions to complete experiments and validate the results) was compared to a reform group engaged in inquiry-based experimental learning. Over the course of three cohorts (2019, 2020, 2021), the reform group consistently outperformed the control group, with statistically significant improvements in average course grades. Specifically, the reform group had mean grade differences of 7.21 points higher in 2019, 4.55 points higher in 2020, and 5.83 points higher in 2021, as demonstrated by t-test results (p < 0.05). The reform group also exhibited more concentrated grade distributions, reflecting enhanced comprehension and retention of key thermal concepts. In addition to improved academic performance, students in the reform group demonstrated superior problem-solving abilities and a heightened awareness of energy conservation and sustainable design practices. This approach not only deepened their understanding of theoretical knowledge but also fostered a greater commitment to integrating sustainability into their architectural projects.

Nowadays, the process of urbanization is accelerating, and the density of buildings is increasing rapidly. Natural ventlation is an energy-saving way of building ventilation and to solve the issue of building overheating. The buildings are all considered as cubes and their arrays are evenly distributed. The results from nearly 100 cases show density is the main factor in uniform arrays and not much difference between the staggered and normal arrangements if consider a year. The method can reflect the ventilation capacity of the buildings, which is somewhat inverse to the air age but different meaning. It can be used to guide the layout and planning in early design stage.

The shape coefficient of building (SCB) characterizes the correlation between building shape and building energy consumption. Strictly restricting the SCB was harmful to reducing energy consumption, neglecting the potential benefits of solar radiation. A novel concept and determining method of modified shape coefficient of building (MSCB) were proposed based on the energy dissipating and solar heat gain. Field measurements of the indoor air temperature of model buildings for solar radiation, building orientations, and U-values under natural and heating conditions were conducted in western Sichuan. Results demonstrated that with identical SCB, the indoor thermal environment was substantially affected by the above parameters, proving the one-sidedness of SCB simultaneously. A simulation method verified via the experiments was employed to forecast the dynamic heating load of a real building. The influence of building orientations on the MSCB under actual climatic conditions from different time scales was discussed. Results illustrated that the SCB could be reduced by 34.6% in the present case. The monthly correction factor trend and the heat consumption were consistent. The restriction on SCB could be liberalized moderately even if the heating demand was tremendous. This research could provide a reference for the energy-saving design of passive buildings.

In the wake of increasing global concern over environmental change and energy consumption, building energy conservation has emerged as a pivotal issue worldwide. The primary energy consumption in buildings stems largely from air conditioning and heating systems. The efficiency of these systems is significantly influenced by the thermal performance of the building's exterior wall insulation layers. In-depth research and optimized design of these insulation layers' thermal performance are thus critical topics in the field of building energy conservation. However, current research methods encounter limitations in addressing these issues, notably neglecting the impact of thermal bridges on the insulation layers' thermal performance and focusing solely on single parameters in insulation optimization design. This study addresses these challenges by conducting a comprehensive analysis and optimization design of the thermal performance of building exterior wall insulation layers. It includes an analysis of heat transfer through thermal bridges and the optimization of insulation parameters, aiming to provide a more holistic and systematic approach to optimizing the thermal performance of building exterior wall insulation layers. Specifically, this study uses thermal simulation software to conduct three-dimensional simulation of thermal bridges, analyzing the temperature distribution and heat flow in the thermal bridge area. According to international or domestic standards, the linear heat transfer coefficient of the thermal bridge is determined through calculation. By using optimization algorithms, the thermal performance parameters of the insulation layer are optimized in design. Through experiments, specific linear heat transfer coefficient and equivalent heat transfer coefficient of thermal bridges are obtained, as well as the extent of the impact of thermal bridges on overall thermal performance. Meanwhile, based on optimization algorithms, a set of materials and structural parameters that enable the building's external wall insulation layer to achieve higher thermal efficiency is obtained. After optimization, a lower heat transfer coefficient of the external wall insulation layer is achieved, improving the insulation performance of the wall. This paper provides a technical method for the analysis of heat transfer in thermal bridges and the optimization of insulation parameters. It helps architects more accurately assess and improve the thermal performance of building exteriors, which is significant for reducing energy loss and lowering operational costs of buildings. The research results can provide scientific basis for the formulation of building energy-saving standards, especially in terms of thermal bridge effects and external wall insulation performance. These standards are crucial in driving the industry towards higher energy-saving goals. [ABSTRACT FROM AUTHOR]

Abstract Coal‐fired thermal power must be flexible to enable the grid absorption of inconsistent photovoltaic (PV) and wind power. Combined heat and power (CHP) coal‐fired plants are the primary source for district heating systems. This paper uses a 330 MW subcritical CHP unit as an example to carry out the study. With the promotion of building energy efficiency, when the thermal index is reduced to below 20 W/m2, the low‐load operation of CHP can meet the wind power and PV feed‐in demand and guarantee residential heating without the need for flexibility modification. Meanwhile, more renewable energy generation can reduce carbon emissions from the power supply, further contributing to reducing carbon emissions from buildings. The impacts of different envelope parameters and supplementary heat sources on building carbon emissions are also studied. The conclusion shows that the degree of their impact on carbon emissions ranks as ESMs (energy supply modes) > Factor D (infiltration N50) > Factor A (external wall heat transfer coefficient) > Factor C (window heat transfer coefficient) > Factor B (roof heat transfer coefficient). When the building's heating energy consumption gradually decreases, the distributed heat pump unit can replace the coal‐fired boiler to supply the peak heat load demand. In the future, China's district heating systems can be gradually changed from the current CHP and coal‐fired boilers to CHP and distributed heat pumps.

Curtain wall systems stand out as a pivotal domain within the construction sector’s endeavors towards energy efficiency and carbon mitigation. To refine the evaluation framework for carbon emissions within this industry, this paper explores the calculation and assessment method for building curtain walls. The article first reviews the current research status regarding carbon emissions from materials and the impact of curtain walls on buildings in the operational stage. Based on lifecycle theory, the carbon emissions from building curtain walls are divided into six stages: material acquisition, processing and production, installation and construction, transportation, use and maintenance, and dismantling. On this basis, this paper proposes a method for calculating carbon emissions from building curtain walls. Following that, a case study is conducted using a specific glass curtain wall project for illustrative analysis. The results indicate that the carbon emissions from the material acquisition stage constitute approximately 90% of the total, serving as the primary source of carbon emissions for glass curtain walls. Furthermore, the scientific application of photovoltaics can significantly reduce the carbon emission levels of building curtain walls. Finally, an analysis was conducted on the current issues existing in the evaluation of carbon emissions.

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The world is emphasizing the need for building design that considers energy performance to deal with climate problems. South Korea has constantly been tightening the design standards for saving building energy but with a focus on thermal performance and equipment systems. Accordingly, this study conducted an energy simulation experiment on office buildings with different window-to-wall ratios (WWRs) to propose a smart glazing plan to improve energy performance. An energy simulation experiment was performed on office buildings with varying WWRs to hierarchically analyze the influence of building window performance elements, including the heat transmission coefficient (U-value), visible light transmittance (VLT), and solar heat gain coefficient (SHGC), on building energy performance. The analysis showed that SHGC had the most significant impact on the heating and cooling load, by 22.13%, with the influences of the variables being 12.4% for the U-value, 4.78% for VLT, and 82.83% for SHGC. The results showed that the solar heat gain coefficient (SHGC) had the greatest impact on energy performance among window performance elements, and the effect increased significantly in certain WWRs. Moreover, to improve the energy performance of buildings with higher WWRs, it is essential to reflect the optimum composition of the U-value and SHGC on the window plan. This study's findings propose measures to supplement existing window plans focusing on thermal performance. Furthermore, these results hold academic value in providing concrete grounds for that. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phase change materials (PCMs) are prospective energy materials that are widely applied in building energy conservation, waste heat recovery, infrared stealth technology and solar dynamic power system. The enhancement of heat transfer and leak-proof performance are critical to PCMs. Although geopolymers have been applied in thermal energy storage, meanwhile, hierarchically porous geopolymers have already shown superb performance in various functional applications, to the authors' knowledge, no report concerning the application of hierarchical porous ones have been issued. This paper concerns the preparation of a shape-stabilized composite PCMs, consisting of hierarchically porous kaolinite-based geopolymer (PKG) embedding polyethylene glycol 4000 (PEG4000), which shows promising prospects in thermal energy storage. Optimized porous geopolymer matrices feature high porosity (>83%), combined with high specific surface area (4.7 m2/g) and thermal conductivity (TC, 1.324 W·m−1·K−1). Furthermore, the shape-stabilized composite PCMs show excellent thermal energy storage properties: loading rate of 80.93 wt%, latent heat of 168.80 J g−1 and TC of ∼0.36 W·m−1·K−1 at 20–30 °C, which is 1.64 times of the TC of pure PEG4000. Finally, the photothermal conversion performances of the shape-stabilized composite PCMs were also simulated. [Display omitted] • A hierarchical porous PKG structure was proposed to carry PCMs. • The hierarchical PKG displayed excellent encapsulation properties. • The PKG/PEG shape-stabilized composite PCMs show prominent thermal energy storage properties. • The photothermal conversion effects of shape-stabilized composite PCMs weresimulated. [ABSTRACT FROM AUTHOR]

This research proposes a novel Trombe wall system using direct absorption solar collector based on phase change slurry (DPTW). The dynamic coupling model of the DPTW system is established, and its accuracy is verified. The indoor temperature of the room under heating conditions in January is simulated. Simulation results indicate that the DPTW system has higher indoor thermal comfort. The indoor personnel activity area temperature was within the range of 18.5–24 °C for 148.4 h, which was 167% longer than that of the traditional Trombe wall system (TW). The indoor thermal comfort index PMV is in the range of −0.5∼0.5 for 119.2 h, an increase of 121% compared with the TW system. In addition, the DPTW system reduces the heat load in winter, which is 39% less than that of the TW system in January. The proportion of solar energy utilization is higher, and the solar fraction of the DPTW system can be increased by 45% at lower temperatures. According to the performance of January, the DPTW system is more robust. Therefore, the TW system can be substituted by the DPTW system because the DPTW system can better maintain the indoor temperature and reduce heating energy consumption. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The roof plays a pivotal role as it directly engages with solar radiation absorption and external heat exchange, significantly influencing the building’s overall energy dynamics. To assess the performance of green roofs and cool roofs, a roof performance test facility was established in Nanjing. Time-difference comparison experiments were conducted to measure and analyze the energy-saving effects of cool roofs, green roofs, and conventional roofs during both summer and winter conditions. The study aimed to investigate how their thermal performance impacts building energy consumption. The study’s findings reveal that under summer conditions, the incorporation of a cool roof system leads to a substantial enhancement in energy efficiency, achieving an impressive 13.2% energy savings compared to conventional roofing solutions. In contrast, the implementation of a green roof system results in a more modest energy-saving rate of 4.1%. Transitioning to winter conditions, the adoption of a cool roof system shows a marginal increase of 2.8% in energy consumption compared to conventional roofs. Interestingly, the green roof system stands out as an energy-efficient option during winter, demonstrating a significant 4.9% reduction in energy consumption. This approach ensured reliable and valid results to provide a comprehensive view of how different roof types respond to varying climatic conditions.

Coal‐fired thermal power must be flexible to enable the grid absorption of inconsistent photovoltaic (PV) and wind power. Combined heat and power (CHP) coal‐fired plants are the primary source for district heating systems. This paper uses a 330 MW subcritical CHP unit as an example to carry out the study. With the promotion of building energy efficiency, when the thermal index is reduced to below 20 W/m2, the low‐load operation of CHP can meet the wind power and PV feed‐in demand and guarantee residential heating without the need for flexibility modification. Meanwhile, more renewable energy generation can reduce carbon emissions from the power supply, further contributing to reducing carbon emissions from buildings. The impacts of different envelope parameters and supplementary heat sources on building carbon emissions are also studied. The conclusion shows that the degree of their impact on carbon emissions ranks as ESMs (energy supply modes) > Factor D (infiltration N50) > Factor A (external wall heat transfer coefficient) > Factor C (window heat transfer coefficient) > Factor B (roof heat transfer coefficient). When the building's heating energy consumption gradually decreases, the distributed heat pump unit can replace the coal‐fired boiler to supply the peak heat load demand. In the future, China's district heating systems can be gradually changed from the current CHP and coal‐fired boilers to CHP and distributed heat pumps. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The indoor environment simulation and optimization of atrium buildings are a research hotspot in the field of architectural technology. This article presents linear atrium buildings as the research object, introduces DeST simulation technology into thermal environment analysis, and studies the dynamic conditions and typical day time, the atrium itself structure, the structure of the rooms around the atrium and the thermal environment of the atrium space and its adjacent rooms. In the research process, two modes of natural ventilation and air conditioning were considered, and the optimal atrium building structure parameters under different outdoor weather conditions were obtained. The research results show that in natural ventilation mode, the thermal comfort temperature is the best when the atrium's aspect ratio is 1.71; when using the air-conditioning mode, the air conditioning load is the smallest when the atrium's aspect ratio is 1.55. In summer, the thermal environment of the linear A-shaped atrium is better than the H-shaped atrium. When the atrium window hole position is about 0.9 ∼ 1.5 m, the thermal environment is comfortable and energy saving. [ABSTRACT FROM AUTHOR]

The photovoltaic (PV) modules were integrated with the assembled concrete using a reverse molding process and the performance of the prepared prefabricated concrete PV facades were studied. The results showed that PV backsheet can meet the requirements of alkali resistance and tensile performance tests, proving that the PV panel can be fixedly bonded to the concrete and not corroded; when the PV module works, the temperature of its own was mainly influenced by the weather, while it was adversely affected by the heat storage in the concrete, the maximum temperature of the prefabricated concrete PV facades throughout one year was 60.4 °C, which was in line with the standard, and it was obtained through PVsyst that the efficiency of PV module's photovoltaic conversion decreased by 8%, whhich basically did not affect its normal use. Meanwhile, when the prefabricated concrete PV facades applied to the facade and generated electricity, the power output per unit area of PV modules was lowest in Summer and highest in Winter, with an increase of approximately 37% due to solar altitude angle and effective irradiance. [ABSTRACT FROM AUTHOR]

Building integrated photovoltaic systems are getting popular worldwide due to their building energy conservation properties alongside emission-free electricity generation capabilities. BIPV is a suitable way to generate renewable energy without wasting any land or building space. Bangladesh has set a target to generate a great portion of its electricity from solar energy and has already implemented different photovoltaic applications. However, Bangladesh still has no policy and guidelines to implement BIPV technology in its different types of buildings. In this study, we investigated the energy conservation potentials of three different configurations of semi-transparent CdTe combined building integrated window systems in an office building considering Bangladesh's climate conditions. To investigate the building energy conservation potentials of BIPV window systems, an EnergyPlus-based numerical simulation model was developed and validated with outdoor experiment data. The annual energy simulation results indicate that in all climate conditions, CdTe combined BIPV windows can save ranging from around 30–61% of electricity consumption compared to conventional window systems. Besides, it generate around 270 kWh electricity and ensure indoor daylight illuminance level at 300 lux. Moreover, in all climate conditions, south-faced BIPV windows are more efficient for power generation, but east-faced windows are more efficient to reduce net electricity consumption. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs), an emerging class of porous sorbents, have become one of the most promising functional materials for indoor moisture regulation. However, the practical application of MOFs in building environments is challenging. Common shaping forms of MOFs (e.g., pellets, tablets, monoliths, granules, coating, etc.) may lead to agglomeration of MOF particles, higher usage costs, low efficiency, and material waste. Here, we report a new MOF-based electrospun nanofiber membrane with high porosity, light weight, and a large surface-area-to-volume ratio. MOF nanoparticles distributed on the fibers can fully contact moisture in the air, thus significantly enhancing MOFs' utilization and performance. The results of the moisture adsorption test show that the improved MOF membrane has significantly higher water vapor uptake than most conventional hygroscopic materials and textiles in built environments. A building energy model was established to evaluate the MOF membrane's effect on building energy consumption under different climates worldwide. The simulation results show that the MOF membrane can efficiently moderate indoor moisture fluctuation and has excellent energy-saving potential. The latent heat load reduction rate in summer can be up to 80–90% in arid/semi-arid climates and around 50% in temperate climates in a purely passive manner. [ABSTRACT FROM AUTHOR]

Accelerating energy conservation and carbon reduction in the building sector is crucial for achieving carbon neutrality. The energy consumption of a building is primarily influenced by room load, service time, service space, and the energy efficiency of equipment. While previous studies have concentrated on reducing room load and enhancing equipment efficiency, research on service time and service space dimensions remains limited. Notably, the evaluation of equipment used for intermittent heating remains incomplete. In this study, the terminals and evaluation methods for intermittent heating were investigated. A temperature response matching coefficient focused on the human scale was proposed. The temperature response matching coefficient indicates the proportion of the actual temperature-rise area to the temperature demand curve area. Experiments were conducted on the intermittent effects of conventional convective and radiant terminals using fan coils and floor heating as examples. The suitability of conventional terminals for intermittent heating was quantitatively assessed, leading to the development of a novel radiant-convective terminal that integrates convection and radiation. Utilizing the phase change of flat heat pipes as a radiant surface, a radiant-convective terminal with low thermal inertia was proposed. Experimental results indicated that the temperature response matching coefficients for convection and radiation modes per 10 min in the first half-hour were 0.24, 0.42, 0.55 and 0.12, 0.21, 0.29, respectively. These results were consistent with those of fan coil and floor heating methods. The new radiant-convective terminal combined the effects of two conventional terminals, thereby simplifying the system. This study provides a reference for the evaluation methods of and terminals used for intermittent heating. • Novel evaluation method for intermittent heating focusing on human scale • Evaluation of intermittent heating effect of different terminals was conducted • A new radiant-convective terminal for intermittent heating was proposed • The new terminal realized the combined-use mode for conventional terminals [ABSTRACT FROM AUTHOR]

[Display omitted] Developing a building-compatible radiative cooler that exhibits an all-day subambient cooling effect and maintains a clean surface for long-term stability is challenging. This study proposes a liquid marble-derived core–shell particle (LM-CSP) that combines excellent anti-wetting capability, efficient and durable daytime radiative cooling properties, and compatibility with building materials. A series of LM-CSP coated samples were fabricated with varying dosages of BaSO 4 and water-repellent agents, as well as different coating thicknesses. Comprehensive characterization of the as-prepared samples revealed that the optimal LM-CSP exhibited a solar reflectance of 91 % with a mid-infrared emissivity of 0.97 and a water contact angle of ∼151.9° with a roll-off angle of ∼7.8°, respectively. In-depth analyses using XRD, FT-IR, TGA/DTG, and XPS elucidated the underlying mechanisms responsible for the enhanced optical and wetting properties of the LM-CSP. The exceptional durability of the LM-CSP was validated by its subambient cooling effects after being contaminated with muddy slurry (subambient temperature drop of ∼5.4 °C) and after being rain-washed (subambient temperature drop of ∼2.1 °C). EnergyPlus simulations were employed to assess the year-round energy-saving potential of the LM-CSP, and a life-cycle economic and environmental analysis was performed to guide the practical application. The findings of this study are expected to provide new insights into functional cementitious materials with efficient and durable cooling capabilities, ultimately contributing to the advancement of sustainable building design and energy efficiency. [ABSTRACT FROM AUTHOR]

Solar shading is important in buildings for better indoor thermal/light environment and energy conservation, especially in the tropical region. Compared with conventional windows with additional fixed shading devices, windows with adaptive self-shading functions take up less space and require less management labor. The present investigation focuses on a compact liquid-infill tunable window, which can provide adaptive shading with colored liquid-infill according to the surrounding environment. The numerical model of the liquid-infill tunable window was established on the basis of the law of energy and mass conservation, which enabled prediction of the adaptive response of the window under different boundary conditions. Then the thermal performance of this innovative window was analyzed in comparison with triple-layered clear glass windows. Influences of solar radiation level, incident angle, and ambient temperature were taken into consideration. The window was proven to be efficient in reducing indoor heat gain in the cooling season under strong solar radiation. With an 60° incident angle, the total indoor heat gain through window can be reduced by 1.60–8.33%. In the future, the established numerical model may be inserted into existing building simulation software as an energy-efficient window module to evaluate its energy and economic performance. The present study may inspire architectures and engineers in the design of near-zero energy and/or carbon neutral buildings. [ABSTRACT FROM AUTHOR]

The world is emphasizing the need for building design that considers energy performance to deal with climate problems. South Korea has constantly been tightening the design standards for saving building energy but with a focus on thermal performance and equipment systems. Accordingly, this study conducted an energy simulation experiment on office buildings with different window-to-wall ratios (WWRs) to propose a smart glazing plan to improve energy performance. An energy simulation experiment was performed on office buildings with varying WWRs to hierarchically analyze the influence of building window performance elements, including the heat transmission coefficient (U-value), visible light transmittance (VLT), and solar heat gain coefficient (SHGC), on building energy performance. The analysis showed that SHGC had the most significant impact on the heating and cooling load, by 22.13%, with the influences of the variables being 12.4% for the U-value, 4.78% for VLT, and 82.83% for SHGC. The results showed that the solar heat gain coefficient (SHGC) had the greatest impact on energy performance among window performance elements, and the effect increased significantly in certain WWRs. Moreover, to improve the energy performance of buildings with higher WWRs, it is essential to reflect the optimum composition of the U-value and SHGC on the window plan. This study’s findings propose measures to supplement existing window plans focusing on thermal performance. Furthermore, these results hold academic value in providing concrete grounds for that.

Based on the different requirements of solar energy integrated with buildings, a hybrid photovoltaic and thermal solar energy collector with integrated phase change material (PVT-PCM) have been developed. The thermal system combines air-based and water-based conditions to meet the building heat demand in different seasons. In addition, PCM is used to absorb the heat that was not taken away by the thermal system. And the vessel is optimized to enhance its thermal conductivity. The results of cross-season test show that the overall efficiency of the system is 39.4%, and the energy-saving efficiency is 64.2%. The system controls the temperature and utilizes the heat through the thermal system. The economic analysis and energy saving potential of the system in low latitude areas are analyzed. The results show that the additional payback period of the system is 13.1 years. And based on the local energy structure, the maximum CO 2 emission can be reduced by 156.1 kg/year. The optimization systems BPVT and CPVT are proposed, and simulation and analysis results show that BPVT is more valuable for further exploration. Compared with the traditional PV system, PVT-PCM system improved the comprehensive utilization rate of solar energy and has a broader research and development prospect. • A new PVT system with switchable working status is designed. • ●The system has potential to reduce CO 2 emissions combined with energy structures. • ●The 13.1 years additional investment payback period show good application potential. • ●The optimization systems are proposed and predicted for further exploration. [ABSTRACT FROM AUTHOR]

In this paper, a series of eutectic hydrated salts was obtained by mixing Na2HPO4·12H2O (DHPD) with K2HPO4·3H2O (DHPT) in different proportions. With the increase in the content of DHPT, the phase transition temperature and melting enthalpy of eutectic hydrated salts decreased gradually. Moreover, the addition of appropriate deionized water improved the thermal properties of eutectic hydrated salts. Colloidal silicon dioxide (SiO2) was selected as the support carrier to adsorb eutectic hydrated salts, and the maximum content of eutectic hydrated salts in composite PCMs was 70%. When the content of the nucleating agent (Na2SiO3·9H2O) was 5%, the supercooling degree of composite PCMs was reduced to the minimum of 1.2 °C. The SEM and FT-IR test results showed that SiO2 and eutectic hydrated salts were successfully combined, and no new substances were formed. When the content of DHPT was 3%, the phase transition temperature and melting enthalpy of composite PCMs were 26.5 °C and 145.3 J/g, respectively. The results of thermogravimetric analysis and heating–cooling cycling test proved that composite PCMs had good thermal reliability and stability. The application performance of composite PCMs in prefabricated temporary houses was investigated numerically. The results indicated that PCM panels greatly increased the Grade I thermal comfort hours and reduced energy consumption. Overall, the composite PCM has great development potential building energy conservation. [ABSTRACT FROM AUTHOR]

In the common method of compiling outdoor design conditions by annual cumulative frequency of occurrence, the probability of simultaneous occurrence of the selected meteorological elements is not considered, which may lead to an overestimation of air-conditioning equipment capacity design. This paper aims at developing a novel approach for producing the outdoor design conditions, taking into consideration the dependency between the air temperature and global solar radiation, which have a strong influence on the HVAC capacity design. These two meteorological elements are analyzed for specific simultaneous occurrence probability based on the joint distribution. For this purpose, the copula approach which can describe the dependence between these two meteorological elements is used for modeling the joint distribution function. We investigated copula family selection for air temperature and global solar radiation at each hour of hourly weather data for 10 years from 2001 to 2010 in Osaka, Japan. The Joe-Frank copula has the best fitting results for the dependence between the air temperature and global solar radiation. According to the comparison of original exceeding probability and simultaneous occurrence probability, the results show that the design conditions based on the common method can significantly exceed that of the simultaneous occurrence probability method. Practical Application: Outdoor design conditions are used in the building design stage to estimate building performance and select the appropriate air conditioning equipment capacity. Excessive air-conditioning capacity may lead to a large amount of unnecessary energy wastage. Insufficient capacity may lead to not meeting the desired indoor environment conditions of utilization in extreme weather conditions, especially for large office buildings. Therefore, this paper provides a new approach to generate more realistic meteorological conditions for air-conditioning design to improve building energy efficiency. [ABSTRACT FROM AUTHOR]

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A major reason for climate change is buildings that consume a huge quantity of energy to keep the inside temperature comfortable. The current energy generation from renewable resources does not match the energy demand. Hence, there is a need to come up with an alternative source to bridge the gap between supply and demand. Energy Storage System (ESS) is a useful factor for enhancing flexibility and controllability due to its flexible charging-discharging properties. Phase change materials (PCMs) are being considered a promising option for lowering energy usage. Past research has looked into a variety of methods for incorporating PCMs into different structures of buildings and has observed that due to the use of PCMs, interior temperature fluctuations may remarkably decrease while keeping optimum thermal comfort. This paper aims to summarize latent heat thermal energy storage (TES) in various applications but mainly focuses on building application along with the phase change material and their classification, techniques of encapsulation and, the method used to characterize the encapsulated PCM. [ABSTRACT FROM AUTHOR]

In response to the challenges of high energy consumption and poor indoor air quality, a novel solar multifunctional louver window has been proposed. This study developed a numerical model to examine the effects of environmental variables and louver angles on the thermal, electrical, and degradation performance of the system. Additionally, an exergy-based evaluative framework was introduced to account for the varying qualities of energy in assessing the performance of solar multifunctional windows. Finally, a comprehensive evaluation was conducted using this framework. The results demonstrate that the exergy efficiency of the solar multifunctional window can be maintained at 20 % or higher, even under reduced solar irradiation, delivering high-quality energy. Lower environmental temperatures and solar radiation intensities were found to negatively affect ventilation, thermal efficiency, and air purification capacity. The thermal, purification, and electrical efficiencies were influenced by the louver angle to varying extents. In terms of air purification, the window achieved the highest Clean Air Delivery Rate (CADR) at louver angles between 80° and 90°, thereby enhancing air purification performance. [ABSTRACT FROM AUTHOR]