Glass Curtain Research Articles

Optimizing the indoor thermal environment and daylight performance of buildings with PCM glazing

With the development of energy efficient technologies for glass envelopes, using thermal storage techniques to improve their thermal inertia has become a trend in research. In the present study, the heat transfer and day-lighting models of a building with PCM glazing curtain wall (PGC) were developed. Multiple parameters such as glazing internal surface temperature, PCM liquid phase rate, indoor temperature, natural illumination, and daylighting coefficient were quantitatively analyzed to evaluate their indoor thermal environment and daylighting performance. The results show that the application of PGC can significantly improve indoor temperature uniformity and indoor thermal comfort compared to silica aerogel glass curtain wall (SGC) and hollow glass curtain wall (HGC). By filling 10 mm thick PCM, the temperature fluctuation of the inner surface of the glass and the midpoint temperature of the room can be reduced by 35 %, the peak temperature of the inner surface of the glass can be delayed by 0.89 h, and the average indoor natural light value and indoor daylight factor are satisfactory at 453.26 lx and 9.63 %, respectively. However, as the thickness of the PCM increases to 15 and 20 mm, the liquid fraction of the PCM and the energy storage performance of the PGC are greatly reduced, and natural daylighting does not meet the GB/t-50033-2013 limit.

A Novel Debonding Damage Identification Approach of Hidden Frame-Supported Glass Curtain Walls Based on UAV-LDV System

A Novel Debonding Damage Identification Approach of Hidden Frame-Supported Glass Curtain Walls Based on UAV-LDV System

Preparation of high-performance laminated glass interlayer by modifying epoxy resin composite polyurethane

Laminated glass has been widely used in glass curtain walls, windshields, and other structures due to its high safety, light weight, and aesthetics. The safety of polymer laminated glass depends on the performance of the polymer between the glasses. Polyurethane elastomer (PU) has become a universal polymer material due to its excellent mechanical strength and toughness. The aliphatic thermoplastic polyurethane has attracted people's interest about its application in the field of laminated safety glass due to its transparency and adhesion. In this work, a polyurethane-modified epoxy (EK-PU) composite film with superior bonding strength, mechanical properties, and transparency was successfully achieved. The tensile strength of the PU composite film was confirmed to be 45 MPa, while the bonding strength was 4.73 MPa. The improvement is attributed to the change of microphase separation structure and the introduction of silicone. The excellent impact resistance of the laminated glass based on polyurethane composite film have been confirmed by the falling ball impact test, which is 6.5 times of the common PU film. The laminated glass based on the EK-PU film will be applied in aerospace, defense, and automotive fields.

Research on the Current Situation and Calculation Method of Carbon Emissions Assessment for Building Curtain Walls

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.

Large eddy simulation of wind pressures on a 600-m-high skyscraper and comparison with field measurements during super typhoon mangkhut

Super Typhoon Mangkhut struck the coastal cities in Southeast China on September 16, 2018, destroying many glass curtain walls of tall buildings. It calls for more investigations of the wind loads on tall buildings during strong tropical cyclones to reduce building damages. Following the field measurements of wind effects on a 600-m-high skyscraper in Shenzhen, China, during Super Typhoon Mangkhut, this study aims to reproduce the wind effects on the supertall building during Mangkhut by large eddy simulation (LES). A wide range of surrounding buildings from the target supertall building (within a radius of 5 km) is explicitly constructed for the LES. The wind profiles obtained from a 356-m-high meteorological tower in Shenzhen and those given in the local design load code are used to set the inflow conditions in the LES. The wind pressures on the supertall building simulated by the LES and monitored by the field measurements are compared and analysed, including their mean, root mean square, peak, probability density function, power spectral density, and correlation. This combined study of numerical simulation and field measurement is an impetus to promote the role of computational fluid dynamics in predictions of the wind effects on high-rise buildings under extreme wind conditions.

Prediction and Optimization Analysis of the Performance of an Office Building in an Extremely Hot and Cold Region

The White Paper on Peak Carbon and Carbon Neutral Action 2022 states that China is to achieve peak carbon by 2030 and carbon neutrality by 2060. Based on the “3060 dual-carbon” goal, how to improve the efficiency of energy performance is an important prerequisite for building a low-carbon, energy-saving, green, and beautiful China. The office performance building studied in this paper is located in the urban area of Turpan, where the climate is characterized by an extremely hot summer environment and a cold winter environment. At the same time, the building is oriented east–west, with the main façade facing west, and the main façade consists of a large area of single-layer glass curtain wall, which is affected by western sunlight. As a result, there are serious problems with the building’s energy consumption, which in turn leads to excessive carbon emissions and high life cycle costs for the building. To address the above problems, this paper analyzes and optimizes the following four dimensions. First, the article creates a Convolutional Neural Network (CNN) prediction model with Total Energy Use in Buildings (TEUI), Global Warming Potential (GWP), and Life Cycle Costs (LCC) as the performance objectives. After optimization, the R2 of the three are 0.9908, 0.9869, and 0.9969, respectively, thus solving the problem of low accuracy of traditional prediction models. Next, the NSGA-II algorithm is used to optimize the three performance objectives, which are reduced by 41.94%, 40.61%, and 31.29%, respectively. Then, in the program decision stage, this paper uses two empowered Topsis methods to optimize this building performance problem. Finally, the article analyzes the variables using two sensitivity analysis methods. Through the above research, this paper provides a framework of optimization ideas for office buildings in extremely hot and cold regions while focusing on the four major aspects of machine learning, multi-objective optimization, decision analysis, and sensitivity analysis systematically and completely. For the development of office buildings in the region, whether in the early program design or in the later stages, energy-saving measures to optimize the design have laid the foundation of important guidelines.

The influence of the application of glass curtain walls on architectural style and architectural facade design techniques

In recent years, with the increasingly rapid development of the glass curtain wall and its gradually mature use in architecture, many designers choose to use glass curtain walls when designing buildings in order to get the desired building facade effect. As a result, there are many new architectural styles and building facade effects. Against this background, this paper discusses how glass curtain wall is applied in architecture and how it helps and influences architectural design styles and techniques. To conclude, the glass curtain wall has been widely used in the design of high-rise buildings and public buildings at this stage, and it also helps designers to more conveniently adjust the virtual-real relationship of building facades and the overall architectural style. The use of large-area glass curtain walls in the design of facades can achieve special effects that cannot be replaced by other materials. At the same time, the application of glass facades also promotes the process of architectural design modernization.

Experimental and simulation study on the thermoelectric performance of semi-transparent crystalline silicon photovoltaic curtain walls

This study aims to evaluate and optimize the thermoelectric performance of semi-transparent crystalline silicon photovoltaic (PV) curtain walls. An integrated thermoelectric performance coupling calculation model was developed, combining heat transfer and electricity generation calculations as a novel approach. Simulations and experiments were conducted to compare the performance of PV curtain walls with conventional curtain walls under various weather conditions, and were validated by experimental data. The results demonstrate that PV curtain walls enhance the thermal environment inside buildings and promote efficient power generation, with the arrangement of PV cells notably affecting performance. Under sunny conditions, the temperatures of the PV cell backplate and glass part backsheet in semi-transparent PV curtain walls exceeded those in ordinary glass curtain walls, yet the indoor air temperature was lower. Furthermore, when the working temperature of PV cells reaches to a certain level, it slightly deviates the electricity generation trend from the real-time solar radiation trend. Under cloudy conditions, the backsheet temperatures of semi-transparent PV curtain walls and standard glass curtain walls align with outdoor temperatures. Different PV module forms demonstrated that striped and square PV module forms offer better lighting effects than whole forms. The working temperatures among the three were close, with an annual average temperature difference of less than 1 °C and a peak temperature difference of approximately 3 °C, impacting the monthly total power generation by less than 1 %. This study presents a more precise and thorough approach for evaluating semi-transparent PV curtain walls' performance, providing insights for future sustainable architectural design.

Engineering application study of high-performance aluminum alloy 6A13-T6

To address the application challenges of the novel high-strength aluminum alloy material 6A13-T6 in engineering, experimental and numerical simulation studies were conducted. Firstly, material tensile tests, axial compression tests, and pure bending tests were conducted, and the applicability of the specification was evaluated. Subsequently, finite element models were employed to analyze the overall mechanical performance and economic indicators of three typical engineering structures (grid shells, grid trusses, and glass curtain walls) based on the test results. The findings indicate that 6A13-T6 exhibits a non-proportional yield strength (f0.2) of 340 MPa, an ultimate strength of 352 MPa, and a post-necking elongation of 14.5%. Design calculations for axially compressed and flexural members made of 6A13-T6 high-strength aluminum alloy can be conservatively carried out following Chinese design specification. The use of 6A13-T6 aluminum alloy can reduce material consumption in structures, with a maximum reduction of up to 29% compared to other commonly used aluminum alloys and up to 72% compared to common steel materials. Therefore, the new high-strength aluminum alloy 6A13-T6 has obvious engineering application value and has been used in a hotel curtain wall project.

Utilizing developed multi-verse optimization algorithm for optimizing envelope design of residential structure

ABSTRACT This study addresses the challenges of designing sustainable structures that minimize energy consumption and costs. It introduces a novel optimization algorithm, the Developed Multi-Verse Optimization Algorithm (DMVO), to overcome the limitations of existing simulation software. The DMVO algorithm optimizes structure envelope parameters, such as walls, windows, and glass curtain walls, to achieve lower energy consumption and construction costs. It outperforms other methods, such as EHO, SAR, LSO, and MVO, in terms of energy efficiency and cost-effectiveness. Moreover, it converges to the optimal solution in fewer iterations, reaching the best result in the 65th iteration. It obtains the minimum values of en v E and en v L as 12,397,493.7 RMB and 48.7673 kWh/m2y, respectively. The proposed algorithm enhances natural ventilation and internal lighting by increasing the glass curtain wall and window areas. It demonstrates its superior performance in saving energy in structures compared to other methods, achieving approximately a 38% reduction in total costs compared to the initial design. This research provides a promising method that can be generalized to various structure types and climates in future projects, contributing to the advancement of sustainable construction practices. Overall, the DMVO algorithm is a significant contribution to the field of sustainable structure design, offering an effective approach to improve energy efficiency and cost-effectiveness while reducing environmental impact.

Safety assessment of existing glass curtain wall based on fuzzy entropy and comprehensive cloud

The occurrence of safety incidents for existing glass curtain walls (EGCWs) pronounced menace to the security of both lives and property. Undertaking safety assessment for EGCWs carries essential practical significance. However, current fuzzy evaluation methods overlook the uncertainty of indicator weights and the intricacies of rank attribution. In response, this paper proposes a novel approach to the safety assessment of EGCWs. This research establishes a framework of evaluation indicators for EGCWs and divides the safety ranks of each indicator into four tiers: Safe, Mild risk, Moderate risk, and High risk. Quantitative and qualitative indicators are quantified via the variable fuzzy cloud algorithm and cloud model. The information cloud combination weighting method is introduced to determine the weight clouds of indicators. Finally, a two-dimensional assessment result is derived using an improved fuzzy comprehensive evaluation method and fuzzy entropy. The exemplified outcomes demonstrate that this approach captures the safety status of evaluation subjects based on risk ranks, and fuzzy entropy addresses two issues: inconsistent level attribution and the comparison of identical risk ranks. The appraisal method further unveils the safety details of EGCWs, with findings that align consistently with the actual situation.

Collaborative Optimized Design of Glazing Parameters and PCM Utilization for Energy-Efficient Glass Curtain Wall Buildings

Glass curtain walls (GCWs) have become prevalent in office buildings, owing to their lightweight and modular characteristics. However, their lower thermal resistance, compared to opaque walls, results in increased energy consumption. Incorporating phase-change materials (PCMs) provides a viable solution through which to address the susceptibility of GCWs to external conditions, thus enhancing thermal performance and mitigating energy concerns. This study delves into the influences of the glazing solar heat gain coefficient (SHGC), the glazing heat transfer coefficient (U-value), and PCM thickness on the energy performance of buildings. Using Design Builder (DB) software version 6.1.0.006, a multi-story office building was simulated in different climatic zones in China, covering the climatic characteristics of severe cold, cold, hot summer and warm winter, cold summer and winter, and mild regions. The simulation results quantitatively elucidated the effects of the glazing parameters and the number of PCMs on thermal regulation and energy consumption. A sensitivity analysis identified the glazing SHGC as the most influential factor in energy consumption. Additionally, by employing Response Surface Methodology (RSM), the researchers aimed to achieve a balance between minimal building energy consumption and economic cost, ultimately determining an optimal design solution. The results demonstrated significant energy savings, ranging from 20.16% to 81.18%, accompanied by economic savings, ranging from 15.78% to 79.54%, across distinct climate zones in China.

Energy Performance Analysis and Study of an Office Building in an Extremely Hot and Cold Region

China is committed to reaching peak carbon by 2030 and carbon neutrality by 2060. The goals of reducing energy consumption and building a “beautiful China” are being urgently pursued in China. The building studied in this paper is located in the city of Turpan, where the problem of excessive energy use among buildings is significant due to the region’s hot summers and cold winters. Additionally, the fact that the office building studied in this paper has an east–west orientation is significant: the building’s main façade is oriented to the west, comprising a large area of single-layer glass curtain wall. Based on this, this paper proposes optimization strategies from two perspectives of renovation and new construction. Four design options are proposed at the retrofit level: glazed circular curtain wall; glazed enclosed curtain wall; west-facing double-glazed curtain wall circulation combined with south-facing light from the east; recycling of windows on the inside of the exterior glass curtain wall. These suggestions focus on retrofitting the glass curtain wall on the west elevation of the building. Two design options are proposed at the new-build level: west-facing south-oriented light and west-facing north-oriented light. These suggestions were primarily built around the idea of changing the orientation of the windows on the west elevation. The results show that the optimal solution is to implement the west-facing double-glazed curtain wall circulation combined with south-facing light from the east. This program shows a 64.14% reduction in heating energy consumption, a 77.12% reduction in cooling energy consumption, and a 69.67% reduction in total energy consumption. The above research has improved the deficiencies in the performance-based energy efficiency retrofit of office buildings in the region and provided new ideas and suggestions for policymakers and designers to build energy-efficiency retrofits in the early stages.

Towards Achieving Sustainable Environmental Efficiency: Rationalizing Energy used in Educational Buildings of University Campus

The research deals with a practical and analytical study comparing the use of the computer program for digital simulation, Design Builder, to calculate the amount of energy consumption in buildings, as the aim of the research is to conclude the most influential architectural elements in reducing energy consumption in the typical building of Al-Azhar College of Engineering for Girls (CEG). This is done by calculating the amount of energy consumption of the college building with its existing specifications while making architectural modifications to the building to conclude which elements have an impact on reducing energy consumption under the influence of the climatic conditions of the city of Cairo. These architectural elements include treating the glass surfaces and curtain walls in the building and increasing the operating temperature of the air conditioners to cool the building, as it is clear from the simulation results that the greatest reduction in the building’s cooling load is by 40%. The research concludes with recommendations that contribute to energy rationalization in educational buildings on campus, thus achieving efficiency in the internal and external environment.

The Influence of Different Terrains on the Wind Pressure Distribution of Glass Curtain Wall in Airport Terminals in Mountainous Areas

Aiming the issue of wind pressure distribution characteristics of airport terminal glass curtain walls in mountainous areas, wind tunnel tests have been conducted to investigate glass curtain walls in airport terminals under different terrains (at mountain heights of 0, 30, 60, 90 m [H1, H2, H3, H4] and under surrounding high mountains of 80, 130, 150 m [H5, H6, H7]). Based on experimental data, a comparative analysis was conducted on the effects of different terrains on the mean and pulsating wind pressures, non‐Gaussian characteristics, peak factor, and extreme wind pressure. The results show that the larger values of the mean and pulsating wind pressures under different terrains appear at the corners of the curtain wall edges. Furthermore, the skewness, kurtosis, and wind pressure probability density function values at the corners of the curtain wall edges significantly deviate from the standard Gaussian distribution, exhibiting significant non‐Gaussian characteristics. The majority values of peak factors range from 3.5 to 5.0, far higher than the recommended value of 2.5 in Chinese specification and code (GB 50009‐2012). Moreover, the values of extreme wind pressure under terrains H1, H2, H3, and H4 were greater than that under terrains H5, H6, and H7. At mountain heights H1, H2, H3, and H4, the increasing mountaintop height has a certain increasing effect on the extreme wind pressure. The maximum increase of 96.5% and 82.8% in mountain height H3 and H4 compared to H1. However, the increase in the height of surrounding mountains has a reducing effect on the extreme wind pressure. Research can provide useful suggestions and references for the design, construction, and site selection of terminals in similar airports.

Overall and Local Wind Loads on Post-Installed Elevator Shaft of Existing Buildings

The glass curtain walls of post-installed elevator shafts in existing buildings can be damaged by local wind loads, and the serviceability of an elevator may be affected by excessive overall wind loads, especially in hurricane-prone areas. The overall and local wind load characteristics of elevator shafts with different arrangements (E-type, H-type, I-type) were studied using wind tunnel tests and computational fluid dynamics (CFD) numerical simulations. Firstly, high-frequency base balance wind tunnel tests of these elevator shafts with three arrangements were carried out to obtain the overall wind loads on the elevator shafts. Secondly, a CFD simulation was performed on the post-installed elevator shafts with three arrangements, obtaining the surface local wind pressure distribution of the elevator shafts under different wind directions. Finally, the wind-induced displacement responses of post-installed elevator shafts were analyzed. The results show that the aerodynamic interference of different elevator arrangements (E-type, H-type, I-type) and wind directions have significant effects on the overall local wind loads and wind-induced responses of the post-installed elevator, while the local wind loads on the area of the elevator door are less influenced by the elevator arrangement type than local wind loads on the surface and the overall wind loads of the elevator shafts. The results and conclusions may be helpful for developing the wind-resistant design of a post-installed elevator shaft.

Use of “Glass Curtain” Systems to Improve the Energy Efficiency and Thermal Comfort of Dwellings in a Warm Semi-Arid Mediterranean Climate

The dry Mediterranean climate (BShs) within a warm semi-arid climate (BSh) is the zone in Europe with the most annual hours of sunlight, and it has a smaller annual temperature variation than most climates. This allows the greenhouse effect caused by windows to be used to heat dwellings in winter. Balcony frameless retractable glazing systems known as “glass curtain” systems offer the highest proportion of glass and maximum openness in the façade, allowing for maximum sunlight and ventilation. This work studies a glazed terrace with a “glass curtain” in a dwelling on the Spanish Mediterranean coastline. The objective is to quantitatively determine the enhancement of the thermal comfort and energy efficiency of a dwelling using “glass curtain” systems. The modification of several design parameters of the glazed terrace is also analysed. The novelty of this study lies in demonstrating that the use and optimised design of “glass curtain” systems allows us to obtain nearly zero-energy buildings (nZEBs) and thermally comfortable dwellings all year round. The research methods include a comparison of the current thermal performance of the dwelling with and without a “glass curtain” system via on-site measurements. The study also evaluates the influence of modifying design parameters using computer simulations. The results show that “glass curtain” systems increase the indoor temperatures inside the dwelling by about 4 °C in winter and reduce the annual indoor thermal oscillation from more than 16 °C to only 10 °C. Consequently, such systems reduce heating energy needs by almost 60%. Glazed terraces using the proposed design parameters show further improvement regarding thermal comfort and practically eliminate heating and cooling needs.

Development of semitransparent CdTe polycrystalline thin-film solar cells modified with a CuCl layer for BIPV

In the current context of renewable energy development, CdTe polycrystalline thin-film solar cells are expected to have broad prospects in fields such as Building Integrated Photovoltaics. It is crucial to fabricate sub-micron-thick, semitransparent CdTe solar cells for photovoltaic glass curtain walls that require a certain degree of transparency. As a result, we have employeded a high-quality deposition technique for sub-micron-thick CdTe polycrystalline films. We have analyzed the influence of post-treatment processes on the film properties and investigated the impact of solution-based CuCl back buffer layer preparation on device performance. By improving the quality of sub-micron-thick CdTe polycrystalline films, and optimizing the concentration and process of Cu doping, we have successfully fabricated semitransparent CdTe solar cells with an average visible light transmittance of 14.21%, ηFront: 6.2%, ηRear: 4.4%, and bifacial factor:0.7.

Design optimization of office building envelope by developed farmland fertility algorithm for energy saving

This study focuses on designing sustainable buildings with a specific emphasis on reducing energy consumption and optimizing costs. To address the time-consuming nature of simulation software like TRNSYS and Energy Plus, a novel meta-heuristic optimization algorithm called the Developed Optimization Algorithm of Farmland Fertility (DFFA) is provided. The DFFA algorithm is utilized to optimize parameters related to the building envelope, encompassing walls, windows, and glass curtain walls, aiming to minimize energy demand and construction expenses. Comparative analysis with other approaches such as EPO, LOA, MVO, and FFA demonstrates significant reductions in energy consumption and building design costs achieved by employing the proposed algorithm. Furthermore, the DFFA algorithm yields the desired results within fewer iterations. By increasing the surface area of the glass curtain wall and total window space, improvements in natural ventilation and interior lighting are observed. Despite similar window opening measurements across the compared methods, the suggested algorithm surpasses others when it comes to overall cost and energy efficiency. The total cost reduction compared to the initial design amounts to 39 %. Thus, the DFFA algorithm proves to be more effective in conserving energy in buildings compared to other analyzed procedures. This research serves as a case study and presents a promising method applicable to designing various building types under different weather conditions in future projects.

Study on the Effect of Monoacrylic Monomers on the Polymer Network Morphology and Electro-Optical Performance of Reverse-Mode Polymer Stabilized Liquid Crystal Devices

A polymer-stabilized liquid crystal (PSLC) device has been a promising candidate in several scenarios like smart vehicle windows and glass curtain walls in recent years due to its remarkable features like a fast switch from the initial transparent state to the scattering state with a rather low driving voltage, high transmittance at off-state, and broad viewing angle. The electro-optical characteristics of PSLC devices are determined by the synergistic attributions of liquid crystal (LC) molecules and the influence of the polymer network exerted on the movement of LC molecules. A systematic study of the influence of the polymer network on the movement of LC molecules is conducted, with the polymer network formed by methoxy/cyano/carboxyl monomers and diacrylate C6M. The polymer network morphology of PSLC film is greatly affected by the molecular structures and content of monoacrylic monomers. Additionally, the electro-optical performance and peel strength of PSLC films could be improved by modulating the molecular structures and morphology of polymer networks. PSLC devices containing carboxyl monomers show enhanced electro-optical performance and peel strength due to their directional filiform topology. This study might provide guidance for optimizing the performance of PSLC devices and establishing the relationship between the molecular structure, polymer network morphology, and electro-optical performance of reverse-mode dimming films.