Double Glass Research Articles

The Optimization of Transparent Domes With Bionic Architecture Approach and Emphasizing on Providing Optimal Daylighting Using Crab Eye Structures

Statement of the problem. The hypothesis of this research is that it is possible to use the eye structure of aquatic animals, which performs well in low light conditions, to improve, optimize and introduce new daylighting systems. The intended transparent dome in this study is a double glass skin dome with placed modules between the two layers of dome to control daylighting. According to the natural structure investigated in this research, these modules are dynamic and variable in two fully open condition to receive maximum daylight in low dim light conditions (e.g., in the cloudy sky) and semi-closed in the completely sunny sky with intense radiation. Results and conclusions. What is intended as an independent variable in this research are: the opening width, and the shape of modules (square, hexagonal and triangular), the height of the modules and the rotation angle of the light reflecting panels of the modules. The dependent variables (appropriate illuminance and appropriate lighting distribution pattern) are investigated by Useful Daylight Illuminance (UDI). Radiance software have been used as daylight simulators. The results of this research include the optimal physical characteristics of the modules and the performance of variables on the illumination under the dome.

Numerical Simulation of the Thermal Performance of a Building Using Electrochromic Devices

More energy-efficient buildings have a significant impact on reducing energy consumption, as they provide thermal comfort to their occupants with lower electricity usage. Aligned with the interpretation of thermal performance, this article analyzes the results of a thermo-energy performance simulation of a residential building located in different bioclimatic zones, Pelotas/RS (BZ2) and Cuiabá (BZ7). For the simulation, the EnergyPlus software was used, varying the configuration of the building's windows, including electrochromic film, double glass, and common glass. The energy consumption results were analyzed, and finally, the thermal comfort of each model was evaluated using the adaptive method of ASHRAE 55 (2017), with the aim of assisting in the design and construction of residential buildings that are truly suitable and adapted to the climate. After conducting the simulations, it was possible to conclude that the use of electrochromic film led to the greatest reduction in energy consumption in both Zones, by 1.8% in BZ2 and 13.9% in BZ7, with an increase in thermal comfort in both simulated cases, showing better results in BZ7, a region with a hot climate.

Investigating the performance of an affordable parabolic dish collector with double glass vacuum cavity cover

Parabolic dish collectors (PDC) are one of the most important ways to concentrate solar energy. In this study, the performance of a low-cost parabolic dish collector with high average output temperatures is investigated. The low-cost PDC has a 45 ° edge angle and a circular receiver. A vacuum double-glazed cavity is used to keep heat inside the receiver and reduce the rate of heat losses. On clear and cloudy days, tests were conducted with thermal oil as a heat transfer fluid (HTF) to analyze the performance of the PDC. The results show that the change in temperature of the heat transfer fluid between the open and closed ends of the cavity receivers affected the receiver heat gain, thermal efficiency, and exergy efficiency. It was also found that the HTF has the highest exit temperature of 221 °C, with an average radiation intensity of 1032 W/m2. With 48.4 % thermal efficiency and 9.1 % exergy efficiency, the results showed the best performance. When it came to total efficiency, PDC showed its highest value of 46.2 % at 13:17 p.m. on January 4th, 2024.

Development of Advanced Solid-State Thermochromic Materials for Responsive Smart Window Applications.

This study introduces the synthesis and detailed characterization of a novel thermochromic material capable of reversible alterations in its thermotropic transmittance. Through an emulsion polymerization process, this newly developed material is composed of 75-85% octadecyl acrylate and 0-7% allyl methacrylate, demonstrating a pronounced discoloration effect across a narrow yet critical temperature range of 24.5-39 °C. The synthesized powder underwent a battery of tests, including differential scanning calorimetry and thermogravimetric analysis, as well as scanning electron microscopy. These comprehensive evaluations confirmed the material's exceptional thermal stability, uniform particle size distribution, and strong anchoring properties. Building upon these findings, we advanced the development of thermochromic polyvinyl butyral films and laminated glass products. By utilizing a coextrusion technique, we integrated these films into laminated glass, setting a new benchmark against existing glass technologies. Remarkably, the incorporation of thermochromic PVB films into laminated glass led to a significant reduction in solar irradiance of 20-30%, outperforming traditional double silver low-emissivity glass. This achievement demonstrates the exceptional shading and thermal insulation properties of the material. The research presented herein not only pioneers a valuable methodology for the engineering of smart materials with tunable thermotropic transmittance but also holds the key to unlocking enhanced energy efficiency across a spectrum of applications. The potential impact of this innovation on the realm of sustainable building materials is profound, promising significant strides toward energy conservation and environmental stewardship.

Double glass transition in polyethylene naphthalate by MDSC, BDS, and TSDC.

In this work, we present an experimental study of the primary and secondary relaxations of the semi-crystalline polymer polyethylene naphthalate by modulated differential scanning calorimetry, Thermally Stimulated Depolarization Currents (TSDCs), and Broadband Dielectric Spectroscopy (BDS) and how they are affected by physical aging. Three dipolar relaxation modes can be observed: from slowest to fastest: the primary α relaxation, which vitrifies at the glass transition temperature, Tgα, and two secondary relaxations, named β* and β. Modulated differential scanning calorimetry results show how the secondary β* relaxation also vitrifies, giving rise to an additional glass transition at Tgβ* < Tgα. In fact, the α and β* relaxations can be considered as part of a very broad and distributed relaxation. Its main part is the primary α relaxation with a shoulder at the high-frequency region corresponding to a complex secondary β* relaxation. BDS results about β* can be modeled by a main contribution (β3*) and two additional ones (β1* and β2*) with a weaker dielectric strength. TSDC results show that each single mode of the relaxation has its own glass transition temperature and they are compatible with the structure inferred by BDS. This scenario gives rise to an extended glass transition dually centered in the Tgβ* ∼ 305K and Tgα ∼ 387K temperatures.

Photovoltaic cells with transparency for glass coverage: case study in party space

Sustainable energy and technological development in electricity generation processes offer opportunities for the development and utilization of new photovoltaic technologies in construction. Photovoltaic cells for glazed surfaces, known as double glass or double-skin, have been applied in modern buildings due to their attributed characteristics that can enhance thermal comfort, provide natural lighting for internal areas, ensure privacy in external environments, and reduce energy consumption. The objective of this study is to investigate the viability of using double glass in the glazed roof of a family party venue. The qualitative method, a case study, was employed to assess the demand for electrical energy in the building and the potential use of double glass photovoltaic technologies. Market research was initially conducted with technology suppliers, enabling the evaluation of characteristics for the technological and economic feasibility of the project. The results show that the installation of double glass photovoltaic technology offers 40% transparency to solar radiation through the roof, resulting in thermal and luminous comfort. In terms of economic viability, the study demonstrates the possibility of return on investment in 4.6 years, considering energy generation, reduced building energy costs, and installation expenses. The installation of double glass technology, according to market research, is economically viable and generates local electrical energy for residents, providing comfort in the environment and enhancing the quality of life for occupants.

Effect of UV ageing on debonding of double glass laminates based on different crosslinking and thermoplastic PV encapsulants

To evaluate the potential of novel thermoplastic polyolefin (TPO) encapsulants as alternative for peroxide crosslinking ethylene vinyl acetate (EVA) copolymer and polyolefin elastomers (POE), compressive shear glass laminates were prepared and characterized using EVA and POE benchmark grades and TPO film adhesives (TPO-3.5, TPO-F and TPO-UV). The specimens were exposed to Xenon arc light with an UV irradiation of 40 W/m2, a black panel temperature of 65 °C and relative humidity of 10 % for up to 3,000 h. Visual, optical, mechanical and chemical changes were assessed by light microscopy, UV–visible–near infrared (UVVISNIR) spectroscopy, compressive shear testing, as well as differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) on fractured surfaces. In contrast to EVA and POE laminates, enhanced birefringence was detected due to a higher degree of crystallinity of the TPO encapsulants. Nevertheless, the investigated TPO double-glass laminates revealed a significantly better ultimate mechanical shear performance at 60 °C, also after UV exposure for 3.000 h. TPO-3.5 was the best-performing grade after 3,000 h followed by TPO-UV, TPO-F, EVA and POE. While the aged and fractured EVA, POE, TPO-F and TPO-UV laminates exhibited carboxylic acid signatures differing in intensity, no carboxylic acid residues were detected on the fractured TPO-3.5 surface. TPO-3.5 is characterized by a lower melt flow index and hence, a higher average molar mass compared to TPO-F and TPO-UV. For the crosslinked EVA and POE, the test temperature was already within the melting range of the non-crosslinked, polyethylene rich phase of these peroxide crosslinked encapsulants.

High-efficiency fabrication of uniform photonic crystals by a vertical deposition method from multiple glass slides of simple moulds and their application in isomer recognitions

Vertical deposition method is a simple, cheap and common method for fabricating photonic crystals (PCs). However, a majority of PCs are obtained based on the traditional vertical deposition method from one glass slide, the method is low efficiency. Herein, it is proposed to efficiently fabricate uniform PCs by an optimized vertical deposition method from double or multiple glass slides of simple moulds. Amounts of SiO2 spheres, distances of two glass slides of moulds, preparation temperatures and different diameters of SiO2 spheres are investigated for obtaining uniform PCs. And different types of PCs (the bottom-middle-top 3D PCs, bilayer 2D PCs and amorphous PCs) are also fabricated based on the optimized vertical deposition method. The above method is a simple, cheap and high-efficiency way for mass production of uniform PCs. Meanwhile, the chemicals with similar refractive indices (isomers and cis-trans isomers) can be easily distinguished under high humidity based on dynamic reflection spectra of the PCs. For example, the difference in the refractive indices of m-xylene and p-xylene is only 0.002, the difference of desorption balance time of PCs is 263 s. The PCs have potential applications in visual detections, isomer recognitions and monitoring of volatilization rates of trace liquids.

Highly precise thickness measurement of multilayer films based on the cross-correlation algorithm using a widely tunable MG-Y laser

Inspired by the demodulation algorithm of Fabry–Perot composite sensors in the field of fiber-optic sensing, this paper proposes a method based on a widely tunable modulated grating Y-branch (MG-Y) laser combined with the cross-correlation algorithm to achieve a highly precise measurement of the optical thickness of each layer of a multilayer optical sample. A sample consisting of a double glass stack was selected, and the interference spectrum of the stacked sample was acquired using a widely tunable MG-Y laser. A fast Fourier transform (FFT) algorithm combined with a finite impulse response (FIR) bandpass filter was utilized to separate the different frequency components of the multilayer optical sample. The normalized spectra of each layer were reconstructed using the Hilbert transform. Subsequently, a cross-correlation algorithm was employed to process the normalized spectrum and determine the optical thickness of each layer with high precision. The samples were measured at predetermined locations, with 150 consecutive measurements performed to assess the repetition of the thickness. The standard deviation of these measurements was found to be lower than 1.5 nm. The results show that the cross-correlation algorithm is advantageous in the optical thickness measurement of multilayer films.

Environmental fatigue crack growth of PV glass/EVA laminates in the melting range

AbstractThe delamination of encapsulants in photovoltaic (PV) modules is a common issue that leads to power loss due to optical losses. Encapsulant debonding is usually examined under monotonic loading conditions subsequent to environmental exposure such as damp heat. Service‐relevant, superimposed environmental‐mechanical fatigue loads are not considered adequately. Hence, the environmental fatigue delamination resistance of thermally toughened double glass laminates with an ethylene vinyl acetate copolymer (EVA) adhesive layer was investigated in this study. Focus was given to the melting range of EVA, in which the non‐crosslinked crystalline phase fraction is already in the partly molten state. Double cantilever beam specimens were tested on an electrodynamic test machine at temperatures of 60, 70, 80, and 90°C and relative humidity (rh) levels of 2%, 30%, 50%, and 80%. The fractured surfaces were characterized by digital microscopy, Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and differential scanning calorimetry (DSC). The cyclic fatigue tests revealed a decay in delamination resistance at elevated temperature and humidity levels. At 70°C, the delamination resistance was low, regardless of the relative humidity. Most of the laminates failed by debonding. XPS analysis showed a reduction of the C=O and C–O content, along with an increase in Si–O content with increasing relative humidity. For laminates tested at 60 and 70°C, an EVA recrystallization peak was observed in DSC experiments. This peak was shifted to significantly higher temperatures at 80% rh. XPS and DSC indicated local hydrolysis within the porous fracture process zone ahead of the crack tip. Consequently, acetic acid formation led to a decrease in delamination resistance, resulting in lower fatigue threshold values. The investigations confirmed the significant impact of environmental conditions on the fatigue delamination resistance within glass/encapsulant laminates. Notably, acetic acid formation and a significant reduction in delamination properties were observed after around 100 h of environmental fatigue exposure.

Semi-experimental investigation on the energy performance of photovoltaic double skin façade with different façade materials

The photovoltaic double skin façade (PV-DSF) is a cutting-edge building envelope renowned for its dynamic nature and power generation capabilities, which attracts substantial scientific attention. However, the current lack of experimental support makes it challenging to draw definitive conclusions about the influence of façade material. This study aims to address this gap by investigating the energy performance of PV-DSF with different façade materials, thereby establishing an empirical foundation for its optimization. In this regard, the full-size comparison experiments on PV-DSF with 20/40% photovoltaic (PV) glass as external façade and laminated/double glass as internal glass were conducted in Harbin, China. The EnergyPlus software is adopted for the simulation of lighting energy consumption. The results indicate that PV-DSF with 40% PV outperforms that with 20% PV, leading to significant reductions in total energy consumption in both summer (22.73%) and winter (16.84%). The double glass can prevent 0.49 MJ of total heat gain in summer, which is accompanied by a marginal 0.03 MJ increase in winter energy consumption. In total, for optimal annual performance, 40% PV and double glass are recommended as the façades of PV-DSF. The results of this investigation can provide an experimental foundation for PV-DSF optimization in sustainable building design.

The Influence of Glass Fiber and Copper Wire z-Binder on the Mechanical Properties of 3D Woven Polymeric Composites

AbstractThree-dimensional composites (3D) have potential applications in various fields due to their enhanced properties compared to conventional two-dimensional composites (2D). This study investigates the effect of different volumes of z-binder made from copper wire and E-glass fiber on the mechanical properties of 3D woven polymeric composites. The tensile, flexural, and fracture toughness behavior of four types of 3D orthogonal woven composites were studied in addition to a comparative 2D composite. The creation of the 3D orthogonal single-ply fabrics involved weaving z-binders using two different copper wire diameters, single fiber bundles, and double fiber bundles, each combined with four layers of woven E-glass fiber. The consolidation process for both 2D fabric and single-fabric 3D woven composites was executed using the hand lay-up technique. The results showed that most 3D woven composites outperformed 2D composites in terms of fracture toughness (stress intensity factor KIC and energy release rate GIC) and flexural strain. However, a decrease in flexural strength and tensile properties was observed for all 3D composites. The specimen with a small copper diameter had the smallest decrease of 5% in tensile strength. Furthermore, a decrease of 9% and 21% was attained by reinforcing with double and single glass fiber bundle z-binders, respectively, as compared with 2D composites. The highest enhancement of 92.5% in flexural failure strain was attained with double glass fiber bundles of z-binder. The maximum improvement in KIC fracture toughness, reaching 126% and 101.5%, was observed in specimens with a single glass fiber bundle z-binder and those with a large copper wire diameter, respectively.

Aesthetic and Thermal Suitability of Highly Glazed Spaces with Interior Roller Blinds in Najran University Buildings, Saudi Arabia

Highly glazed spaces are visually appealing and trendy, but effectively managing their temperature in hot arid climates remains a significant challenge. This study evaluates the effectiveness of dark-tinted double low-E glass with internal roller blinds in reducing heat gain in glazed spaces in hot arid climates and investigates architects’ perspectives on these facades. It combines field measurements and a survey to assess the balance between thermal control and aesthetics in such environments. This study reveals that the current glazing significantly attenuates solar radiation ingress, evidenced by a marked indoor-–outdoor temperature differential (ΔT) of approximately 9.2 °C. The mean radiant temperature registers at 1.5 °C above the indoor air temperature, which can be attributed to the glazing’s propensity to absorb and retain solar heat, resulting in an inner glass surface temperature of 43 °C. The implementation of adjustable blinds has a dynamic influence on the heat transfer coefficient (HTC), effectively modulating the temperature by impeding natural convection currents. With the blinds retracted, the HTC stands at an average of 7.1 W/m2K, which diminishes to 5 W/m2K when the blinds are 50% closed and further reduces to 4.2 W/m2K when the blinds are fully closed (100%). Survey results suggest that architects prioritise glazed facades for aesthetics (52%) while facing challenges in thermal and energy efficiency (44%). Future studies should concentrate on developing novel glazing systems that integrate solutions for visual appeal, lighting and thermal efficiency in glazed facades, particularly in hot arid climates.

Impact of the Saudi Building Code on Residential Construction Costs

The government of Saudi has implemented the Saudi Building Code (SBC) for residential buildings to set standards for their design, construction, and maintenance. However, this may result in unexpected costs that are passed on to the citizens and thus have a certain economic impact. Therefore, this study examined the additional costs imposed on citizens and the economic impact of implementing the SBC on residential buildings. This study surveyed building developers, architects, and citizens to gather data on the costs associated with adhering to the code such as material and labor costs. This study found that the additional costs imposed on citizens and the economic impact of implementing the SBC in residential buildings were relatively small. The potential long-term benefits of the SBC such as energy efficiency savings and reduced environmental impact outweigh the short-term costs. The case that applied the SBC had operating costs that were almost 44% lower. Energy efficiency was increased by the SBC’s contribution to reducing heat transfer through building components and external elements. In order to minimize heat absorption and electricity usage, thermal insulation, double and heat-reflecting glass, and light exterior colors are all recommended. The findings of this research provide valuable insights for policymakers and stakeholders in the construction industry because they consider the implementation and enforcement of building codes in the Kingdom of Saudi Arabia.

Pengaruh Kaca Penutup Double Slope dengan Piramida Menggunakan Pelat Penyerap Sirip terhadap Kinerja Solar Still

Solar desalination technology is a technology that utilizes sunlight as the main energy resource to produce clean water through the process of heating seawater. This study compared solar stills using a double slope cover glass model with a pyramid model. The study used an experimental method to compare the cover glass of the double slope model and the pyramid model. The data taken are temperature, solar radiation intensity and water productivity. The thickness of the water above the basin is 1 cm. The study resulted in the highest productivity and efficiency of solar stills using the highest double slope model cover glass of 2,780 liters and an efficiency of 37.79% compared to solar stills using pyramid model cover glass with a productivity of 2,580 liters and an efficiency of 35.16%.

Analysis of water and refrigerant-based PV/T systems with double glass PV modules: An experimental and computational approach

Water and refrigerant-based photovoltaic/thermal (PV/T) systems have substantial promise as sustainable energy solutions for commercial and residential buildings. Integrated photovoltaic and solar thermal systems outperform discrete systems in conversion efficiency and space utilization. There is a dearth of quantitative comparative studies on these systems despite their functional similarities. This study offers a comparative analysis of PV/T systems employing water and refrigerant as heat transfer fluids. Both systems are characterized by identical size and collector design. Prototypedevelopment, experimental research, and parametric assessments using computer models are used to attainthis target. Furthermore, the design of the PV/T collector in this research study involved the utilization of a double glass PV module instead of a tedlar back sheet PV module. Based on ambient conditions, refrigerant-based PV/T systems can reach a final water temperature of 7 °C to 14.9 °C higher than water-based systems. In low irradiance conditions, the refrigerant-based system generates hot water more reliably than the water-based system.

Thermal performance of a solar heat collection and storage wall with night insulation in winter: A numerical study

The application of phase change material (PCM) in Trombe walls (TW) can improve all-day indoor thermal comfort. However, the heat loss via the glass is relatively large, resulting in low thermal efficiency at night. This paper designs a double glass and a thermal insulation curtain used to increase the thermal efficiency of a TW with PCM at night. In addition, a mathematical model based on the implicit difference method was established to study the thermal efficiency and heat loss of the proposed wall in Beijing. The findings indicate that the thermal efficiency at night is improved by 16.23 % compared to a traditional TW, while heat loss at night drops by 7.75 %. The heat gain at night first increased and then decreased with the augment of phase change temperature. As the latent heat or thermal conductivity of PCM increases, the heat gain declines during the day and increases during the night. The most suitable thickness of PCM is 0.02 m. The farther the insulation curtain is from the inner glass, the greater the heat loss and the smaller the indoor heat gain at night. And the later the opening time of the air vents during the day, the smaller the heat gain during the day and the greater the heat loss. But the resulting increase in nighttime heat gain is not significant. This study can offer design suggestions for enhancing indoor thermal comfort and nighttime insulation performance.

Thermal Comfort and Cognitive Performance under Glass Facade Buildings

Glass is one of the most adaptable modern materials. However, the use of glass can have unfavorable effects such as glare, heat, and discomfort. This study focuses on the issue of designing contemporary glass buildings and facades in humid tropical environments to evaluate the thermal comfort of building occupants and assess its effects on the completion of cognitive tasks. The Wet-Bulb Globe Temperature (WBGT) parameter was used to measure thermal comfort, and the ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) scale was used to assess thermal comfort perception. The Montreal Cognitive Assessment was used to assess eight female respondents’ cognitive abilities, and the cut-off point was 26. The WBGT has a temperature range of 25, 54°–28, 83°C, in terms of thermal sensation, 54% of respondents feel hot and 62% are uncomfortable. In the completion of cognitive tasks, 75% received a score of less than 26. The results show that there is an effect of thermal comfort on cognitive performance. Due to respondents feeling uncomfortable in high-rise buildings with glass facades, as well as with cognitive outcomes that are below the cut-off point, recommendations for improvement are needed to increase thermal comfort, such as double glass facades.

INVESTIGATION OF THE EFFECT OF WINDOW SHADES TYPE ON THE OTTV IN U COLLEGE BUILDING OF BANDUNG STATE POLYTECHNIC

The U building is the college building for the Department of Refrigeration and Air Conditioning, Bandung State Polytechnic. However, during the afternoon teaching, the third floor is often complained of feeling hot and disrupting the teaching and learning process. This is caused by the size of the window on the third floor is too large and does not use any shade. This research was conducted to determine the OTTV value of the existing U Building and then investigate the potential for improving the OTTV value by changing window glass materials or adding shading such as window film. This study used primary and secondary data collection methods. The primary data consisted of: building dimensions, glass dimensions, door dimensions, ambient temperature, inside temperature, wall and glass surface temperatures, and glass types. Meanwhile, some secondary data, namely building U as built drawings, wall specifications, and glass specifications used. It was found that the existing OTTV value of the Lecture U Building reached 39.78 W/m2 where this value was above the SNI 03-6389 2011 standard. By investigating the installation of shading such as window film and double glass it was possible to minimize the building's OTTV value to 36.78 W/m2 for window film and 33.86 W/m2 for the addition of double glass accompanied by window film.

Novel design of sapphire/spinel transparent ceramic joints with double glass interlayers by coating and bonding

Transparent sapphire and magnesium aluminum spinel (MgAl2O4) ceramic was first brazed using La2O3-SiO2-B2O3-Nb2O5 (LSBN) or La2O3-SiO2-B2O3-Nb2O5-MgO (LSBNM) glass filler. The Al2O3 layer was formed at MgAl2O4/LSBN interface or sapphire/LSBNM interface, which caused the decrease of light transmission of joints. To avoid the formation of this interface layer, sapphire/LSBN/LSBNM/MgAl2O4 joints with double glass interlayers were fabricated by using a two-step joining method consisting of high-temperature coating and low-temperature bonding. After the first step of high-temperature coating, no interfacial layer was observed in sapphire/LSBN glass and MgAl2O4/LSBNM glass samples. During the bonding process, low bonding temperature (750 °C) resulted in cracks and unbonding, while high bonding temperature (950 °C) caused the crystallization of glass interlayers. However, when the bonding temperature was 850 °C, the in-line transmission and shear strength of the sapphire/MgAl2O4 joints reached 78.3% and 52 MPa, respectively.