Window Research Articles

OPTIMIZING ELECTROCHROMIC SMART GLASS WINDOWS PERFORMANCE WITH SOLAR CONTROL FOR SUSTAINABLE OFFICE ENVIRONMENTS IN THE HOT AND HUMID CLIMATE OF SAUDI ARABIA

ABSTRACT Energy-saving strategies are of paramount importance, especially in office buildings located in hot-humid climates. This study explores the potential for energy savings and assesses visual comfort in such environments by introducing Electrochromic (EC) smart glass in the window glazing. To bolster credibility and provide essential information, we employ a state-of-the-art building simulation tool. The research focuses on evaluating the energy performance and visual comfort of EC glass windows when controlled by solar controllers. Through meticulous simulations, we pinpoint the optimal setpoint radiation levels for EC glass windows across all building orientations. The results conclusively indicate that deploying EC glass windows with solar controllers, each set to the recommended radiation levels, leads to remarkable energy savings, up to 20%. Importantly, these savings are achieved without compromising visual comfort in any of the building's zones, regardless of orientation. This research underscores the potential for EC glass windows to significantly improve energy efficiency in office buildings, emphasizing their applicability in hot-humid climates. The findings call for further exploration in different building types and climate zones, as the practical implications of these results could revolutionize energy-efficient building design and retrofits.

Highly transparent and highly hydrophobic coating for outdoor camera window glass: Fabrication, transparency, and hydrophobicity

Highly transparent, superhydrophobic coatings are highly desirable for maintaining long-lasting clarity for outdoor camera windows. In this study, the authors present a simple approach to create a wide–range anti-reflective and highly hydrophobic layer on a glass surface. This is accomplished through a hydrothermal alkali etching process combined with a dip-coating process using 1 H, 1 H, 2 H, 2 H-Perfluorooctyltrimethoxysilane (POTS). The sample, etched for 20 h and modified by POTS, exhibiting an average transmittance of 96.5 %, a water contact angle (WCA) of 140° and a sliding angle (SA) of 40°. The results of the water spray experiment indicate this surface exhibits excellent water repellent performance, preventing water droplets larger than 0.01 mm in size. The relationship between optical transmittance and etching depth was thoroughly studied, revealing that an etched depth ranging from 200 nm to 600 nm yields optimal wide-spectrum anti-reflective properties. Furthermore, the influence of surface roughness on apparent WCA and SA was investigated. It was found that root mean square (RMS) roughness can be an effective factor to predict the apparent WCA of a surface, while both the RMS roughness and morphological structure affect the SA.

Analysis of Internal Conditions and Energy Consumption during Winter in an Apartment Located in a Tenement Building in Poland

The residential sector of existing buildings has great potential in energy savings and the improvement of indoor conditions. The modernization of buildings is of particular concern to the policies of the European Union, local governments, and building users. The aim of this paper is to present an analysis of indoor parameters and energy consumption for heating for an apartment located in a pre-war tenement building before and after thermomodernization. The analysis was conducted for winter conditions and was based on measurements and simulations. Originally, the building had not undergone any thermomodernization actions since its reconstruction after WWII. Interior, exterior, and surface temperatures were recorded to describe the thermal conditions of the apartment, while gas meter readings were used to estimate energy consumption for heating purposes. WUFI Plus software (v.3.2.0.1) was used to estimate energy consumption and perform energy simulations for the apartment over an extended period of time. The best thermomodernization effect resulted from the replacement of windows and the inefficient heating system, avoiding surface condensation and reducing final energy consumption by more than 50%. The extended options resulted in energy savings higher than 70%. The presented analysis shows the importance of retrofit measures and proves that even a small improvement can bring significant benefits.

TRANSPARENT SOLAR PANELS

This article is about Transparent Solar Panels. Discusses current and future applications of Transparent Solar Panels. Here the pros and cons of Transparent solar panels are discussed. The different characteristics of transparent solar panels from conventional solar panels are discussed in detail. The replacement of window panes with solar panels is being discussed in the construction industry. Most importantly, information is given on the wide application of all these in the near future. In addition, this article extensively mentions the pros and cons of transparent solar panels. The article notes that transparent solar panels produce less electricity than conventional solar panels. This article compares the production costs of transparent solar panels and conventional window glass and conventional solar panels. Obviously, transparent solar panels are more expensive than window glass, but transparent solar panels are cheaper than conventional solar panels. Currently, these solar panels are not widely used. Because it was discovered very recently, but all this cannot stop the development of transparent solar panels. My main purpose in writing this article is to explain to people the importance of this discovery.

Single-Layer Frequency-Selective Surface on Window Glass for 5G Indoor Communications

Single-Layer Frequency-Selective Surface on Window Glass for 5G Indoor Communications

A New Approach to the Economic Evaluation of Thermomodernization: Annual Assessment Based on the Example of Production Space

Energy and economic assessments are of great relevance in the context of decision processes for the most optimal solutions for building renovations. Following the method recommended by UNIDO, economic analyses of thermal modernization options are carried out based on the Simple Payback Time (SPBT), Net Present Value Ratio (NPVR) and Internal Rate of Return (IRR) indices. Incorporating these indicators and a new approach that involves aggregating thermomodernization activities not only in the cold and warm seasons separately, but throughout the whole year, an economic evaluation of the thermomodernization of a production space was carried out. In this case study, the renovation options included wall insulation, window replacement, the installation of infrared heater, a two-flow air diffuser (TFAD) and variable air volume. The economic effect indicated by the highest NPVR over a normative period of 15 years was obtained for the installation of an infrared heater and a TFAD with a variable mode ventilation system. The SPBT for this case was also the lowest.

Enhancement of electrochemical reversibility in Poly 3-hexylthiophene layers for flexible dynamic glass windows applications

Thin films of Poly 3-hexylthiophene (P3HT) were deposited onto Indium Tin Oxide (ITO) coated glass substrates using a spin coating method and the films were vacuum annealed at different temperatures to study the effect of annealing on the electrochemical reversibility. From the absorption spectra, the variation of the optical band gap with annealing temperature was studied for different annealing temperatures. The optical band gap obtained for P3HT film deposited at room temperature (RT) was around 1.94 eV and 1.92 eV for the sample annealed at 100 °C. A cyclic voltammetry (CV) analysis showed that at certain applied redox potentials, P3HT thin films changed the colour from magenta to transparent and then back to magenta in the reverse potential. P3HT films annealed at 100 °C showed the best electrochemical reversibility among all the annealed samples. These electrically switchable electrochromic P3HT thin films can be used in flexible dynamic windows (FDWs) as smart windows for controlling the temperature and light in buildings, displays and mirror light modulators.

Modulation of an Si-O-Si structure in uniformly photochromic microcapsules for solar heat and daylight management

Photochromic microcapsules adjust to sunlight adaptively and using them to fill windows is an attractive option for constructing smart windows that can manage solar heat and daylight. However, fabricating high-durability polymer-composite photochromic microcapsules for use in outdoor glass windows remains challenging, requiring high contrast ratio, high transparency, and low haze. Herein, we synthesized a novel poly(urea-siloxane) shell monomer containing Si-O-Si bonds and successfully prepared a photochromic microcapsule by modulating the mass ratios of shell monomers and emulsifiers. The photochromic poly(urea-siloxane)-based microcapsule-coated glass (PCPUS MCG) showed high luminance transmittance (83.66 %) and low haze (20.31 %). The as-prepared PCPUS MCG exhibited self-adaptive sunlight control without additional energy input, with strong solar modulation ability (Δτsol of 38.30 %). Furthermore, the response indoor air temperature was reduced by approximately 3.7 °C in a field test using a model house equipped with PCPUS MCG windows, showing promising energy-saving potential compared with conventional windows. Therefore, uniform photochromic-microcapsule modification using Si-O-Si bonds warrants attention in future energy-saving window designs.

Dynamical Janus-Like Behavior Excited by Passive Cold-Heat Modulation in the Earth-Sun/Universe System: Opportunities and Challenges.

The utilization of solar-thermal energy and universal cold energy has led to many innovative designs that achieve effective temperature regulation in different application scenarios. Numerous studies on passive solar heating and radiation cooling often operate independently (or actively control the conversion) and lack a cohesive framework for deep connections. This work provides a concise overview of the recent breakthroughs in solar heating and radiation cooling by employing a mechanism material in the application model. Furthermore, the utilization of dynamic Janus-like behavior serves as a novel nexus to elucidate the relationship between solar heating and radiation cooling, allowing for the analysis of dynamic conversion strategies across various applications. Additionally, special discussions are provided to address specific requirements in diverse applications, such as optimizing light transmission for clothing or window glass. Finally, the challenges and opportunities associated with the development of solar heating and radiation cooling applications are underscored, which hold immense potential for substantial carbon emission reduction and environmental preservation. This work aims to ignite interest and lay a solid foundation for researchers to conduct in-depth studies on effective and self-adaptive regulation of cooling and heating.

STRATEGY FOR RESTORATION OF APARTMENT BUILDINGS AS A CONSEQUENCE OF MILITARY AGGRESSION, TAKING INTO ACCOUNT THE ENERGY EFFICIENCY FACTOR

This article analyses the most frequent measures applied for to restore apartment buildings as a result of military aggression. By analysing the applications submitted, it was found that the most common measures are window replacement and facade insulation. These measures were found to be popular due to their effectiveness in improving energy efficiency, providing comfort for residents and increasing building security. Additional benefits are the support of funding programmes and grants, which makes them more affordable for HOAs. The findings of this study may be useful for construction professionals and NGOs involved in the reconstruction of buildings affected by military aggression.

Frequency-domain searching algorithm in deflectometry for measuring the surface of a transparent planar element.

This Letter presents the frequency-domain searching algorithm in deflectometry (FSAD). By encoding specialized multi-frequency fringe patterns and employing a correlation searching algorithm, the limitations of existing frequency-domain methods can be overcome to some extent, thereby separating front and back surface reflections to obtain complete measurement data. The principles of FSAD are described in detail. In the experiment, a piece of window glass with thickness of 10 mm and a square area of 96 × 96 mm is measured to verify the proposed method.

Thermochromic Hydrogels with Adjustable Transition Behavior for Smart Windows.

With the fast economic development and accelerating urbanization, more and more skyscrapers made entirely of concrete and glass are being constructed. To keep a comfortable indoor environment, massive energy for air conditioning or heating appliances is consumed. A huge amount of heat (>30%) is gained or released through glass windows. Using smart windows with the capability to modulate light is an effective way to reduce building energy consumption. Thermochromic hydrogel is one of the potential smart window materials due to its excellent thermal response, high radiation-blocking efficiency, cost-effectiveness, biocompatibility, and good uniformity. In this work, polyhydroxypropyl acrylate (PHPA) hydrogels with controllable lower critical solution temperature (LCST) were prepared by photopolymerization. The transition temperature and transition rate under "static transition" conditions were investigated. Unlike "static" conditions in which the transition temperature was not affected by the initial and final temperature and heating/cooling ramp, the transition temperature varied with the rate of temperature change under dynamic conditions. The "dynamic" transition temperature of the PHPA hydrogel gradually increased with the increase of the heating rate. It was the result of the movement of the molecular chains lagging behind the temperature change when the temperature change was too fast. The results of the solar irradiation experiment by filling PHPA hydrogels into double glazing windows showed that the indoor temperature was about 15 °C lower than that of ordinary glass windows, indicating that it can significantly reduce the energy consumption of air conditioning. In addition, a wide range of adjustable transition temperatures and fast optical response make PHPA hydrogels potentially applicable to smart windows.

Comparative dose distribution profiles in a water-filled tube, jet, and tray treated with 1–5 MeV electrons

Accelerated electrons up to 5 MeV energy are relatively low-penetrating, and in the second half of the penetration length, the non-uniformity of energy deposition can increase by 20–50% per 1 mm of material depth. This feature of 1–5 MeV electrons, widely used in technology and research, as well as the high cost of beam power, requires the researcher to have the skills to identify areas of optimal energy deposition and develop measures to reduce energy loss. This work examines the dependence of the average absorbed dose and dose non-uniformity for three modes of electron beam treatment of water, taking into account the beam direction (horizontal or vertical, 1–5 MeV), beam window foil thickness (20–100 μm Al or Ti) and glass wall thickness (0.2–2 mm Pyrex). The dependencies are applicable to clarify, predict and analyze the dose distribution in a liquid irradiated in a tube, jet or tray.

Strategies for Enhanced Optical Performance and Durability of VO2‐Based Thermochromic Windows

Due to the growing need for smart windows for buildings to reduce energy usage, vanadium dioxide (VO2) has been investigated as a potential material for thermochromic smart windows due to its ease of implementation and simplicity in industrial production. VO2 undergoes a reversible phase shift from a monoclinic (M, P21/c) semiconductor to a rutile (R, P42/mnm) metal at a critical temperature of 68 °C. This transition is accompanied by acute variations in IR reflectance, transmittance, and electrical resistance. Despite substantial developments in thermochromic materials, their optical and transition properties are still unsatisfactory. In the past several decades, many methods for enhancing optical properties have been reported, including composite films, multilayer structures, and element doping. Recent developments in thermochromic smart windows to improve both optical properties and durability have been surveyed in this review. Additionally, future growth trends have been provided by the possibility of commercially manufacturing VO2 smart windows.

Energy and economic performance optimization of a window with variable transparency shape-stabilized PCM in hot summer and cold winter climate zone

Improving the thermal performance of windows is important for building energy efficiency. Filling windows with variable transparency shape-stabilized phase change materials (VTSS-PCM) improves the thermal inertia of windows while avoiding the leakage of PCM. In this paper, a new type of VTSS-PCM window was proposed, tested, simulated and optimized in hot summer and cold winter climate zone. A numerical model of the VTSS-PCM window was built, and the model was validated using experimental tests. On this basis, three key parameters of VTSS-PCM were investigated and optimized. Finally, the energy and economic performance of the optimized VTSS-PCM window were compared with a typical hollow glass window. The results showed that the total annual unfavourable heat transfer (TAHT) and the annual investment cost (AIC) of the VTSS-PCM window obtained from the optimization were 118.16 kWh/m2 and 8.53 CNY/m2, respectively. Compared with the hollow glass window, the VTSS-PCM window reduced the TAHT by 30.14% and the total annual cost by 28.39%. The VTSS-PCM window produced a better development potential in terms of energy performance and economic performance. This study provided a reference for the application of the VTSS-PCM window in hot summer and cold winter regions of China.

Optically transparent meta-window for satellite signal reception

Glass window, as a widely used functional unit in architecture and transportation, is a visual bridge connecting the indoor and outdoor world, and also a wireless communication window that is easily overlooked. In order to explore additional possibilities of glass window in the field of wireless communication, we propose to use meta-windows combining traditional window glass with metasurface to manipulate electromagnetic waves in microwave frequency band while ensuring its good optical transparency. Here, the meta-window is constructed by rotated meta-atoms made of fine copper wires printed on glasses to minimize the loss of optical transparency. As a proof of concept, we design and fabricate an optically transparent focusing meta-window for receiving satellite signals. In the experiment of television reception from the ChinaSat 9 satellite, stable high-definition video reception has been verified. The meta-windows endow traditional glass windows with new capabilities in electromagnetic modulations, which may be applied in 5G/6G communications, satellite ground integrations, and smart cities.

196 Quantifying Cholinergic Cortical Response to Deep Brain Stimulation in Murine Models

INTRODUCTION: Deep brain stimulation has become a potential treatment for mental disorders. We have previously documented that chronic, one-hour daily, intermittent stimulation of the basal forebrain causes increases in cortical levels of acetylcholine and demonstrates improvement in working memory behavior in monkeys and mice. Continuous stimulation, in contrast, appears to deplete releasable acetylcholine in roughly one minute (Blake et al., Brain Stimulation, 2023; 16(1): 364). This study serves as the first quantification of cortical acetylcholine response to stimulation. METHODS: Viral vectors encoding cell surface receptors fluorescent to acetylcholine are injected into superficial cortex in mice through a small craniotomy. After three weeks, the craniotomy is enlarged for glass window affixation above the injection site. Electrodes are implanted posteriorly and angled to contact the basal forebrain. Cortical expression of acetylcholine in response to stimulation is visualized via two-photon microscopy through the window and quantified over time. RESULTS: Preliminary data suggest that the physiologic half-life of acetylcholine in the cerebral cortex is 10-12 seconds. Also, the system expressed acetylcholine at normal levels after 20 minutes following 100 seconds of 60Hz stimulation (6000 total pulses). Based on these observations, each second of 60 Hz stimulation of the basal forebrain requires 12 seconds of recovery time. CONCLUSIONS: These data are foundational for future explorations in developing treatments for pathology involving cholinergic exchange and recycling, with implications in optimizing deep brain stimulation and tailoring pharmaceuticals that augment acetylcholine reuptake. These data also suggest that high-frequency stimulation decreases neurotransmitter output through depletion. Additional experimentation in the future will incorporate acetylcholinesterase inhibitors and additional stimulation patterns to assess clinical response.

Preparation of TiO2 Nanorods Composites Doped with Silver Nanoparticles and Their Bactericidal Properties under Visible Light Irradiation

AbstractTiO2 is a widely used photocatalytic antibacterial material and shows good antibacterial properties under ultraviolet light. However, its antibacterial efficacy under visible light still remains limited. To develop low‐cost and biocompatible antibacterial materials, this article provides a facile method for in situ preparation of a trace amount of silver (Ag) doped TiO2 nanorods (TiO2NR–Ag) composites, which cannot only enhance the antibacterial properties under visible light, but also has good biocompatibility. Two representative epidemic strains, Staphylococcus aureus and Escherichia coli, are selected for analysis of the antibacterial properties of the obtained TiO2NR–Ag composite nanoparticles. The results demonstrate that even if the Ag doping level is as low as 2.5 × 10−4 wt% (i.e., Ag/TiO2 = 2.50 µg g−1), the TiO2NR–Ag composite nanoparticle coatings are transparent and exhibit exceptional antibacterial properties, which is attributed to synergistic enhanced bactericidal effect of the active substances generated by TiO2NR–Ag under visible light. The cytotoxicity and hemolysis rate results indicate that TiO2NR–Ag composite exhibit excellent biocompatibility. This study effectively improves the antibacterial effect of TiO2 photocatalytic nanomaterials while maintaining their biocompatibility, and the prepared TiO2NR–Ag composite nanoparticles can be applied in various fields such as window glasses, medical device surfaces, furniture surfaces, and optical devices, etc.

Energy Performance Analysis of the Renovation Process in an Italian Cultural Heritage Building

Renovating buildings with cultural heritage significance is an important step toward achieving sustainability in our cities. The benefits are not only energy-related but also encompass social aspects that make these renovations a high apriority. The present work investigates the renovation process of a cultural heritage building in the Municipality of Trento in Italy, specifically focusing on achieving energy savings and renewable energy integration by implementing various renovation actions. These renovation actions include improvements to the building envelope, such as roof insulation and window replacements. Additionally, the renovation actions for active systems involve the installation of a ground-source heat pump for heating/cooling coupled with a borehole thermal energy storage system, which is an innovative technology for the renovation of cultural heritage buildings. The electrical systems of the building are upgraded through the addition of standard rooftop photovoltaics, innovative building-integrated photovoltaics (shingles), and the installation of an LED lighting system. The baseline and the renovation scenarios are studied using the dynamic simulation tool INTEMA.building, written in the programming language Modelica. This tool simulates both the building envelope and the energy systems with a high level of detail, using advanced control systems and adjustable time steps. According to the simulation analysis, the primary energy demand is reduced by 30.49%, the final energy demand by 36.74%, and the net electricity demand by 8.72%. Results from this study can be useful to interested stakeholders (e.g., building owners, architects, construction companies, public agents, and urban planners) dealing with the renovation of cultural heritage and protected buildings. Also, the results can be exploited for estimating energy savings by applying advanced renovation strategies for cultural heritage buildings.

Multi-Objective Optimization with Active–Passive Technology Synergy for Rural Residences in Northern China

Due to the serious problems with energy efficiency, carbon emissions, and thermal comfort of rural residences in northern China, an optimization of active and passive heating technologies for rural residences is necessary. In this paper, an optimization for rural residences in northern China is conducted with four objectives: the whole life cycle carbon emission; the annual energy consumption through heating, ventilation, and air conditioning systems; the annual cost; and thermal comfort. In addition, the optimization model with active–passive heating technology synergy is resolved by NSGA-II genetic algorithm. The active and passive design variables, including the type of air source heat pump, orientation, the type and thickness of envelope insulation, the layer of window glass, the window-to-wall area ratio, as well as sunspace parameters are preferred to obtain the optimal solution. The results indicate that the optimal solution obtained by the ideal point method gives the most outstanding performance. Compared with the prototype, the optimized carbon emissions in severe cold and cold regions decreased by 56.1% and 54.6%, respectively. The annual energy consumption decreased by 59.7% and 62.2%. Finally, the roof insulation thickness is the most sensitive design variable in Pareto-optimal solution sets. This paper offers significant guidance in the application of the optimization method of active–passive technology synergy to the energy-saving design of buildings.