Effect of Distance between Double Glazing on the Performance of a Solar Thermal Collector Control

In this research paper, an attempt has been made to come across the effect of distance between double glazing on the efficiency of a solar thermal collector. Experiments were carded out on an active solar energy demonstration system （ET 200）. Commercial glass pane of 3 mm thick having the same dimensions as that of the apparatus was placed above the collector at a distance of 2 cm, 4 cm and 6 cm. Tests were done with and without the added glass. Experiments were performed for double glazing with two positions of the light meter. In one position, it was placed in the middle of the collector surface. While, in the other one, the light meter was placed in the middle of the added glass. To study the effect of double glazing on the performance of the solar collector ET 200, the correct position of the light meter was to place it exactly in the middle of the additional pane under the lamp. Double glazing does not enhance the performance of the solar collector because of the high resistance of the system glass air glass. The efficiency of double glazing solar collector decreases with the increasing the distance of the two separated glasses.

PROPERTIES AND PERFORMANCE OF VACUUM INSULATED GLAZING

As energy codes become more stringent, maximising the energy efficiency of the glazing used in buildings becomes of greater importance. Many new solutions have been proposed to reduce heat transfer through windows. One such technology that is currently growing in prominence is vacuum insulated glazing (VIG). VIG has been manufactured successfully in Japan for over 16 years, and although used primarily in Asian markets, its use has been growing in both Europe and North America over the last five years. VIG is different from other insulated glass technologies, providing excellent energy efficiency whilst maintaining an ultra-thin form factor-6.2 mm being the thinnest. A large range of product options are available and will be described in detail in this article, as well as a number of examples of their use. The advantages of using VIG in both retrofit of older buildings and the glazing of new construction will be detailed and new developments in the technology discussed. It will be demonstrated that VIG will be a key technology in the future, giving new options to building designers.

Thermal stress investigation of glazing unit filled with paraffin in cold regions

In this study,based on the established heat transfer and mechanical stress models,thermal stress distribution of glazing unit filled with paraffin was studied for various temperature differences between indoor and outdoor conditions.The strain produced on the surface of glazing unit filled with paraffin varies greatly in the outdoor temperature range of-30℃-40 ℃.Furthermore,phase change material(PCM) layer between the glass panes significantly affects the strain values at different temperatures,which can respectively reach up to about 250×10^(-6) and down to-300×10^(-6) for tensile and compressive strains once the paraffin is in liquid state.Additionally,impacts of boundary conditions on the strain values are more pronounced within the distance of 0.01 m from the edges of the glazing window.The presented model and outcomes can be used as a guide to simulate thermal stress in glazing units filled with paraffin.

LASER GLAZING OF Ni-Nb AND Ni-Nb-Cr ALLOYS AND CORROSION RESISTANCE OF AMORPHOUS LAYERS

Partially amorphous Ni-Nb alloy was made by 1.91 kW cw CO_2 laser melt-quenching, and fully amorphous by 4.5 kW and 4.9 kW.The corrosion resistance of the amor- phous layer was improved by adding Cr.Potentiodynamic polarization curves show that the amorphous Ni_(50)Nb_(40)Cr_(10) is in more corrosion-resistant than the amorphous Ni_(60)Nb_(40)and 18-8 stainless steel.

Designing interactive glazing through an engineering psychology approach:Six augmented reality scenarios that envision future car human-machine interface

Background With an increasing number of vehicles becoming autonomous,intelligent,and connected,paying attention to the future usage of car human-machine interface with these vehicles should become more relevant.Several studies have addressed car HMI but were less attentive to designing and implementing interactive glazing for every day(autonomous)driving contexts.Methods Reflecting on the literature,we describe an engineering psychology practice and the design of six novel future user scenarios,which envision the application of a specific set of augmented reality(AR)support user interactions.Additionally,we conduct evaluations on specific scenarios and experiential prototypes,which reveal that these AR scenarios aid the target user groups in experiencing a new type of interaction.The overall evaluation is positive with valuable assessment results and suggestions.Conclusions This study can interest applied psychology educators who aspire to teach how AR can be operationalized in a human-centered design process to students with minimal pre-existing expertise or minimal scientific knowledge in engineering psychology.

Assessment of the Energy Impact of Using Building Integrated Photovoltaic and Electrochromic Glazing in Office Building in UAE

The aim of this research was to explore the energy benefits and future potential of using Building Integrated Photovoltaic (BIPV) and Electrochromic Glazing (EG) within the climatic conditions of the city of Abu Dhabi. The Integrated Environmental Solutions (IES-VE) energy modeling software was used to assess the energy performance, mainly the reductions in HVAC and lighting, for different configurations and compare that to the base case scenario for south, east, west, and north facing facades. The results showed that the BIPV is most advantageous on the south fa?ade while the EC glazing performs best on the north facing windows. Moreover, the change in sensor location increased the energy savings for both cases, although the change was very marginal compared to the change of the glass properties. Using an automated light control system with dimming for both models, compared against the standard on-off lighting mechanism in the base case, the BIPV proves to have a higher total annual energy saving potential for most orientations, upto 33.5% while dynamic EC was best suited for the North orientation resulting in 7.4% reduction in the total annual energy consumption.

The Effect of Transition Hysteresis Width in Thermochromic Glazing Systems

Thermochromic glazing theoretically has the potential to lead to a large reduction in energy demand in modern buildings by allowing the transmission of visible light for day lighting whilst reducing unwanted solar gain during the cooling season, but allowing useful solar gain in the heating season. In this study building simulation is used to examine the effect of the thermochromic transition hysteresis width on the energy demand characteristics of a model system in a variety of climates. The results are also compared against current industry standard glazing products. The results suggest that in a warm climate with a low transition temperature and hysteresis width energy demand can be reduced by up to 54% compared to standard double glazing.

IDENTIFYING OPTIMUM GLAZING PROPERTY FOR CONSERVING ENERGY IN HOT SEMI-ARID CLIMATE REGIONS

Globally,the building sector is responsible for 40%of energy use and 30%of GHG emissions.The greatest portion of the energy is used during the operational phase(use stage)of buildings.The building envelope,especially the glazed components,plays an important role in determining the energy requirement of buildings.These glazed parts of the building envelope exposed to direct solar radiation are most vulnerable to heat loss and gain.Heat loss and gain through the glazing material depend on glazing properties(U-value,SHGC,VT)and building energy use changes according to the properties of the glazing system.A variety of glazing types has been developed over recent decades that use the properties of the glass as a means of responding to environmental conditions.This study is carried out to identify the optimum glazing property for conserving energy in cooling dominant regions using an early design energy modeling tool.It was found that a low SHGC is the most important glazing property for reducing cooling energy consumption.SHGC of less than 0.3 is found useful.This study would help building industry professionals evaluate the best glazing property while selecting the glazing type.

EVALUATION OF PV POWERED SWITCHABLE GLAZING TECHNOLOGIES IN TERMS OF THEIR SUITABILITY FOR OFFICE WINDOWS IN MODERATE CLIMATES

In the search for façade solutions that meet requirements for energy efficiency and office space use comfort,it seems promising to apply a combination of photovoltaic(PV)technology with switchable glazing.It is believed that the merging of these two technologies might benefit the cooperation between regulated solar protection and energy efficiency.This article provides a design outlook on the use of PV-EC,PV-SPD,and PV-LCD technologies in terms of their utility for office buildings in moderate climates.This study concerns thermal,optical-visual,energetic,and technical issues,and a comparative method was applied.Based on current scientific research,the results of the analysis were juxtaposed with the requirements of the office working environment:natural lighting,thermal protection,glare protection,privacy control,energy efficiency,and technical reliability.The juxtaposition of these aspects revealed the advantages and disadvantages of a given solution from an architectural point of view.PV-EC technology in a side-by-side system was found to be the most appropriate solution and the results may be applied to make preliminary design decisions.

An Advanced Control Technology Robotic Casting and Glazing for Ceramic Bowls

Glazes on ceramics provide a durable finish as well as a protective layer, impervious, sanitary, and generally easily cleaned surface, have the advantage of having a very wide spectrum of colors. As a result, color has a lot of variability, luminosity and permanence. This method of coating is suitable for products that are not too big a smooth and can be done quickly such as plating of coffee mugs, cups or bowls. Putting the product in the enameled tank must not be soaked for too long as it will thicken the coating. When the coating is dry it will slip off easily. Therefore, this research is to provide product dipping. Good and consistent plating at all times and then industrial robots are used to help in plating or dipping. The robot can control the work quickly. According to the position and speed control can reduce the working time in the further.

Optical and thermal performance analysis of aerogel glazing technology in a commercial building of Hong Kong

Improving the thermal insulation of glazing units is a common strategy of reducing building energy use for spacing cooling.This paper newly examined the application of aerogel glazing technology in Hong Kong by the means of laboratory testing and simulation.Nine prototypes of granular aerogel glazing were selected to examine their optical properties,and the measured optical properties of aerogel were used to calculate the total window thermal performance indices.A typical 40-story commercial office building was chosen for energy simulation to compare the thermal performance of aerogel glazing with different glazing technologies in Hong Kong.The results showed that aerogel glazing could achieve the promising reduction of window heat gain up to 57%and cooling energy up to 8.5%compared with double glazing.The heat insulation performance of aerogel glazing is even better than the double glazing with low-E coating in Hong Kong.Therefore,aerogel glazing can be a good alternative of glazing to comply with the existing local Overall Thermal Transfer Value(OTTV)requirement and to reduce the building energy use for space cooling in Hong Kong and other regions.

Microstructure modification of Y2O3 stabilized ZrO2 thermal barrier coatings by laser glazing and the effects on the hot corrosion resistance

Y2O3 stabilized ZrO2(YSZ)thermal barrier coatings(TBCs)are prone to hot corrosion by molten salts.In this study,the microstructure of atmospheric plasma spraying YSZ TBCs is modified by laser glazing in order to improve the corrosion resistance.By optimizing the laser parameters,a^18μm smooth glazed layer with some vertical cracks was produced on the coating surfaces.The as-sprayed and modified coatings were both exposed to hot corrosion tests at 700 and 1000℃for 4 h in V2O5 molten salt,and the results revealed that the modified one had improved corrosion resistance.After hot corrosion,the glazed layer kept structural integrity,with little evidence of dissolution.However,the vertical cracks in the glazed layer acted as the paths for molten salt penetration,accelerating the corrosion of the non-modified coating.Further optimization of the glazed layer is needed in the future work.

Secondary solar heat gain modelling of spectral-selective glazing based on dynamic solar radiation spectrum

The secondary solar heat gain,defined as the heat flows from glazing to indoor environment through longwave radiation and convection,grows with the increasing of glazing absorption.With the rapid development and application of spectrally selective glazing,the secondary solar heat gain becomes the main way of glazing heat transfer and biggest proportion,and indicates it should not be simplified calculated conventionally.Therefore,a dynamic secondary solar heat gain model is developed with electrochromic glazing system in this study,taking into account with three key aspects,namely,optical model,heat transfer model,and outdoor radiation spectrum.Compared with the traditional K-Sc model,this new model is verified by on-site experimental measurements with dynamic outdoor spectrum and temperature.The verification results show that the root mean square errors of the interior and exterior glass surface temperature are 3.25°C and 3.33°C,respectively,and the relative error is less than 10.37%.The root mean square error of the secondary heat gain is 13.15 W/m2,and the dynamic maximum relative error is only 13.2%.The simulated and measured results have a good agreement.In addition,the new model is further extended to reveal the variation characteristics of secondary solar heat gain under different application conditions(including orientations,locations,EC film thicknesses and weather conditions).In summary,based on the outdoor spectrum and window spectral characteristics,the new model can accurately calculate the increasing secondary solar heat gain in real time,caused by spectrally selective windows,and will provide a computational basis for the evaluation and development of spectrally selective glazing materials.

Synthesis and Coloring Mechanism of Metallic Glaze in R_(2)O-RO-Al_(2)O_(3)-SiO_(2)-P_(2)O_(5)System

A copper-red and silver-white metallic glaze of R_(2)O-RO-Al_(2)O_(3)-SiO_(2)-P_(2)O_(5)system was synthesized by adjusting the firing temperature and glaze components.The coloration mechanism of the metallic glaze was revealed via investigation of the microstructure of the glaze.Our research reveals that the metallic glaze with different colors is mainly due to the amount of Fe_(2)O_(3).The metallic glaze shows a silver-white luster due to a structural color ofα-Fe_(2)O_(3)crystals with a good orientation when the sample contains 0.0939 mol of Fe_(2)O_(3),maintaining temperatures at 1150℃for 0.5 h.The metallic glaze is copper-red which is dominated by the coupling of chemical and structural color ofα-Fe_(2)O_(3)crystals when the sample contains 0.0783 mol of Fe_(2)O_(3).After testing the amount of SiO_(2),we find that 4.0499 mol is the optimal amount to form the ceramic network,and 0.27 mol AlPO_(4)is the best amount to promote phase separation.

Mechanism of slag pellets sticking on the wall of reduction pot in magnesium production by Pidgeon process

In the preparation of magnesium by Pidgeon process,the phenomenon slag pellets sticking on the wall of reduction pot always appear,and the glaze sticking on the inner wall of the reduction pot is difficult to remove.The mechanism of this phenomenon is studied in this work by X-ray fluorescence spectrometer(XRF)measurement,electron probe microanalyzer scanning(EPMA)analysis,differential scanning calorimetry(DSC)analysis,and thermodynamic calculations.The main components of the glaze are MgO,Ca_(12)Al_(14)F_(2)O_(32),CaF_(2),CaO,and a small amount of Ca_(4)Si_(2)O_(7)F_(2).The solid-liquid transition temperature of Ca_(12)Al_(14)F_(2)O_(32)and CaF_(2)is close to the production temperature of Pidgeon process,which leads to the bonding between the slag pellets and the pot wall.The loss of CaF_(2)in glaze layer will reduce the total amount of liquid phase and increase the temperature at which Ca_(12)Al_(14)F_(2)O_(32)is completely transformed into liquid phase,which causes glaze layer sticking on the inner wall of the reduction pot.

Investigation on surface figuration and microstructure of laser glazed nanostructure zirconia thermal barrier coatings

CO2 continuous wave laser beam had been applied to the laser glazing of plasma sprayed nanostructure zirconia thermal barrier coatings. The effects of laser glazing processing parameters on the surface figuration and microstructure change had been carried out, the microstructure and phase composition of the coatings had been evaluated by the scanning electron microscope （ SEM） and the X-ray diffraction （ XRD ）. SEM observation indicates that the microstructure of the as-glazed coating could be altered from singlecolumnar structure to a combination of the columnar grain and fine equiaxed grain with the different laser glazing conditions. XRD analysis illustrates that the predominance phase of the us-glazed coating is the metastable tetragonal phase, and the glazed coating with the single columnar structure has shown the clear orientation in （220） and （400） peaks while the other coatings do not show that.

Dynamic performance of cable net facade with consideration of glass panels under earthquake

Shaking table tests and theoretical analysis were conducted to study the dynamic performance of cable net facade with consideration of glass panels under earthquake. Firstly,the dynamic response of cable net faade under earthquake was investigated with shaking table test. Then the working mechanism of glass panels in coordination with cable net was proposed. Accordingly,a numerical simulation model of glass panel's working in coordination with cable net was built for the dynamic analysis.And then the seismic response was analyzed with this model theoretically. The study indicates that the seismic response of the cable net with glass panels on most occasions is mainly decided by the symmetric modes,and the first vibration mode is dominant. The damping of cable net facade is mainly decided by glass panels. And it is very good for cable net faade to restrain its dynamic response under earthquake.

Risk Assessment and Optimisation of Blast Mitigation Strategies for Design and Strengthening of Built Infrastructure

A probabilistic risk assessment procedure is developed which can predict risks of explosive blast damage to built infrastructure, and when combined with life-cycle cost analysis, the procedure can be used to optimise blast mitigation strategies. The paper focuses on window glazing since this is a load-capacity system which, when subjected to blast loading, has caused significant damage and injury to building occupants. Structural reliability techniques are used to derive blast reliability curves for annealed and toughened glazing subjected to explosive blast for a variety of threat scenarios. The probabilistic analyses include the uncertainties associated with blast modelling, glazing response and glazing failure criteria. Damage risks are calculated for an individual window and for windows in the facade of a multi-storey commercial building. The paper shows an illustrative example of how this information, when combined with risk-based decision-making criteria, can be used to optimise blast mitigation strategies.

Greenhouse Farming as Adaptation to Climate Change in Nigeria

The effect of climate change in recent times has disrupted the onset and duration of seasons in Nigeria manifesting in the reduction of both staple and cash crops, and livestock yields. This has transformed the country to a major importer of those agricultural produce she hitherto exported. As a country where over 70% of the population depends on agriculture for survival, the impacts of climate change are a major threat to both food security and the general econoray. Remedial measures which have been suggested including adoption of agronomic and tested practices, reduced burning and afforestation. An option that could be of great potential in ameliorating this situation but which has not been practiced especially in the production of specialty crops is the use of greenhouse farming. This paper discusses the impact of climate change on Nigerian agriculture. The potentials and logistics are required for effective use of greenhouse farming as an adaptation to climate change in Nigeria. It is suggested that research should be carded out to select appropriate glazing materials. The provisions of training and credit facilities for interested farmers are recommended for effective utilization of the system.

DESIGN GUIDELINES FOR THE UTILIZATION OF TILTED FAÇADES TO ENHANCE BUILDING ENERGY PERFORMANCE

Intense solar radiation is one of the key design problems for buildings in tropical regions.The recommended practice is to install shading devices,particularly to protect glazing systems.However,many design factors do not allow shading devices to be implemented in all cases;shading devices may not be appropriate to particular design concepts.To serve the designers’preference,alternative solutions should be provided.This study aims at investigating the performance of a new design alternative—the tilted façade.By simply tilting a wall downward,solar radiation can be minimized in the same way as a shading device.The state-of-the-art energy software,eQUEST,was used to simulate energy performance of buildings in Bangkok,Thailand.At the same time,simulated results were confirmed by using experimental data monitoring from specially customized test cells.A wide range of WWR(Window to Wall Ratio)was tested against different façade orientations,glazing types,and shading devices with similar projected lengths.Tilted façades can be most effective for all orientations except for the north.Also,tilted façades allow designers to use more glass without any additional energy consumption.Based on these results,a set of design guidelines for using tilted facades are proposed.Designers can not only utilize these guidelines to effectively adjust façade angle but also optimize the glazing size for the best energy performance.