Glazing Type Research Articles

The Impact of Glazing Types and Window-to-Wall Ratios on Energy Consumption in Semi-arid, Mediterranean and Arid Climates

A reduction in energy consumption and energy efficiency improvement in buildings have become one of the main objectives in national and international energy policies. In an optimization process, and in order to find the most influential parameters to achieve net zero energy, several ameliorations need to be made to residential buildings. In this paper, two measures are discussed; the effects of locally available glazing types and window-to-wall ratios, tested under three different Algerian climates; semi-arid, Mediterranean and arid-climate. For the purpose of calculating energy use intensity savings, optimal values and payback periods for each of the mentioned measures the building information modelling software Autodesk Revit® and the energy simulation plugin Sefaira have been used. According to the findings, double glazing with Argon has the greatest potential for lowering the energy use intensity, whereas the window-to-wall ratios has a significant effect on the energy consumption of buildings in the studied climates, and the optimal ratio for a given orientation varies according to the type of glazing used. Moreover, very high payback periods were found compared to other countries, and only a few studied variables could be achieved with profitability. This paper is helpful for professionals who are responsible for decision-making during the design process of energy-efficient residential buildings.

Energy Saving Opportunities through Glazing and Shading Alternatives

Windows are the weakest elements due to their high heat transfer coefficient and are responsible for 60% energy heat/gain loss. Healthcare buildings are one of the biggest consumers of energy due to continuous occupation hours and medical requirements, providing comfortable conditions for people in need of care and staff; yet recently less attention was given to healthcare buildings due to their unique operational requirements and advanced medical equipment. Thus, the main purpose of this study was to evaluate energy saving potentials of windows through glazing and shading alternatives over a case study. Within this study, a single patient room in Izmir Turkey has been chosen as a case study, and the room was simulated for sixteen scenarios generated by using four different glazing and shading systems. Each design scenario was simulated using DALEC for their lighting, heating, cooling, and total energy consumption. Results showed that lighting energy consumption constitutes the highest energy demand (up to 52%) and high transmitting glazing usage can reduce lighting loads. Finally, up to 16.3%, energy saving is possible only by changing shading and glazing types. Though there is a great diversity of glazing and shading types, this study’s outputs only reflect the selected four glazing and four shading system types that are offered by DALEC. Healthcare buildings spend a vast amount of energy to provide thermal and visual comfort for various user profiles. Considering the large number of patient rooms in healthcare facilities, only careful consideration of glazing or shadings can significantly contribute to energy savings. This study focuses on shading and glazing alternatives as an energy-saving strategy. For simulation, an underrecognized BES tool DALEC was hyped to show integrated thermal and visual energy consumption. The findings highlight that energy savings of up to 16.3% is possible.

ASSESSMENT OF THE 2016 THERMAL REGULATION FOR AN ALGERIAN BUILDING. CASE STUDY: IMPACT OF WINDOW TYPE, ORIENTATION AND OPENING RATIO ON ENERGY LOAD USING TRNSYS

Statement of the problem. The Algerian building sector is responsible for over 40 % of global final consumption and nearly 35 % of the total CO2 emissions. At the same time the energy demand from buildings continues to rise, for this reason in 2016 the Algerian government launched a new version of thermal regulation for buildings. This regulation replaces the thermal ones of 1997 and 2011 introducing more stringent measurement of thermal insulation in order to decrease the high consumption. Overall, this RT2016 aims at reducing the energy consumption in Algerian buildings. This version imposes the requirements for insulation of the envelope, heating and cooling demand, and windows configuration. The window performance is important to the energy consumption in the building; the façade openings have a great impact of the overall energy consumption. The present research investigates the effect of orientation and façades openness and glazing type on global energy consumption in an Algerian building with a different scenario by using TRNSYS software version 16. A series of simulations has been performed in order to establish the optimal window configuration in terms of area orientation and glazing type. This study aims to address the gap between the requirement in the thermal regulation version and the optimal case through a case study for an Algerian building. Results. The methodology is demonstrated by means of a building case. In the first case we calculated the energy demand for heating and cooling based on the window performance standards in the thermal regulation 2016, in the second one we defined the optimal window by TRNSYS simulation which corresponds to the best window design.

Assessment of Dynamic Photovoltaic Shading Systems on Energy Performance of Commercial Buildings

Abstract In this paper, the energy benefits of dynamic photovoltaic (PV)-integrated overhang systems are evaluated for office buildings. The benefits of dynamic PV-integrated overhangs combined energy efficiency by decreasing both heating and cooling energy demand and on-site renewable power generation by deploying tracking PV panels. The energy performance of dynamic PV-integrated overhangs is considered for various design and operation conditions. Specifically, the impacts of various design features are considered such as overhang depth, window size, glazing type, and heating, ventilation, and air conditioning (HVAC) system type. Moreover, the effects of operating conditions are assessed including the location of the building and the control strategy of the dynamic PV-integrated systems such as load-tracking, demand-tracking, and PV-tracking. The results of the various analyses indicate that the heating and cooling energy demands of the dynamic overhangs are mostly affected by the window glazing type and window overhang depths. The analysis shows that the use of demand-tracking maximizes the energy performance of the dynamic PV-integrated overhangs when deployed to US office buildings.

On the tradeoffs between embodied and operational carbon in building envelope design: The impact of local climates and energy grids

The building envelope has a substantial influence on a building’s life cycle operational and embodied carbon emissions. Window-to-wall ratios, wall assemblies, shading and glazing types, have been shown to have a significant impact on total emissions. This paper provides building designers, owners, and policy makers with actionable guidance and a prioritization framework for establishing co-optimized lifecycle carbon performance of facade assembly components in a broad spectrum of climate contexts and energy carbon intensities. A large parametric study of building envelopes is conducted using building performance simulation and cradle-to-gate embodied carbon calculations in 6 US cities. The authors derive the total carbon emissions optimization for commercial office and residential space types using standard code-reference models and open-source lifecycle data. Comparisons between optimal total carbon solutions and (i) optimal operational carbon and (ii) minimum required assemblies, show the impact of under and over investing in envelope-related efficiency measures for each climate. Results show how the relationship between embodied and operational carbon is highly localized, that optimal design variables can vary significantly. In low carbon intensity energy grids, over investment in envelope embodied carbon can exceed as 10 kgCO2e/m2, while under investment in high carbon intensity grids can be higher than 150 kgCO2e/m2.

Optimization of energy transmittance through building envelope for hot dry climate

Fenestrations of the buildings are playing an important role in the building’s energy efficiency for the tropical climate. The energy that comes from the glass window into the building can be restricted by providing shading on the windows. So, to provide the shading on the window, the most common way is fixed shade like overhang and fin. Shading devices are very helpful to control the SHGC and light transmittance through the fenestrations of the building. Most of the studies analyze the impact of WWR, shadings, and SHGC on a building’s energy demand but did not consider the combined effect of these parameters. By considering all the parameters of the building envelope in the analysis like WWR, orientation, shading devices, projection factor, and type of glass, the energy demand in the building can be significantly reduced. The goal of this paper is to analyze the variation of residential envelope transmittance value with the window-wall ratio, projection factor, and fixed shading devices and also to optimize the energy from building envelope elements in residential buildings using a statistical method, namely the Taguchi method. The transmittance of energy through the building envelope is calculated in 8 cardinal directions by providing shading with the fin and overhang. Based on the result, the optimum energy saving achieved by selecting the optimum combination of the process parameters for minimizing the energy from the building envelope is A1B1C3D2 i.e. window to wall ratio 7%, triple glazing type of glass used, shading with the overhang fin, and orientation in the west direction. The result shows the most significant factor among the selected parameter is the window to wall ratio. Also, by focusing on the building envelope parameters, an architectural designer may reduce the building energy demand significantly and offer more alternatives to achieve energy-efficient buildings.

Identifying relative importance of solar design determinants on office building façade for cooling loads and thermal comfort in hot-humid climates

Solar radiation makes great influence on cooling load and occupants’ well-being in hot and humid climate zone. Particularly, occupants suffered different extent of solar radiation owing to their positions; thus, assessing the spatial and temporal thermal comfort is essential. It is worthwhile to identify the relative importance of passive solar design parameters for building envelope that these parameters directly affect thermal comfort and energy use. This study confirmed the distribution frequency of cooling loads and temporal thermal comfort usability of the simulation cases in selected cities based on the MRT algorithm that considered the impact of solar radiation. Based on the results, sensitivity analysis was used to analyze the relative importance of passive solar design parameters to clarify the priority when drawing up the façade design strategies. Eventually, correlation among facade parameters, energy use, thermal comfort, and geographic location is revealed. Furthermore, the improvement potential for energy-saving and thermal comfort by adjusting the variables in specific ranges is also demonstrated. The results indicated that within all selected cities, adjusting glazing type makes greatest influence on improvement potential that ranges from 22.8% to 39.5% in annual cooling load and 58.6%–87.5% in temporal thermal comfort usability, whereas the improvement potential for orientation is weaker than other parameters. Moreover, the absolute effect of solar design determinants is also disclosed respectively to discuss the importance of each parameter. Comprehensively, the proposed findings are expected to act as instruction when formulating the passive building envelope design related to solar radiation.

Energy Optimization for Fenestration Design: Evidence-Based Retrofitting Solution for Office Buildings in the UAE

With the prevalent use of large glazings, particularly in office buildings, offices receive an abundance of light and are among the largest consumers of electricity. Moreover, in an extreme hot arid climate such as in the UAE, achieving comfortable daylighting levels without increasing solar heat gain is a challenge, in which the window or fenestration design plays an essential role. This research adopts a case study of a higher education (HE) office building on the United Arab Emirates University (UAEU) campus, selected to investigate an evidence-based retrofitting solution for the west façade that can be applied in existing office buildings in the UAE in order to reduce cooling energy load as well as enhance indoor environmental quality. To achieve an evidence-based retrofitting solution, the research design built upon a comprehensive exploratory investigation that included indoor environmental quality physical monitoring and occupant satisfaction surveying. Model simulation was performed by means of DesignBuilder software to perform a single- and multiparameter sensitivity analysis for three key passive window design parameters, i.e., window-to-wall ratio, glazing type, and external shading, aimed towards minimizing annual cooling load and solar heat gain, while maintaining appropriate indoor daylight illuminance levels. The results highlight the importance of the window-to-wall ratio (WWR), as it is the single most significant parameter effecting total energy consumption and daylighting levels. The results recommend 20–30% WWR as the optimum range in the west façade. However, by utilizing high performance glazing types and external shading, equal energy savings can be achieved with a larger WWR. Double Low E tinted glazing and 0.4 projection shading overhang and side fin revealed a noteworthy reduction of energy use intensity of 14%. The study concludes with final retrofitting solutions and design recommendations that aim to contribute validated knowledge towards enhancing window performance in a hot arid climate to guide architects and stakeholders to apply a range of passive parameters towards reducing energy consumption and improving occupant comfort in office buildings.

Evaluation and Simulation of the Effect of the Types of Glazing and the Choice of Materials on the Energy Efficiency of a Building

Tunisia is one of the pioneering developing countries in terms of energyefficiency policy initiated since the mid-1980s. Indeed, energy efficiencyhas become one of the main pillars of the country’s energy strategy,especially with the increase in energy prices. The main objective of thiswork is to give an idea of the impact that certain choices made during thedesign of a building can have on its energy balance, namely the orientationof the facades, the types of glazing and their surfaces, the choice ofmaterials, etc. The calculation of the building’s energy requirement wasdetermined using the transient systems simulation program TRNSYS(version 18) with a modular structure.

A Guideline for Developing Resilient Office Buildings using Nanotechnology Applications

Resilient buildings have become a widely researched topic in the engineering discipline. A building has enabled connectivity between building systems, including air conditioning, ventilation, safety and security system. They are even more important with growing pandemic risks and the spread of airborne viruses such as Covid-19. The literature indicates that nanotechnology applications can have a great role in the designing resilient office buildings. Nanotechnologies play a major role in architectural design; building materials combined with nanotechnology became smaller, lighter, and more efficient than conventional materials. Thus, this research aims to develop design guidelines for resilient office buildings in Egypt using nanotechnology applications. The methodology applied includes a review on nanotechnology and resilient office buildings key design features, following a simulation using design builder program where conducted to modify the nanomaterials in resilient office buildings recorded through quantified data. After applying the nanotechnology concept on walls, the roof and glazing types by inserting nanomaterials. The research concluded that the use of vacuum insulation panel, Nano-gel glass and Nano-painting had the highest impact on decreasing the total energy consumption by 14.5% and carbon dioxide emissions by 42%.

Integrated energy, daylighting, comfort and environmental performance analysis of window systems in patient rooms

This study investigates the influence of window system configurations on the energy use/cost, access to daylight and view, visual comfort and environmental performance in a one-bed hospital patient room located in a temperate climate. The methodology combines dynamic energy simulations, visual comfort and daylight analysis in a life cycle assessment study of window systems, covering a wide range of environmental indicators. In this study, multi-criteria evaluation approach is used to analyse the different design alternatives. A graphical optimization method was elaborated to filter the solutions and select the most appropriate window design based on project objectives and architectural preferences. The results show that glazing with ‘0.30 < g-values≤0.50’ and ‘0.50 < Tvis < 0.75’ have lower energy use and/or cost, lower environmental impacts while maintaining sufficient daylight levels (sDA > 55%) and showing higher quality for visual comfort. These type of glazing allows for using bigger windows which leads to a higher percentage of the outside view.

Evaluation and Simulation of the Effect of the Types of Glazing and the Choice of Materials on the Energy Efficiency of a Building

Tunisia is one of the pioneering developing countries in terms of energyefficiency policy initiated since the mid-1980s. Indeed, energy efficiencyhas become one of the main pillars of the country’s energy strategy,especially with the increase in energy prices. The main objective of thiswork is to give an idea of the impact that certain choices made during thedesign of a building can have on its energy balance, namely the orientationof the facades, the types of glazing and their surfaces, the choice ofmaterials, etc. The calculation of the building’s energy requirement wasdetermined using the transient systems simulation program TRNSYS(version 18) with a modular structure.

Experimental Investigation of Thermal Bridges and Heat Transfer through Window Frame Elements at Achieving Energy Saving

Windows are responsible for significant amounts of energy loss through typical building envelopes. There have been multiple studies on heat loss through the glazing unit and frame system. This study presents an experimental investigation of a window unit and focuses specifically on the conductance between the structural elements and the frame system of a conventional house in the city of Xanthi, northern Greece. It is obvious that even a perfect window system cannot reduce heat transfer between the base of the frame and the upper surface of the floor. The experimental and simulation procedure of this project includes the installation of an insulating layer in front of the window unit for a variety of frames (solid wood, aluminum, PVC, etc.) at different distances. The main objective of this paper is to determine how effective an insulating barrier can be in respect to different types of frame, glazing, and weather conditions for the control of heat loss. Through the application of this technique, in combination with an appropriate insulating frame and window unit, designers can control the temperature inside the room at close proximity to the windows, in order to contribute to energy saving, aiming towards a building with zero energy demand.

Advantageous optical characteristics of tantalum vanadium oxide as counter electrode in electrochromic devices

Smart windows are an important technology in terms of energy saving potential in the building sector due to their ability to control visible light and thermal radiation. The essential component of this type of window glazing is an electrochromic thin film. In addition to the widely established tungsten oxide as the optically active material, in particular the counter electrode offers significant potential for improving the overall device performance. In this study, tantalum vanadium oxide films are prepared by reactive radio-frequency sputtering on fluorine-doped tin oxide substrates and optimized in terms of their spectro-electrochemical properties as ion storage layer. We show that an oxide-based tantalum-vanadium alloy is a promising approach to address the open challenges of pure vanadium pentoxide. The coatings exhibit color neutrality in combination with a high transmittance of up to 80% in the as-prepared state and suitable optical transmittance switching. Additionally, we find both a sufficient stability upon cycling and a suitable charge density of about 35 mC cm−2. Thus, the presented oxide-based alloy offers a beneficial performance as an ion storage layer in electrochromic devices.

PCM-enhanced sunspace for energy efficiency and CO2 mitigation in a house in mediterranean climate

In this study, a phase change material (PCM) was integrated to a partition wall between the sunspace and the room of a detached house to reduce energy use. To find the optimal sunspace configuration, various phase transition temperatures, glazing types, and locations of PCM in the partition wall and the presence of active shading were evaluated in terms of energy saving and consumption in Mediterranean climate. Furthermore, economic and CO2 emission analyses were conducted to reveal potential savings for the optimal sunspace-PCM design. The optimal phase transition temperature was found as 27 °C for cooling and 21 °C for heating application, regardless of the location of the PCM in the wall. A glass with low U-value and high SHGC was beneficial in winter, whereas a glass with high U-value and low SHGC was appropriate in summer. Not using an active shading device in summer increased energy consumption, but the negative effect was compensated by effective exploitation of the latent heat content of the PCM. In the yearly energy analysis, the optimal phase transition temperature was 27 °C and the PCM was located at the front of the partition wall. A glazing type with high SHGC and high U-value (SG-1), or low SHGC and low U-value (TG-2) was recommended to minimize the annual energy demand. A reduction in CO2 emissions of 98 kg was achieved with the optimal configuration compared to a case without sunspace.

A Comparative Energy Analysis of Dynamic External Shadings for Office Buildings

Abstract In this paper, the energy performance of dynamic instead of static shading devices is investigated for prototypical US office spaces. Specifically, six dynamic shading systems are considered to assess their ability to reduce heating and cooling thermal loads, total building energy use, and electrical peak demand. The most promising dynamic shading is the rotating overhang and is evaluated further using a wide range of design and operation conditions. It is found that rotating overhangs can provide effective and easily controllable dynamic shading systems for windows to reduce the energy consumption of US office buildings by up to 39% especially for mild US climates. Moreover, the rotating overhangs have the added benefit to support PV panels for on-site electricity generation. A series of sensitivity analysis results indicate that the performance of the dynamic external shading systems depends on its depth and orientation, the location climate, the window size, and the glazing type have significant impacts. For instance, the dynamic shading device can reduce annual heating and cooling energy end-use for an office space located in Boulder, CO, compared to no shading case by 19% for a window-to-wall ratio (WWR) of 15% and by 31% for a WWR of 30%.

An evaluation of the glazing type impact on building energy performance through a building simulation

Buildings are responsible for most of the energy consumption in countries, thence energy saving in buildings is a high priority issue. Windows and glazing types are one of the factors that greatly affect the performance of buildings, both in terms of thermal comfort and energy consumption for heating or cooling. The proper selection of window glazing is one of the effective strategies to minimize energy consumption. In this study, an office building was designed to determine the most suitable glazing type for office buildings, which is the main purpose, and the energy efficiency of the building was examined with Openstudio and Energyplus software. Energy modeling of the office building was conducted for four different types of glazing by using VRF systems for air-conditioning and a dedicated outdoor air system for ventilation. The effect of different windows glazing system properties on the energy performance and total energy need was calculated by considering the fixed indoor thermal and visual comfort conditions were evaluated. The study results indicated that energy consumption can reduce about 24.88 kBtu/ft2 (25%) using suitable glazing material.

Glaze characterization of the glazed pottery from the medieval workshop of Vega (Burgos, Spain)

AbstractSixteen glazes on medieval (14th–16th century AD) pottery fragments from Vega pottery workshop (Burgos, Spain) were characterized to investigate the production technology. To this end, Raman spectroscopy and scanning electron microscopy coupled with energy dispersive X‐ray spectroscopy (SEM‐EDX) were used. The studied glaze samples correspond to fragments of high‐quality glazed ware used by the wealthiest society in the city of Burgos. The most representative types of glazes, corresponding to honey‐marble, honey‐yellow, bright light green, and dark green types, were analysed. Raman spectroscopy shows lead was used as a fluxing agent in glaze production. SEM‐EDX analysis confirms the use of lead oxide and evidences that most of the samples underwent at least two firing processes. No Raman signals of crystalline phases were detected on either glaze surfaces or glaze thin‐sections. The exception is the single firing of dark green glazes, which show pseudobrookite and rutile at the clay body/glaze interface measured in thin section. No colouring crystalline phases were identified by Raman spectroscopy either. However, SEM‐EDX shows iron was the most‐used colouring agent whereas copper was used for bright light green glazes. The polymerization index (Ip) values were used to estimate the firing temperatures. The polymerization index values are typically low for lead glazes and indicate firing temperatures below 700°C.

Indoor Built Environments Attended by Primary School Children and Its Microbiology: A Cross-Project Study

Exposure to indoor pollutants may exert a significant effect on children health as they spend most of their time in enclosed environments. This research compared the association of biological concentrations with indoor characteristics and building materials in places where children spend significant time indoors. It was compared the results of two autonomous research projects conducted in Porto primary schools and households. Both the projects included a walkthrough inspection and biological measurements in indoor environments in primary school classrooms and home bedrooms, respectively. Floor covering material was the major building characteristic associated with fungal concentrations. In addition, significant associations were observed between the heating system and Fusarium sp. and the type of glazing and Fumigatus sp. A comparison of the results between the two projects demonstrated similarities in the association of microbial concentrations with building materials, particularly with the floor type. This demonstrated that specific building materials could be a source of exposure to indoor pollutants. The influence of building materials on indoor air quality (IAQ) should be considered using building codes. When performing building retrofitting, professionals should be aware of the nexus between building materials-energy-IAQ-health, which, if not properly managed, could negate the efforts of meeting climate and related sustainable development goals.

Thermal Performance and Optimizing of Composite Trombe Wall with Temperature-Controlled DC Fan in Winter

This paper discusses an improved approach to the Trombe wall: an insulated panel is installed on the inner side, and vents are installed at the top and bottom to connect the outer and inner air layer with the interior. Direct current (DC) fans are installed in the upper vents for stable control of the air circulation. The study first analyzed the thermal performance of this composite Trombe wall, for which the heat load was 27.3% less compared to the classic Trombe wall and 32.1% less compared to the case without the Trombe wall. However, its efficiency for heating the room temperature was not high without heating. Then, we optimized the ventilation efficiency, the proportion of the Trombe wall in the room, and the type of glazing. The highest heat load savings could be achieved when the ventilation openings used high ventilation with temperature-controlled fans and the Trombe wall about 3% of the house floor area. With the use of Low-e double-glazing, we were able to save nearly 41.3% of the heat load than that with the regular single-glazing. For the composite Trombe wall, after taking into account the optimization factors, the room temperature was significantly higher, and could save nearly 52.3% of energy compared to the pre-optimization period.