Glazing Type Research Articles

THERMAL AND ECONOMIC ANALYSES OF DIFFERENT GLAZING SYSTEMS FOR A COMMERCIAL BUILDING IN VARIOUS MOROCCAN CLIMATES

The windows are considered the most sensitive part against external conditions in the building envelope. A suitable window selection reduces the energy requirements of a given building in a given climate. This article presents a parametric study of annual heating and cooling requirements for a commercial building, depending on the type and size of glazing in different climatic regions in Morocco. The study was carried out for six climatic zones: Agadir, Errachidia, Fez, Ifrane, Marrakech, and Tangier. Seven types of windows were studied, including single-glazing, double-glazing, and triple-glazing with inert gases in the cavity. The results obtained using the TRNSYS software show that the energy savings depend on the window type and size and also on the climatic conditions of the place. It is demonstrated that with triple-glazing with xenon, energy savings can reach more than 90% with a window/wall ratio of 90% in all climatic zones. Related payback periods were found to be between 4.4 and 7 years. Furthermore, the optimization of windows ratio and type can induce significant energy savings, but strongly rely on the investment cost of glazing materials.

The introduction of the tin opacified glaze technique in Switzerland at the end of the 15th century CE – A SEM study of stove tiles from the canton Bern

Late 15th century tin glazed stove tile fragments from Bern, Fraubrunnen and Nidau are among the oldest witnesses of this advanced glaze technique in Switzerland and coexist with traditional lead glazed tiles. On a single tile, both glazes can also occur (two-glaze technique). In this SEM-BSE and -EDS study, bodies, slips and glazes of 14 tin and 2 lead glazed tiles were examined in order to constrain the raw material sources, the recipes, the application technique and the firing parameters. Mostly all ceramic bodies are of the traditional low Ca type. With the exception of two samples, they all have a slip that either belongs to the traditional quartz-rich, CaO-poor and SiO2-rich type I or a new CaO-rich type II. The latter is the earliest known use (so far) in tin-glazed stoves from Switzerland. Slip I can be found under both glazes, slip II only under tin glazes. Uncovered or slip covered bodies were biscuit fired before glazing. Firing temperatures were mostly in the range 950–1050 °C. Important chemical exchanges between the liquid glazes took place during firing. The lead glazes digested minerals of the latter, while lead infiltrated the porous ceramic substrate. The transparent monochromatic lead glazes are green with Cu, or yellow and brown, depending on the Fe content and the presence or absence of a slip. The opaque tin glazes have SnO2 concentrations of 6–17 mass%. Objects with two-glaze technique show 4 of the 6 possible combinations of slip and glaze types. This indicates that the potters did not follow a unique (new) recipe, but tried many mix of old and new techniques.

Influence of sunspace on energy consumption of rural residential buildings

In this work, a detailed investigation is carried out to evaluate the effects of using sunspace on heating energy consumption of a rural house by considering utilized sunspace glazing type, the filling gas type and the gas layer thickness. In the first part of the study, the effect of a sunspace on the energy consumption of a typical rural building located in a severe cold region of China is investigated. The results showed that the sunspace having single pane reduces the energy consumption by about 4.6% with respect to the reference building considering the coldest month, January. In addition, sunspace with double glazed unit is investigated and compared with the singleglazed. It is observed that a larger amount of energy (11.3%) is saved compared to the reference building in January, and the optimum air layer thickness of double glazed sunspace is determined as 12 mm. In the second part, different filling gasses (air, argon and krypton) are taken into account to optimize the gas layer thickness with respect to filling gas. It is found that the thickness of gas layer resulting in the minimum energy consumption significantly depends on the type of filling gas. The optimum gas layer thickness values are found as 12, 15 and 9 mm for air, argon and krypton, respectively. It is concluded that the sunspace with 9 mm thickness of double glazed unit filled with krypton can be suggested for the highest energy saving. Also, the results revealed the importance of comprehensive analyses on sunspaces regarding various parameters.

Effect of window-to-wall-area ratio on thermal performance of building wall materials in Elazığ, Turkey.

In this study, the effect of glazing-to-total-wall-area ratio on the thermal performance of different wall materials is numerically investigated in terms of heat transmission load. The investigation was performed for a South-facing wall in Elazığ, Turkey. The heat transmission load through walls and windows are determined separately for summer and winter climate conditions. In this analysis, the frame area of the window is not considered. Therefore, whereas the glazing area on uninsulated and insulated walls is increased from 0% to 100%, the heat gain and losses are calculated separately according to the glazing type. The transmission loads through the wall are determined by an implicit finite difference procedure under steady periodic conditions. Concrete, briquettes, bricks, and autoclaved aerated concrete are selected as structure materials. Results show that in the uninsulated wall, the wall material affected the glazing area, whereas in the insulated wall, the effect of wall material on glazing area is insignificant.

BIM-based techno-economic assessment of energy retrofitting residential buildings in hot humid climate

Buildings in hot humid climates are energy intensive to operate. Energy consumption in Saudi Arabia is almost three times higher than the global average, and one of the major contributors to that is the residential sector. Increasing environmental and economic concerns, in the form of Saudi Vision 2030, mean that the existing unsustainable residential building stock has to be energy retrofitted. This study examines the techno-economic feasibility of retrofitting existing homes in Eastern Province, Saudi Arabia. A Building Information Modelling (BIM)-based retrofit framework has been adopted and investigated on two case studies. Eight Energy Efficiency Measures (EEMs) have been implemented including increasing cooling set point temperature, using energy efficient appliances, replacing conventional lights with more efficient lights, applying window shading, improving glazing type, improving air tightness, using more efficient air conditioning system, and adding envelope insulation. A three-level energy retrofit plan is proposed. Results indicate that annual energy consumption in a villa is reduced by 13.79%, 19.27% and 56.9%, and in the apartment building by 22.84%, 28.85% and 58.5% through a level 1, 2 and 3 retrofit respectively. Compound Payback Period (CPP) was computed to assess the economic viability. For the villa, investing in a level 1, 2 and 3 retrofit will pay back in 0.92, 8.37 and 25.15 years respectively, while for the apartment building, the payback period is 0.60, 11.28 and 24.60 years respectively. Thus, energy retrofitting of existing homes has the potential to significantly reduce energy consumption, however, it is economically not viable in the existing scenario. Electricity tariffs need to be further increased and coupled with incentive programs to render deep energy retrofits feasible. Furthermore, the investigated BIM-based approach can be adopted to investigate energy retrofitting in other climate zones of Saudi Arabia and other countries in the region, and eventually be adopted to efficiently effectuate the colossal task of retrofitting the whole existing residential building stocks of these countries.

O elemento janela versus desempenho e conforto térmico: uma sistematização de literatura

Em 2050 o mundo terá quase 10 bilhões de pessoas e o comprometimento dos limites ecológicos será um problema. O objetivo do artigo foi identificar quais são as características da janela mais abordadas na produção científica internacional, com ênfase na obtenção do desempenho energético da edificação e o conforto térmico. Foram utilizados dados bibliográficos indexados nas bases de dados Scopus, Web of Science e Science Direct. Os procedimentos metodológicos definiram os critérios para a escolha das bases de dados eletrônicas, as estratégias de pesquisa e definição dos descritores de busca e identificaram os parâmetros de relevância dos procedimentos para análise do conteúdo e sua sistematização. As informações obtidas resultaram em 744 artigos relacionados ao objeto de estudo. Para melhor organização dos resultados, a classificação do conteúdo pesquisado foi dividida em duas categorias: os elementos e posicionamento da janela; e os fatores que influenciam no desempenho da edificação. Os resultados mostraram que, dentre os elementos, o tipo de envidraçamento das janelas é o assunto mais estudado, já entre os fatores, o consumo de energia lidera. Tem-se a China como principal país pesquisador sobre o assunto, tendo o Brasil ficado com a 17ª posição. O ano de 2017 apresentou o maior número de publicações.

Effect of Smart Glazing Window on Energy Consumption inside Office Building

The office buildings in Egypt, especially in Upper Egypt, reflect serious problems in achieving for energy efficiency as a result of increasing the use of mechanical refrigeration devices in office rooms, due to solar radiation and rising summer temperatures in recent years. Smart windows can play an important role in reducing significantly the energy consumption and maintaining energy inside buildings, also helps to control incoming solar radiation in order to minimize solar gain, especially in summer as well as ensuring the best natural lighting conditions without glare inside a room. This paper aims to evaluate the most efficient daylight and thermal performance of various types of the smart glazing and its impact on the energy consumption in the climatic conditions of one of the office buildings (Diwan governorate) in Sohag governorate as one of Upper Egypt governorates, with determining the best smart glass types for efficient use of energy. The paper follows the theoretical, applied, by studying types of smart glazing and their relation to achieving the energy efficiency. Then using (Energy Plus) simulation tool, which has been used in utilizing its modeling orientation (Design Builder) to study using types of smart glazing on the model of an office room in Building of Diwan governorate of Sohag in the four different orientations (North, East, South and West), when window-to-floor ratios (WFRs) (8%, 16%, 24% and 32%). The paper ends with a presentation of the most important results, recommendations and determination the best types of smart glass that provides energy, daylight without glare and providing greater comfort to users.

Optimization of envelope design for housing in hot climates using a genetic algorithm (GA) computational approach

Little attention has been given to the use of optimization approach in the envelope design of thermally-massive structures in extreme hot climates. In addition, limited studies are reported to compare the optimal envelope design with those stipulated in standards and codes, considering the 3Es: energy, economic and environment. This study employs a computational approach for optimizing envelope design for housing in hot climates using a genetic algorithm (GA) technique, and a life cycle cost (LCC) analysis coupled with the EnergyPlus simulation program. A sensitivity analysis was performed using a verified housing model to determine the upper and lower limits of the optimization search domain. Several envelope design strategies were evaluated including walls and roof insulation, thermal mass, air tightness, window's areas, types of glazing, and window's shading. The optimization was then conducted for the subsidized and unsubsidized energy cost scenarios under three representative hot climates of Oman. The results indicated that window's shading is thermally and economically attractive across all climates. Depending on the energy cost scenario, 2.5 cm–5 cm more of thermal insulation is cost-optimal for envelope systems in hot climates when compared to warm-humid climate. The optimized cases were then compared to design cases following four prevalent regional thermal regulations; the Saudi code, the Estidama requirements, the Kuwaiti code, and the Gulf Cooperation Council (GCC) thermal regulations. Similar to the cost-optimal design, the GCC design case is proven to be economically attractive across all climates. With the exception of the warm-humid climate, other code-compliant design cases are economically feasible, provide more energy savings and have less impact on the environment for the hot climates. The government may provide rebates or incentives by redirecting the subsidy fund to promote these requirements.

Assessment of energy saving in residential buildings using energy efficiency measures under Cairo climatic conditions

This paper investigates the residential building energy needs in Egypt. Firstly, the energy needs of residential building are evaluated in compliance with Energy Efficiency Residential Building Code as a base case. Then, Energy Efficiency Measures (EEMs) defined as measures that reduce energy consumption whilst maintaining the same or better indoor climate conditions are implemented as a modified case using building simulation technique. The considered EEMs include adding thermal insulation to the exterior walls, adding external shading, using lighting fixture with high efficacy and using window glazing type with high thermal and radiation characteristic. Finally, a comparison between the base and modified cases is made.The reported results showed that the thermal cooling demand, heating demand and total electricity demand of the base case are 130 kWh/m2.a, 6.5 kWh/m2a and 114 kWh/m2.a, respectively. It is found that as the overall heat transfer coefficient of external wall decreases from 1.7 W/m2K to 0.58W/m2K causes the cooling and heating demands to decrease by 7% and 60%, respectively. Adding shading with a projection factor of 0.9 for all external windows decreases the cooling demands by 13%. Using double glazing decreases the cooling and heating demands by 14% and 30%, respectively. Installing LED lighting type reduces the annual space cooling demand and electricity consumption by 17% and 26%, respectively. The values of each EEM which are the lowest energy needs, combining to get the optimized case in which the cooling demand, total electricity and the heating demand decrease by 34%, 17% and 11% respectively.

Use of Local Omani Clays with Low and Mid-Range Temperature Glazes for Art Educational Purposes: Possibilities and Limitations

In this study, red clays, the main industrial material of the Alanwar Ceramic Tiles Plant (ACTP) in Oman, were investigated for use in making glazed ceramics in local educational institutions. Different low and mid-range temperature glazes, which contained various compositions and properties, were examined in the glazing lab at Sultan Qaboos University. The study’s aims were to develop and test low- and mid-range temperature glazes to explore if they could fit the red clays used by ACTP, so that the surface could be adhesively bonded. The laboratory glazes were obtained following technical rules to confirm the possibility of using different types of glazes on ACTP clays in Omani schools and universities. This could help reduce the cost of importing clays from overseas to use in Omani education institutions.

The Energy Saving Potential of Wide Windows in Hospital Patient Rooms, Optimizing the Type of Glazing and Lighting Control Strategy under Different Climatic Conditions

If not properly designed, the adoption of large windows can sometimes have a negative impact on building energy demand. For this reason, aggravated by the outdated building envelope of the healthcare building stock, large fenestration systems are usually avoided in hospitals, especially in old structures. However, with appropriate glazing specifications, the adoption of wider openings can result into significant energy savings, lower costs and strong positive effects on patients and staff well-being. The present study investigates how different window sizes and types of glazing affect heating, cooling and lighting energy demand in a hospital patient room. The objective is to evaluate the energy savings that may be obtained when installing larger windows and to identify the glazing properties allowing one to reach the maximum energy reductions. Simulations were carried out using nine diverse glazing systems, already available on the market, and their energy performance was evaluated in relation to two different window areas: a common size opening, characterized by a 25% Window-to-Wall Ratio (WWR), and a floor to ceiling window, with 77% WWR. The analysis was conducted taking into consideration four different orientations in four Italian cities, supposing two artificial lighting control strategies. The results highlighted how the adoption of wider windows with appropriate glazings and a daylight-linked dimming lighting control strategy may lower the primary energy demand up to 17%.

Energy savings and daylighting evaluation of dynamic venetian blinds and lighting through full-scale experimental testing

Commercial buildings consume around 20% of the total energy utilized in the U.S. The use of shading devices in buildings has the potential to reduce building energy consumption while also providing a more desirable indoor environment for building occupants. Similarly, lighting device controls help reduce lighting energy consumption as well as internal loads. However, there is lack of full-scale experimental testing of integrated dynamic shading and lighting controls. This study presents full-scale experimental testing data to quantify these energy and daylighting impacts. Testing was performed utilizing two different control strategies, in three different orientations under three different types of sky conditions. The shading device was also used in conjunction with two different types of glazing. An average of 25.4% cooling energy savings and 48.5% lighting energy savings was achieved. Visual discomfort evaluated using Simplified Daylight Glare Probability was prevented more than 85% of time during occupied hours. Improvement in daylight levels evaluated using Useful Daylight Illuminance was also achieved. Finally, analysis of the relationship between the illuminance level measured at the work plane and a ceiling illuminance sensor is performed to translate the real-world applicability of shading device controls.

Impact of glazing area on the thermal performance of buildings

In this paper, the impact of glazing area on the thermal performance of buildings is numerically investigated by considering orientation, wall insulation and type of glazing. The investigation is carried out for all months of the year in the climatic conditions of Elazığ, Turkey. Firstly, the transmission loads through the wall are calculated using an implicit finite difference method. Secondly, the transmission loads through the window glass are also calculated for single and double glass. Then, while the glazing area percentage (GAP) is increased from %0 to %100, the transmission loads are determined according to the type of glazing for uninsulated and insulated walls. It is seen that in single glazing, as GAP increases, the heating and cooling transmission loads increase for all wall orientations. The results show that double glazing provides a significant reduction in especially the heating load for all building orientations when compared to single glazing.

Providing an Optimal Execution Model for Windows Based on Glazing to Reduce Fossil Fuel Consumption (Case Study: Asman Residential Complex of Tabriz)

According to statistics provided by the Iranian Statistics Center,40% of energy consumption is related to the housing sector. Windows as a component of exterior wall, Responsible for 20-30% of all energy infiltration. Therefore, the purpose of this study, is to optimize residential windows in cold and dry climate of Tabriz in order to reduce energy consumption. The research method is based on simulation with two methods parametric optimization and genetic algorithm. The research tool is Design Builder software. So, the amount of annual gas consumption in the case study was received from the National Iranian Gas Company and then the basic research model is modeled in software and after converting the unit from kWh to m3 and validating the obtained results from simulation, in the next step, the type of glazing and frame are changed and then the sensitivity is analyzed by the two mentioned methods. The results showed that by replacing windows with triple glazed-glazing with low emission coating filled with argon, krypton and xenon gas and UPVC frame with clear double glazed-glazing filled with argon gas and iron frame, annual gas consumption for heating decreased by 52.43%, 55.34% and 56.60% and the heat loss from the windows is reduced by 7.97%, 9.54% and 10.49%, respectively.

Using smart glazing for reducing energy consumption on existing office building in hot dry climate

ABSTRACT Office buildings in Upper Egypt suffer from high temperature in summer due to solar radiation of this extreme hot arid climatic region. The effect of smart glass on reducing energy consumption in office buildings is well studied in temperature climates but rarely addressed for this Region. This paper aims to compare different types of glazing to define which achieves a better balance between reducing cooling energy consumption and daylight saving. Six types of glazing were simulated on the main office building of Sohag governorate – Egypt. The simulation was carried out for all orientations. Energy Plus-Design Builder simulation tool has been used to study the effect of smart glass on increasing energy efficiency. The window area-to-floor ratio was 8%, 16%, 24% and 32%. Simulation results show that smart glazing is more effective than traditional windows. Electro-chromic glass achieved the best results in reducing cooling energy consumption for window area of 32%. Also, achieving a significant reduction in cooling loads up to 43% in East orientation, 46% in South orientation and 45% in West orientation. On the other hand, it reduced glare in the East and West orientation by 64%. And, it reduced consumption of lighting energy by 60%, 61% and 57% in East, South and West, respectively. The effect of Gaso-chromic was increased when the window area ratio increased to 32%. For window area 32%, Gaso-chromic achieved the results of light energy similar to Electro-chromic.

Glazed balconies and their influence on the temperature reduction factor during the heating season

Glazed buffer spaces have an important influence on the energy performance of buildings, especially in the case of dwellings located in multi-family buildings. The ability to utilize solar radiation during the heating season can be assessed with the use of the temperature reduction factor, expressing the relative temperature rise in the solar space above the outside air temperature. The paper is based on the results of the internal temperature monitoring in dwellings with glazed balconies of different envelope construction and airtightness. The dwellings were located in buildings in Lublin and Zamość, cities in the eastern part of Poland. The measurements took place from July 2017 until September 2018, and the temperature was recorded with the use of iButton sensors. The measurement results were supplemented with the weather data coming from the database of the Polish Institute of Meteorology and Water Management. Thanks to the collected data it was possible to calculate the temperature reduction factor during the subsequent months of the heating season, and to check its relationship with the factors such as the balconies’ orientation, envelope construction and airtightness or the glazing type. The analyses also included the calculation of heat losses reduction achieved thanks to the solar spaces.

Mitigating CO2 Emissions of Academic Buildings in Pakistan Using Energy Conservation Techniques

Energy use data of the sample school was gathered from available records as well as measured using an in-house developed metering device that recorded the electric consumption data on hourly bases. Building energy simulations were also carried out using TRNSYS© software for validating and comparing the actual energy consumed and optimal energy consumption resulting from building energy simulation of the existing and re-designed building. The results highlighted that if the building had been designed with proper considerations for energy efficiency, up to 30% of energy could have been saved. The measurements and analysis indicated that other measures like the use of different types of window glazing, LED Lighting, efficient gas heating, and improvement in behavior pattern could also result in substantial energy savings. The maximum achievable savings can be as much as 50% of the energy cost of the school buildings. Additionally, once extrapolated over the entire school-going population of Pakistan the CO2 emission savings come out to be substantial, amounting to 3.07 M tonnes annually.

Influence of commercial glazing and wall colours on the resulting non-visual daylight conditions of an office

Daylight is ever more recognised as a major synchroniser of circadian rhythms, linking us to the 24 h solar day. However, the time that urbanised humans spend outdoors has decreased substantially during the last century, which highlights the importance of appropriate indoor daylighting. Quality and quantity of daylight in indoor environments are primarily modulated by the characteristics of the building envelope. In this context, a combined in-situ experimental (Ljubljana, Slovenia) and simulation study of a cellular office model was executed in order to evaluate the impact of different glazing types and internal wall colours on the non-visual potential of daylight. In particular, the impact of seven glazing types and six different wall cover hues at three reflectance levels was determined. Among these, three glazing types and three wall colours of equal reflectance were further evaluated through diurnal simulations of the indoor luminous environment. Low-e glazing with high visual transmittance and blue coloured wall were indicated as combinations with the highest non-visual entrainment, while the opposite is true for the combination of bronze tinted solar protective glazing and orange walls. In general, a better non-visual environment can be achieved using materials characterised by higher spectrally neutral transmissivity or reflectance than with those characterised by spectrally non-neutral properties and of lower transmissivity or reflectance.

The earliest glazed ceramics in Constantinople: A regional or international phenomenon?

This paper aims to stimulate research into the different classes of glazes applied to Byzantine ceramics in the fifth to late antique/early Christian centuries by pointing out that the Constantinopolitan Byzantine potters’ early experiments with alkaline-fluxed glazes have not previously been noted. As the techniques of lead and alkaline glazing were used in the east Mediterranean throughout the fourth to seventh centuries at monasteries in Egypt and Jordan, they were then likely to have been used also in Constantinople. The main subject of this paper is Byzantine ceramics, domestic and architectural, with both lead and alkaline glazes on the same objects. They fall into the classification, according to Byzantine terminology, of ‘Polychrome White Wares’, on account of their white fabric. It is suggested that although classifications to date of Polychrome Ware have concentrated on the colours or a combination of colour, shape, and fabric to reach chronological conclusions, it might be more fruitful to concentrate on the technology of the different glazes. From an examination of the available evidence a working hypothesis is presented, namely, Polychrome Wares with turquoise alkaline glazes should be dated before AD 900. It is proposed that the first step in advancing our knowledge of early productions of Polychrome Wares is to make glaze types the primary level of classification.

Weight determination of glazing properties for Trombe wall application in Johannesburg: An entropy method implementation

Glazing materials have been found to greatly influence the performance of trombe wall systems. this is due to its role in determining the quantity of thermal energy that reaches the massive wall. in this article, a multi-criteria decision-making analysis for proper glazing selection for trombe wall system was considered, the location of interest is johannesburg metropolis. four different glazing types and four criteria were considered using the entropy method for weight determination. the four criteria considered were the solar heat gain coefficient (shgc), the u-value, visible transmittance and cost respectively. the result showed that the u-value is of utmost importance vis-a-vis other performance criteria for the glazing material. decreasing order of weights assigned was as follows; 71.2% weight factor for the u-value, 16% weight factor to cost, 10.2% weight factor to shgc and 2.6% weight factor to the visible transmittance respectively.