Glazing Type Research Articles

Spectrophotometric Characterization of Simple Glazings for a Modular Façade

A large variety of transparent materials is available for uses in buildings façades and all glazing properties must be considered in their choice. Such a selection should be a careful process of evaluation and weighing of tradeoffs. The correct glazing specifications for façades can reduce energy consumption in buildings, because the heat exchange and passage of radiation into the building as light and heat occur through transparent surfaces. Therefore, glazing significantly contributes to the heat transfer between outdoor and indoor spaces, which act directly on daylighting and thermal comfort. This manuscript addresses a spectrophotometric characterization of glazings for the study of components for the design of a modular façade system based on the climate of Portugal. The study focused on results of spectrophotometric measurements of an optical behavior in different solar spectrum intervals (ultraviolet, visible and near infrared), specifically the transmittance of some types of simple glazings. The results show the percentage of transmission to spectrum intervals, which enabled the analysis (OK?) of the efficiency of the glazing regarding daylighting and correlation to the thermal performance. Indications for specifications and adequate uses based on transmission of transparent surfaces have been obtained and complemented the datasheets available from the manufactures.

Parametric study of a cost-optimal, energy efficient office building in Serbia

Recent building regulations in Serbia prescribe the design of highly insulated, airtight buildings with low U-value glazing. Serbia has continental climate with hot summers, so that for office buildings, whose internal gains are higher from the presence of people, computer systems and lighting, this means that far more focus has to be put on cooling demands than on heating demands. This shift toward cooling is studied here through exhaustive simulation of combinations of selected passive solar design parameters for a model of an office building in Belgrade. Design parameters include glazing type, window-to-wall ratio of façades, presence of exterior shading and U-value of opaque envelope components. Optimal variants of the model have been determined with respect to construction cost and heating, cooling and lighting energy use. Results reveal that exterior shading, which has to sustain occasional strong winds in Belgrade, is too expensive to appear in cost-optimal solutions. Hot summers of Belgrade climate imply that cost-optimal solutions have close-to-minimal window-to-wall ratio at the southern façade and significantly larger window-to-wall ratio at the northern façade. Results further show that glazing in cost-optimal solutions has to have small U-value and medium solar heat gain coefficient, although specific choices of optimal glazing type, as well as thermal insulation level, depend on future electricity prices. The case study is repeated for climates of Frankfurt and Stockholm as well, which yield similar results with respect to glazing type and the absence of exterior shading, but with different patterns of window-to-wall ratios at the southern and northern façades.

Glazed ware from here and there: Petrographic analysis of the technological transfer of glazing knowledge

The typical method employed to analyze glaze surfaces has been chemical analysis often by means of scanning electron microscopy, which provides visual information as well. However, glazes can also be examined petrographically and their features related directly to the paste of the ceramic body. The link between raw materials used for producing the pottery and glaze features can inform on the technological transfer of glazing knowledge. Two case studies, one from Medieval Egypt and the other from pre-Hispanic and early Colonial New Mexico, provided an opportunity to explore the adoption and adaptation of glaze technology by potters working in different areas. In the case of Medieval Egypt, the industrial setting of pottery production and the extensive exchange networks resulted in the accurate reproduction of various types of glazes on locally made pottery. On the other hand, glaze ware production at the household level in New Mexico shows a change in glaze paint appearance that probably relates to the use of different glazing raw materials and/or a lack of knowledge of the recipe by potters located outside the original area of manufacture. Thus, petrography can provide valuable information on the ways technological knowledge of glazing was acquired and modified as the idea spread.

An attempt to achieve efficient energy design for High-Income Houses in Egypt

Abstract Taking into consideration the economic status in Egypt in recent years, especially the investment sector will demonstrate the enormous increase in the residential buildings sector, which created massive energy consumption that never was in proportion with the growth in generated power in Egypt. As the residential sector consumes around 42.3% of the total energy used in Egypt, one of the main factors that waste that energy is artificial lighting and electric ventilation. Meanwhile, the architects who design those building never pay the enough attention to the energy in the design process. This paper tackles many strategies for the environmental control of building designs besides showing that now, it is essential to take into consideration energy performance efficiency and the compatibility of the building with the environment by optimizing the design of the building envelope elements such as a window to wall ratio (WWR), the glazing type. This paper will not cover the details of construction and structure, but it sheds light on many guidelines to help to raise the thermal and environmental quality of the envelope of the building. A computer-based simulation tool (Autodesk Ecotect) was used to measure current building energy and lighting performance in one of the modern cities like Madenaty city. By the end of this study, some of the characteristics of the building envelope will be concluded like the window wall ratio in the aim to reduce the energy waste in the case study, as well as the different criteria of designing process for residential buildings in Egypt in the near future.

Development of Decorative Ceramic Glaze from Palm Fiber Ash

Palm fiber ashes are the industrial waste which is abundantly available in Malaysia. In this study, palm fiber ash were used to produce decorative ceramic glaze. The content of minerals in the palm fiber ash were analyzed by using X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF), respectively. The formulations of glaze with different composition of raw materials were studied by adding different amount of calcium carbonate and feldspar. The glaze slurries then coated on ball clay body bisque which was obtained from Kg. Dengir and sintered at 1200 ° C for two hours.The glaze was characterized in term of its physical appearance such as type of glaze and colour. Both glossy and matte glaze produced by using different composition of glaze formulation. The presence of silica minerals (79 %) contributed to glossy surface to the glaze. It is clearly seen that the glossiness of glaze improved by increasing amount of feldspar. Feldspar acts as fluxing agent which form a glassy phase at lower temperature. In addition, the presence of small amount of iron oxide (2.2 wt.%) contributed to brown colour of glaze. An addition of calcium carbonate give effect to the colour of glaze, which change from brown to yellow colour as amount of CaCO3 increased. As a conclusion, the palm fibre ashes were highly suitable to supply abundant and cheap raw materials to produce decorative ceramic glaze.

Influence of Glazing Types on the Indoor Thermal Performance of Tropical High-Rise Residential Buildings

In tropical climates, the solar radiation absorption of glazed windows results in overheated indoor environments and increased cooling energy loads during daytime. Meanwhile, situations differ during nighttime. The present study focuses on the effects of glazing type on the indoor temperature in high-rise residential buildings in the hot and humid climate of Malaysia. The primary objective of this study is to assess the effects of six glazing types on the indoor air temperature of the base case room oriented toward the southwest with a Window Wall Ratio WWR of 45% under both ventilated and unventilated conditions. The effects during daytime and nighttime are investigated separately. A computerized simulation tool (Virtual Environment by Integrated Environmental Solutions) is used to conduct the investigation. Penang is selected as the empirical background location of a hot and humid climate. The study found that reflective double glazing exhibits lower indoor air temperature throughout the day regardless of the ventilation condition, with an optimum improvement of up to 107% and 14% in unventilated and ventilated rooms, respectively, compared with single clear glazing. The study recommends the use of reflective single or double glass in regions with a hot and humid climate similar to that of Malaysia.

Mitigation of light-induced damage on modern digital prints: Photographs and documents

This study is part of a larger research project dedicated to digital print preservation issues – the Digital Print Preservation Portal (DP3). This work quantifies the potential of glazing materials to mitigate different types of light-induced damage – colorant fade, paper yellowing, changes in paper gloss, and loss of optical brightening agent (OBA) function – that occur to digitally printed photographs and documents when on display. Prints were subjected to xenon lighting to simulate daylight through window glass in a series of arrangements: without glazing, with plain framing glass (soda-lime) in a sealed or unsealed package, and with UV blocking glass in a sealed or unsealed package. Sealed packages served the purpose of isolating the samples from atmospheric pollutants, known to contribute to the deterioration of certain print types. In this study, the use of UV-filtering glass protected prints from colorant fade, paper yellowing, and paper gloss change to an extent. Protection conveyed by plain glass was less comprehensive and less effective than UV glass. Neither type of glazing was able to keep the OBAs functional by the end of the light exposure. It was also seen that light-induced damage to digital prints is due not only to UV radiation, but also to visible light, and that different digital prints may be more vulnerable to one or the other. Protecting sensitive prints from UV radiation and budgeting the amount of light they may be exposed to should be essential to any print display policy in order to ensure longevity.

Determination of Glazing Material’s Influence on the Energy Performance of Office Buildings Using Dynamic Simulation Techniques

This investigation presents a detailed analysis in an effort of building energy performance improvement from the aspect of building envelope and glazing influence on the annual heating and cooling energy demand. This work is the continuance of our previous envelope optimization investigation and elaborates the influence of five different glazing types on the annual heating and cooling energy demand of the reference office building in compliance with energy efficiency regulations. Total annual energy demands were determined according to the building envelope’s thermal performance and glazing characteristics. Findings from the dynamic simulations indicated the influence of glazing parameters (U-value, Solar heat gain coefficient) on the annual heating and cooling demand of the multi-zone building model. From the five simulated envelopes it was concluded that with adequate window application the annual heating demand could be reduced by 27% and the annual cooling demand by approximately 40%.

Neutral daylight illumination with variable transmission glass: Theory and validation

The dynamic control of daylight is seen as key for the effective exploitation of natural illumination in buildings. Traditional control solutions are invariably used in a sub-optimal manner: blinds/shades are left down for long periods and lights are left switched on. A glazing with a transmissivity that varies continuously between clear and dark extremes, and which can be controlled automatically, could be much more effective in providing a ‘well-tempered’ daylit environment that meets occupants needs. Amongst the different types of variable transmission glazing that have undergone extensive research and development in the last few decades, those based on electrochromism appear to have the best performance characteristics and the greatest market potential. Electrochromic (EC) glazing generally exhibits a shift in spectral transmission as the glass darkens, e.g. causing it to appear blue as it tints. Occupants, however, are believed to prefer a neutral spectrum of daylight illumination without any pronounced hue. In this paper, the authors show that it is possible to maintain a neutral spectrum of illumination with electrochromic (EC) glazing under normal operation provided that just a small proportion of the EC glazing is kept in the clear state. A theoretical model to predict the daylight spectrum resulting from any arbitrary combination of clear and tinted glazing is described. Predictions from the model are compared with measurements of the daylight spectra in an office with EC glazing under various states of tint. The predicted spectra show excellent agreement with the measurements. The model is applicable to any combination of clear and/or tinted glass panels irrespective of the glazing type(s). The paper concludes with a discussion of design considerations for the effective deployment of EC glazing.

Coaxial personalized ventilation system and window performance for human thermal comfort in asymmetrical environment

This paper assesses the energy performance and occupant comfort of a ceiling-mounted coaxial personalized ventilation (PV) system in presence of radiation asymmetry due to a large window for different glazing systems. Detailed 3-D computational fluid dynamics (CFD) simulations were performed to study the flow and thermal fields in the conditioned office space and evaluate longwave and diffuse shortwave radiation effect on the occupant seated directly below the PV nozzle. The CFD model was coupled to a bioheat model to predict the corresponding local and overall thermal comfort of human body parts subject to the asymmetrical environment. The CFD model is validated by conducting experiments in a climatic room equipped with the PV system and using a thermal manikin facing a hot surface. Predicted and measured values of segmental skin and air temperature at the vicinity of the thermal manikin are compared. Good agreement (less than 8% error) was found between the measured and predicted values.Extensive simulations were performed to evaluate the effect of different types of window glazing on the perceived thermal comfort under various PV operating parameters. For high performance window, the coaxial PV system achieved remarkable energy savings up to 36% when was compared to mixing ventilation (MV) system at the same level of thermal comfort and environmental outdoor conditions.

The Impact of Alternative Window Glazing Types and a Shading System on the Daylighting of Hospital Patient Rooms: Simulation Analysis under a Desert Clear Sky

This paper aimed at identifying the most effective glazing type that suits different patient room layouts under desert clear skies. Year-round daylighting performance of three glazing types was compared with that of a 45 degree sun breaker for three different patient room layouts. Simulations were conducted for rooms facing south in Cairo, Egypt. The daylighting performance of the tested glazing types was less than that of a sun breaker. Electrochromic-60 and low E glazing were successful in the outboard bathroom design only, for large window sizes. The electrochromic-30 glass did not produce acceptable results in any of the tested cases.

AN EMPIRICAL STUDY ON THE USE OF WATER FILM IN GLAZED BUILDINGS TO REDUCE SOLAR RADIATION TRANSMITTANCE IN THE TROPICS

Solar radiation is the cause of large heat gain in glazed buildings particularly in the tropics, thus the aim of this study is to investigate the impact of a sustainable water film on glazing transmittance to solar radiation. The experimental investigation measured two parameters, namely, type of glazing and solar radiation intensity, utilizing glazed façades oriented west in two full-scale rooms. It was found that the water film on the glazed façade increases the transmittance of solar radiation behind the glazing by 2% - 6.8% depending on the solar intensity and glass type, while the indoor temperature was reduced. The study concluded that the increment of the solar radiation (300–2500nm) transmittance is an increment in the range of the visible light (daylighting).

Retrofit Strategies for the Improvement of Visual Comfort and Energy Performance of Classrooms with Large Windows Exposed to East

The typical orientation of the facades of school buildings, along with the presence of large windows and permanent position of the students, can create uncomfortable environmental conditions caused by eye strain due to glare and local thermal discomfort due to asymmetrical thermal radiation. In this work, the effectiveness of various types of high performance glazing and external shading is evaluated, by means of simulations of visual comfort and energy efficiency. Simulations were carried out for a case study which is representative of a typical classroom of a school, located in a town of Tuscany, where instrumental monitoring of existing thermal and lighting conditions was conducted. The case study was selected through an analysis of energy consumption of the whole school building stock of the city, over a period of five years. The analysis has allowed to select the most critical one in terms of energy consumption and the most representative one regarding the Italian school building stock. The selected building has been analyzed by means of building performance simulation software. A survey about the school users’ perception of comfort levels was also carried out by means of questionnaires.

An assessment of energy-saving solutions for the envelope design of high-rise buildings in temperate climates: A case study in the Netherlands

The building envelope is the interface between the interior of the building and the outdoor environment. A building's energy consumption to a large extent depends on certain envelope design elements. As a consequence, for achieving high levels of energy-saving in buildings, design measures with high impact should be firstly defined and then optimised. This paper aims at finding energy-saving solutions for the envelope design of high-rise office buildings in temperate climates. For this purpose an existing tall office building is selected as a typical high-rise design in the Netherlands and the energy use prior and after refurbishment is compared through computer simulations with DesignBuilder. A sensitivity analysis in line with a large number of energy performance simulations showed which building envelope parameters have a significant impact on the building's energy consumption; hence need more consideration for improvement. The four measures selected for uplifting the energy performance of the building envelope include glazing type, window-to-wall ratio, sun shading and roof strategies. By taking the base case as a reference and optimising one parameter at each step, this study resulted in a high-performance envelope design that offers a considerable energy-saving by around 42% for total energy use, 64% for heating and 34% for electric lighting.

Modelling the effect of energy performance certificate rating on property value in the Belfast housing market

Purpose – This study aims to investigate the relationship between energy performance and property sale price in the Belfast housing market. How energy efficiency is contributes to sale price and thus appraisal value is of growing concern. The obligatory measurement of energy efficiency in private dwellings seeks to encourage improvements in energy performance. This may be capitalised into property value and may stimulate demand for energy-efficient buildings. However, the relationship between energy performance and property value remains nebulous, complex and under-researched – in part due to data limitations. Design/methodology/approach – Using a hedonic pricing specification, this paper measures the effect of energy performance certificates (EPCs) on residential property value. It examines the relationship between 3,797 residential sales transactions across the Belfast housing market, showing the percentage effect on property value with respect to energy performance. Findings – The results indicate a small but positive relationship between better energy performance and higher selling prices. Nonetheless, the findings point towards strong preference, demand tastes and a complex intra-relationship between EPCs and their capitalisation into property value. Pertinently, the findings point towards any energy-efficient-related price effect affect to be marginal alongside more “quality”-based market behaviours. Research limitations/implications – Analogous with other studies, data deficiencies and a lack of incorporating price determining variables (missing determinants) such as heating type and glazing type introduces omitted variable bias and endogeneity problems within the model structure. Originality/value – This paper contributes to emerging literature and policy debate surrounding the measurement and implementation of energy-efficiency certification through a greater understanding of energy performance characteristics in determining property value.

Performance demonstration and simulation of thermochromic double glazing in building applications

The application performance of a type of thermochromic double glazing is first demonstrated in a full-scale room. The experimental results show that the low-mass room with a VO2 double window consumes approximately 11.1% less cooling energy than that with an ordinary double window. Three types of windows, a VO2 double window, an ordinary double window and a VO2 single window, are then analyzed as improvements for an ordinary single window. The analysis indicates that in hot climate conditions, the application of the VO2 single window uses less energy than that of the ordinary double one but uses more energy than that of the VO2 double window. Two widely investigated methods to enhance the energy performance of a window, optimizing the capacity for the regulation of solar radiation and improving the thermal insulation performance, are embodied in applications of two hypothetical windows and then further discussed. The results indicate that, in a hot climate, whether a window with an extremely low U-value is favorable for energy efficiency will depend on the set point of the indoor temperature: an indoor temperature lower than 23°C makes the window more efficient than an ordinary single window. However, the low U-value window still has worse energy performance than a window with an appropriate solar heat gain coefficient, which highlights the effect of regulating the solar radiation.

Composition and colouring agents of historical Islamic glazes measured with EPMA and μ-XRD2

Glazes from tiles of representative historic Islamic buildings and tableware ceramic from Central Asia, the Middle East, Asia Minor and North Africa were analysed by electron probe microanalysis (EPMA) and two-dimensional micro-X-ray powder diffraction (μ-XRD 2 ). From major element compositions, three main glaze types were identified: alkali, alkali–lead and lead glazes. Quartz frit and clay ceramics form the substrates of the glazes. A slight influence of the ceramic on the glaze compositions can be found for SiO 2 , Al 2 O 3 and K 2 O, but only for quartz frit substrates. PbO and/or alkali oxides were used as fluxes. Na 2 O is the dominant oxide in the alkali flux. MgO and P 2 O 5 are the decisive components for the discrimination between mineral soda and plant ash as a source of the alkali flux. The use of plant ash beside the established mineral soda as flux for the glazes was introduced during the 13 th century in Iran, latest during the 13 th /14 th century in Afghanistan, and during the 14 th /15 th century in Uzbekistan. Hence, a change of the flux happened later for the glazes than for local glass of the same regions. Lead-glaze compositions occur in almost all considered epochs and locations. Colouring ions are Co 2+ (blue), Cu 2+ (green in a Pb-rich matrix), Fe 3+ and Mn 4+ (brown/black) and Mn 3+ (violet). Pigments, such as SnO 2 , SiO 2 and PbSiO 4 , are whitening agents; Pb 2 Sn 2 O 6 was used for yellow colours. Iron-containing clinopyroxenes and Cu-Cr-Mn-oxides are found in black glazes.

The Effects of Envelope Design Alternatives on the Energy Consumption of Residential Houses in Indonesia

As an emerging country and one of the most populous countries in the world, Indonesia requires a sufficient energy supply to ensure the nation’s continued development. In response to this increasing energy demand, various studies have proposed energy-saving measures; building envelope design is considered to be a typical energy-saving technique. A significant goal in achieving greener buildings is learning how to reduce a building’s energy consumption by applying an efficient energy-saving design. This study used the eQUEST software to investigate how different types of roof construction, glazing and sun-shading techniques affect the energy consumption of residential structures in Indonesia in common scenarios. The results indicate that window shading has the most significant impact on a building’s overall energy consumption, followed by the use of an appropriate glazing, whereas the roof type produced smaller energy efficiency benefits.

The thermal and microstructural behavior of a R2O–RO–(ZnO)–Al2O3–(TiO2)–SiO2 based macro-crystalline raw glaze system

Macro-crystalline glazes containing significantly large crystals visible to the naked eye are a type of artistic glaze with a decorative and esthetic performance. The use of raw glaze compositions is a cost effective alternative for these types of crystal glazes. In the present study, R2O–RO–(ZnO)–Al2O3–(TiO2)–SiO2-based raw glaze system was studied to produce macro-crystalline glazes for Limoges porcelain bodies. The influence of the addition of TiO2 as a nucleating agent or major phase was evaluated in zinc-based glazes as well as ZnO-free ones. Designed glaze compositions were fired according to a special heat treatment cycle and characterized in terms of thermal and microstructural behavior using a digital microscope, differential thermal analyses, hot stage microscopy, X-ray diffraction, a scanning electron microscope, and energy-dispersive X-ray spectroscopy.

Effect of Architectural Glazing Parameters, Shading, Thermal Mass and Night Ventilation on Public Building Energy Consumption under Hungarian Climate

An important field of improving energy eciency of public and oce buildings with glazed facades is a conscious design of the building skin. The study first sets categories of available (conventional and sophisticated) glazing product types used in exterior walls on the basis of thermal transmission, solar heat gain and light transmission properties. A large number of computer simulations has been run using different glazing types, fenestration rates, fixed and moveable (controlled) external shadings, night ventilation rates and internal heat storage capacity in order to determine their effect on energy demands. The study compares heating, cooling and lighting energy demands of the internal spaces, independently from choice of mechanical systems and energy sources in order to analyse the clear effect of building skin and related parameters on energy needs. The simulation were run for Hungarian location (Szombathely), however the results and findings can be adopted for regions of similar continental climate. The target of the study is to set guidelines for the early stages of architectural design of energy efficient glazed façade constructions and buildings.