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Effects of High Degrees of Biaxial Stretch Forming on Crazing and Other Properties of Acrylic Plastic Glazing

Description: Memorandum presenting an investigation of the effects of higher degrees of forming in biaxial stretch-forming of polymethyl methacrylate to about 50-percent strain. Sheets of commercial cast polymethyl methacrylate were hot-stretched approximately 100 and 150 percent, respectively, and tests were conducted on this material and on unstretched cotton material. Results regarding the standard tensile tests, stress-solvent crazing, surface abrasion tests, and x-ray diffraction patterns are provided.
Date: May 29, 1953
Creator: Wolock, I.; Axilrod, B. M. & Sherman, M. A.
Partner: UNT Libraries Government Documents Department

Glazes for Metals

Description: The purpose of this study was to endeavor to find through experimentation satisfactory glazes for metals which would be available to the amateur craftsman. Attention was given to reasons for the experimental research, to the metals best suited for glazing, and to the development of satisfactory inexpensive glazes.
Date: August 1949
Creator: Floyd, Emma Lou
Partner: UNT Libraries

Effects of Multiaxial Stretching on Crazing and Other Properties of Transparent Plastics

Description: Memorandum presenting an investigation of the effects of orientation by multi-axial stretching on properties of various plastic glazing materials. The materials studied were Lucite HC-222, Plexiglass 55, Gafite, and resin C. Some of the tests conducted included dimensional stability at elevated temperatures, surface abrasion, standard tensile tests, and stress-solvent crazing tests using ethylene dichloride.
Date: October 20, 1954
Creator: Wolock, Irvin & George, Desmond A.
Partner: UNT Libraries Government Documents Department

Advances in Glazing Materials for Windows

Description: No one type of glazing is suitable for every application. Many materials are available that serve different purposes. Moreover, consumers may discover that they need two types of glazing for a home because of the directions that the windows face and the local climate. To make wise purchases, consumers should first examine their heating and cooling needs and prioritize desired features such as daylighting, solar heating, shading, ventilation, and aesthetic value. Research and development into types of glazing have created a new generation of materials that offer improved window efficiency and performance for consumers. While this new generation of glazing materials quickly gains acceptance in the marketplace, the research and development of even more efficient technology continues.
Date: November 1994
Partner: UNT Libraries Government Documents Department

Singapore's Zero-Energy Building's daylight monitoring system

Description: A setup to monitor the daylighting performance of different glazing types in Singapore is presented. The glazing is installed in the facade of four dedicated testing chambers in BCAA's Zero Energy Building in Singapore. These test rooms are equipped with sensors that both record illuminances on the work plane, and luminances as seen by occupants. The physical and logical design of the monitoring system is presented. Criteria to assess the daylighting performance are introduced, and initial results of the work in progress are presented.
Date: February 28, 2010
Creator: Grobe, Lars; Wittkopf, Stephen; Pandey, Anupama Rana; Xiaoming, Yang; Seng, Ang Kian; Scartezzini, Jean-Louis et al.
Partner: UNT Libraries Government Documents Department

Modeling Windows in Energy Plus with Simple Performance Indices

Description: The building energy simulation program, Energy Plus (E+), cannot use standard window performance indices (U, SHGC, VT) to model window energy impacts. Rather, E+ uses more accurate methods which require a physical description of the window. E+ needs to be able to accept U and SHGC indices as window descriptors because, often, these are all that is known about a window and because building codes, standards, and voluntary programs are developed using these terms. This paper outlines a procedure, developed for E+, which will allow it to use standard window performance indices to model window energy impacts. In this 'Block' model, a given U, SHGC, VT are mapped to the properties of a fictitious 'layer' in E+. For thermal conductance calculations, the 'Block' functions as a single solid layer. For solar optical calculations, the model begins by defining a solar transmittance (Ts) at normal incidence based on the SHGC. For properties at non-normal incidence angles, the 'Block' takes on the angular properties of multiple glazing layers; the number and type of layers defined by the U and SHGC. While this procedure is specific to E+, parts of it may have applicability to other window/building simulation programs.
Date: October 12, 2009
Creator: Arasteh, Dariush; Kohler, Christian & Griffith, Brent
Partner: UNT Libraries Government Documents Department

Highly Insulating Glazing Systems using Non-Structural Center Glazing Layers

Description: Three layer insulating glass units with two low-e coatings and an effective gas fill are known to be highly insulating, with center-of-glass U-factors as low as 0.57 W/m{sup 2}-K (0.10 Btu/h-ft{sup 2}- F). Such units have historically been built with center layers of glass or plastic which extend all the way through the spacer system. This paper shows that triple glazing systems with non-structural center layers which do not create a hermetic seal at the edge have the potential to be as thermally efficient as standard designs, while potentially removing some of the production and product integration issues that have discouraged the use of triples.
Date: April 9, 2008
Creator: Kohler, Christian; Arasteh, Dariush; Goudey, Howdy & Kohler, Christian
Partner: UNT Libraries Government Documents Department

[Painting bowls]

Description: Photograph of the Kiyomizu Pottery Community in Kyoto, Japan. In the foreground, two women sit at tables glazing bowls. A row of people watches in the left foreground. Shelves full of finished bowls are visible in the background.
Date: 1978
Creator: Gough, Ray
Partner: UNT College of Visual Arts + Design

The national energy requirements of residential windows in the U.S.: Today and tomorrow

Description: This paper describes an end-use analysis of the national energy requirements of US residential window technologies. The authors estimate that the current US stock of 19 billion square feet of residential windows is responsible for 1.7 quadrillion BTUs (or quads) per year of energy use--1.3 quads of heating and 0.4 quads of cooling energy--which represents about 2% of total US energy consumption. They show that national energy use due to windows could be reduced by 25% by the year 2010 through accelerated adoption of currently available, advanced window technologies such as low-e and solar control low-e coatings, vinyl and wood frames, and superwindows. The authors evaluate the economics of the technologies regionally, considering both climatic and energy price variations, and find that the technologies would be cost effective for most consumers.
Date: March 1, 1996
Creator: Frost, K.; Eto, J.; Arasteh, D. & Yazdanian, M.
Partner: UNT Libraries Government Documents Department

Energy Simulation studies in IEA/SHC Task 18 advanced glazing and associated materials for solar and building applications

Description: Researchers participating in IEA/SHC Task 18 on advanced glazing materials have as their primary objective the development of new innovative glazing products such as high performance glazings, wavelength selective glazings, chromogenic optical switching devices, and light transport mechanisms that will lead to significant energy use reductions and increased comfort in commercial and residential buildings. Part of the Task 18 effort involves evaluation of the energy and comfort performance of these new glazings through the use of various performance analysis simulation tools. Eleven countries (Australia, Denmark, Finland, Germany, Italy, Netherlands, Norway, Spain, Sweden, Switzerland, and the United States) are contributing to this multi-year simulation study to better understand the complex heat transfer interactions that determine window performance. Each country has selected particular simulation programs and identified the following items to guide the simulation tasks: (1) geographic locations; (2) building types; (3) window systems and control strategies; and (4) analysis parameters of interest. This paper summarizes the results obtained thus far by several of the research organizations.
Date: April 1, 1995
Creator: Sullivan, R.; Selkowitz, S. & Lyons, P.
Partner: UNT Libraries Government Documents Department

Windows and daylighting: A brighter outlook

Description: This is an overview of energy efficient window glazing and framing technology. The topics of the report include: windows and energy use, a point of view; a challenging federal opportunity; DOE window research; advanced optical technologies such as spectrally selective glazing, switchable glazing, super windows with low-emissivity coatings and noble gas fills; and performance evaluation and design tools.
Date: November 1, 1994
Partner: UNT Libraries Government Documents Department

Solar absorption in thick and multilayered glazings

Description: Thick and multilayered glazings generally have a nonuniform distribution of absorbed solar radiation which is not taken into account by current methods for calculating the center of glass solar gain and thermal performance of glazing systems. This paper presents a more accurate method for calculating the distribution of absorbed solar radiation inside thick and multilayered glazings and demonstrates that this can result in a small but significant difference in steady-state temperature profile and Solar Heat Gain Coefficient for some types of glazing systems when compared to the results of current methods. This indicates that a more detailed approach to calculating the distribution of absorbed solar radiation inside glazings and resulting thermal performance may be justified for certain applications.
Date: February 1, 2002
Creator: Powles, Rebecca; Curcija, Dragan & Kohler, Christian
Partner: UNT Libraries Government Documents Department

Advanced Interactive Facades - Critical Elements for Future GreenBuildings?

Description: Building designers and owners have always been fascinated with the extensive use of glass in building envelopes. Today the highly glazed facade has almost become an iconic element for a 'green building' that provides daylighting and a visual connection with the natural environment. Even before the current interest in green buildings there was no shortage of highly glazed building designs. But many of these buildings either rejected sunlight, and some associated daylight and view with highly reflective glazings or used highly transmissive glass and encountered serious internal comfort problems that could only be overcome with large HVAC systems, resulting in significant energy, cost and environmental penalties. From the 1960's to the 1990's innovation in glazing made heat absorbing glass, reflective glass and double glazing commonplace, with an associated set of aesthetic features. In the last decade there has been a subtle shift from trying to optimize an ideal, static design solution using these glazings to making the facade responsive, interactive and even intelligent. More sophisticated design approaches and technologies have emerged using new high-performance glazing, improved shading and solar control systems, greater use of automated controls, and integration with other building systems. One relatively new architectural development is the double glass facade that offers a cavity that can provide improved acoustics, better solar control and enhanced ventilation. Taken to its ultimate development, an interactive facade should respond intelligently and reliably to the changing outdoor conditions and internal performance needs. It should exploit available natural energies for lighting, heating and ventilation, should be able to provide large energy savings compared to conventional technologies, and at the same time maintain optimal indoor visual and thermal comfort conditions. As photovoltaic costs decrease in the future, these onsite power systems will be integrated within the glass skin and these facades will become local, non-polluting ...
Date: November 1, 2003
Creator: Selkowitz, Stephen; Aschehoug, Oyvind & Lee, Eleanor S.
Partner: UNT Libraries Government Documents Department

Chromogenic switchable glazing: Towards the development of the smart window

Description: The science and technology of chromogenic materials for switchable glazings in building applications is discussed. These glazings can be used for dynamic control of solar and visible energy. Currently many researchers and engineers are involved with the development of products in this field. A summary of activities in Japan, Europe, Australia, USA and Canada is made. The activities of the International Energy Agency are included. Both non-electrically activated and electrically activated glazings are discussed. Technologies covered in the first category are photochromics, and thermochromics and thermotropics. A discussion of electrically activated chromogenic glazings includes dispersed liquid crystals, dispersed particles and electrochromics. A selection of device structures and performance characteristics are compared. A discussion of transparent conductors is presented. Technical issues concerning large-area development of smart windows are discussed.
Date: June 1, 1995
Creator: Lampert, C.M.
Partner: UNT Libraries Government Documents Department

Technology reviews: Glazing systems

Description: We present a representative review of existing, emerging, and future technology options in each of five hardware and systems areas in envelope and lighting technologies: lighting systems, glazing systems, shading systems, daylighting optical systems, and dynamic curtain wall systems. The term technology is used here to describe any design choice for energy efficiency, ranging from individual components to more complex systems to general design strategies. The purpose of this task is to characterize the state of the art in envelope and lighting technologies in order to identify those with promise for advanced integrated systems, with an emphasis on California commercial buildings. For each technology category, the following activities have been attempted to the extent possible: Identify key performance characteristics and criteria for each technology; determine the performance range of available technologies; identify the most promising technologies and promising trends in technology advances; examine market forces and market trends; and develop a continuously growing in-house database to be used throughout the project. A variety of information sources have been used in these technology characterizations, including miscellaneous periodicals, manufacturer catalogs and cut sheets, other research documents, and data from previous computer simulations. We include these different sources in order to best show the type and variety of data available, however publication here does not imply our guarantee of these data. Within each category, several broad classes are identified, and within each class we examine the generic individual technologies that fag into that class.
Date: September 1, 1992
Creator: Schuman, J.; Rubinstein, F.; Papamichael, K.; Beltran, L.; Lee, E. S. & Selkowitz, S.
Partner: UNT Libraries Government Documents Department

Switchable window modeling. Task 12: Building energy analysis and design tools for solar applications, Subtask A.1: High-performance glazing

Description: This document presents the work conducted as part of Subtask A.1, High-Performance Glazing, of Task 12 of the IEA Solar Heating and Cooling Program. At the start of the task, the participants agreed that chromogenic technology (switchable glazing) held considerable promise, and that algorithms to accurately model their dynamic behavior were needed. The purpose of this subtask was to develop algorithms that could be incorporated into building energy analysis programs for predicting the thermal and optical performance of switchable windows. The work entailed a review of current techniques for modelling switchable glazing in windows and switchable windows in buildings and methods for improving upon existing modeling approaches. The proposed approaches correct some of the shortcomings in the existing techniques, and could be adapted for use in other similar programs. The proposed approaches generally provide more detailed calculations needed for evaluating the short-term (hourly and daily) impact of switchable windows on the energy and daylighting performance of a building. Examples of the proposed algorithms are included.
Date: June 30, 1992
Creator: Reilly, S.; Selkowitz, S. & Winkelmann, F.
Partner: UNT Libraries Government Documents Department

Focused R&D For Electrochromic Smart Windowsa: Significant Performance and Yield Enhancements

Description: There is a need to improve the energy efficiency of building envelopes as they are the primary factor governing the heating, cooling, lighting and ventilation requirements of buildings--influencing 53% of building energy use. In particular, windows contribute significantly to the overall energy performance of building envelopes, thus there is a need to develop advanced energy efficient window and glazing systems. Electrochromic (EC) windows represent the next generation of advanced glazing technology that will (1) reduce the energy consumed in buildings, (2) improve the overall comfort of the building occupants, and (3) improve the thermal performance of the building envelope. ''Switchable'' EC windows provide, on demand, dynamic control of visible light, solar heat gain, and glare without blocking the view. As exterior light levels change, the window's performance can be electronically adjusted to suit conditions. A schematic illustrating how SageGlass{reg_sign} electrochromic windows work is shown in Figure I.1. SageGlass{reg_sign} EC glazings offer the potential to save cooling and lighting costs, with the added benefit of improving thermal and visual comfort. Control over solar heat gain will also result in the use of smaller HVAC equipment. If a step change in the energy efficiency and performance of buildings is to be achieved, there is a clear need to bring EC technology to the marketplace. This project addresses accelerating the widespread introduction of EC windows in buildings and thus maximizing total energy savings in the U.S. and worldwide. We report on R&D activities to improve the optical performance needed to broadly penetrate the full range of architectural markets. Also, processing enhancements have been implemented to reduce manufacturing costs. Finally, tests are being conducted to demonstrate the durability of the EC device and the dual pane insulating glass unit (IGU) to be at least equal to that of conventional windows.
Date: January 31, 2003
Creator: Burdis, Mark & Sbar, Neil
Partner: UNT Libraries Government Documents Department

Electrochromic Windows: Process and Fabrication Improvements for Lower Total Costs

Description: The overall goal with respect to the U.S. Department of Energy (DOE) is to achieve significant national energy savings through maximized penetration of EC windows into existing markets so that the largest cumulative energy reduction can be realized. The speed with which EC windows can be introduced and replace current IGU's (and current glazings) is clearly a strong function of cost. Therefore, the aim of this project was to investigate possible improvements to the SageGlass{reg_sign} EC glazing products to facilitate both process and fabrication improvements resulting in lower overall costs. The project was split into four major areas dealing with improvements to the electrochromic layer, the capping layer, defect elimination and general product improvements. Significant advancements have been made in each of the four areas. These can be summarized as follows: (1) Plasma assisted deposition for the electrochromic layer was pursued, and several improvements made to the technology for producing a plasma beam were made. Functional EC devices were produced using the new technology, but there are still questions to be answered regarding the intrinsic properties of the electrochromic films produced by this method. (2) The capping layer work was successfully implemented into the existing SageGlass{reg_sign} product, thereby providing a higher level of transparency and somewhat lower reflectivity than the 'standard' product. (3) Defect elimination is an ongoing effort, but this project spurred some major defect reduction programs, which led to significant improvements in yield, with all the implicit benefits afforded. In particular, major advances were made in the development of a new bus bar application process aimed at reducing the numbers of 'shorts' developed in the finished product, as well as making dramatic improvements in the methods used for tempering the glass, which had previously been seen to produce a defect which appeared as a pinhole. (4) Improvements have ...
Date: March 31, 2007
Creator: Burdis, Mark & Sbar, Neil
Partner: UNT Libraries Government Documents Department

Issues associated with the use of infrared thermography for experimental testing of insulated systems

Description: Infrared scanning radiometers are used to generate temperature maps of building envelope components (windows, insulation), which may assist in evaluating their thermal performance. Accuracy of an IR scanner for laboratory-based surface temperature measurements was evaluated and details for achieving max accuracy identified. Minimum uncertainty in IR temperature measurement is {+-}0.5 C. Using an external reference emitter to scale the absolute value of IR scanner temperature measurements can improve the accuracy from 2 C to as low as 0.5 C for a 5 C span, which is comparable to accuracy of type T thermocouples. Operational procedures can easily increase errors; actual accuracy of an IR measurement will vary with test speciment geometry, temperature gradients, and scanner settings (emissivity, etc.). Future efforts for standard IR thermographic test procedures that should address standardization of various items are outlined. A database of temperature maps for a range of window systems is being created; representative data are presented for two insulated glazing units with different spacer systems.
Date: December 1, 1995
Creator: Griffith, B.; Beck, F.; Arasteh, D. & Tuerler, D.
Partner: UNT Libraries Government Documents Department

Surface temperatures of insulated glazing units: Infrared thermography laboratory measurements

Description: Data are presented for the distribution of surface temperatures on the warm-side surface of seven different insulated glazing units. Surface temperatures are measured using infrared thermography and an external referencing technique. This technique allows detailed mapping of surface temperatures that is non-intrusive. The glazings were placed between warm and cold environmental chambers that were operated at conditions corresponding to standard design conditions for winter heating. The temperatures conditions are 2 1.1{degrees}C (70{degrees}F) and -17.8{degrees}C (0{degrees}F) on the warm and cold sides, respectively. Film coefficients varied somewhat with average conditions of about 7.6 W/m{sup 2}{circ}K (1.34 Btu/h-ft{sup 2}{circ}{degrees}F) for the warm-side and 28.9 W/m{sup 2}{circ}K (5.1 Btu/h{circ}ft{sup 2}{circ}{degrees}F) for the cold-side. Surface temperature data are plotted for the vertical distribution along the centerline of the IG and for the horizontal distribution along the centerline. This paper is part of larger collaborative effort that studied the same set of glazings.
Date: December 1, 1995
Creator: Griffith, B.T.; Tuerler, D. & Arasteh, D.
Partner: UNT Libraries Government Documents Department

Florida Solar Energy Center: Final report 1996

Description: A small research group at the Florida Solar Energy Center has been working for several years to perform research and other work in support of U.S. Department of Energy and State of Florida energy efficiency objectives in the area of windows, skylights, clerestories, and other glazed apertures in buildings, generically called fenestrations. This work includes not only thermal energy transfer through fenestration systems but also the controlled introduction of daylight illumination for the displacement of electric lighting energy. Work in the last few years has focused almost entirely on providing technical support to the National Fenestration Rating Council`s program to introduce energy performance rating and labelling of windows into the United States. This work has included a variety of activities. (1) Annual energy performance simulations aimed at determining the relative performances of a variety of residential window and glazing options for different climates. (2) Evaluation of Lawrence Berkeley Laboratory reports and software products in the area of fenestrations. (3) Development of better computational tools for predicting the solar spectral irradiance incident on fenestration systems and contributing to solar radiant heat gain, and the effects of exterior shading. (4) Service on various committees and task groups of the NFRC as well as participation in and technical support for ASHRAE`s technical committee 4.5 on fenestrations. (5) Evaluation of the daylighting potential of commercial buildings in hot humid climates.
Date: July 18, 1996
Partner: UNT Libraries Government Documents Department

Architectural Surety Applications for Building Response to Dynamic Loads

Description: This paper provides a summary introduction to the emerging area of Architectural Surety{trademark} applications for buildings and infrastructures that are subjected to dynamic loads from blast and naturally occurring events. This technology area has been under investigation to assist with the definition of risks associated with dynamic loads and to provide guidance for determining the required upgrading and retrofitting techniques suggested for reducing building and infrastructure vulnerabilities to such dynamic forces. This unique approach involves the application of risk management techniques for solving problems of the as-built environment through the application of security, safety, and reliability principles developed in the nuclear weapons programs of the United States Department of Energy (DOE) and through the protective structures programs of the German Ministry of Defense (MOD). The changing responsibilities of engineering design professionals are addressed in light of the increased public awareness of structural and facility systems' vulnerabilities to malevolent, normal, and abnormal environment conditions. Brief discussions are also presented on (1) the need to understand how dynamic pressures are affected by the structural failures they cause, (2) the need to determine cladding effects on columns, walls, and slabs, and (3) the need to establish effective standoff distance for perimeter barriers. A summary description is presented of selected technologies to upgrade and retrofit buildings by using high-strength concrete and energy-absorbing materials and by specifying appropriately designed window glazing and special masonry wall configurations and composites. The technologies, material performance, and design evaluation procedures presented include super-computational modeling and structural simulations, window glass fragmentation modeling, risk assessment procedures, instrumentation and health monitoring systems, three-dimensional CAD virtual reality visualization techniques, and material testing data.
Date: February 10, 1999
Creator: Matalucci, R.V. & Mayrhofer, C.
Partner: UNT Libraries Government Documents Department

Energy performance of evacuated glazings in residential buildings

Description: This paper presents the results of a study investigating the energy performance of evacuated glazings or glazings which maintain a vacuum between two panes of glass. Their performance is determined by comparing results to prototype highly insulated superwindows as well as a more conventional insulating glass unit with a low-E coating and argon gas fill. The authors used the DOE-2.1E energy analysis simulation program to analyze the annual and hourly heating energy use due to the windows of a prototypical single-story house located in Madison, Wisconsin. Cooling energy performance was also investigated. The results show that for highly insulating windows, the solar heat gain coefficient is as important as the window`s U-factor in determining heating performance for window orientations facing west-south-east. For other orientations in which there is not much direct solar radiation, the window`s U-factor primarily governs performance. The vacuum glazings had lower heating requirements than the superwindows for most window orientations. The conventional low-E window outperformed the superwindows for southwest-south-southeast orientations. These performance differences are directly related to the solar heat gain coefficients of the various windows analyzed. The cooling performance of the windows was inversely related to the heating performance. The lower solar heat gain coefficients of the superwindows resulted in the best cooling performance. However, the authors were able to mitigate the cooling differences of the windows by using an interior shading device that reduced the amount of solar gain at appropriate times.
Date: October 1, 1996
Creator: Sullivan, R.; Beck, F.; Arasteh, D. & Selkowitz, S.
Partner: UNT Libraries Government Documents Department