01624nas a2200133 4500008004100000020002200041245003300063210003300096260006100129520106300190653014601253100002101399856007001420 2018 eng d a978-0-12-812817-600aInnovative Glazing Materials0 aInnovative Glazing Materials aCambridgebButterworth-Heinemann, Elsevier Inc.c11/20183 a

Windows have the unique capability of being able to achieve a net zero energy impact by admitting solar gains in the winter to offset thermal losses and admitting daylight to offset electric lighting. If rejection or admission of solar heat gains and daylight are appropriately timed, then heating, cooling and lighting energy use at the perimeter zone can be reduced to net zero energy levels. Nano-scale switchable coatings on glass have been developed to actively modulate solar intensity and spectral transmission. We provide a brief overview of these switchable glazing materials, discuss the desired performance objectives for such materials, and present results from recently completed monitored studies of state-of-the-art switchable windows, particularly with respect to occupant response and market factors. Careful application of state-of-the-art switchable windows and new material science developments on the horizon can deliver the desired net zero energy performance while meeting critical human factors and market related requirements.

10aElectrochromics; Thermochromics; Switchable windows; Smart windows; Solar control; Daylighting; Building energy efficiency; Building controls1 aLee, Eleanor, S. uhttps://facades.lbl.gov/publications/innovative-glazing-materials01539nas a2200241 4500008003900000022001400039245011000053210006900163260001100232300001400243490000700257520076200264653003001026653002201056653002601078100001701104700002801121700002201149700001501171700001601186700001901202856007601221 2012 d a0884-291400aImproved structural and electrical properties of thin ZnO:Al films by dc filtered cathodic arc deposition0 aImproved structural and electrical properties of thin ZnOAl film c3/2012 a857 - 8620 v273 a

Transparent conducting oxide films are usually several 100-nm thick to achieve the required low sheet resistance. In this study, we show that the filtered cathodic arc technique produces high-quality low-cost ZnO:Al material for comparably smaller thicknesses than achieved by magnetron sputtering, making arc deposition a promising choice for applications requiring films less than 100-nm thick. A mean surface roughness less than 1 nm is observed for ZnO:Al films less than 100-nm thick, and 35-nm-thick ZnO:Al films exhibit Hall mobility of 28 cm2/Vs and a low resistivity of 6.5 × 10−4 Ωcm. Resistivity as low as 5.2 × 10−4 Ωcm and mobility as high as 43.5 cm2/Vs are obtained for 135-nm films.

10aphysical vapor deposition10aPlasma deposition10aTransparent conductor1 aZhu, Yuankun1 aMendelsberg, Rueben, J.1 aLim, Sunnie, H.N.1 aZhu, Jiaqi1 aHan, Jiecai1 aAnders, André uhttps://facades.lbl.gov/publications/improved-structural-and-electrical02051nas a2200109 4500008003900000245015100039210006900190260001200259520157900271100002201850856006901872 2012 d00aIntegrated control of operable fenestration systems and thermally massive HVAC systems: Methods and simulation studies of energy savings potential0 aIntegrated control of operable fenestration systems and thermall c10/20123 a

The future design of high performance buildings is expected to involve more active facade technologies, acting in intelligent collaboration with the HVAC and lighting systems to produce comfortable indoor environments with reduced energy consumption. Integrated control of active facade systems and HVAC is challenging, particularly with thermally-massive HVAC systems such as radiant floors and ceilings. This paper describes methods for devising near-optimal controllers for such integrated systems, allowing for any arbitrary level of complexity in the facade system. An offline-optimization approximation to model predictive control is used with a model consisting of a reduced- order approximation of the zone and HVAC thermal properties and an interpolation grid of the daylight and solar gains attributes of the facade in its various possible states. The optimization over the 24-hour prediction horizon is split into two levels, with GenOpt used at the top level to deal with the complexity of the facade, alongside a linear programming solution to the chilled slab control. The model can be calibrated to match monitored data, or some combination of whole-building energy modeling and Radiance outputs. To test the methods and to estimate energy savings potential, case studies were performed with a calibrated model based on an EnergyPlus ASHRAE 90.1-2010 office building, modi ed to use radiant slabs and operable Venetian blinds (either internal or external) or electochromic glazing. Results are shown for four US climates. Further research is discussed.

1 aCoffey, Brian, E. uhttps://facades.lbl.gov/publications/integrated-control-operable02357nas a2200193 4500008003900000245006700039210006600106260006100172520166400233100002101897700002701918700002901945700002201974700002201996700002002018700002502038700002202063856007802085 2009 d00aInnovative Façade Systems for Low-energy Commercial Buildings0 aInnovative Façade Systems for Lowenergy Commercial Buildings aBerkeleybLawrence Berkeley National Laboratoryc11/20093 a

Glazing and façade systems have very large impacts on all aspects of commercial building performance. They directly influence peak heating and cooling loads, and indirectly influence lighting loads when daylighting is considered. In addition to being a major determinant of annual energy use, they can have significant impacts on peak cooling system sizing, electric load shape, and peak electric demand. Because they are prominent architectural and design elements and because they influence occupant preference, satisfaction and comfort, the design optimization challenge is more complex than with many other building systems.

Façade designs that deliberately recognize the fundamental synergistic relationships between the façade, lighting, and mechanical systems have the potential to deliver high performance over the life of the building. These "integrated" façade systems represent a key opportunity for commercial buildings to significantly reduce energy and demand, helping to move us toward our goal of net zero energy buildings by 2030.

Provision of information — technology concepts, measured data, case study information, simulation tools, etc. — can enable architects and engineers to define integrated façade solutions and draw from a wide variety of innovative technologies to achieve ambitious energy efficiency goals.

This research is directed toward providing such information and is the result of an on‐going collaborative research and development (R&D) program, supported by the U.S. Department of Energy and the California Energy Commission Public Interest Energy Research (PIER) program.

1 aLee, Eleanor, S.1 aSelkowitz, Stephen, E.1 aDiBartolomeo, Dennis, L.1 aKlems, Joseph, H.1 aClear, Robert, D.1 aKonis, Kyle, S.1 aKonstantoglou, Maria1 aPerepelitza, Mark uhttps://facades.lbl.gov/publications/innovative-fa-ade-systems-low-energy01044nas a2200133 4500008004100000050001500041245008000056210006900136260002500205520056300230100001900793700002100812856007700833 2005 eng d aLBNL-5702000aThe Impact of Overhang Designs on the Performance of Electrochromic Windows0 aImpact of Overhang Designs on the Performance of Electrochromic  aOrlando, FLc08/20053 a

In this study, various facade designs with overhangs combined with electrochromic window control strategies were modeled with a prototypical commercial office building in a hot and cold climate using the DOE 2.1E building energy simulation program. Annual total energy use (ATE), peak electric demand (PED), average daylight illuminance (DI), and daylight glare index (DGI) were computed and compared to determine which combinations of façade design and control strategies yielded the greatest energy efficiency, daylight amenity, and visual comfort.

1 aTavil, Aslihan1 aLee, Eleanor, S. uhttps://facades.lbl.gov/publications/impact-overhang-designs-performance03116nas a2200145 4500008004100000050001500041245007600056210006900132260002600201300001200227520260800239100002702847700002102874856007502895 2004 eng d aLBNL-5456700aIntegrating Automated Shading and Smart Glazings with Daylight Controls0 aIntegrating Automated Shading and Smart Glazings with Daylight C aTokyo, Japanc03/2004 aB13-B203 a

Most commercial buildings utilize windows and other glazed envelope components for a variety of reasons. Glass is a key element in the architectural expression of the building and typically provides occupants with a visual connection with the outdoors and daylight to enhance the quality of the indoor environment. But the building skin must serve a crucial function in its role to help maintain proper interior working environments under extremes of external environmental conditions. Exterior temperature conditions vary slowly over a wide range and solar and daylight fluxes can vary very rapidly over a very wide range. The technical problem of controlling heat loss and gain is largely solved with highly insulating glazing technologies on the market today. The challenge of controlling solar gain and managing daylight, view and glare is at a much earlier stage. In most cases a static, fixed control solution will not suffice. Some degree of active, rapid response to changing outdoor conditions and to changing interior task requirements is needed. This can be provided with technology within the glass or glazing assembly itself, or the functionality can be added to the facade either on the interior or exterior of the glazing. In all cases sensors, actuators, and a control logic must be applied for proper functionality. Traditional manually operated mechanical shading systems such as blinds or shades can be motorized and then controlled by occupant action or by sensors and building controls. Emerging smart glass technology can dynamically change optical properties, and can be activated manually or by automated control systems. In all of these cases electric lighting should be controlled to meet occupant needs, while maximizing energy efficiency and minimizing electric demand. As with the fenestration controls, lighting control requires sensors (photocells or the human eye), actuation (switching or dimming) and a control logic that determines what action should be taken under each set of conditions. Some variation on the combination of all of these elements comprises the typical equipment and systems found in most commercial buildings today. The new challenge is to provide a fully functional and integrated facade and lighting system that operates appropriately for all environmental conditions and meets a range of occupant subjective desires and International Symposium on objective performance requirements. And finally these rigorous performance goals must be achieved with solutions that are cost effective and operate over long periods with minimal maintenance.

1 aSelkowitz, Stephen, E.1 aLee, Eleanor, S. uhttps://facades.lbl.gov/publications/integrating-automated-shading-and01932nas a2200205 4500008004100000245010200041210006900143260001200212490000700224520122700231100002001458700002601478700002701504700002401531700002501555700002401580700002301604700002301627856007601650 2002 eng d00aIn Situ X-Ray Absorption Spectroscopy Study of Hydrogen Absorption by Nickel-Magnesium Thin Films0 aIn Situ XRay Absorption Spectroscopy Study of Hydrogen Absorptio c02/20030 v673 a

Structural and electronic properties of co-sputtered Ni-Mg thin films with varying Ni to Mg ratio were studied by in situ x-ray absorption spectroscopy in the Ni L-edge and Mg K-edge regions. Codeposition of the metals led to increased disorder and decreased coordination around Ni and Mg compared to pure metal films. Exposure of the metallic films to hydrogen resulted in formation of hydrides and increased disorder. The presence of hydrogen as a near neighbor around Mg caused a drastic reduction in the intensities of multiple scattering resonances at higher energies. The optical switching behavior and changes in the x-ray spectra varied with Ni to Mg atomic ratio. Pure Mg films with Pd overlayers were converted to MgH2: The H atoms occupy regular sites as in bulk MgH2. Although optical switching was slow in the absence of Ni, the amount of H2 absorption was large. Incorporation of Ni in Mg films led to an increase in the speed of optical switching but decreased maximum transparency. Significant shifts in the Ni L3 and L2 peaks are consistent with strong interaction with hydrogen in the mixed films.

1 aFarangis, Baker1 aNachimuthu, Ponnusamy1 aRichardson, Thomas, J.1 aSlack, Jonathan, L.1 aPerera, Rupert, C.C.1 aGullikson, Eric, M.1 aLindle, Dennis, W.1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/situ-x-ray-absorption-spectroscopy02156nas a2200169 4500008004100000050001500041245008000056210006900136260003400205520156000239100002501799700002001824700002201844700002201866700002401888856007401912 2001 eng d aLBNL-4814700aImproving Information Technology to Maximize Fenestration Energy Efficiency0 aImproving Information Technology to Maximize Fenestration Energy aClearwater Beach, FLc12/20013 a

Annual heating and cooling energy loads through fenestration products in both residential and commercial buildings are a significant fraction of national energy requirements. In the residential sector, 1.34 and 0.37 quads are required for heating and cooling respectively (DOE Core Data Book, 2000). In commercial buildings, cooling energy use to compensate for fenestration product solar heat gain is estimated at 0.39 quads; heating energy use to compensate for heat loss through fenestration products is estimated at 0.19 quads. Advanced products offer the potential to reduce these energy uses by at least 50% (Frost et. al. 1993). Potential electric lighting savings from fenestration products are estimated at 0.4 quads if daylight can be used effectively so that electric lighting in commercial building perimeter zones can be reduced.

Software has begun to make an impact on the design and deployment of efficient fenestration products by making fenestration product performance ratings widely available. These ratings, which are determined in part using software programs such as WINDOW/THERM/Optics, VISION/FRAME, and WIS, can now easily be used by architects, engineers, professional fenestration product specifiers, and consumers. Information on the properties of fenestration products has also influenced state and national codes (IECC, ASHRAE 90.1) and aided voluntary market transformation programs, such as the Efficient Windows Collaborative and the Energy Star Windows program, which promote efficient fenestration products.

1 aArasteh, Dariush, K.1 aMitchell, Robin1 aKohler, Christian1 aHuizenga, Charlie1 aCurcija, Dragan, C. uhttps://facades.lbl.gov/publications/improving-information-technology01998nas a2200145 4500008004100000050001500041245009300056210006900149260003100218520146000249100002401709700001801733700002501751856007601776 2001 eng d aLBNL-4737300aInfrared Thermography Measurements of Window Thermal Test Specimen: Surface Temperatures0 aInfrared Thermography Measurements of Window Thermal Test Specim aAtlantic City, NJc01/20023 a

Temperature distribution data are presented for the warm-side surface of three different window specimens. The specimens were placed between warm and cold environmental chambers that were operated in steady state at two different standard design conditions for winter heating. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) temperature conditions were 21.1 deg. C (70 deg. F) and -17.8 deg. C (0 deg. F) on the warm and cold sides, respectively. The International Standards Organization (ISO) temperature conditions were 20.0 deg. C (68.0 deg. F) and 0.0 deg. C (32.0 deg. F) on the warm and cold sides, respectively. Surface temperature maps were compiled using an infrared thermographic system with an external referencing technique, a traversing point infrared thermometer and thermocouples. The infrared techniques allow detailed, non-intrusive mapping of surface temperatures. Surface temperature data are plotted for the vertical distribution along the centerline of the window specimen. This paper is part of larger round-robin collaborative effort that studied this same set of window specimens. These studies were conducted to improve and check the accuracy of computer simulations for predicting the condensation resistance of window products. Data collected for a Calibrated Transfer Standard showed that convective effects outside the window gap are important for predicting surface temperatures.

1 aGriffith, Brent, T.1 aGoudey, Howdy1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/infrared-thermography-measurements00427nas a2200121 4500008004100000245005600041210005000097100001900147700001900166700001800185700002500203856007700228 2001 eng d00aThe Integrated Energy-Efficiency Window-Wall System0 aIntegrated EnergyEfficiency WindowWall System1 aArney, Michael1 aFairman, James1 aCarmody, John1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/integrated-energy-efficiency-window02906nas a2200121 4500008004100000050001500041245006600056210006600122260003000188520246400218100002702682856007502709 2001 eng d aLBNL-4794800aIntegrating Advanced Façades into High Performance Buildings0 aIntegrating Advanced Façades into High Performance Buildings aTampere, Finlandc06/20013 a

Glass is a remarkable material but its functionality is significantly enhanced when it is processed or altered to provide added intrinsic capabilities. The overall performance of glass elements in a building can be further enhanced when they are designed to be part of a complete façade system. Finally the façade system delivers the greatest performance to the building owner and occupants when it becomes an essential element of a fully integrated building design. This presentation examines the growing interest in incorporating advanced glazing elements into more comprehensive façade and building systems in a manner that increases comfort, productivity and amenity for occupants, reduces operating costs for building owners, and contributes to improving the health of the planet by reducing overall energy use and environmental impacts. We explore the role of glazing systems in dynamic and responsive façades that provide the following functionality:

Enhanced sun protection and cooling load control while improving thermal comfort and providing most of the light needed with daylighting;

Enhanced air quality and reduced cooling loads using natural ventilation schemes employing the façade as an active air control element;

Reduced operating costs by minimizing lighting, cooling and heating energy use by optimizing the daylighting- thermal tradeoffs;

Net positive contributions to the energy balance of the building using integrated photovoltaic systems;

Improved indoor environments leading to enhanced occupant health, comfort and performance.

In addressing these issues façade system solutions must of course respect the constraints of latitude, location, solar orientation, acoustics, earthquake and fire safety, etc. Since climate and occupant needs are dynamic variables, in a high performance building the façade solution must have the capacity to respond and adapt to these variable exterior conditions and to changing occupant needs. This responsive performance capability can also offer solutions to building owners where reliable access to the electric grid is a challenge, in both less-developed countries and in industrialized countries where electric generating capacity has not kept pace with growth. We find that when properly designed and executed as part of a complete building solution, advanced façades can provide solutions to many of these challenges in building design today.

1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/integrating-advanced-fa-ades-high02358nas a2200157 4500008004100000050001500041245011400056210006900170260003400239520175500273100002102028700002902049700002102078700002702099856007402126 1998 eng d aLBNL-4144300aIntegrated Performance of an Automated Venetian Blind/Electric Lighting System in a Full-Scale Private Office0 aIntegrated Performance of an Automated Venetian BlindElectric Li aClearwater Beach, FLc09/19983 a

Comprehensive results are presented from a full-scale testbed of a prototype automated venetian blind/lighting system installed in two unoccupied, private offices in Oakland, California. The dynamic system balanced daylight against solar heat gains in real-time, to reduce perimeter zone energy use and to increase comfort. This limited proof-of-concept test was designed to work out practical "bugs" and refine design details to increase cost effectiveness and acceptability of this innovative technology for real-world applications. We present results from 14 months of tuning the system design and monitoring energy performance and control system operations. For this southeast-facing office, we found that 1-22% lighting energy savings, 13-28% cooling load reductions, and 13-28% peak cooling load reductions can be achieved by the dynamic system under clear sky and overcast conditions year round, compared to a static, partly closed blind with the same optimized daylighting control system. These energy savings increase if compared to conventional daylighting controls with manually-operated blinds. Monitored data indicated that the control system met design objectives under all weather conditions to within 10% for at least 90% of the year. A pilot human factors study indicated that some of our default control settings should be adjusted to increase user satisfaction. With these adjustments, energy savings will decrease. The final prototype design yielded a 10-year simple payback for this site. If mechanical system downsizing opportunities and qualitative improvements to worker's comfort are included, this innovative technology could be more cost effective. Marketing information for commercializing this technology is given.

1 aLee, Eleanor, S.1 aDiBartolomeo, Dennis, L.1 aVine, Edward, L.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/integrated-performance-automated02461nas a2200145 4500008004100000245012500041210006900166490001600235520189500251100002402146700002402170700001902194700002502213856007702238 1997 eng d00aImproving Computer Simulations of Heat Transfer for Projecting Fenestration products: Using Radiation View-Factor Models0 aImproving Computer Simulations of Heat Transfer for Projecting F0 v104, Part 13 a

The window well formed by the concave surface on the warm side of skylights and garden windows can cause surface heat-flow rates to be different for these projecting types of fenestration products than for normal planar windows. Current methods of simulating fenestration thermal conductance (U-value) use constant boundary condition values for overall surface heat transfer. Simulations that account for local variations in surface heat transfer rates (radiation and convection) may be more accurate for rating and labeling window products whose surfaces project outside a building envelope. This paper, which presents simulation and experimental results for one projecting geometry, is the first step in documenting the importance of these local effects.

A generic specimen, called the foam garden window, was used in simulations and experiments to investigate heat transfer of projecting surfaces. Experiments focused on a vertical cross section (measurement plane) located at the middle of the window well on the warm side of the specimen. The specimen was placed between laboratory thermal chambers that were operated at American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) winter heating design conditions. Infrared thermography was used to map surface temperatures. Air temperature and velocity were mapped throughout the measurement plane using a mechanical traversing system. Finite-element computer simulations that directly modeled element-to-element radiation were better able to match experimental data than simulations that used fixed coefficients for total surface heat transfer. Air conditions observed in the window well suggest that localized convective effects were the reason for the difference between actual and modeled surface temperatures. U-value simulation results were 5 to 10% lower when radiation was modeled directly.

1 aGriffith, Brent, T.1 aCurcija, Dragan, C.1 aTurler, Daniel1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/improving-computer-simulations-heat01883nas a2200253 4500008004100000050001500041245008500056210006900141260003000210520107000240653001301310653002001323653004101343653001501384653002201399653001801421653000901439100002301448700002701471700002301498700002401521700001901545856006501564 1997 eng d aLBNL-4155000aInfluence of stoichiometry on the electrochromic cerium-titanium oxide compounds0 aInfluence of stoichiometry on the electrochromic ceriumtitanium  aHonolulu, Hawaiic11/19973 a

CeO2-TiO2 finds use as passive counter-electrode in electrochromic devices. Thin films were produced by dc-sputtering in a wide range of compositions. Influence of total pressure and oxygen partial pressure on the optical constants of TiO2 was investigated. Slightly substoichiometric TiO2 films exhibit a red-shift of the bandgap. The TiO2 content in the compound essentially determines the degree of cathodical coloring upon Li+ intercalation. However, pure TiO2 films with comparable visible transmittance in the clear state behave differently during electrochemical cycling depending on oxygen stoichiometry. Films that are deposited at higher total pressure are more oxygen rich and require initial formatting until current voltage cycles become stable. CeO2-TiO2 films of intermediate compositions have the relatively highest charge capacity. Comparison with atomic force microscopy indicates a correlation of small grain size with high charge capacity.

10aband gap10acharge capacity10aelectrochromic cerium titanium oxide10agrain size10aoptical constants10arms roughness10atio21 avon Rottkay, Klaus1 aRichardson, Thomas, J.1 aRubin, Michael, D.1 aSlack, Jonathan, L.1 aKullman, Lisen uhttps://facades.lbl.gov/publications/influence-stoichiometry01697nas a2200205 4500008004100000245008500041210006900126300000800195490000800203520102000211100001901231700003101250700002101281700002501302700002301327700002301350700002101373700002101394856007601415 1996 eng d00aImpact of Growth Temperature, Pressure and Strain on the Morphology of GaN Films0 aImpact of Growth Temperature Pressure and Strain on the Morpholo a2270 v4493 a

GaN films grown on sapphire at different temperatures are investigated. A Volmer-Weber growth mode is observed at temperatures below 1000K that leads to thin films composed of oriented grains with finite size. Their size is temperature dependent and can actively be influenced by strain. Largest grains are observed in compressed films. It is argued that diffusing Ga ad-atoms dominate the observed effects with an activation energy of 2.3 ± 0.5 eV. Comparably large grain sizes are observed in films grown on off-axes sapphire substrates and on bulk GaN. This assures that the observed size limitation is a consequence of the 3D growth mode and not dependent on the choice of the substrate. In addition, the grain size and the surface roughness of the films depend on the nitrogen partial pressure in the molecular beam epitaxy (MBE) chamber,most likely due to collisions between the reactive species and the background gas molecules. This effect is utilized to grow improved nucleation layers on sapphire.

1 aFujii, Hiroaki1 aKisielowski, Christian, F.1 aKrüger, Joachim1 aLeung, Michael, S.H.1 aKlockenbrink, Ralf1 aRubin, Michael, D.1 aWeber, Eicke, R.1 aKrüger, Joachim uhttps://facades.lbl.gov/publications/impact-growth-temperature-pressure02195nas a2200277 4500008004100000022001400041245010300055210006900158260001200227300001200239490000700251520133500258653002301593653000801616653003301624653002401657100001301681700001901694700002001713700002001733700001801753700002301771700002301794700002101817856007901838 1995 eng d a0361-523500aThe Influence of Nitrogen Ion Energy on the Quality of GaN Films Grown with Molecular Beam Epitaxy0 aInfluence of Nitrogen Ion Energy on the Quality of GaN Films Gro c04/1995 a249-2550 v243 a

Since the growth of GaN using molecular beam epitaxy (MBE) occurs under metastable growth conditions, activated nitrogen is required to drive the forward synthesis reaction. In the process of exciting the nitrogen using a plasma or ion-beam source, species with large kinetic energies are generated. Impingement on the growth surface by these species can result in subsurface damage to the growing film, as well as an enhancement of the reverse decomposition reaction rate. In this study, we investigate the effect of the kinetic energy of the impinging nitrogen ions during growth on the resulting optical and structural properties of GaN films. Strong band-edge photoluminescence and cathodoluminescence are found when a kinetic energy of ~10 eV are used, while luminescence is not detectable when the kinetic energies exceeds 18 eV. Also, we find that the use of conductive SiC substrates results in more homogeneous luminescence than the use of insulating sapphire substrates. This is attributed to sample surface charging in the case of sapphire substrates and subsequent variation in the incident ion flux and kinetic energy across the growth surface.This study clearly shows that the quality of GaN films grown by MBE are presently limited by damage from the impingement of high energy species on the growth surface.

10aActivated nitrogen10aGaN10amolecular beam epitaxy (MBE)10anitrogen ion energy1 aFu, T.C.1 aNewman, Nathan1 aJones, Erin, C.1 aChan, James, S.1 aLiu, Xiaohong1 aRubin, Michael, D.1 aCheung, Nathan, W.1 aWeber, Eicke, R. uhttps://facades.lbl.gov/publications/influence-nitrogen-ion-energy-quality02751nas a2200145 4500008003900000245012300039210006900162260001200231520219600243100002202439700002402461700001902485700002502504856007602529 1995 d00aAn Infrared Thermography-Based Window Surface Temperature Database for the Validation of Computer Heat Transfer Models0 aInfrared ThermographyBased Window Surface Temperature Database f c03/19953 a

Fenestration heat transfer simulation codes are used in energy performance rating and labeling procedures to model heat transfer through window systems and to calculate window U-values and condensation resistance factors. Experimental measurements of window thermal performance can direct the development of these codes, identify their strengths and weaknesses, set research priorities, and validate finished modeling tools. Infrared (IR) thermography is a measurement technique that is well suited to this task. IR thermography is a relatively fast, non-invasive, non-destructive technique that can resolve thermal performance differences between window components and window systems to a higher degree than a conventional hot box test. Infrared thermography provides spatial resolution of system performance by generating surface temperature maps of windows under controlled and characterized environmental conditions.

This paper summarizes basic theory and techniques for maximizing the accuracy and utility of infrared thermographic temperature measurements of window systems and components in a controlled laboratory setting. The physical setup of a complete infrared thermographic test facility at a major U.S. national research laboratory is described. Temperature measurement issues, and accuracy limits, for quantitative laboratory infrared thermography are discussed. An external reference emitter allows test-specific correction of absolute temperatures measured with an infrared scanner, resulting in 'an absolute measurement accuracy of ±O.5°C. Quantitative IR thermography is used to form a database of window surface temperature profiles for the validation of finite-element and finite-difference fenestration heat transfer modeling tools. An IR window surface temperature database with complete technical drawings of the windows tested; specification of all test window dimensions, materials, and thermal conductivities; environmental conditions of the tests with associated measurement errors; and two-dimensional surface temperature maps and selected cross sectional temperature profiles in a spreadsheet database format on an electronic media are presented.

1 aBeck, Fredric, A.1 aGriffith, Brent, T.1 aTurler, Daniel1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/infrared-thermography-based-window02245nas a2200157 4500008004100000024001200041245010600053210006900159260003400228520166300262100002401925700002201949700002501971700001901996856007202015 1995 eng d aUC-160000aIssues Associated with the Use of Infrared Thermography for Experimental Testing of Insulated Systems0 aIssues Associated with the Use of Infrared Thermography for Expe aClearwater Beach, FLc12/19953 a

Infrared scanning radiometers are used to generate temperature maps of building envelope components, including windows and insulation. These temperature maps may assist in evaluating components thermal performance. Although infrared imaging has long been used for field evaluations, controlled laboratory conditions allow improvements in quantitative measurements of surface temperature using reference emitter techniques.

This paper discusses issues associated with the accuracy of using infrared scanning radiometers to generate temperature maps of building envelope components under steady-state, controlled laboratory conditions. Preliminary experimental data are presented for the accuracy and uniformity of response of one commercial infrared scanner. The specified accuracy of this scanner for temperature measurements is 2 °C or 2% of the total range of values (span) being measured. A technique is described for improving this accuracy using a temperature-controlled external reference emitter. Minimum temperature measurement accuracy with a reference emitter is estimated at ±0.5 °C for ambient air and background radiation at 21.1 °C and surface temperatures from 0 °C to 21 °C.

Infrared imaging, with a reference emitter technique, is being used to create a database of temperature maps for a range of window systems, varying in physical complexity, material properties, and thermal performance. The database is to be distributed to developers of fenestration heat transfer simulation programs to help validate their models. Representative data are included for two insulated glazing units with different spacer systems.

1 aGriffith, Brent, T.1 aBeck, Fredric, A.1 aArasteh, Dariush, K.1 aTurler, Daniel uhttps://facades.lbl.gov/publications/issues-associated-use-infrared01629nas a2200145 4500008004100000050001400041245009300055210006900148260002600217520109700243100002501340700002401365700001801389856007601407 1994 eng d aLBL-3541700aIntegrated Window Systems: An Advanced Energy-Efficient Residential Fenestration Product0 aIntegrated Window Systems An Advanced EnergyEfficient Residentia aSan Jose, CAc06/19943 a

The last several years have produced a wide variety of new window products aimed at reducing the energy impacts associated with residential windows. Improvements have focused on reducing the rate at which heat flows through the total window product by conduction/convection and thermal radiation (quantified by the U-factor) as well as in controlling solar heat gain (measured by the Solar Heat Gain Coefficient (SHGC) or Shading Coefficient (SC).

Significant improvements in window performance have been made with low-E coated glazings, gas fills in multiple pane windows and with changes in spacer and frame materials and designs. These improvements have been changes to existing design concepts. They have pushed the limits of the individual features and revealed weaknesses. The next generation of windows will have to incorporate new materials and ideas, like recessed night insulation, seasonal sun shades and structural window frames, into the design, manufacturing and construction process, to produce an integrated window system that will be an energy and comfort asset.

1 aArasteh, Dariush, K.1 aGriffith, Brent, T.1 aLaBerge, Paul uhttps://facades.lbl.gov/publications/integrated-window-systems-advanced02485nas a2200157 4500008004100000050001400041245007000055210006600125260002800191520191900219100003402138700002802172700002702200700002202227856007802249 1986 eng d aLBL-2053600aThe Integration of Operable Shading Systems and Lighting Controls0 aIntegration of Operable Shading Systems and Lighting Controls aLong Beach, CAc11/19863 a

Using daylighting in commercial buildings may significantly reduce electric lighting requirements if appropriatesphotoelectric controls are used to adjust the electric lighting output according to the available daylight. Prior analysis andsresults from monitored buildings and scale-model measurements suggest that the selection, placement, and installation ofsthe control photosensor is a difficult task, even with simple non-operable fenestration systems, since the daylightscontributions from sun, sky, and ground change continuously. The problem becomes even more complex forsfenestration systems that incorporate operable shading devices, because every adjustment changes the systems opticalsproperties. This paper presents results from measurements in a scale model under real skies, designed to bettersunderstand the problem of integrating fenestration and lighting controls. The scale model represented a typical officesspace and was equipped with motorized venetian blinds. Three control photosensors mounted on the ceiling weresconsidered for the operation of the electric lighting system, and two control strategies were considered for the operation ofsthe venetian blinds. Two ground-plane reflectances and two window orientations were examined. Results indicate thatsthe signal from a ceiling-mounted control photosensor shielded from direct light from the window shows the bestscorrelation with daylight work-plane illuminance, regardless of ground plane reflectance or venetian blind slat angle for allsslat angles that do not allow penetration of direct solar radiation. Results also indicate that the control strategies of thesvenetian blinds that were considered for the purposes of this study may result in significantly different slat angles, andsthus different daylighting work-plane illuminances and electric lighting requirements, especially when the ground-planesreflectance is high.

1 aPapamichael, Konstantinos, M.1 aRubinstein, Francis, M.1 aSelkowitz, Stephen, E.1 aWard, Gregory, J. uhttps://facades.lbl.gov/publications/integration-operable-shading-systems