02919nas a2200181 4500008004100000245011300041210006900154260001200223520228500235100002102520700002402541700001802565700002702583700001702610700001802627700002002645856007202665 2017 eng d00aDemonstration of Energy Efficient Retrofits for Lighting and Daylighting in New York City Office Buildings0 aDemonstration of Energy Efficient Retrofits for Lighting and Day c04/20173 a

The U.S. Department of Energy's (DOE) Commercial Buildings Integration (CBI) program's mission (and that of the New York State Energy Research & Development Authority (NYSERDA)) is to accelerate the adoption of cost-effective, underutilized building technologies with large energy savings potential. The key question which CBI asks for each high impact technology is: "What can the DOE do to improve the market adoption of this technology?" Answering this relies on an assessment of the most significant barriers, including:

Innovative, automated shading and LED lighting controls were identified as key technologies that have the potential to significantly reduce perimeter zone energy use and peak demand in existing commercial buildings.  Technological advances in the field of low-cost embedded controls have enabled high-resolution sensing and more optimal control on a per fixture or shade basis. The Lawrence Berkeley National Laboratory (LBNL) partnered with the Building Energy Exchange (BEEx) and a commercial building owner to evaluate leading-edge technologies on a 40,000 ft2 floor in an occupied, high-rise commercial office building in New York, New York. This “Living Laboratory” was monitored for a year prior to and six months following the installation of four sets of lighting and shading technologies and their performance was compared to a parallel reference floor in the same building.

The Living Laboratory demonstrated that there were many competitive products on the market, that the products were able to meet current needs, and that the various advanced features provided significant added value over and above that of conventional products. Monitored data provided detailed insights into how and why each technology performed the way it did, and what the impacts were on energy-efficiency, peak demand, visual and thermal comfort, indoor environmental quality, and occupant acceptance and satisfaction within the resultant environment.

1 aLee, Eleanor, S.1 aFernandes, Luis, L.1 aWang, Taoning1 aSelkowitz, Stephen, E.1 aMesh, Steven1 aFrank, Yetsuh1 aYancey, Richard uhttps://facades.lbl.gov/publications/demonstration-energy-efficient02631nas a2200169 4500008004100000245009900041210007000140260002400210520201600234100002702250700002002277700002302297700002202320700001902342700002102361856007902382 2011 eng d00aCOMFEN 3.0: Evolution of an Early Design Tool for Commercial Façades and Fenestration Systems0 aCOMFEN 30 Evolution of an Early Design Tool for Commercial Façad aPomona, CAc03/20113 a

Achieving a net-zero energy building cannot be done solely by improving the efficiency of the engineering systems. It also requires consideration of the essential nature of the building including factors such as architectural form, massing, orientation and enclosure. Making informed decisions about the fundamental character of a building requires assessment of the effects of the complex interaction of these factors on the resulting performance of the building. The complexity of these interactions necessitates the use of modeling and simulation tools to dynamically analyze the effects of the relationships, yet decisions about the building fundamentals are often made in the earliest stages of design, before a 'building' exists to model.

To address these issues, Lawrence Berkeley National Laboratory (LBNL) has developed an early-design energy modeling tool (COMFEN) specifically to help make informed decisions about building façade fundamentals by considering the design of the building envelope, orientation and massing on building performance. COMFEN focuses on the concept of a "space" or "room" and uses the EnergyPlus, and Radiance™ engines and a simple, graphic user interface to allow the user to explore the effects of changing key early-design input variables on energy consumption, peak energy demand, and thermal and visual comfort. Comparative results are rapidly presented in a variety of graphic and tabular formats to help users move toward optimal façade and fenestration design choices.

While COMFEN 1.0 utilized an Excel™–based user interface, COMFEN 3.0 has been reworked to include a simple, more intuitive, yet powerful Graphic User Interface (GUI), a broader range of libraries for associated system and component choices and deliver a wider range of graphic outputs and options.

This paper (and presentation) outlines the objectives in developing and further refining COMFEN, the mechanics of the program, and plans for future development. 

1 aSelkowitz, Stephen, E.1 aMitchell, Robin1 aMcClintock, Maurya1 aMcQuillen, Daniel1 aMcNeil, Andrew1 aYazdanian, Mehry uhttps://facades.lbl.gov/publications/comfen-30-evolution-early-design-tool02555nas a2200205 4500008003900000245009100039210006900130260001200199300001200211490000800223520188300231100002102114700002902135700002202164700002202186700002002208700002102228700002202249856007802271 2009 d00aField Measurements of Innovative Indoor Shading Systems in a Full-Scale Office Testbed0 aField Measurements of Innovative Indoor Shading Systems in a Ful c10/2009 a706-7280 v1153 a

The development of spectrally selective low-e glass with its superior solar control and high daylight admission has led to widespread use of large-area, "transparent" or visually clear glass windows in commercial building facades. This type of façade can provide significant inherent daylighting potential (ability to offset lighting energy use) and move us closer to the goal of achieving zero energy buildings, if not for the unmitigated glare that results from the unshaded glazing. Conventional shading systems result in a significant loss of daylight and view. Can innovative shading solutions successfully balance the tradeoffs between daylight, solar heat gains, discomfort glare, and view?

To investigate this issue, a six-month solstice-to-solstice field study was conducted in a sunny climate to measure the thermal and daylighting performance of a south-facing, full- scale, office testbed with large-area windows and a variety of innovative indoor shading systems. Indoor shading systems included manually-operated and automated roller shades, Venetian blinds, daylight-redirecting blinds, and a static translucent diffusing panel placed inboard of the window glazing. These innovative systems were compared to a reference shade lowered to block direct sun.

With continuous dimming controls, all shading systems yielded lighting energy savings between 43-69% compared to a non-dimming case, but only the automated systems were able to meet visual comfort criteria throughout the entire monitored period. Cooling loads due to solar and thermal loads from the window were increased by 2-10% while peak cooling loads were decreased by up to 14%. The results from this experiment illustrate that some indoor shading systems can preserve daylight potential while meeting comfort requirements. Trends will differ significantly depending on application.

1 aLee, Eleanor, S.1 aDiBartolomeo, Dennis, L.1 aKlems, Joseph, H.1 aClear, Robert, D.1 aKonis, Kyle, S.1 aYazdanian, Mehry1 aPark, Byoung-Chul uhttps://facades.lbl.gov/publications/field-measurements-innovative-indoor05111nas a2200217 4500008004100000245007400041210006900115260001200184520439000196100002104586700002704607700002904634700002204663700002204685700002004707700002604727700002104753700002004774700002504794856007404819 2009 eng d00aHigh Performance Building Facade Solutions: PIER Final Project Report0 aHigh Performance Building Facade Solutions PIER Final Project Re c12/20093 a

Building façades directly influence heating and cooling loads and indirectly influence lighting loads when daylighting is considered, and are therefore a major determinant of annual energy use and peak electric demand. façades also significantly influence occupant comfort and satisfaction, making the design optimization challenge more complex than many other building systems.

This work focused on addressing significant near-term opportunities to reduce energy use in California commercial building stock by a) targeting voluntary, design-based opportunities derived from the use of better design guidelines and tools, and b) developing and de ploying more efficient glazings, shading systems, daylighting systems, façade systems and integrated controls.

This two-year project, supported by the California Energy Commission PIER program and the US Department of Energy, initiated a collaborative effort between The Lawrence Berkeley National Laboratory (LBNL) and major stakeholders in the façades industry to develop, evaluate, and accelerate market deployment of emerging, high-performance, integrated façade solutions. The LBNL Windows Testbed Facility acted as the primary cata lyst and mediator on both sides of the building industry supply-user business transaction by a) aiding component suppliers to create and optimize cost effective, integrated systems that work, and b) demonstrating and verifying to the owner, designer, and specifier community that these integrated systems reliably deliver required energy performance. An industry consortium was initiated amongst approximately seventy disparate stakeholders, who unlike the HVAC or lighting industry, has no single representative, multi-disciplinary body or organized means of communicating and collaborating. The consortium provided guidance on the project and more importantly, began to mutually work out and agree on the goals, criteria, and pathways needed to attain the ambitious net zero energy goals defined by California and the US.

A collaborative test, monitoring, and reporting protocol was also formulated via the Windows Testbed Facility in collaboration with industry partners, transitioning industry to focus on the import ance of expecting measured performance to consistently achieve design performance expectations. The facility enables accurate quantification of energy use, peak demand, and occupant comfort impacts of synergistic façade-lighting-HVAC systems on an apples-to-apples comparative basis and its data can be used to verify results from simulations.

Emerging interior and exterior shading technologies were investigated as potential near-term, low-cost solutions with potential broad applicability in both new and retrofit construction. Commercially-available and prototype technologies were developed, tested, and evaluated. Full-scale, monitored field tests were conducted over solstice-to-solstice periods to thoroughly evaluate the technologies, uncover potential risks associated with an unknown, and quantify performance benefits. Exterior shading systems were found to yield net zero energy levels of performance in a sunny climate and significant reductions in summer peak demand. Automated interior shading systems were found to yield significant daylighting and comfort-related benefits.

In support of an integrated design process, a PC-based commercial fenestration (COMFEN) software package, based on EnergyPlus, was developed that enables architects and engineers to x quickly assess and compare the performance of innovative façade technologies in the early sketch or schematic design phase. This tool is publicly available for free and will continue to improve in terms of features and accuracy. Other work was conducted to develop simulation tools to model the performance of any arbitrary complex fenestration system such as common Venetian blinds, fabric roller shades as well as more exotic innovative façade systems such as optical louver systems.

The principle mode of technology transfer was to address the key market barriers associated with lack of information and facile simulation tools for early decisionmaking. The third party data generated by the field tests and simulation data provided by the COMFEN tool enables utilities to now move forward toward incentivizing these technologies in the marketplace.

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 aHitchcock, Robert, J.1 aYazdanian, Mehry1 aMitchell, Robin1 aKonstantoglou, Maria uhttps://facades.lbl.gov/publications/high-performance-building-facade01581nas a2200181 4500008004100000050001500041245011400056210006900170520095200239100001901191700002201210700001701232700002201249700002001271700002001291700001601311856007201327 2009 eng d aLBNL-1881E00aHigh quality ZnO:Al transparent conducting oxide films synthesized by pulsed filtered cathodic arc deposition0 aHigh quality ZnOAl transparent conducting oxide films synthesize3 a

Aluminum-doped zinc oxide, ZnO:Al or AZO, is a well-known n-type transparent conducting oxide with great potential in a number of applications currently dominated by indium tin oxide (ITO). In this study, the optical and electrical properties of AZO thin films deposited on glass and silicon by pulsed filtered cathodic arc deposition are systematically studied. In contrast to magnetron sputtering, this technique does not produce energetic negative ions, and therefore ion damage can be minimized. The quality of the AZO films strongly depends on the growth temperature while only marginal improvements are obtained with post-deposition annealing. The best films, grown at a temperature of about 200°C, have resistivities in the low to mid 10-4Ω cm range with a transmittance better than 85% in the visible part of the spectrum. It is remarkable that relatively good films of small thickness (60 nm) can be fabricated using this method.

1 aAnders, André1 aLim, Sunnie, H.N.1 aYu, Kin, Man1 aAndersson, Joakim1 aRosén, Johanna1 aMcFarland, Mike1 aBrown, Jeff uhttps://facades.lbl.gov/publications/high-quality-znoal-transparent02585nas a2200205 4500008004100000245005400041210005100095260006100146300001000207520191200217100002002129700002202149700002202171700002302193700002502216700002202241700001602263700002402279856007602303 2008 eng d00aWINDOW 6.2/THERM 6.2 Research Version User Manual0 aWINDOW 62THERM 62 Research Version User Manual aBerkeleybLawrence Berkeley National Laboratoryc01/2008 a1-1263 a

WINDOW 6 and THERM 6 Research Versions are software programs developed at Lawrence Berkeley National Laboratory (LBNL) for use by manufacturers, engineers, educators, students, architects, and others to determine the thermal and solar optical properties of glazing and window systems.

WINDOW 6 and THERM 6 are significant updates to LBNL's WINDOW 5 and THERM 5 computer program because of the added capability to model complex glazing systems, such as windows with shading systems, in particular venetian blinds. Besides a specific model for venetian blinds and diffusing layers, WINDOW 6 also includes the generic ability to model any complex layer if the Transmittance and Reflectance are known as a function of incoming and outgoing angles.

The algorithms used in these versions of the programs to determine the properties of windows with shading layers are relatively new and should be considered as informative but not definitive.

As such, for windows with shading layers, the results are intended for research purposes only. Pending further validation efforts, results for windows with sh ading layers should not be used for NFRC certified calculations of design decisions in real buildings.

All calculations for products without shading layers are identical to those from WINDOW 5.2.

WINDOW 6 Research Version includes all of the WINDOW 5 capabilities with the addition of shading algorithms from ISO15099 which are incorporated into the program, as well as an extension of those algorithms with the matrix calculation method.

THERM 6 Research Version includes all of the THERM 5 capabilities with the addition of being able to import and model WINDOW 6 glazing systems with shading devices. Those THERM 6 files with shading devices can them be imported into the WINDOW 6 Frame Library and whole windows with shading devices can then be modeled in WINDOW 6.

1 aMitchell, Robin1 aKohler, Christian1 aKlems, Joseph, H.1 aRubin, Michael, D.1 aArasteh, Dariush, K.1 aHuizenga, Charlie1 aYu, Tiefeng1 aCurcija, Dragan, C. uhttps://facades.lbl.gov/publications/window-62therm-62-research-version01940nas a2200181 4500008004100000245004500041210004200086260001200128490000700140520137800147653003101525653003001556653003801586653001801624100001901642700002401661856007301685 2007 eng d00aA low-energy linear oxygen plasma source0 alowenergy linear oxygen plasma source c04/20070 v783 a

A new version of a constricted plasma source is described, characterized by all metal-ceramic construction, a linear slit exit of 180 mm length, and cw operation typically 50 kHz at an average power of 1.5 kW. The plasma source is here operated with oxygen gas, producing streaming plasma that contains mainly positive molecular and atomic ions, and to a much lesser degree, negative ions. The maximum total ion current obtained was about 0.5 A. The fraction of atomic ions reached more than 10% of all ions when the flow rate was less then 10 SCCM O2, corresponding to a chamber pressure of about 0.5 Pa for the selected pumping speed. The energy distribution functions of the different ion species were measured with a combined mass spectrometer and energy analyzer. The time-averaged distribution functions were broad and ranged from about 30 to 90 eV at 200 kHz and higher frequencies, while they were only several eV broad at 50 kHz and lower frequencies, with the maximum located at about 40 eV for the grounded anode case. This maximum was shifted down to about 7 eV when the anode was floating, indicating the important role of the plasma potential for the ion energy for a given substrate potential. The source could be scaled to greater length and may be useful for functionalization of surfaces and plasma-assisted deposition of compound films.

10aatomic and molecular ions10aConstricted plasma source10aion energy distribution functions10aoxygen plasma1 aAnders, André1 aYushkov, Georgy, Yu uhttps://facades.lbl.gov/publications/low-energy-linear-oxygen-plasma01663nas a2200325 4500008004100000024002100041245004200062210004200104260001200146520070300158653002500861653001300886653002500899653002700924653002200951653001800973653001600991653002301007653001901030100002101049700002701070700002201097700002901119700002201148700002401170700002201194700002401216700002101240856007601261 2006 eng d aCEC-500-2006-05200aAdvancement of Electrochromic Windows0 aAdvancement of Electrochromic Windows c04/20063 a

This guide provides consumer-oriented information about switchable electrochromic (EC) windows. Electrochromic windows change tint with a small applied voltage, providing building owners and occupants with the option to have clear or tinted windows at any time, irrespective of whether it's sunny or cloudy. EC windows can be manually or automatically controlled based on daylight, solar heat gain, glare, view, energy-efficiency, peak electricity demand response, or other criteria. Window controls can be integrated with other building systems, such as lighting and heating/cooling mechanical systems, to optimize interior environmental conditions, occupant comfort, and energy-efficiency.

10acommercial buildings10adaylight10adaylighting controls10aElectrochromic windows10aenergy efficiency10ahuman factors10apeak demand10aswitchable windows10avisual comfort1 aLee, Eleanor, S.1 aSelkowitz, Stephen, E.1 aClear, Robert, D.1 aDiBartolomeo, Dennis, L.1 aKlems, Joseph, H.1 aFernandes, Luis, L.1 aWard, Gregory, J.1 aInkarojrit, Vorapat1 aYazdanian, Mehry uhttps://facades.lbl.gov/publications/advancement-electrochromic-windows02135nas a2200205 4500008004100000050001500041245005900056210005600115520147900171100002101650700002701671700002201698700002901720700002201749700002401771700002201795700002401817700002101841856006701862 2006 eng d aLBNL-5995000aA Design Guide for Early-Market Electrochromic Windows0 aDesign Guide for EarlyMarket Electrochromic Windows3 a

Switchable variable-tint electrochromic windows preserve the view out while modulating transmitted light, glare, and solar heat gains and can reduce energy use and peak demand. To provide designers objective information on the risks and benefits of this technology, this study offers data from simulations, laboratory tests, and a 2.5-year field test of prototype large-area electrochromic windows evaluated under outdoor sun and sky conditions. The study characterized the prototypes in terms of transmittance range, coloring uniformity, switching speed, and control accuracy. It also integrated the windows with a daylighting control system and then used sensors and algorithms to balance energy efficiency and visual comfort, demonstrating the importance of intelligent design and control strategies to provide the best performance. Compared to an efficient low-e window with the same daylighting control system, the electrochromic window showed annual peak cooling load reductions from control of solar heat gains of 19-26% and lighting energy use savings of 48-67% when controlled for visual comfort. Subjects strongly preferred the electrochromic window over the reference window, with preferences related to perceived reductions in glare, reflections on the computer monitor, and window luminance. The EC windows provide provided the benefit of greater access to view year-round. Though not definitive, findings can be of great value to building professionals.

1 aLee, Eleanor, S.1 aSelkowitz, Stephen, E.1 aClear, Robert, D.1 aDiBartolomeo, Dennis, L.1 aKlems, Joseph, H.1 aFernandes, Luis, L.1 aWard, Gregory, J.1 aInkarojrit, Vorapat1 aYazdanian, Mehry uhttps://facades.lbl.gov/publications/design-guide-early-market02228nas a2200205 4500008004100000245010200041210006900143260003300212490001600245520148700261653003701748653002201785653002501807100002101832700002901853700002201882700002101904700002701925856007001952 2006 eng d00aMonitored Energy Performance of Electrochromic Windows Controlled for Daylight and Visual Comfort0 aMonitored Energy Performance of Electrochromic Windows Controlle aQuebec City, Canadac10/20060 v112 Issue 23 a

A 20-month field study was conducted to measure the energy performance of south-facing large-area tungsten-oxide absorptive electrochromic (EC) windows with a broad switching range in a private office setting. The EC windows were controlled by a variety of means to bring in daylight while minimizing window glare. For some cases, a Venetian blind was coupled with the EC window to block direct sun. Some tests also involved dividing the EC window wall into zones where the upper EC zone was controlled to admit daylight while the lower zone was controlled to prevent glare yet permit view. If visual comfort requirements are addressed by EC control and Venetian blinds, a 2-zone EC window configuration provided average daily lighting energy savings of 10-15% compared to the reference case with fully lowered Venetian blinds. Cooling load reductions were 0-3%. If the reference case assumes no daylighting controls, lighting energy savings would be 44-11%. Peak demand reductions due to window cooling load, given a critical demand-response mode, were 19-26% maximum on clear sunny days. Peak demand reductions in lighting energy use were 0% or 72-100% compared to a reference case with and without daylighting controls, respectively. Lighting energy use was found to be very sensitive to how glare and sun is controlled. Additional research should be conducted to fine-tune EC control for visual comfort based on solar conditions so as to increase lighting energy savings.

10abuilding automation and controls10aBuilding envelope10acommercial buildings1 aLee, Eleanor, S.1 aDiBartolomeo, Dennis, L.1 aKlems, Joseph, H.1 aYazdanian, Mehry1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/monitored-energy-performance02280nas a2200133 4500008004100000050001500041245009700056210006900153520178900222100002102011700002102032700002702053856006602080 2004 eng d aLBNL-5496600aThe Energy-Savings Potential of Electrochromic Windows in the US Commercial Buildings Sector0 aEnergySavings Potential of Electrochromic Windows in the US Comm3 a

Switchable electrochromic (EC) windows have been projected to significantly reduce the energy use of buildings nationwide. This study quantifies the potential impact of electrochromic windows on US primary energy use in the commercial building sector and also provides a broader database of energy use and peak demand savings for perimeter zones than that given in previous LBNL simulation studies. The DOE-2.1E building simulation program was used to predict the annual energy use of a three-story prototypical commercial office building located in five US climates and 16 California climate zones. The energy performance of an electrochromic window controlled to maintain daylight illuminance at a prescribed setpoint level is compared to conventional and the best available commercial windows as well as windows defined by the ASHRAE 90.1-1999 and California Title 24-2005 Prescriptive Standards. Perimeter zone energy use and peak demand savings data by orientation, window size, and climate are given for windows with interior shading, attached shading, and horizon obstructions (to simulate an urban environment).

Perimeter zone primary energy use is reduced by 10-20% in east, south, and west zones in most climates if the commercial building has a large window-to-wall area ratio of 0.60 compared to a spectrally selective low-e window with daylighting controls and no interior or exterior shading. Peak demand for the same condition is reduced by 20-30%. The emerging electrochromic window with daylighting controls is projected to save approximately 91.5-97.3 1012 Btu in the year 2030 compared to a spectrally selective low-E window with manually-controlled interior shades and no daylighting controls if it reaches a 40% market penetration level in that year.

1 aLee, Eleanor, S.1 aYazdanian, Mehry1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/energy-savings-potential02249nas a2200181 4500008004100000245009800041210006900139260001200208520162500220100002101845700001301866700002101879700002401900700002401924700002301948700002701971856006901998 2002 eng d00aEnergy Performance Analysis of Electrochromic Windows in New York Commercial Office Buildings0 aEnergy Performance Analysis of Electrochromic Windows in New Yor c11/20023 a

A DOE-2.1E energy simulation analysis of a switchable electrochromic (EC) glazing with daylighting controls has been conducted for prototypical office buildings in New York (NY). The modeling included four types of office buildings: "old" and "new" vintages and large (10,405 m2, 112,000 ft2) and small (502m2, 5400 ft2) buildings. Five commercially available, base case windows with and without interior shades were modeled. Window area varied from 0 to 60% of the exterior floor-to-floor wall area. The electric lighting had either no controls or continuous daylighting controls. The prototypes were modeled in New York City or Buffalo.

Energy performance ata are given for each of the four perimeter zones. Data are presented as a function of window-to-wall ratio in order to better understand the interactions between 1) electric lighting energy use and daylight admission and 2) solar heat gains and space-conditioning energy use. Maximum and minimum reductions in energy use between the EC glazing and all other base case conditions are also presented. Projected energy use reductions relative to typical specified NY office buildings are presented as an indication of the potential impacts EC glazings might have in retrofit and new construction.

The energy and demand reductions provided by EC glazings with daylighting controls relative to what is typically specified in office buildings in NY are quite substantial. EC glazings will also dampen fluctuations in interior daylight levels and window brightness, potentially increasing visual comfort.

1 aLee, Eleanor, S.1 aZhou, L.1 aYazdanian, Mehry1 aInkarojrit, Vorapat1 aSlack, Jonathan, L.1 aRubin, Michael, D.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/energy-performance-analysis01962nas a2200169 4500008004100000050001500041245010000056210006900156260003100225490001600256520135300272100002401625700002901649700002101678700002501699856006801724 1997 eng d aLBNL-4069000aThe Significance of Bolts in the Thermal Performance of Curtain-Wall Frames for Glazed Façades0 aSignificance of Bolts in the Thermal Performance of CurtainWall  aSan Francisco, CAc01/19980 v104, Part 13 a

Curtain walls are assemblies of glazings and metal frames that commonly form the exterior glass façades of commercial buildings. Evaluating the thermal performance of the bolts that hold curtain wall glazings in place is necessary to accurately rate the overall thermal performance of curtain walls. Using laboratory tests and computer simulations, we assessed the thermal performance of several different configurations of bolts and glazings. Curtain-wall samples were tested in the infrared thermography laboratory at the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California. Experimental results were compared to two-dimensional simulations approximating the thermal effect of the bolts using the parallel path and the isothermal planes calculation methods. We conclude that stainless steel bolts minimally affect curtain-wall thermal performance (approximately 18%) when spaced at least nine inches apart, which is the industry standard. Performance is increasingly compromised when there is less than nine inches between bolts or when steel bolts are used. We also show that the isothermal planes method of approximating curtain wall thermal performance can be used with 2-D heat transfer software typical of that used in the window industry to give conservative results for the thermal bridging effect caused by bolts.

1 aGriffith, Brent, T.1 aFinlayson, Elizabeth, U.1 aYazdanian, Mehry1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/significance-bolts-thermal01437nas a2200157 4500008004100000050001500041245009200056210006900148260003100217520085700248100002001105700002001125700002501145700002101170856008801191 1996 eng d aLBNL-3969200aThe National Energy Requirements of Residential Windows in the U.S.: Today and Tomorrow0 aNational Energy Requirements of Residential Windows in the US To aPacific Grove, CAc08/19963 a

This paper describes an end-use analysis of the national energy requirements of U.S. residential window technologies. We estimate that the current U.S. 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 U.S. energy consumption. We 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. We 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.

1 aFrost, Karl, J.1 aEto, Joseph, H.1 aArasteh, Dariush, K.1 aYazdanian, Mehry uhttp://aceee.org/files/proceedings/1996/data/papers/SS96_Panel10_Paper07.pdf#page=100835nas a2200145 4500008004100000050001400041245004700055210004700102260003400149520037100183100002200554700002100576700002000597856007200617 1995 eng d aLBL-3774700aMeasured Performance of Selective Glazings0 aMeasured Performance of Selective Glazings aClearwater Beach, FLc12/19953 a

Measurements of the net heat flow through four selective glazings in comparison with clear double glazing under late summer outdoor conditions are presented. The solar heat gain coefficient (SHGC) for each glazing is extracted from the data and shown to be angle-dependent. Good agreement is found between measured properties and calculations with WINDOW 4.1.

1 aKlems, Joseph, H.1 aYazdanian, Mehry1 aKelley, Guy, O. uhttps://facades.lbl.gov/publications/measured-performance-selective01409nas a2200241 4500008004100000050001400041245008900055210006900144520063300213100001900846700001300865700001200878700002900890700002300919700002000942700002000962700002300982700002201005700001701027700002301044700002101067856007901088 1994 eng d aLBL-3729600aFundamental Materials-Issues Involved in the Growth of GaN by Molecular Beam Epitaxy0 aFundamental MaterialsIssues Involved in the Growth of GaN by Mol3 a

Gallium nitride is one of the most promising materials for ultraviolet and blue light-emitting diodes and lasers. Both Molecular Beam Epitaxy (MBE) and Metal-Organic Chemical Vapor Deposition (MOCVD) have recently made strong progress in fabricating high-quality epitaxial GaN thin films. In this paper, we review materials-related issues involved in MBE growth. We show that a strong understanding of the unique meta-stable growth process allows us to correctly predict the optimum conditions for epitaxial GaN growth. The resulting structural, electronic and optical properties of the GaN films are described in detail.

1 aNewman, Nathan1 aFu, T.C.1 aLiu, Z.1 aLiliental-Weber, Zuzanna1 aRubin, Michael, D.1 aChan, James, S.1 aJones, Erin, C.1 aRoss, Jennifer, T.1 aTidswell, Ian, M.1 aYu, Kin, Man1 aCheung, Nathan, W.1 aWeber, Eicke, R. uhttps://facades.lbl.gov/publications/fundamental-materials-issues-involved01301nas a2200133 4500008004100000050001400041245009400055210006900149490001600218520081200234100002101046700002201067856007801089 1993 eng d aLBL-3471700aMeasurement of the Exterior Convective Film Coefficient for Windows in Low-Rise Buildings0 aMeasurement of the Exterior Convective Film Coefficient for Wind0 v100, Part 13 a

The MoWiTT field facility is used to measure the convective film coefficient over the exterior surface of a window. The MoWiTT-measured data is compared to some commonly-used experimental and theoretical models. The comparison shows that the MoWiTT data disagrees with the previously used models such as the ASHRAE/DOE-2 model. The reasons for these disagreements are discussed. An experimental model, based on the MoWiTT data, is presented to correlate the film coefficient with the difference in temperatures of the exterior glass surface and the ambient, in the natural convection region, and with the site wind speed, in the forced convection region. The wind speed is considered both in windward and leeward hemispheres. The validity of the MoWiTT model for low-rise buildings is then discussed.

1 aYazdanian, Mehry1 aKlems, Joseph, H. uhttps://facades.lbl.gov/publications/measurement-exterior-convective-film