02275nas a2200277 4500008003900000245015300039210006900192260001200261300001200273490000800285520134500293653003301638653002101671653001601692653002501708653002001733653001801753653001301771100002101784700002101805700001901826700002401845700002201869700002901891856007701920 2016 d00aBalancing daylight, glare, and energy-efficiency goals: An evaluation of exterior coplanar shading systems using complex fenestration modeling tools0 aBalancing daylight glare and energyefficiency goals An evaluatio c01/2016 a279-2980 v1123 a

Exterior shades are the most effective way to control solar load in buildings. Twelve different coplanar shades with different geometry, material properties and cut-off angles were investigated for two California climates: the moderate San Francisco Bay Area climate and a hot and dry Southern California climate. The presented results distinguish themselves from other simulation studies by a newly developed method that combines three research-grade software programs (Radiance, EnergyPlus and Window 7) to calculate heat transfer, daylight, and glare resulting from optically-complex fenestration systems more accurately. Simulations were run for a case with constant electric lighting and a case with daylighting controls for a prototypical, internal load dominated office building.

In the case of daylighting controls, the choice of slat angle and solar cut-off angle of a fixed exterior slat shading system is non trivial. An optimum slat angle was identified for the considered cases. Material properties (e.g., solar and visible reflectance) did not affect energy use if constant electric lighting was assumed, but they did have a significant influence on energy use intensity (EUI) when daylighting controls were assumed. Energy use increased substantially when an additional interior shade was used for glare control.

10aComplex fenestration systems10aDiscomfort Glare10aEnergy Plus10aEnergy Use Intensity10aExterior shades10aGlare Control10aradiance1 aHoffmann, Sabine1 aLee, Eleanor, S.1 aMcNeil, Andrew1 aFernandes, Luis, L.1 aVidanovic, Dragan1 aThanachareonkit, Anothai uhttps://facades.lbl.gov/publications/balancing-daylight-glare-and-energy02083nas a2200193 4500008004100000024001600041245011200057210006900169260006500238520134600303100002101649700002901670700001901699700002401718700002401742700002701766700002701793856006901820 2016 eng d aET14PGE857100aTechnology Assessments of High Performance Envelope with Optimized Lighting, Solar Control, and Daylighting0 aTechnology Assessments of High Performance Envelope with Optimiz aBerkeley, CAbLawrence Berkeley National Laboratoryc09/20163 a

Innovative, cost-effective, energy efficiency technologies and strategies for new and retrofit construction markets are essential for achieving near-term, broad market impacts. This study focuses on innovative shading and daylighting technologies that have the potential to significantly curtail annual cooling and lighting electricity use and reduce summer peak electric demand, particularly in the hot, sunny, inland areas where there has been significant population growth.

The building industry is well aware that energy-efficiency potential does not always match actual, real world performance in the field due to a variety of mitigating factors. Third party verification of the energy savings potential of innovative technologies is important for market adoption. In the case of shading and daylighting technologies, new simulation tools have only recently been developed to improve modeling accuracy. Market acceptance is also heavily dependent on how well the technology balances comfort and indoor environmental quality (IEQ) requirements (e.g., view, brightness, etc.). PG&E commissioned this full-scale monitored study to better understand the impact of mitigating factors on performance so as to make more informed decisions when constructing program interventions that support technology adoption in the market.

1 aLee, Eleanor, S.1 aThanachareonkit, Anothai1 aTouzani, Samir1 aDutton, Spencer, M.1 aShackelford, Jordan1 aDickerhoff, Darryl, J.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/technology-assessments-high02717nas a2200133 4500008003900000245007200039210006900111260001200180520224000192100002402432700002102456700002902477856007702506 2015 d00aElectrochromic Window Demonstration at the Donna Land Port of Entry0 aElectrochromic Window Demonstration at the Donna Land Port of En c05/20153 a

The U.S. General Services Administration (GSA) Public Buildings Service (PBS) has jurisdiction, custody or control over 105 land ports of entry throughout the United States, 35 of which are located along the southern border. At these facilities, one of the critical functions of windows is to provide border control personnel with direct visual contact with the surrounding environment. This also can be done through surveillance cameras, but the high value that U.S. Customs and Border Protection (CPB) officers place on direct visual contact can be encapsulated in the following statement by a senior officer regarding this project: “nothing replaces line of sight.” In sunny conditions, however, outdoor visibility can be severely compromised by glare, especially when the orb of the sun is in the field of view. This often leads to the deployment of operable shading devices, such as Venetian blinds. While these devices address the glare, they obstruct the view of the surroundings, negating the visual security benefits of the windows.

Electrochromic (EC) windows have the ability to adjust their tint dynamically in response to environmental conditions. This provides the potential to control glare by going to a dark tint at times when extreme glare is likely. In previous studies, these windows have shown that this ability to control glare has the potential to increase the amount of time during which view is unobstructed. This technology is available in the U.S. as a commercial product from two vendors with high-capacity manufacturing facilities, and could be deployed on a nationwide scale if successful in a pilot test.

In this project, EC windows were installed at a land port of entry near Donna, Texas. The technical objectives of the study were to determine whether the installation of the EC windows resulted in the following:

1 aFernandes, Luis, L.1 aLee, Eleanor, S.1 aThanachareonkit, Anothai uhttps://facades.lbl.gov/publications/electrochromic-window-demonstration03205nas a2200421 4500008003900000245005700039210005600096260001200152520188100164653002202045653002502067653005202092653003702144653003302181653001602214653003302230653002002263653002102283653002002304653001802324653002502342653003002367653002202397653001202419653002902431653002302460653001902483653002402502653002502526100002102551700002202572700002402594700002102618700001902639700002902658700002202687856007402709 2014 d00aHigh Performance Building Façade Solutions-Phase II0 aHigh Performance Building Façade SolutionsPhase II c03/20143 a

The High Performance Building Façade Solutions–Phase II project was initiated through the California Energy Commission’s Public Interest Energy Research (PIER) program in July 2010 to support industry’s development and deployment of both incremental and breakthrough façade technologies in partnership with the U.S. Department of Energy (DOE). The objective of this three-year project was to develop, or support the development and deployment of, promising near-term and emerging zero net energy building façade technologies for solar control and daylighting, addressing two of the largest end uses in California commercial buildings: cooling and lighting. In partnership with industry (such as manufacturers), three classes of technologies were investigated: daylighting systems, angular-selective shading systems, and dynamic façade systems. Commercially available and emerging prototype technologies were developed and evaluated using laboratory tests. Simulations, full-scale outdoor tests in the Advanced Window Testbed, and demonstration projects quantified energy and peak electric demand reductions and occupant satisfaction, acceptance, and comfort associated with the resultant indoor environment. Several new technologies were developed using virtual prototyping tools. Integrated control systems were developed using model predictive controls. Simulation tools were developed to model operable complex fenestration systems such as shades and microprismatic films. A schematic design tool called COMFEN was developed to facilitate evaluation of these advanced technologies in the early design phase. All three classes of technologies resulted in significant reductions in perimeter zone energy use and peak electric demand, providing viable options that can support California’s long-term goal of achieving zero net energy use in the next decade.

10aautomated shading10abetween-pane shading10abidirectional scattering distribution functions10abuilding energy simulation tools10aComplex fenestration systems10adaylighting10adaylighting simulation tools10aelectrochromics10aexterior shading10agoniophotometer10alight shelves10amicroprismatic films10amodel predictive controls10amotorized shading10ashading10asolar-optical properties10aswitchable windows10athermochromics10avirtual prototyping10awindow heat transfer1 aLee, Eleanor, S.1 aCoffey, Brian, E.1 aFernandes, Luis, L.1 aHoffmann, Sabine1 aMcNeil, Andrew1 aThanachareonkit, Anothai1 aWard, Gregory, J. uhttps://facades.lbl.gov/publications/high-performance-building-fa-ade02991nas a2200217 4500008003900000245010400039210006900143260004200212300001000254490000700264520225800271653003202529653001602561653002402577653001902601653001202620100002902632700002102661700001902682856007202701 2013 d00aEmpirical Assessment of a Prismatic Daylight-Redirecting Window Film in a Full-Scale Office Testbed0 aEmpirical Assessment of a Prismatic DaylightRedirecting Window F aHuntington Beach, Californiac10/2013 a19-450 v103 a

Daylight redirecting systems with vertical windows have the potential to offset lighting energy use in deep perimeter zones. Microstructured prismatic window films can be manufactured using low-cost, roll-to-roll fabrication methods and adhered to the inside surface of existing windows as a retrofit measure or installed as a replacement insulating glass unit in the clerestory portion of the window wall. A clear film patterned with linear, 50-250 micrometer high, four-sided asymmetrical prisms was fabricated and installed in the south-facing, clerestory low-e, clear glazed windows of a full-scale testbed facility. Views through the film were distorted. The film was evaluated in a sunny climate over a two-year period to gauge daylighting and visual comfort performance. The daylighting aperture was small (window-to-wall ratio of 0.18) and the lower windows were blocked off to isolate the evaluation to the window film. Workplane illuminance measurements were made in the 4.6 m (15 ft) deep room furnished as a private office. Analysis of discomfort glare was conducted using high dynamic range imaging coupled with the evalglare software tool, which computes the daylight glare= probability and other metrics used to evaluate visual discomfort.

The window film was found to result in perceptible levels of discomfort glare on clear sunny days from the most conservative view point in the rear of the room looking toward the window. Daylight illuminance levels at the rear of the room were significantly increased above the reference window condition, which was defined as the same glazed clerestory window but with an interior Venetian blind (slat angle set to the cut-off angle), for the equinox to winter solstice period on clear sunny days. For partly cloudy and overcast sky conditions, daylight levels were improved slightly. To reduce glare, the daylighting film was coupled with a diffusing film in an insulating glazing unit. The diffusing film retained the directionality of the redirected light= spreading it within a small range of outgoing angles. This solution was found to reduce glare to imperceptible levels while retaining for the most part the illuminance levels achieved solely by the daylighting film.

10abuildings energy efficiency10adaylighting10amicrostructure film10aprismatic film10awindows1 aThanachareonkit, Anothai1 aLee, Eleanor, S.1 aMcNeil, Andrew uhttps://facades.lbl.gov/publications/empirical-assessment-prismatic02354nas a2200229 4500008003900000245013200039210006900171260001200240300001000252490000800262520159100270653003201861653001801893653001801911653001201929100002101941700001801962700002101980700001802001700002902019856007602048 2013 d00aAn empirical study of a full-scale polymer thermochromic window and its implications on material science development objectives0 aempirical study of a fullscale polymer thermochromic window and  c09/2013 a14-260 v1163 a

Large-area polymer thermochromic (TC) laminated windows were evaluated in a full-scale testbed office. The TC interlayer film exhibited thermochromism through a ligand exchange process, producing a change in solar absorption primarily in the visible range while maintaining transparent, undistorted views through the material. The film had a broad switching temperature range and when combined to make an insulating window unit had center-of-glass properties of Tsol=0.12-0.03, Tvis=0.28-0.03 for a glass temperature range of 24-75°C. Field test measurements enabled characterization of switching as a function of incident solar irradiance and outdoor air temperature, illustrating how radiation influences glass temperature and thus effectively lowers the critical switching temperature of TC devices. This was further supported by EnergyPlus building energy simulations. Both empirical and simulation data were used to illustrate how the ideal critical switching temperature or temperature range for TC devices should be based on zone heat balance, not ambient air temperature. Annual energy use data are given to illustrate the energy savings potential of this type of thermochromic. Based on observations in the field,a broad switching temperature range was found to be useful in ensuring a uniform appearance when incident irradiance is non-uniform across the facade. As indicated in prior research, a high visible transmittance in both the switched and unswitched state is also desirable to enable reduction of lighting energy use and enhance indoor environmental quality.

10abuildings energy efficiency10aSolar control10aThermochromic10awindows1 aLee, Eleanor, S.1 aPang, Xiufeng1 aHoffmann, Sabine1 aGoudey, Howdy1 aThanachareonkit, Anothai uhttps://facades.lbl.gov/publications/empirical-study-full-scale-polymer02589nas a2200289 4500008004100000245010600041210006900147260003400216520165800250653001701908653001701925653001701942653002701959653001201986653002801998653002602026653001202052653001802064100002102082700001602103700002502119700001802144700002202162700002102184700002602205856006802231 2010 eng d00aExperimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames0 aExperimental and Numerical Examination of the Thermal Transmitta aClearwater Beach, FLc09/20103 a

While window frames typically represent 20-30% of the overall window area, their impact on the total window heat transfer rates may be much larger. This effect is even greater in low-conductance (highly insulating) windows which incorporate very low conductance glazings. Developing low-conductance window frames requires accurate simulation tools for product research and development.

The Passivhaus Institute in Germany states that windows (glazing and frames, combined) should have U-values not exceeding 0.80 W/(m2 K). This has created a niche market for highly insulating frames, with frame U-values typically around 0.7-1.0 W/(m2 K). The U-values reported are often based on numerical simulations according to international simulation standards. It is prudent to check the accuracy of these calculation standards, especially for high performance products before more manufacturers begin to use them to improve other product offerings.

In this paper the thermal transmittance of five highly insulating window frames (three wooden frames, one aluminum frame and one PVC frame), found from numerical simulations and experiments, are compared. Hot box calorimeter results are compared with numerical simulations according to ISO 10077-2 and ISO 15099. In addition CFD simulations have been carried out, in order to use the most accurate tool available to investigate the convection and radiation effects inside the frame cavities.

Our results show that available tools commonly used to evaluate window performance, based on ISO standards, give good overall agreement, but specific areas need improvement.

10aexperimental10aFenestration10aframe cavity10aheat transfer modeling10ahot box10ainternational standards10athermal transmittance10aU-value10awindow frames1 aGustavsen, Arlid1 aTalev, Goce1 aArasteh, Dariush, K.1 aGoudey, Howdy1 aKohler, Christian1 aUvsløkk, Sivert1 aJelle, Bjørn, Petter uhttps://facades.lbl.gov/publications/experimental-and-numerical02703nas a2200205 4500008004100000245008300041210006900124260001200193300001400205490000700219520204000226653002402266653002302290653001602313653002702329653002202356100002102378700001902399856007902418 2007 eng d00aEnergy and visual comfort performance of electrochromic windows with overhangs0 aEnergy and visual comfort performance of electrochromic windows  c06/2007 a2439-24490 v423 a

DOE-2 building energy simulations were conducted to determine if there were practical architectural and control strategy solutions that would enable electrochromic (EC) windows to significantly improve visual comfort without eroding energy-efficiency benefits. EC windows were combined with overhangs since opaque overhangs provide protection from direct sun which EC windows are unable to do alone. The window wall was divided into an upper and lower aperture so that various combinations of overhang position and control strategies could be considered. The overhang was positioned either at the top of the upper window aperture or between the upper and lower apertures. Overhang depth was varied. EC control strategies were fully bleached at all times, modulated based on incident vertical solar radiation limits, or modulated to meet the design work plane illuminance with daylight. The EC performance was compared to a state-of-the-art spectrally selective low-e window with the same divided window wall, window size, and overhang as the EC configuration. The reference window was also combined with an interior shade which was manually deployed to control glare and direct sun. Both systems had the same daylighting control system to dim the electric lighting. Results were given for south-facing private offices in a typical commercial building.

In hot and cold climates such as Houston and Chicago, EC windows with overhangs can significantly reduce the average annual daylight glare index (DGI) and deliver significant annual energy use savings if the window area is large. Total primary annual energy use was increased by 2-5% for moderate-area windows in either climate but decreased by 10% in Chicago and 5% in Houston for large-area windows. Peak electric demand can be reduced by 7-8% for moderate-area windows and by 14-16% for large-area windows in either climate. Energy and peak demand reductions can be significantly greater if the reference case does not have exterior shading or state-of-the-art glass.

10abuilding simulation10aControl algorithms10adaylighting10aElectrochromic windows10aenergy efficiency1 aLee, Eleanor, S.1 aTavil, Aslihan uhttps://facades.lbl.gov/publications/energy-and-visual-comfort-performance01648nas a2200121 4500008004100000050001500041245007000056210006900126520122000195100001901415700002101434856007101455 2006 eng d aLBNL-6113700aEffects of Overhangs on the Performance of Electrochromic Windows0 aEffects of Overhangs on the Performance of Electrochromic Window3 a

In this study, various facade designs with overhangs combined with electrochromic (EC) window control strategies were modeled for a typical commercial office building in a hot and cold climate using the DOE 2.1E building energy simulation program. EC windows were combined with overhangs since opaque overhangs provide protection from direct sun which EC windows are unable to do alone. The window wall was divided into an upper and lower aperture so that various combinations of overhang position and control strategies could be considered. The overhang was positioned either at the top of the upper window aperture or between the upper and lower apertures. Overhang depth was varied. EC control strategies were fully bleached at all times, modulated based on incident vertical solar radiation limits, or modulated to meet the design work plane illuminance with daylight. Annual total energy use (ATE), peak electric demand (PED), average daylight illuminance (DI), and daylight glare index (DGI) for south-facing private offices 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/effects-overhangs-performance01044nas 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-performance00500nas a2200109 4500008004100000245008400041210006900125260006000194300000800254100001700262856011100279 2005 eng d00aMaster of the House: Why a Company Should Take Control of Its Building Projects0 aMaster of the House Why a Company Should Take Control of Its Bui bHarvard Business School Publishing Corporationc10/2005 a1-81 aThurm, David uhttp://hbr.org/2005/10/master-of-the-house-why-a-company-should-take-control-of-its-building-projects/ar/102345nas a2200145 4500008004100000245010600041210006900147260003100216520178400247100002102031700002702052700002202079700002102101856007702122 2004 eng d00aMarket Transformation Opportunities for Emerging Dynamic Facade and Dimmable Lighting Control Systems0 aMarket Transformation Opportunities for Emerging Dynamic Facade  aPacific Grove, CAc08/20043 a

Automated shading and daylighting control systems have been commercially available for decades. 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 objective performance requirements. These rigorous performance goals must be achieved with solutions that are cost effective and can operate over long periods with minimal maintenance. It will take time and effort to change the marketplace for these technologies and practices, particularly in building a series of documented success stories, and driving costs and risks to much lower levels at which their use becomes the norm. In recent years, the architectural trend toward highly-transparent all-glass buildings presents a unique challenge and opportunity to advance the market for emerging, smart, dynamic window and dimmable daylighting control technologies.

We believe it is possible to accelerate product market transformation by developing projects where technical advances and the interests of motivated manufacturers and innovative owners converge. In this paper we present a case study example that explains a building owners decision-making process to use dynamic window and dimmable daylighting controls. The case study project undertaken by a major building owner in partnership with a buildings R&D group was designed explicitly to use field test data in conjunction with the market influence of a major landmark building project in New York City to stimulate change in manufacturers product offerings. Preliminary observations on the performance of these systems are made. A cost model that was developed with the building owner is explained.

1 aLee, Eleanor, S.1 aSelkowitz, Stephen, E.1 aHughes, Glenn, D.1 aThurm, David, A. uhttps://facades.lbl.gov/publications/market-transformation-opportunities02647nas a2200193 4500008004100000050001500041245007200056210006900128260003100197520201300228100002002241700001902261700001802280700002502298700001802323700002002341700001702361856007502378 2002 eng d aLBNL-5142500aEnergy Efficient Windows in the Southern Residential Windows Market0 aEnergy Efficient Windows in the Southern Residential Windows Mar aPacific Grove, CAc08/20023 a

The greatest potential in the U.S. for cost-effective energy savings from currently available energy efficient residential windows and skylights exists in the southern market. Prindle and Arasteh recently reported that ten southern states could save over 400 million kwh and 233 MW of peak electricity generating capacity annually by adopting the International Energy Conservation Code (IECC) standard of 0.40 (or less) solar heat gain coefficient (SHGC) for new construction (Prindle & Arasteh 2001). In 2000, Anello et al. demonstrated savings of 14.7 percent in reduced cooling load with high-performance windows (Anello et al. 2000). In 2002, Wilcox demonstrated savings of 20 percent while simulation analysis estimates cooling energy savings in the 30 percent range (Wilcox 2002).

In the southern market, there is significant opportunity for reducing cooling energy use with low solar gain low-E windows. Yet, the southern market has been slow to embrace this new technology. Market research shows that while low-E products have achieved up to 70 percent of the market share in some colder climates (Jennings, Degens & Curtis 2002), they have gained less than 10 percent of the southern windows market (Prindle & Arasteh 2001).

This paper will explore the residential windows market by considering the following: market barriers unique to the southern market; distribution channels in the South; the roles of utilities, codes officials, and other organizations; and other indirect factors that influence this market. This paper will profile current market transformation efforts with case studies of the Florida Windows Initiative, sponsored by the Efficient Windows Collaborative at the Alliance to Save Energy, and the Texas Windows Initiative, sponsored by the American Electric Power Company. Finally, this paper will identify the next steps that will be critical to transforming the southern residential windows market to more efficient window and skylight products.

1 aTribble, Alison1 aOffringa, Kate1 aPrindle, Bill1 aArasteh, Dariush, K.1 aZarnikau, Jay1 aStewart, Arlene1 aNittler, Ken uhttps://facades.lbl.gov/publications/energy-efficient-windows-southern01599nas a2200265 4500008004100000245008300041210006900124260001200193300001200205490001200217520077700229653001001006653003101016653001101047653001501058653002201073100002701095700002001122700002401142700002601166700002501192700002201217700002301239856007101262 2002 eng d00aX-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films0 aXRay Absorption Spectroscopy of Transition MetalMagnesium Hydrid c08/2003 a204-2070 v356-3573 a

Mixed metal thin films containing magnesium and a first-row transition element exhibit very large changes in both reflectance and transmittance on exposure to hydrogen gas. Changes in electronic structure and coordination of the magnesium and transition metal atoms during hydrogen absorption were studied using dynamic in situ transmission mode X-ray absorption spectroscopy. Mg K-edge and Ni, Co, and Ti L-edge spectra reflect both reversible and irreversible changes in the metal environments. A significant shift in the nickel L absorption edge shows it to be an active participant in hydride formation. The effect on cobalt and titanium is much less dramatic, suggesting that these metals act primarily as catalysts for formation of magnesium hydride.

10aEXAFS10aHydrogen storage materials10aNEXAFS10athin films10ax-ray diffraction1 aRichardson, Thomas, J.1 aFarangis, Baker1 aSlack, Jonathan, L.1 aNachimuthu, Ponnusamy1 aPerera, Rupert, C.C.1 aTamura, Nobumichi1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/x-ray-absorption-spectroscopy02449nas a2200157 4500008004100000050001500041245014100056210006900197260003400266520183000300100002402130700001902154700001802173700002502191856007502216 1998 eng d aLBNL-4177200aExperimental Techniques for Measuring Temperature and Velocity Fields to Improve the Use and Validation of Building Heat Transfer Models0 aExperimental Techniques for Measuring Temperature and Velocity F aClearwater Beach, FLc12/19983 a

When modeling thermal performance of building components and envelopes, researchers have traditionally relied on average surface heat-transfer coefficients that often do not accurately represent surface heat-transfer phenomena at any specific point on the component being evaluated. The authors have developed new experimental techniques that measure localized surface heat-flow phenomena resulting from convection. The data gathered using these new experimental procedures can be used to calculate local film coefficients and validate complex models of room and building envelope heat flows. These new techniques use a computer controlled traversing system to measure both temperatures and air velocities in the boundary layer near the surface of a building component, in conjunction with current methods that rely on infrared (IR) thermography to measure surface temperatures. Measured data gathered using these new experimental procedures are presented here for two specimens: (1) a Calibrated Transfer Standard (CTS) that approximates a constant-heat-flux, flat plate; and (2) a dual-glazed, low-emittance (low-e), wood-frame window. The specimens were tested under steady-state heat flow conditions in laboratory thermal chambers. Air temperature and mean velocity data are presented with high spatial resolution (0.25- to 25-mm density). Local surface heat-transfer film coefficients are derived from the experimental data by means of a method that calculates heat flux using a linear equation for air temperature in the inner region of the boundary layer. Local values for convection surface heat-transfer rate vary from 1 to 4.5 W/m2K. Data for air velocity show that convection in the warm-side thermal chamber is mixed forced/natural, but local velocity maximums occur from 4 to 8 mm from the window glazing.

1 aGriffith, Brent, T.1 aTurler, Daniel1 aGoudey, Howdy1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/experimental-techniques-measuring01829nas a2200169 4500008004100000050001500041245008200056210006900138260003900207520123000246100002401476700002201500700001801522700001901540700002501559856007501584 1998 eng d aLBNL-4135200aRapid field testing of low-emittance coated glazings for product verification0 aRapid field testing of lowemittance coated glazings for product  aClearwater Beach, Floridac12/19983 a

This paper analyzes prospects for developing a test device suitable for field verification of the types of low-emittance (low-e) coatings present on high-performance window products. Test devices are currently available that can simply detect the presence of low-e coatings and that can measure other important characteristics of high-performance windows, such as the thickness of glazing layers or the gap in dual glazings. However, no devices have yet been developed that can measure gas concentrations or distinguish among types of coatings. This paper presents two optical methods for verification of low-e coatings. The first method uses a portable, fiber-optic spectrometer to characterize spectral reflectances from 650 to 1,100 nm for selected surfaces within an insulated glazing unit (IGU). The second method uses an infrared-light-emitting diode and a phototransistor to evaluate the aggregate normal reflectance of an IGU at 940 nm. Both methods measure reflectance in the near (solar) infrared spectrum and are useful for distinguishing between regular and spectrally selective low-e coatings. The infrared-diode/phototransistor method appears promising for use in a low-cost, hand-held field test device.

1 aGriffith, Brent, T.1 aKohler, Christian1 aGoudey, Howdy1 aTurler, Daniel1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/rapid-field-testing-low-emittance02461nas 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-heat02680nas a2200181 4500008004100000245003200041210002800073260002400101520214100125100003402266700001802300700002402318700002102342700002202363700002102385700002702406856006502433 1996 eng d00aThe Building Design Advisor0 aBuilding Design Advisor aTucson, AZc03/19963 a

The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, schematic design phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to benefit from the capabilities of multiple tools. The BDA provides a graphical user interface that consists of two main elements: the Building Browser and the Decision Desktop. The Browser allows building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to any number of parameters addressed by the tools linked to the BDA. The BDA is implemented as a Windows™-based application for personal computers. Its initial version is linked to a Schematic Graphic Editor (SGE), which allows designers to quickly and easily specify the geometric characteristics of building components and systems. For every object created in the SGE, the BDA supplies モsmartヤ default values from a Prototypical Values Database (PVD) for all non-geometric parameters required as input to the analysis and visualization tools linked to the BDA. In addition to the SGE and the PVD, the initial version of the BDA is linked to a daylight analysis tool, an energy analysis tool, and a multimedia Case Studies Database (CSD). The next version of the BDA will be linked to additional tools, such as a photo-accurate rendering program and a cost analysis program. Future versions will address the whole building life-cycle and will be linked to construction, commissioning and building monitoring tools.

1 aPapamichael, Konstantinos, M.1 aLaPorta, John1 aChauvet, Hannah, L.1 aCollins, Deirdre1 aTrzcinski, Thomas1 aThorpe, Jack, A.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/building-design-advisor01252nas a2200145 4500008004100000050001400041245008200055210006900137260002800206520072500234100002400959700002500983700001901008856007901027 1995 eng d aLBL-3809300aGas Filled Panels: An Update on Applications in the Building Thermal Envelope0 aGas Filled Panels An Update on Applications in the Building Ther aWashington, DCc11/19953 a

This paper discusses the application of Gas-Filled Panels to the building thermal envelope. Gas-Filled Panels, or GFPs, are thermal insulating devices that retain a high concentration of a low-conductivity gas, at atmospheric pressure, within a multilayer infrared reflective baffle. The thermal performance of the panel depends on the type of gas fill and the baffle configuration. We present computer simulation results showing the improvement in thermal resistance resulting from using an argon-GFP in place of glass fiber batt insulation in wood-frame construction. This report also presents estimates of the quantity and cost of material components needed to manufacture GFPs using current prototype designs.

1 aGriffith, Brent, T.1 aArasteh, Dariush, K.1 aTurler, Daniel uhttps://facades.lbl.gov/publications/gas-filled-panels-update-applications02751nas 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-infrared01611nas a2200157 4500008004100000024001100041245009900052210006900151260001200220490000800232520107300240100002401313700001901337700002501356856007201381 1995 eng d aTA-35200aSurface Temperatures of Insulated Glazing Units: Infrared Thermography Laboratory Measurements0 aSurface Temperatures of Insulated Glazing Units Infrared Thermog c12/19950 v1023 a

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 21.1 °C (70 °F) and -17.8 °C (0 °F) on the warm and cold sides, respectively. Film coefficients varied somewhat with average conditions of about 7.6 W/m2 K (1.34 Btu/h ft2 °F) for the warm-side and 28.9 W/m2 K (5.1 Btu/h ft2 °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.

1 aGriffith, Brent, T.1 aTurler, Daniel1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/surface-temperatures-insulated02870nas a2200157 4500008004100000050001400041245013200055210006900187260002900256520225900285100002202544700002402566700001902590700002502609856007802634 1995 eng d aLBL-3697500aUsing Infrared Thermography for the Creation of a Window Surface Temperature Database to Validate Computer Heat Transfer Models0 aUsing Infrared Thermography for the Creation of a Window Surface aToronto, Canadac06/19953 a

Infrared thermography is a non-invasive, non-destructive technique for measuring surface temperatures of an object. These surface temperatures can be used to understand the thermal performance of window components and complete window systems. Infrared (IR) thermography has long been used for qualitative field assessment of window thermal performance, and is now being used in the laboratory for quantitative assessments of window thermal performance. As windows become better and better, more refined test methods and/or simulation tools are required to accurately detect performance changes and make comparisons between products. While hot box calorimetery has worked well to characterize the thermal performance of conventional insulating products, differences in the thermal performance of new highly insulating systems are often less than the resolution of conventional hot box calorimeters. Infrared imaging techniques offer the opportunity to resolve small differences in the thermal performance of components of highly insulating window systems that hot box measurements are not able to identify.

Lawrence Berkeley Laboratory (LBL), a U.S. national research laboratory, is currently using infrared thermography to develop a database of measured surface temperature profiles for a number of different fenestration products for use in validating both basic and advanced two- and three-dimensional finite element method (FEM) and finite difference method (FDM) fenestration heat transfer simulation programs. IR surface temperature data, when taken under controlled laboratory conditions, can be used to direct the development of these simulation codes, identify their strengths and weaknesses, set research priorities, and validate finished modeling tools. Simulation of fenestration heat transfer is faster and less expensive than hot box testing of fenestration products, and forms the basis of window energy codes being implemented, developed, or considered in the US, Canada, the Former Soviet Union, Europe, and Australia. The National Fenestration Rating Council (U. S.) has developed a simulation-based standard which is used to rate and label window U-values for a published directory of over 10,000 different window products.

1 aBeck, Fredric, A.1 aGriffith, Brent, T.1 aTurler, Daniel1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/using-infrared-thermography-creation01409nas 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-involved01675nas a2200145 4500008004100000050001400041245009100055210006900146260002300215520114400238100002401382700001901406700002501425856007901450 1993 eng d aLBL-3613400aOptimizing the Effective Conductivity and Cost of Gas-Filled Panel Thermal Insulations0 aOptimizing the Effective Conductivity and Cost of GasFilled Pane aTempe, AZc11/19933 a

Gas-Filled Panels, or GFPs, are an advanced theimal insulation that employ a low-conductivity, inert gas, at atmospheiic pressure, within a multilayer reflective baffle. The thermal performance of GFPs varies with gas conductivity, overall panel thickness, and baffle construction. Design parameters of baffle constructions that have a strong effect on GFP thermal resistance are (1) cavities per thickness, (2) cavity surface emittance, and (3) conductance of the baffle materials. GFP thermal performances, where the above parameters were varied, were modeled on a spreadsheet by iterative calculation of one-dimensional energy balances. Heat flow meter apparatus measurements of prototype GFP effective conductivities have been made and are compared to results of the calculations. The costs associated with varying baffle constructions are estimated based on the prices of commercial material components. Results are presented in terms of cost per area per unit thermal resistance ($/Area*R-Value) and are usefid for optimizing GFP designs forsair, argon, or krypton gas fills and a desired effective conductivity and thickness.

1 aGriffith, Brent, T.1 aTurler, Daniel1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/optimizing-effective-conductivity-and