Glazings for the 21st Century - Windows and Daylighting Group

More documents

Recommendations

Info

F A L LW I N T E R1 9 9 710Fenestration Facts“When shopping forwindows and skylights, payclose attention to whetherthe U-factor listed by themanufacturer applies to theglazing only or to the entireunit. If it is for the glazingonly, the overall U-factormay be considerably higherbecause of the frame andspacer effects. These effectsincrease with decreasingtotal window area.”Selecting Windows forEnergy EfficientyU.S. Department of Energy1997LAWRENCE BERKELEYNATIONALLABORATORYENVIRONMENTALENERGYTECHNOLOGIES DIVISIONBUILDING TECHNOLOGIESPROGRAMWINDOWS & DAYLIGHTINGGROUPRecent ResearchPublicationsElectrochromic Lithium NickelOxide by Pulsed LaserDepositionand Sputtering. 1996. Rubin M.,Wen S-H., Richardson T., Kerr J.,von Rottkay K., Slack J. SPIE InternationalSymposium on OpticalMaterials Technology for EnergyEfficiency and Solar Energy ConversionXV, Freiburg, Germany. Tobe published in Solar Energy Materialsand Solar Cells.Abstract: Thin films of lithiumnickel oxide were deposited bysputtering and pulsed laser deposition(PLD) from targets of pressedLiNiO 2 powder. The compositionand structure of these films wereanalyzed using a variety of techniques,such as nuclear-reactionanalysis, Rutherford backscatteringspectrometry (RBS), x-ray diffraction,infrared spectroscopy, andatomic force microscopy. Crystallinestructure, surface morphologyand chemical composition ofLi x Ni 1-x O thin films depend stronglyon deposition oxygen pressure,temperature, as well as substratetargetdistance. The films producedat temperatures lower than 600°Cspontaneously absorb CO 2 and H 2 Oat their surface once they are exposedto the air. The films depositedat 600°C proved to be stable inair over a long period. Even at roomtemperature the PLD films aredenser and more stable than sputteredfilms. RBS determined thecomposition of the best films to beLi 0.5 Ni 0.5 O deposited by PLD at 60mTorr O 2 pressure. Electrochemicaltests show that the films exhibit excellentreversibility in the range 1.0Vto 3.4 Vversus lithium. Electrochemicalformatting which is usedto develop electrochromism in otherfilms is not needed for the stoichiometricfilms. The optical transmissionrange is almost 70% at 550 nmfor 150-nm thick films. Devicesmade from these films were analyzedusing novel reference electrodesand by disassembly after cycling.Energy Performance of EvacuatedGlazings in Residential Buildings.1995. Sullivan R., Beck F.,Arasteh D., Selkowitz S. ASHRAETransactions 102(2) (1996). (LBL-37130 Rev.)Abstract: This paper presents theresults of a study investigating theenergy performance of evacuatedglazings or glazings which maintaina vacuum between two panes ofglass. Their performance is measuredby comparing results to prototypehighly insulated superwindowsas well as a more conventional insulatingglass unit with a low-Ecoating and argon gas fill. We usedthe DOE-2.1E energy analysis simulationprogram to analyze the annualand hourly heating energy usedue to the windows of a prototypicalsingle-story house located inMadison, Wisconsin. Cooling energyperformance was also investigated.Our results show that for highlyinsulating windows, the solar heatgain coefficient is as important asthe window's U-factor in determiningheating performance for windoworientations facing west-southeast.For other orientations inwhich there is not much direct solarradiation, the window's U-factorprimarily governs performance.The vacuum glazings had lowerheating requirements than the superwindowsfor most window orientations.The conventional low-Ewindow outperformed the superwindowsfor southwest-southsoutheastorientations. These performancedifferences are directlyrelated to the solar heat gain coefficientsof the various windows analyzed.The cooling performance ofthe windows was inversely relatedto the heating performance. Thelow solar heat gain coefficients ofthe superwindows resulted in thebest cooling performance. However,we were able to mitigate thecooling differences of the windowsby using an interior shading devicethat reduced the amount of solargain.Advanced Optical DaylightingSystems: Light Shelves and LightPipes. 1995. Beltrán L.O., LeeE.S., and Selkowitz S.E. 1996.IESNAAnnual Conference, August4-7, 1996, Cleveland, OH, and to beconsidered for publication in theJournal of the IES and Lighting Designand Application. (LBL-38133)Abstract: We present two perimeterdaylighting systems that passivelyredirect beam sunlight furtherfrom the window wall usingspecial optical films, an optimizedgeometry, and a small glazing aperture.The objectives of these systemsare (1) to increase daylight illuminancelevels at 4.6-9.1 m (15-30 ft) from the window aperturewith minimum solar heat gains and(2) to improve the uniformity of thedaylighting luminance gradientacross the room under variablesolar conditions throughout theyear. The designs were developedthrough a series of computer-assistedray-tracing studies, laser visualizationtechniques, and photometricmeasurements and observationsusing physical scale models. Bidirectionalilluminance measurementsin combination with analytical routineswere then used to simulatedaylight performance for any solarposition, and were incorporated intothe DOE-2.1E building energy analysiscomputer program to evaluateenergy savings. Results show increaseddaylight levels and an improvedluminance gradient throughoutthe year compared to conventionaldaylighting systems.Surface Temperatures of InsulatedGlazing Units: Infrared ThermographyLaboratory Measurements.1995. Griffith B.T., TürlerD., and Arasteh D. 1996 ASHRAETransactions 102(2), San Antonio,TX. (LBL-38117)Abstract: Data are presented forthe distribution of surface temperatureson the warm-side surface ofseven different insulated glazingunits. Surface temperatures aremeasured using infrared thermographyand an external referencingtechnique. This technique allowsdetailed mapping of surface temperaturesthat is non-intrusive. Theglazings were placed between warmand cold environmental chambersthat were operated at conditionscorresponding to standard designconditions for winter heating. Thetemperature conditions are 21.1°C(70°F) and -17.8°C (0°F) on thewarm and cold sides, respectively.Film coefficients varied somewhatwith average conditions of about7.6 W/m 2. K (1.34 Btu/h . ft 2.° F) forthe warm-side and 28.9 W/m 2. K(5.1 Btu/h . ft 2.° F) for the cold-side.Surface temperature data are plottedfor the vertical distribution alongthe centerline of the IG and for thehorizontal distribution along thecenterline. This paper is part of alarger collaborative effort that studiedthe same set of glazings.For copies contactPat Ross(510) 486-6845 Fax (510) 486-4089e-mail: PLRoss@lbl.govhttp://eande.lbl.gov/btp
UserFacilitiesIndustry is invited to collaboratein the use of these facilities. Ineach issue of FenestrationR&D we will take a closer lookat one of our user facilities.Please contact the individual researcherlisted under each facilityto discuss potential use.❐ Mobile Window Thermal TestFacility (MoWiTT) The MoWiTTfacility contains two highly instrumented,side-by-side calorimetrictest chambers that are used to testwindow and wall elements underactual outdoor conditions. The facilitymay be rotated to face in anydirection and is currently located inReno, Nevada, which experiencesboth summer and winter extremeclimate conditions. It can directlymeasure solar heat gain and can beused to determine window andshading system properties for awide variety of solar control options.With 200 data channels collectingdata every few seconds, thefacility can directly measure coolingload shapes on peak summerdays with excellent time resolution.The facility can also be used to validatecomputer models and to comparevarious technologies in realtime. Industry has used MoWiTTresults to justify new product development.ContactJoseph Klems(510) 486-5564 Fax (510) 486-4089e-mail: JHKlems@LBL.gov❐ IR Camera Test Facility Thisfacility includes a high-resolution,infrared imaging camera, a computerprocessor/printer, and a cold/hotchamber to hold samples for testing.The camera system is portableand can measure surface temperaturesthat can then be correlated tovarious heat loss or gain parameters.The IR camera is useful for assessingheat loss from existingbuildings in the field as well asfrom building components and appliancesin the laboratory setting.ContactBrent Griffith(510) 486-6061 Fax (510) 486-4089e-mail: BTGriffith@LBL.gov❐ Thin-Film Materials LaboratoryThis laboratory includes a widerange of apparatus to deposit andanalyze thin-film coatings for energycontrol purposes. The laboratory’sthin-film deposition systemsare used to make new types of selectiveand electrochromic coatings.The laboratory also includes spectrophotometersto measure solar,near IR, and far IR properties.ContactMike Rubin(510) 486-7124 Fax (510) 486-6099e-mail: MDRubin@LBL.gov❐ Sky Simulator The 24-foot-diametersky simulator is a hemisphericalfacility used to test daylightingperformance in scalemodelbuildings under controlledand reproducible conditions. Computerizedcontrol of light sourceswithin the hemisphere can createluminous distributions typical ofclear, uniform, or overcast skiesrepresentative of any desired location,orientation, climate, and seasonon Earth. It can also be used asa sun simulator to test shadingstrategies in scale models up to 1.5square meters in size. Light levelswithin the models are measured by60 photosensors and the measurementsare used to predict daylightilluminance conditions within fullsizedbuildings.ContactStephen Selkowitz(510) 486-5064 Fax (510) 486-4089e-mail: SESelkowitz@LBL.gov❐ Solar Heat Gain Scanner Thisdevice is used to characterize thecomplex optical properties of glazingsand shading systems that aregeometrically complex, such asvenetian blinds. The system measurestransmitted and reflected energyand light at all incidence andoutgoing angles. The scanner hasbeen used to develop a new procedureto predict solar heat gainthrough complex shading systems.ContactJoseph Klems(510) 486-5564 Fax (510) 486-4089e-mail: JHKlems@LBL.govSoftwareAvailable❐ ADELINE 2.0 analyzes lightingenergy savings in buildings that utilizedaylighting. Its unique collectionof software tools for the MS-DOS platform includes Radiancev2.4, Superlite 2.0 IEA, Scribe (a3D editor for simple scenes), and aWindows-like graphical user interfacethat ties these tools together.The package comes with an extensive475 page manual in a looseleaf3-ring binder, context-sensitivehelp menus, online hyper-text help,and installs from CD-ROM.ContactCharles EhrlichFAX (510) 486-4089e-mail: CKEhrlich@lbl.govWeb: http://radsite.lbl.gov/adeline/HOME.html❐ RESFEN 3.0 is a WINDOWS95 (or NT)-based PC program forcalculating residential fenestrationheating and cooling energy use andcosts. This new program (whichuses the DOE-2 calculation engine)is currently being evaluated for possibleuse as part of a window ratingsystem being developed by the NationalFenestration Rating Council(NFRC).❐ SUPERLITE 2.0 is a PC programthat calculates daylight illuminancedistributions for complexroom and light source geometrieswith tested accuracy. SUPERLITEwill model daylight coming throughas many as five openings and beingreflected from as many as 20opaque surfaces oriented in any direction.❐ WINDOW 4.1 is a thermalanalysis PC program that is the defacto standard used by U.S. manufacturersto characterize productperformance. The program is usedby the National Fenestration RatingCouncil as the basis for developmentof energy rating labels forwindows.❐ THERM 1.0 is a MicrosoftWindows-based 2D heat transferanalysis tool, based on finite elementanalysis and can model twodimensionalheat transfer with aminimum of simplifications toexact cross-section geometries.ContactPat Ross(510) 486-6845 Fax (510) 486-4089e-mail: PLRoss@LBL.gov11The Fenestration R&Dnewsletter provides a periodicupdate on U.S. Departmentof Energy-sponsoredwindows and glazings researchat Lawrence BerkeleyNational Laboratory, aswell as other DOE-supportedactivities at Florida SolarEnergy Center, NationalRenewable Energy Laboratory,Oak Ridge NationalLaboratory, University ofMassachusetts, and TuftsUniversity.Fenestration R&D ismade possible with supportfrom the U.S. Departmentof Energy, Assistant Secretaryfor Energy Efficiencyand Renewable Energy, Officeof Building Technology,State and CommunityPrograms, Office of BuildingSystems.Samuel J. TaylorProgramManager, Building Systemsand Materials DivisionLBNL’s Windows andDaylighting Group developsadvanced optical materials,studies fenestrationperformance, and createscomputer-based tools andapplications guides for improvingthe energy-relatedperformance of windows.Stephen E. SelkowitzProgram Head, BuildingTechnologiesF A L LW I N T E R1 9 9 7LAWRENCE BERKELEYNATIONALLABORATORYENVIRONMENTALENERGYTECHNOLOGIES DIVISIONBUILDING TECHNOLOGIESPROGRAMWINDOWS & DAYLIGHTINGGROUP
Page 4 and 5: 4Contributing EditorsRoss McCluneyF
Page 6: 6Fenestration Facts“The most prom
Page 9: Exciting New Publicationsfor the Bu

Glazings for the 21st Century - Windows and Daylighting Group

Create successful ePaper yourself

Delete template?

Save as template?