Application Summary Report 15:LED Floodlights

May 2012

Prepared for:

Solid-State Lighting ProgramBuilding Technologies ProgramOffi ce of Energy Effi ciency and Renewable EnergyU.S. Department of Energy

Prepared by:

Pacifi c Northwest National Laboratory

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1 Preface TheU.S.DepartmentofEnergy(DOE)CALiPERprogramhasbeenpurchasingandtestinggeneralilluminationsolidstatelighting(SSL)productssince2006.CALiPERreliesonstandardizedphotometrictesting(followingtheIlluminatingEngineeringSocietyofNorthAmerica[IES]approvedmethodLM79081)conductedbyaccredited,independentlaboratories.2ResultsfromCALiPERtestingareavailabletothepublicviadetailedreportsforeachproductorthroughsummaryreports,whichassembledatafromseveralproducttestsandprovidecomparativeanalyses.3

ItisnotpossibleforCALiPERtotesteverySSLproductonthemarket,especiallygiventherapidlygrowingvarietyofproductsandchangingperformancecharacteristics.Startingin2012,eachCALiPERsummaryreportfocusesonasingleproducttypeorapplication.Productsareselectedwiththeintentofcapturingthecurrentstateofthemarketacrosssectionrangingfromexpectedlowtohighperformingproductswiththebulkcharacterizingtheaverageoftherange.Theselectiondoesnotrepresentastatisticalsampleofallavailableproducts.Toprovidefurthercontext,CALiPERtestresultsmaybecomparedtodatafromLEDLightingFacts,4ENERGYSTARperformancecriteria,5technicalrequirementsfortheDesignLightsConsortium(DLC)QualifiedProductsList(QPL),6orotherestablishedbenchmarks.CALiPERalsotriestopurchaseconventional(i.e.,nonSSL)productsforcomparison,butbecausetheprimaryfocusisSSL,theprogramcanonlytestalimitednumber.

ItisimportantforbuyersandspecifierstoreduceriskbylearninghowtocompareproductsandbyconsideringeverypotentialSSLpurchasecarefully.CALiPERtestresultsareavaluableresource,providingphotometricdataforanonymouslypurchasedproductsaswellasobjectiveanalysisandcomparativeinsights.However,LM7908testingaloneisnotenoughtofullycharacterizeaproductquality,reliability,controllability,physicalattributes,warranty,compatibility,andmanyotherfacetsshouldalsobeconsideredcarefully.

FormoreinformationontheDOESSLprogram,pleasevisithttp://www.ssl.energy.gov.

1IESLM7908,ApprovedMethodfortheElectricalandPhotometricMeasurementsofSolidStateLightingProducts,coversLEDbasedSSLproductswithcontrolelectronicsandheatsinksincorporated.Formoreinformation,visithttp://www.iesna.org/.2CALiPERonlyusesindependenttestinglaboratorieswithLM7908accreditationthatincludesproficiencytesting,suchasthatavailablethroughtheNationalVoluntaryLaboratoryAccreditationProgram(NVLAP).3CALiPERsummaryreportsareavailableathttp://www.ssl.energy.gov/reports.html.Detailedtestreportsforindividualproductscanbeobtainedfromhttp://www.ssl.energy.gov/search.html.4LEDLightingFactsisaprogramoftheU.S.DepartmentofEnergythatshowcasesLEDproductsforgeneralilluminationfrommanufacturerswhocommittotestingproductsandreportingperformanceresultsaccordingtoindustrystandards.TheDOELEDLightingFactsprogramisseparatefromtheLightingFactslabelrequiredbytheFederalTradeCommission(FTC).Formoreinformation,seehttp://www.lightingfacts.com.5ENERGYSTARisafederalprogrampromotingenergyefficiency.Formoreinformation,visithttp://www.energystar.gov.6TheDesignLightsConsortiumQualifiedProductsListisusedbymemberutilitiesandenergyefficiencyprogramstoscreenSSLproductsforrebateprogrameligibility.Formoreinformation,visithttp://www.designlights.org/.

http://www1.eere.energy.gov/buildings/ssl/search.htmlhttp:http://www.designlights.orghttp:http://www.energystar.govhttp:http://www.lightingfacts.comhttp://www.ssl.energy.gov/reports.htmlhttp:http://www.iesna.orghttp:http://www.ssl.energy.gov

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2 Report Summary Thisreportanalyzestheindependentlytestedperformanceof10LEDfloodlightspurchasedbetweenAugustandDecember2011.Thegroupincludedawiderangeofproducts,bothphysicallyandinperformancecharacteristics,whichmirrorsthenearlyindefiniterangeofconventionalluminairesdesignatedasfloodlights.Althoughholisticevaluationsareinappropriate,theresultsprovideseveralkeytakeawaysregardingthefuturegrowthnecessaryforLEDfloodlightstocompetewithandovertakeconventionalproducts.Primarily,therangeoflumenoutputandavailableluminousintensitydistributionsmustexpandtocoverthefullrangeofconventionalproducts.Specifically,higherlumenoutputandnarrowspotdistributionsarecurrentlychallengingforLEDproducts.Further,manycurrentlyavailableLEDfloodlightsdonotofferthesamelevelofcustomizationasconventionalfloodlights,whichusedifferentcombinationsoflamps,reflectors,andaccessoriestoofferavarietyofproductsinthesameformfactor.Despitecurrentlimitations,LEDfloodlightshaveadvantages,suchascolorqualityanddimmability,whichprovideapotentialavenueforwidespreadfutureadoption.

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3 Background Whatisafloodlight?Thetermcanmeandifferentthingstodifferentpeople;itissometimesappliedtotheluminousintensitydistributionofaproductandsometimestotheproductitself.Often,floodlightisuseddifferentlyinthecontextofresidentialandcommercialbuildingsalthoughthereissomeoverlapreferringeithertodirectionallampsortoluminairesusedforfaade,surface,orarealighting.Colloquially,floodlightmightbeusedtodescribethesecuritylightingforaresidence,butitisalsousedtodescribetheluminairesthatilluminatethefaadesofskyscrapers.Clearly,theworldoffloodlightsisdiverse!

Inthisreport,thetermfloodlightreferstoaluminairetypicallyusedtolightexteriorsurfaces.Theaimingangleofthisluminairetypeisusuallyadjustable;thatis,theluminairetypicallyincorporatesalockablehinge(i.e.,knuckle)orswivelpoint.Further,fortypicalconventionalproductsthedistributionisshapedbytheluminairesopticalsystem(s),ratherthanbythelamp(e.g.,PARlamps).Still,thevarietyoffloodlightsissubstantialbecausetheyareusedinmanyapplications.Forexample,floodlightscanbeusedtohighlightasmallsigninfrontofastore,ortoilluminateamonument,orforsecuritylightingoutsideabuilding.Itisalsoimportanttonotethatfloodlightsdonotalwayshaveawidedistribution(e.g.,flood).Theycanhavedistributionsrangingfromverynarrowtoverywideinordertosuittheobjectbeingilluminated,andareoftenasymmetric(i.e.,widerinonedirectionthananother).Simplystated,itisdifficulttocategorizefloodlightsusingasinglemetric.

Conventionalfloodlightluminairesusedincommercialapplicationstypicallyutilizehighintensitydischarge(HID)(e.g.,highpressuresodium[HPS]ormetalhalide)orcompactfluorescent(CFL)lamps.Incandescentorhalogenlampsareusedinafewselectapplications.Becausetheyusethetraditionalmodularapproach,itispossibleforconventionalfloodlightluminairestobeconfiguredwithavarietyoflampsoperatingatdifferentwattagesinordertomeetthelumenoutputneedsofspecificapplications.Similarly,conventionalfloodlightsmayutilizemodularopticstoadjusttheluminousintensitydistributionofasinglebaseunit.7Further,optionalaccessoriescanbeusedtopreventglareandlighttrespass,ortocropaluminairesdistributiontomeetthespecificboundariesofasurface.

LEDFloodlightsThefloodlightmarkethasreceivedrelativelylittleattentionfromLEDfixturemanufacturers,likelyduetoacombinationofseveralfactors.OneissueisthatHIDtechnologymeetstheneedsoffloodlightingapplicationsfairlywellmetalhalidelampshaverelativelyhighefficacyandcanproducealotoflumens,thedistributioniseasilymodifiedwithoptics,andthecolorqualitycanrangefromacceptabletoexcellent.Further,tunability(i.e.,fineadjustmentofoutputandcolor)andcontrollability(i.e.,compatibilitywithdimmersandsensors),twopotentialadvantagesofLEDsinindoorapplications,arenotascriticalforfloodlightingbecausethepurposeisusuallytolightobjectsparticularlyinexteriorenvironmentsratherthanprovidelightforvisualwork.Nonetheless,thesefeaturescanstillbebeneficialincertainapplications.

AsLEDtechnologycontinuestodevelop,thelumenoutputandefficacyofsomeLEDfloodlightsarebecomingcompetitivewithorexceedingconventionalproducts.Further,LEDsdonotsufferfromsomeofthelimitationsofconventionallamps.Forexample,theoutputofCFLlampsisaffectedbytemperatureanddimmingcanbecostly.Similarly,HIDlampshavearestrikedelay,cannotbeeasilydimmed,andtheoutputisdependentonthelamporientation.Althoughtheseissuesmaynotbecriticalforthisproductcategory,theabilityofLEDfloodlightstoaddresstheseshortcomingsispotentiallyvaluable.Additionally,thereismoreopportunitytotune

7Modificationsareusuallynotachievableinthefield,butratheraspecificconfigurationisspecifiedduringorderingandassembledbythemanufacturer.Theballast,socket,opticalsystem,andlampmustallbecompatible.

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theemittedspectrumofLEDsources,whichallowsforgreaterprecisioninmatchingthelightsourcewiththematerial(s)beingilluminated.

SpecifyingFloodlightsFloodlightsaremostoftenspecifiedbasedontheirlumenoutputandbeamshape.Inmanycases,thegeometryoftheluminaireplacementrelativetothetargetsurfacewilldictatetherequiredcharacteristics.Thefurtherthethrowdistance(i.e.,higherorlonger),themorelumenoutputisneeded.Similarly,narrowbeamsatafardistancecanbeusedtoilluminatethesameareaasawidebeamatashortdistance.Table1illustratestheclassificationsystemoftheNationalElectricalManufacturersAssociation(NEMA).UsingtheNEMAsystem,aluminairecanbeclassifiedas13,forexample,wherethefirstdigitcorrespondstothehorizontalfieldangleandtheseconddigitcorrespondstotheverticalfieldangle.8

Inadditiontolumenoutputandbeamshape,itisimportantforspecifierstoconsidersecondaryaspectsofdistribution.Theseincludetheevennessacrossthebeam,thesmoothnessorabruptnessattheedgeofthebeam,aswellastheeffectoflightemittedoutsidethebeam.

TestingFloodlightsFloodlights,includingthosetestedforthisreport,arecustomarilycharacterizedusingTypeBphotometry.Thissystem,whichisdifferentfromwhatisusedformostotherluminairetypes(TypeC),9specifiesthattheoriginofverticalandhorizontalanglesistheprimaryaimingaxisoftheluminaire.Bothhorizontalandverticalanglesrangefrom90to90.Thepracticalconsequencesofthisdifferencearenegligible,andsoftwareusedtoviewphotometricreportsistypicallycapableofautomaticallyconvertingbetweenthetwosystems.Nonetheless,foranyoneviewinganLM7908reportforafloodlight,itisimportanttounderstandthetypeofinformationbeingpresented.

TheperformanceofLEDfloodlightsisnotaffectedbyorientation;however,thelumenoutputofmanymetalhalidelampsisaffectedbytilt.Duringtesting,theorientationisfixed,soitmaybenecessarytoapplyadditionallightlossfactorswhencalculatingtheperformanceofluminairesusingmetalhalidelamps.

8Fieldangle,aswellasothertermsusedinthisreport,isdefinedinAppendixB.9TypeAphotometryisusedforautomotiveheadlights.ThefundamentalsoftypeA,B,orCphotometryarethesame,butthetestingconfigurationsandreportingformatsaredifferent.MoreinformationcanbefoundinIESLM7501,GoniophotometerTypesandPhotometricCoordinates.

Table1. NEMAsystemforluminaireclassification.Thissystemisprimarilyusedforfloodlightingandsportslighting.

NEMABeamType FieldAngle(degrees)1 10182 18293 29464 46705 701006 1001307 130+

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4 Results

CALiPERLEDFloodlightDataThisreportanalyzestheindependentlytestedperformanceof10LEDfloodlightsreferredtoastheSeries15productspurchasedbetweenAugustandDecember2011.Thewiderangeinproducts,bothphysicallyandinperformancecharacteristics,isindicativeoftheextensiverangeoffloodlights.Ratherthanfocusingonasingleapplicationtype,thisgroupofproductsdemonstratesthebreadthofLEDfloodlights.Formoreontheproductselectionparameters,bothingeneralandastheypertaintothisgroupofproducts,seeAppendixA.TheSeries15productsareshowninFigure1.

AlloftheunitsweretestedaccordingtoIESLM7908,usingbothanintegratingsphereandgoniophotometerthedifferenceinmeasuredlumenoutputforeachoftheSeries15productswaslessthan4%,whichistypical.Exceptforluminousintensitydistributioncharacteristics,allvaluesincludedinthisreportweremeasuredusinganintegratingsphereandspectroradiometer.Onlyonesampleofeachproductwastested.Table2summarizesresultsforenergyperformanceandcolorcharacteristicsoftheSeries15products.

LEDfloodlightshavenotbeenpreviouslytestedbyCALiPER.Further,theydonotfallunderthepurviewofENERGYSTAR,norhavespecificationsbeendevelopedbytheDLCoranyotherenergyefficiencyprogram.TheLEDLightingFactsprogramdoesnothaveaseparatecategoryforLEDfloodlights.Asthisproductcategorymatures,newspecificationsandperformancecriteriawillbedeveloped;however,itwilllikelybedifficulttoestablishsomeofthecriteriagiventhenebulousnatureofthefloodlightcategory.

Figure1. PhotographsofproductsincludedinthisseriesofCALiPERtesting.Images arenottoscale.

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CALiPERTestingofConventionalProductBenchmarksOnebenchmarkconventionalfloodlightwasevaluatedinconjunctionwiththisseriesoftesting.Aswithmanyfloodlights,thespecificationsheetlistedavarietyoflampingoptionsinthiscase,HPSormetalhalidelampsrangingfrom50to175W,whichrangeinoutputfromlessthan4,000lumenstomorethan15,000lumens.Themanufacturersdatalistedtheluminaireasbeingapproximately60%to75%efficient,dependingontheconfiguration.Theproductwasavailableinsevendifferentdistributions,rangingfromspottoflood,andhadnumerousaccessoriesavailableforfurthercustomization.Inaddition,thesamemanufacturerofferedasimilarproductthatusesCFLlamp(s),andalargerversionwasavailabletoaccommodate200to400WHIDlamps.Themanufacturerprovidedphotometricdataforwellover100combinationsoflampsandoptics.OneconfigurationwaschosenfortestingbyCALiPER.

InordertoprovideamoredirectcomparisontotheSeries15LEDfloodlights,theCALiPERbenchmarkwastestedusingabsolutephotometry.10Astested,thenarrowdistributionproductemitted5,238lumensandhadaninputpowerof131.2W(40lm/W)a100WED17metalhalidelampwasinstalledduringtesting.Ithada

10Conventionalproductsareusuallytestedusingrelativephotometry.Formoreonthedifferencebetweenabsoluteandrelativephotometry,seetheDOEfactsheet,UnderstandingLM79Reports,availableathttp://www1.eere.energy.gov/buildings/ssl/factsheets.html

Table2. ResultsofCALiPERtestsfortheSeries15LEDfloodlights.Performancecriteriaincludeinitialoutput,totalinputpower,luminousefficacy,powerfactor,colorrenderingindex(CRI),specialcolorrenderingindexR9,correlatedcolortemperature(CCT),andDuv.

DOECALiPERTestID

InitialOutput(lm)

TotalInputPower(W)

LuminousEfficacy(lm/W)

PowerFactor

CRI

R9

CCT(K)

Duv1

1170 773 15.9 49 1.00 72 7 6060 0.0025

1171 8044 251.4 32 0.99 83 27 4057 0.0011

1177 5685 86.0 66 0.98 72 18 6099 0.0037

1178 4173 79.2 53 0.97 70 17 4043 0.0060

1199 2692 40.4 67 0.99 68 24 4290 0.0029

11100 2991 56.6 53 1.00 68 33 5288 0.0045

11101 4170 53.7 78 1.00 66 52 4902 0.0125

11105 6178 76.6 81 0.98 67 20 4341 0.0014

1201 4417 89.2 50 0.99 66 33 4232 0.0055

1206 844 12.4 68 0.80 82 16 3646 0.0001

Minimum 773 12.4 32 0.80 66 52 3646 Mean 3997 76.2 59 0.97 71 15 4696 Maximum 8044 251.4 81 1.00 83 16 6099

Notes:1.RedvaluesareoutsideofANSIdefinedlimitsforgeneralindoorlightingapplications(ANSIC78.377).

http://www1.eere.energy.gov/buildings/ssl/factsheets.html

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centerbeamcandlepower(CBCP)of120,076cd,withfieldanglesof12and20(NEMA12).Theinstalledlamphadaninitialratedoutputof8,500lumens;thus,thefixturewasmeasuredtobe62%efficient.Themanufacturersreporteddataforthe12configurationusedadifferentlamp,sodirectcomparisonbetweenthetestedandreporteddataisnotpossible.Nonetheless,thelistedefficacyforthetestedluminaireconfigurationwas49lm/W,whichismorethan20%greaterthantheefficacymeasuredbyCALiPER.11Thisdifferenceillustratestheimportanceofconsideringbothlampandluminaireperformanceforconventionallightingproducts.Moregenerally,allreasonableeffortsshouldbemadetoensuredesigncalculationsarebasedonthespecifichardwareintendedforinstallation.

CharacterizingConventionalProductsCALiPERisfocusedontestingSSLproductsandisonlyabletotestalimitednumberofbenchmarkconventionalproducts.Especiallyforfloodlights,CALiPERcannottestenoughconventionalproductstocovertheentirescopeofthemarket.TosupplementthelimitedCALiPERdataandinformalcharacterizations,aprofileoftheconventionalproductmarketwasestablishedbyreviewingmanufacturerliterature.12Thereviewincluded126productsfromsevendifferentmanufacturers,allofwhichusedmetalhalidelampsbetween20and150W.Thisrangedoesnotcoverallpossiblefloodlights,butissimilartotherangeoftheSeries15LEDfloodlights.

LumenOutputandEfficacyTheconventionalfloodlightmarketmustbecharacterizedbyconsideringsystemperformance,ratherthanlamporluminaireperformance.Forexample,lumenoutputisdependentonbothlamplumensandtheefficiencyoftheluminaireopticalsystem.Typically,conventionalfloodlightluminairesare45%to85%efficient,withsomedependenceonthelamptypeused.Outputrangesfromabout1,000lumenstomorethanto20,000lumens.UsinganHIDlamp,luminaireefficacywilltypicallybebetween30and80lm/W.EfficacywilltendtobeslightlylowerwhenusingaCFLlampandlessthan20lm/Wforhalogenlamps.

InthereviewofconventionalmetalhalidefloodlightsconductedbyCALiPER,themeanluminaireefficiencywas65%andthemeanluminaireefficacywas51lm/W(seeTable3).Therangeinperformancewasconsiderable,withluminaireefficacyrangingfrom25to83lm/W.Fortheparticularsetofproductssampled,theluminaireoutputrangedfrom1,245to12,716lumens,withameanof6,520lumens.

Lamppropertiescanhaveasubstantialeffectonfloodlightperformance.Forexample,manyHIDlampsareavailablewitheitheraclearoracoatedbulb,whichcanaffectboththeluminaireefficacyandthespatial

11Some,butnotall,ofthisdifferencecanbeattributedtoabsoluteversusrelativephotometry.Othercontributingfactorsinclude:(1)themagneticballastusedintheCALiPERtestfixture(BK1169)hadaballastefficiencyof76%andthemanufacturersIESformatfilelistedaballastefficiencyof79%;and(2)theratedefficacyfortheCALiPERtestedlampwas85lm/W,whereasthelampfromthemanufacturersIESformatfilehadaratedefficacyof93lm/W.12Thereviewwasnotintendedtobecomprehensive,butsimplyindicativeofthetypicalrangeofperformance.

Table3. SummaryperformancecharacteristicsfortheCALiPERsurveyof20to150Wmetalhalidefloodlights.Thetotalsamplesizewas126products,representingsevendifferentmanufacturers.

LuminaireEfficiency

(%)

InitialLuminaireOutput(lm)

TotalInputPower(W)

LuminaireEfficacy(lm/W)

MaximumIntensity

(cd)Minimum 32.0% 1,245 37 24.6 1,024Mean 65.0% 6,520 129 50.9 16,409Maximum 97.0% 12,716 210 82.6 169,307StandardDeviation 12.5% 2,741 47 14.3 29,706

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distributionoflightemitted.Allotherfactorsbeingequal,coatedlampsarelessefficaciousthanclearlamps,butcanimprovelumenmaintenance,reduceflicker,andimprovecolorconsistency.Thelumenoutputofmostmetalhalidelampsisalsosubstantiallyaffectedbytheorientationofthelamp.Thedifferenceinoutputbetweenverticalandhorizontalorientationcanbeasmuchas20%,andthedifferencecanmanifestitselfinitiallyorovertime.Additionally,metalhalidelampsareavailablewithspecificorientationratings:verticalonly,horizontalonly,universal,orwithinasmallrange.Althoughtheyarenotaffectedbyorientation,CFLshavetheirownlimitations.Forexample,theoutputofnonamalgamfluorescentlampsisaffectedbyambienttemperatureactuallumenoutputcanbe50%lessthantheratedlumenoutputwhentheambienttemperatureisat0C(32F).Thisissueispartiallyremediedbyamalgamlampsandenclosedluminairesthatactivelywarmthelamp(s).Beyondtemperaturedependence,fluorescentlampshavealargeluminousarea,makingpreciseopticalcontrolmoredifficult.

DistributionofLightTheluminousintensitydistributionsofconventionalfloodlightscanbeverydifferent,rangingfromverynarrowtoverywide;itisimportantforspecifierstohavearangeofoptions.Table4providesasummaryofdistributioncharacteristicsforthesurveyedproducts,whereasTable5providesabreakdownoftheNEMAclassificationsforhorizontalandverticalfieldangles.Keyobservationsinclude:

Amajorityofthesurveyedproductshadwidedistributions. Onaverage,thehorizontalanglewaswiderthantheverticalangle.Similarly,moreproductshada

narrow(NEMA14)verticalfieldanglethananarrowhorizontalfieldangle.

Table4. SummaryofdistributioncharacteristicsfortheCALiPERsurveyof20to150Wmetalhalidefloodlights.Thetotalsamplesizewas126products,representingsevendifferentmanufacturers.

HorizontalBeamAngle

(deg)

VerticalBeamAngle

(deg)

HorizontalFieldAngle

(deg)

VerticalFieldAngle

(deg)

HorizontalAngleRatio1

VerticalAngleRatio2

Minimum 8 6 19 13 0.11:1 0.13:1Mean 73 46 111 89 0.63:1 0.49:1Maximum 137 117 160 150 0.92:1 0.87:1StandardDeviation 32 31 39 42 0.15:1 0.18:11.Theratioofthehorizontalbeamangleandhorizontalfieldangle.Avaluecloserto1:1indicatesasharperbeamedge.2.Theratiooftheverticalbeamangleandverticalfieldangle.Avaluecloserto1:1indicatesasharperbeamedge.

Table5. SummaryNEMAclassificationsfortheCALiPERsurveyof20to150Wmetalhalidefloodlights.Thetotalsamplesizewas126products,representingsevendifferentmanufacturers.

NEMAClassificationHorizontalCount Percent

VerticalCount Percent

1(1018) 0 0% 5 4%2(1829) 8 6% 10 8%3(2946) 9 7% 8 6%4(4670) 4 3% 16 13%5(70100) 12 10% 27 21%6(100130) 40 32% 34 27%7(130+) 53 42% 26 21%

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Therangeintheratioofbeamangletofieldangle,ameasurecharacterizesthesharpnessofthebeamedge,wasverywide.

Amajorityofproducts(64%)haddistributionswheretheNEMAclassificationwasdifferentforthehorizontalandverticalangle.

ColorCharacteristicsThecolorqualityofconventionalfloodlightsisdependentsolelyontheinstalledlampexcludingwhenaspecificcoloralteringaccessoryisused.HPSlampstypicallyhaveaCRIofabout20andaCCTaround2000K;13becauseofthis,theymaynotbesuitableforsomeapplications.StandardquartzarctubemetalhalidelampstypicallyhaveaCRIbetween60and80,withaCCTbetween3000Kand4500K,whereasceramicarctubemetalhalide(CMH)lampstypicallyhaveaCRIbetween80and95,withaCCTbetween3000Kand4500K.CFLlampsmostoftenhaveanominalCCTbetween2700Kand4000K,withCRIsinthe80s.TolerancesforthecolorimetricperformanceoffluorescentlampsaredefinedinANSIC78.376.TherearenocolorimetricstandardsforHIDlamps.

Beyondstandardcolorqualityissues,colorshiftovertimeisanotableconcernforanyproducttypeusingmetalhalidelamps.TheCCTofquartzmetalhalidelampscanshiftbyupto500Kat40%ofratedlife;CMHlampsdonotshiftasmuch(200K).14Compoundingthisissue,thedirectionoftheshiftinchromaticityisvariable.Forexample,giventhreemetalhalidefloodlights,onemightshiftpink,anotherblue,andtheothergreen.

OtherFactorsOtherimportantcharacteristicsofnoteinclude:

Conventionalfloodlightswithmagneticballaststhemostcommonlyusedtypeareconsideredtohaveahighpowerfactorwhenitisabove0.90.Anormalorlowpowerfactorisbetween0.40and0.60,whereasapowerfactorbetween0.60and0.90isoftencalledpowerfactorcorrected.

ThelifetimeofmetalhalideandCFLlampsusedinfloodlightsistypically6,000to20,000hours.HPSlampstendtolastlonger(20,000to30,000hours).

13SomespecialHPSlampswithincreasedsodiumpressurehaveaCRIaround85andaCCTofapproximately2700K.However,theexpectedlifetimeisreducedandefficacyislowerthanstandardHPSlamps.14SpecifierReports:Lowwattagemetalhalidelightingsystems.Volume10Number1,October2006.LightingResearchCenter,RensselaerPolytechnicInstitute.

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5 Analysis

LumenOutputandEfficacyTherangeofmeasuredoutputfortheSeries15LEDfloodlights,773to8,044lumens,wassubstantialalthoughnotunexpectedgiventheaimsforproductselection.However,themaximumofthatrangeisonlycomparabletoafloodlightusinga100Wor150WHIDlamp.Notably,atleastoneoftheproductstestedwasavailableinaversionwithalistedlumenoutputover18,000lumens(comparabletoa250Wor320WHIDfixture).Still,LEDfloodlightscannotyetmatchtheperformanceofmanyhigherwattage(400Wormore)conventionalfloodlights.Further,becausehighlumenoutputrequiresalargequantityofLEDs,theformfactorforhighoutputproductsmaybelargerand/ortheLEDsmustbeoperatedataveryhighdrivecurrent,whichcanbedetrimentaltolifetime.

Therewasalsoawiderangeofperformancewithregardtoefficacy,withthebestproductdelivering81lm/Wandtheworstproductdelivering32lm/W(lessthantypicalHIDproducts).Notably,theproductdelivering32lm/W(1171)emittedthemostlumensitalsodrew251W.Excludingthisproduct,therangeinefficacywas49to81lm/W,whichisatthehighendofthetypicalrangeforconventionalHIDfloodlights.EfficacyversuslumenoutputisshowninFigure2.

DistributionofLightLuminousintensitydistributioncharacteristicsareparamounttotheperformanceoffloodlights.Onedistributionisnotnecessarilybetterthananother;rather,itiscriticaltoselectaproductwiththecorrectcharacteristicsfortheapplication.DistributioncharacteristicsfortheSeries15productsarelistedinTable6.

Figure2. EfficacyversuslumenoutputofLEDfloodlightscomparedtoconventionalproductperformance.TheSeries15LEDfloodlightsperformedwellintermsofefficacy,butdidnotmatchthelumenoutputoffloodlightsusinghigherwattagemetalhalidelamps.Theapproximaterangesrepresentluminaireperformance.

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Fourofthetenproductshadaverywidedistribution,andeightofthetenproductshadasymmetricdistribution(i.e.,theyhadthesameNEMAclassificationforthehorizontalandverticalangles).Thisisnottypicalofthebulkofconventionalfloodlights,andmayindicateanareawhereLEDfloodlightsneedtoofferaddedcapability.TwooftheSeries15LEDfloodlights(11100and11105)hadnoopticalcontrolsystem;hence,theyhadverywideluminousintensitydistributions.Anuncontrolleddistributioncanresultinstraylight,whichrepresentswastedenergyandcanposeproblemsintermsofglareandlightpollution.

Notallaspectsofdistributioncanbecapturednumerically.Insomeapplications,thesmoothnessofthebeampatternfromthecentertotheedgecanbeveryimportant.Thischaracteristiclacksametric,butadjectivessuchassmooth,spotty,orunevenaresometimesused.ThephotographsinFigure3illustratethebeampatternscreatedbytheSeries15floodlights.TheLEDfloodlightstendedtohaveverysmoothdistributionsproduct1177wastheexception.Thischaracteristicissomewhatdifferentfromtheconventionalbenchmark,product1169.

Figure3alsoillustratesthedifferencebetweenasoftandhardbeamedge,acharacteristicthatcantypicallybeinferredfromtherelationshipbetweenthebeamangleandfieldangleofagivenproductthegreaterthedifferencebetweenbeamangleandfieldangle,thesharperthebeamwillappear.Forexample,product1201(0.5:1ratioofbeamangletofieldangle)hasafairlysharpbeamedge,whereasproduct11105(0.73:1ratioof

Table6. LuminousintensitydistributioncharacteristicsoftheSeries15LEDfloodlightsandtheconventionalbenchmark.Thevalueslistedforthebenchmarkproductareforthespecificconfigurationthatwastested.Thebenchmarkisnotincludedinthesummarystatistics.

DOECALiPERTestID

CBCP(cd)

MaxIntensity

(cd)

HorizontalBeamAngle

(deg)

VerticalBeamAngle

(deg)

HorizontalFieldAngle

(deg)

VerticalFieldAngle

(deg)

NEMAClassification

(HV)

BK1169 120,076 120,076 4 10 12 20 12

1170 1,269 1,270 36 36 83 84 55

1171 44,464 44,464 22 22 43 42 33

1177 1,909 3,912 141 65 165 116 76

1178 65,241 65,241 12 12 24 23 22

1199 15,703 15,772 48 10 64 20 42

11100 1,082 1,083 114 113 147 148 77

11101 2,381 2,483 80 74 131 131 77

11105 2,148 2,153 114 114 156 155 77

1201 26,577 26,577 22 21 43 41 33

1206 8,580 8,580 14 14 30 31 33

Minimum 1,082 1,083 12 10 24 20 Mean 16,935 17,154 60 48 89 79 Maximum 65,241 65,241 141 114 165 155

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Figure3. PhotographsdemonstratingthedistributionoftheSeries15floodlights.Thefirstcolumnshowstheproductaimedstraightatthewall(i.e.,theaxisofthebeamwasperpendiculartothewall).Thesecondandthirdcolumns(ifapplicable)showthedistributionoflightcreatedwiththeluminairepositionedatthebaseofthewall,aimingstraightup.ThehorizontalandverticalcolumnsvisuallyrepresentthehorizontalandverticalanglevalueslistedinTable6.Allphotographsweretakenusingthesameexposuresettingsandfromthesamelocation,withtheluminairemountedatthesameposition.

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beamangletofieldangle)hasasofterbeamedge.Overall,therangeofbeamedgecharacteristicsfortheSeries15LEDfloodlightsandthesurveyedconventionalfloodlightswassimilar.

ColorCharacteristicsInmanyapplicationswherefloodlightsareused,colorqualityisasecondaryconsideration.Insomeapplications,thecolorofaspecificobject(e.g.,aredbrickwallorabronzesculpture)dictatesthecolorqualitythatisnecessary,butthiscannotnecessarilybecapturedwithametric.Sometimes,analyzingthespectralpowerdistributionorvisuallyevaluatingamockuparethebestoptions.Giventheseconsiderations,rigidcriteriaforcolorqualityarenotappropriateforfloodlights;nonetheless,itshouldnotbeignored.

TheCCToftheSeries15LEDfloodlightsrangedfrom3646Kto6099K,andseveraloftheproductsextendedabovetherangetypicalofmetalhalideandCFLlamps.Oneofthoseproducts(11101)alsofelloutsidetheANSIdefinedlimitsfornominallywhitelightwhichareintendedonlyforsolidstatelightingproductsusedindoorshavingaDuvof0.0125.AlthoughhigherCCTsmaybeappropriateinsomeapplications,theprevalenceoftheseproductsamongthesamplesuggeststhatmoreworkisnecessarytoensureLEDfloodlightsareanequivalentalternativetoconventionalfloodlights.

EachoftheproductshadaCRIbetween66and83,withameanforthegroupof71.OnlytwoproductshadaCRIgreaterthan80(1171and1206).TheseCRIsaretypicalofstandardquartzmetalhalidelamps,butonlythetwohighestbegintomatchtheperformanceofCFLorCMHlamps,asshowninFigure4.SimilartootherrecentCALiPERtesting,theR9valuesfortheSeries15LEDfloodlightshadastrongcorrelationwithCRI;theproducts

Figure4. Colorrenderingindex(CRI)versuscorrelatedcolortemperature(CCT)fortheSeries15LEDfloodlightsincomparisontotypicalrangesforconventionalproducts.TheCCTforseveraloftheSeries15productsextendsbeyondthetypicalrangeforconventionalfloodlights.HPSlamps(notshown)typicallyhaveaCRIofabout20andaCCTofabout2000K.

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thathadaCRIbelow80allhadanR9oflessthanzero.Aspreviouslynoted,however,theselowvaluesarenotnecessarilyinappropriateforfloodlights.

ElectricalCharacteristicsInputpowerfortheSeries15productsrangedfrom12.4to251.4W,correspondingtothesubstantialdifferenceinlumenoutput.Themeasuredpowerfactorrangedfrom0.80to1.00,withameanof0.97.Nineofthetenproductshadapowerfactorof0.97orgreater,whichisconsiderablybetterthantypicalconventionalproducts.

VariabilityandCustomizationOnecommonattributeofmanyconventionalfloodlightsistheabilitytocustomizeperformanceusingdifferentlamps,opticalsystems,andaccessories(e.g.,snoots,louvers,barndoors).Formanyinstallations,itisnecessarytouseacombinationofdifferentdistributions/outputstoachieveaspecificvisualeffect.Itisalsodesirabletohaveallthefixturehousingsbeidentical,necessitatingthenumerousoptions.AsshowninTable7,someoftheSeries15LEDfloodlightsaffordedthisflexibility,butothersdidnot.Itislikelythatproductsonlyofferingasingledistributiontypeandsinglelumenpackagewillbelesssuitedforanygivenapplication,andmayberelegatedtolessrefinedinstallations.Inthefuture,itwouldbebestifallLEDfloodlightsofferedthesamecustomizabilitycurrentlyavailablefromconventionalfloodlights.

ManufacturerClaimsEvaluatingtheaccuracyofmanufacturersperformanceclaimsisanimportantcomponentoftheCALiPERprogram.AlthoughseveraloftheSeries15productsdidnotlistkeyperformancecriteriaontheirspecificationsheet,sixofthetenproductshadmeasuredperformancewithin10%ofallthelistedvalues,whichisconsideredaccurate.Thosefailingtomeetatleastonemanufacturerclaiminclude:

Product1171,whichproducedfewerlumensandhadalowerefficacythanclaimed(8,044lumensmeasuredcomparedto9,532lumenslisted[16%fewer];33lm/Wcomparedto38lm/W[13%lower]).

Product11100,whichproducedfewerlumens,hadalowerefficacy,andhadalowerCRIthanclaimed

Table7. CustomizabilityoftheSeries15LEDfloodlights.Theattributesweredeterminedbyreviewingtheproductspecificationsheets.

DOECALiPERTestID Accessories/ShieldsListed ListedLumenPackages ListedDistributions1170 No 1 11171 No 1 61177 No 1 31178 Yes 2 61199 Yes 1 311100 No 1 111101 No 2 111105 No 4 11201 Yes 6 71206 Yes 1 1

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(2,991lumensmeasuredcomparedto4,320lumenslisted[31%fewer];53lm/Wcomparedto80lm/W[34%lower];CRIof68comparedtoaCRIof80).

Product11101,whichhadameasuredCRIof66,butclaimedaCRIof83.

Product1206,whichhadameasuredinputpowerof12.4W,butaclaimedinputpowerof18W.Thisproductdidnotlistlumenoutputorefficacyontheproductspecificationsheet.Thiscouldbetheresultofproductimprovementsnotbeingrepresentedinmanufacturerliterature.

Ensuringthatlistedinformationreflectstheperformanceofproductsbeingsoldisimportantforbuildingconsumerandspecifierconfidence.AlthoughCALiPERhasnoticedimprovementinthisareaoverthepastseveralyears,evaluationoftheSeries15productsillustratesthatitisstillaconcern.Regardlessoftheabilityofconventionalproductstomeetthesame10%criterion,asanewtechnologyitisespeciallyimportantforLEDproductstomeetexpectations.Furthermore,itisdesirableforproductstolistbasicperformanceparameters(e.g.,lumenoutput,inputpower,CCT,CRI),whichwasnotthecaseforsomeoftheSeries15products.

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6 Conclusions Giventhebroadandambiguouslydefinednatureofthefloodlightcategory,makingabsoluteconclusionsregardingtheperformanceoftheSeries15productsisinappropriate.Eachmaybeeffectiveforagivenapplication.

ThisseriesoftestinghighlightedseveralkeyareasinwhichLEDproductscanimproveinordertobemorecompetitivewithconventionalfloodlightsoralreadyofferanadvantage:

Conventionalfloodlightsareavailableexceeding20,000lumens,butfew(ifany)LEDfloodlightscanmatchthisperformance.ThemaximumlumenoutputfortheSeries15productswasapproximately8,000lumens.Currently,generatinghighlumenoutputrequiresalargesurfaceareafornumerousLEDpackages.LEDscanbedrivenathigheroperatingcurrentstoincreaselightoutput,butamongothertradeoffs,lifetimeusuallydecreases.ImprovementinLEDpackageswillhelpresolvethislimitation,butitislikelyalongtermchallenge.

TheefficacyofmanyoftheSeries15LEDfloodlightswasequaltoorbetterthanthetypicalefficacyofconventionalfloodlightsusingmetalhalideorCFLlamps.

MostoftheSeries15LEDfloodlightshadwide,symmetricdistributions.Formanyapplications,thisisnotappropriate,whichlimitsthemarketforLEDproducts.BecauseLEDfloodlightsrequireanarrayofLEDs,ratherthanthesinglepointsourceofametalhalidefloodlight,producingnarrowspotdistributionscanbedifficult.

Theoutputofconventionalfloodlightsishighlycustomizableusingmodularlamps,reflectors,andaccessories,dozensofoptionsareavailableinthesamehousing.Thisofferstremendousflexibilitytoenablespecifierstomeetexactingperformancecriteria.AlthoughsomeoftheSeries15LEDfloodlightsfollowedasimilarapproach,othersofferednovariation.DevelopingmorecompleteproductlineswouldhelpLEDfloodlightsfillthesameroleasconventionalproducts.

Althoughcolorrenditionisnotasimportantforfloodlightsasitisforsomeotherproductcategories,itisoneareawhereLEDshaveapotentialadvantage.However,manyoftheSeries15LEDfloodlightsdidnotexploitthisopportunity,andmanyhadCCTsoutsidethetypicalrangeforthecompetingconventionalfloodlights.Ontheotherhand,thecolorconsistencyandcolorstabilityofLEDfloodlightsislikelyfavorablecomparedtoconventionalfloodlightsusingmetalhalidelamps.

ThepowerfactoroftheSeries15LEDfloodlightswasconsiderablybetterthanthatofconventionalfloodlights.

AlthoughnotspecificallyexaminedormeasuredbyCALiPER,theratedlifetimeofLEDfloodlightsistypicallyaslongorlongerthantheratedlifetimeforconventionalfloodlights.

AswithallLEDproducts,manufacturerclaimsmustbeaccurate.FourofthetenSeries15productsfailedtomeetatleastonemanufacturerclaim.Tostrengthenconsumerconfidence,thisdeficiencyshouldberemedied.

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7 Appendix A: Product Selection ProductselectionisanimportantpartoftheCALiPERprocess.Productsareselectedwiththeintentofcapturingthecurrentstateofthemarketacrosssectionrangingfromexpectedlowtohighperformingproductswiththebulkcharacterizingthemiddleoftherange.However,theselectiondoesnotrepresentastatisticalsampleofallavailableproducts.

Productselectionstartswithareviewofthetechnology.Beyondrelyingonprofessionalexperience,theteamsurveys:

Tradepublications,includingLightingDesign+Application,LEDsMagazine,MondoARC,andArchitecturalLighting

Internetwebsites,includingElumit,DesignLightsConsortium,ENERGYSTAR,LEDLightingFacts,ESource,andLightsearch

Nationalretailers,includingGrainger,Goodmart,TheHomeDepot,Lowes,Amazon,andSears Othersources,includingtradeshows(localandnational)andmanufacturersrepresentatives

Aftersurveyingavailableproducts,theCALiPERteamcharacterizesthefeaturesoftheproductsanddetermineswhatcanbestandardizedtoeasecomparison.ForthisreportfocusingonLEDfloodlights,thefollowingfeatureswereevaluatedandledtothefinalselection:

LumenpackageLuminaireswithoutputbetween3,000and6,000lumensweresought,whichisroughlyequivalenttotheoutputof70to150WHIDfloodlights.MostLEDproductssurveyedwerewithinthisrange,butproductsaboveandbelowwereselectedaswell.

ColortemperatureACCTof4000to4500Kisrepresentativeofmetalhalidesources,but3000Kand6000Kmetalhalidelampsarealsoavailable.NotallLEDproductswereavailablewithinthisrange.

ColorrenditionACRIof70orbetterwassoughtwhenconsideringluminairesforacquisition. DedicatedwhiteColorchanging/tunableLEDfloodlightswerenotconsideredforinclusioninthis

seriesoftesting.

Someothernonperformancerelatedcriteriaarealsoconsidered:

ProductavailabilityAsafederallyfundedprogram,CALiPERfocusesonproductsavailableintheUnitedStates.

EnergyefficiencyprogramsSomeemphasisisgiventoincludingproductslistedbylargeenergyefficiencyprograms(e.g.,ENERGYSTAR).

Afterestablishingalistofappropriateproducts,attemptsaremadetoanonymouslypurchasetheproductsthroughstandardindustryresources(e.g.,distributors,retailers).Sometimes,productsarenotavailableorcannotbeshippedinatimelymanner.Thus,thefinalgroupofproductstesteddoesnotalwaysmatchtheintendedresultsoftheselectionprocess.

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8 Appendix B: Definitions

BeamAngleDegrees()

Theanglebetweenthetwodirectionsforwhichtheintensityis50%ofthemaximumintensity(ANSI/IESRP1610)orcenterbeamintensity(ANSIC78.3792006),asmeasuredinaplanethroughthebeamaxis.Forexample,ifthemaximumintensityis1000cd,theangleatwhichtheintensityis500cdishalfofthebeamangle.If500cdoccursat20fromcenterbeam,thenthebeamangleis40.

CenterBeamCandlepower(CBCP)Candela(cd)

Theluminousintensityatthecentralaxisofthebeam,whichtypicallycorrespondstoaverticalangleof0(callednadirforlampsorienteddownward).Althoughcandlepowerisadeprecatedterm,itisstillwidelyusedinthiscontext.

CorrelatedColorTemperature(CCT)Kelvin(K)

Theabsolutetemperatureofablackbodyradiatorhavingachromaticitythatmostnearlyresemblesthatofthelightsource.CCTisusedtodescribethecolorappearanceoftheemittedlight.

ColorRenderingIndex(CRIorRa)

AmeasureofcolorfidelitythatcharacterizesthegeneralsimilarityincolorappearanceofobjectsunderagivensourcerelativetoareferencesourceofthesameCCT.Themaximumpossiblevalueis100,withhigherscoresindicatinglessdifferenceinchromaticityforasampleofeightcolorsamplesilluminatedwiththetestandreferencesource.Seealso:SpecialColorRenderingIndexR9.

Duv ThedistancefromthePlanckianlocusontheCIE1960UCSchromaticitydiagram(alsoknownasu,2/3v).Apositivevalueindicatesthemeasuredchromaticityisabovethelocus(appearingslightlygreen)andanegativevalueindicatesthemeasuredchromaticityisbelowthelocus(appearingslightlypink).TheAmericanNationalStandardsInstituteprovideslimitsforDuvfornominallywhitelight.

LuminousEfficacyLumensperwatt(lm/W)

Thequotientofthetotalluminousfluxemittedandthetotalinputpower.

FieldAngleDegrees()

Theanglebetweenthetwodirectionsforwhichtheintensityis10%ofthemaximumintensity(ANSI/IESRP1610)orcenterbeamintensity(ANSIC78.3792006),asmeasuredinaplanethroughthebeamaxis.Forexample,iftheCBCPis1000cd,theangleatwhichtheintensityis100cdishalfofthefieldangle.If100cdoccursat32fromcenterbeam,thenthefieldangleis64.

InputPowerWatts(W)

Thepowerrequiredtooperateadevice(e.g.,alamporaluminaire),includinganyauxiliaryelectroniccomponents(e.g.,ballastordriver).

LuminousIntensityDistributionCandela(cd)

Thedirectionalityofradiantenergyemittedbyasource,whichmaybeshownusingoneofseveraltechniques.Itismostoftenpresentedasapolarplotofthecandelasemittedinaverticalplanethroughthecenterofthelamporluminaire.

OutputLumens(lm)

Theamountoflightemittedbyalamporluminaire.Theradiantenergyisweightedwiththephotopicluminousefficiencyfunction,V().

PowerFactor Thequotientofrealpower(watts)flowingtotheload(e.g.,lamporfixture)andtheapparentpower(voltamps)inthecircuit.Powerfactorisexpressedasanumberbetween0and1,withhighervaluesbeingmoredesirable.

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SpecialColorRenderingIndexR9

AmeasureofcolorfidelitythatcharacterizesthesimilarityincolorappearanceofdeepredobjectsunderagivensourcerelativetoareferencesourceofthesameCCT.Themaximumpossiblevalueis100,withhigherscoresindicatinglessdifferenceinchromaticityforthecolorsampleilluminatedwiththetestandreferencesource.R9andRa(CRI)arepartofthesameCIETestColorMethod,buttheR9colorsampleisnotincludedincalculationofRa.

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DOESSLCommerciallyAvailableLEDProductEvaluationandReportingProgramNOCOMMERCIALUSEPOLICY

The U.S. Department of Energy (DOE) is a federal agency working in the publicinterest.Published information from theDOESSLCALiPERprogram, including testreports,technical information,andsummaries, is intendedsolelyforthebenefitofthe public, in order to help buyers, specifiers of new SSL products, testinglaboratories, energy experts, energy program managers, regulators, and othersmakeinformedchoicesanddecisionsaboutSSLproductsandrelatedtechnologies.

Such informationmaynotbeused inadvertising,topromoteacompanysproductorservice,ortocharacterizeacompetitorsproductorservice.ThispolicyprecludesanycommercialuseofanyDOESSLCALiPERProgrampublished information inanyformwithoutDOEsexpresswrittenpermission.

BUILDING TECHNOLOGIES PROGRAM

1 Preface2 Report Summary3 BackgroundLED FloodlightsSpecifying FloodlightsTesting Floodlights

4 ResultsCALiPER LED Floodlight DataCALiPER Testing of Conventional Product BenchmarksCharacterizing Conventional ProductsLumen Output and EfficacyDistribution of LightColor CharacteristicsOther Factors

5 AnalysisLumen Output and EfficacyDistribution of LightColor CharacteristicsElectrical CharacteristicsVariability and CustomizationManufacturer Claims

6 Conclusions7 Appendix A: Product Selection8 Appendix B: Definitions