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Russell,Sage.TheArchitectureofLight/bySageRussell.p.cm.Includesindex.ISBN-13:978-0-9800617-1-0ISBN-10:0-9800617-1-7eBookISBN:978-0-9800617-4-1LibraryofCongressControlNumber:20129076321.Electriclighting.2.Lighting,Architecturalanddecorative.I.Title

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WELCOMETOTHESECONDEDITION.

Wow!Itishardtobelieveithasbeenfouryearssincethefirstcopiesofthisbookhittheshelves.Ican’texpressenoughgratitudetoalloftheinstructors,students,designersandjustplain“lightaficionados”outtherewhohavejoinedTheArchitectureofLightfamily.Iloveyourfeedbackandamthrilledtohavesuchanenthusiasticaudience.

What’snewinthesecondedition?Besidesnewdiagrams,designprocessideas,sampleprojectsandanexpanded“basicluminaire”family,thissecondeditionaddressestherapidchangesthathaveaffectedthelightingdesignpractice.

Lightingdesignhasbeenmovingatablisteringpaceoverthelastfewyears,primarilyintherealmsofcodecompliance,sustainabledesign,andofcourselightemittingdiode(LED)technology.

EnergycodesandcomplianceTherollingwaveofnationalandlocalenergycomplianceregulationshasvastlyexpandedtheresponsibilitiesoftheLightingDesigner.Expertiseintheseconstantlychangingcodesisabsolutelycriticalnotonlyforoutstandingdesign,butforefficiencyindealingwiththedocumentationandthirdpartysoftwarethatdemonstratecompliance.Whetherit’sASHRAE,DOEoryourlocalcodes,expertiseisabsolutelyexpectedoftheseriousLightingDesigner.

SustainabilityincentivesProjectsofallscaleandscopearepursuingthebenefitsthatcomefromsustainabledesign.Betweengovernmentsponsoredincentives,life-cycleeconomicbenefitsandjustplainprideofgooddesign,thereisnoshortageofprograms-well-knownandobscure-toguidedesigndirection.TheEPA,DOE,EnergyStarandtheUSGBC’sLEEDprogramsprovideresourcesandassistanceforallmannerofefficientdesign.Sustainabilityisabroad,fast-changingareaofexpertisethatagooddesignermuststayontopof.

ResourcesforresearchingcodecomplianceandsustainabilityincentivescanbefoundinAppendixBatthebackofthisbook.

LightsourceandLuminairetechnologiesThewaysweconvertelectricitytovisiblelight,anddeliverthatlighttothedesignedenvironmenthavechangeddramaticallysincethefirstprintingofthistext.Backthen,LED’swereaworkinprogress;moreusefulforcolorchangingeffectsthananythingtaskrelated.HIDluminaireswerejustbeginningtomakein-roadsincolorcriticalinteriorenvironments,andtheincandescentsourcewasnotbeingpushedtowardsphasedextinction.

Myhowthingshavechanged!Throughoutthisvolume,youwillseeevidenceoftheseever-evolvingtechnologiesandbestpracticesforimplementingthelatestgenerationofelectriclightsourcesanddaylighttechnologies.

Solet’sgetonwithit…

Thissecondeditionisdesignedtoefficientlyandenjoyablydeliveralightingdesigneducationthatisimmediatelyusefulforthereader.Itincludesknowledgethateludedmeuntilwellintomyprofessionalcareer.Ibelievethistextwillmakeyouabetterdesigner,regardlessofyourdesignfocus.

Butfirst…

MyheartfeltthankstotheexceptionalpeoplethatmadeTheArchitectureofLightpossibleandassistedincreatingthissecondedition:

DavidDiLaura,forinspiringanunfailinginterestinthescienceofillumination.PatrickQuigley,theinspirationbehindallthingschoreographyrelated.GregGorman,whotaughtmethatlightisresponsibleforbeauty.NancyClanton,adrivingforceinspreadingthewordaboutlightandtheenvironment.CynthiaBurke,mylongtimedesigncolleaguewhogavemeeveryopportunitytoshine.JenniferLuce,whoshapedmyideaofthedesignprocess.ChadWatters,DianeBorys,andJennDoran…Thestudiocrewthatkeptlightingdesignfun.

Iwouldalsoliketoextendspecialthankstomyeditors.Withoutthesededicatedsouls,thereisnodoubtthatthecontentandlegibilityofthistextwouldhavesufferedgreatly.Inthesamebreath,Iwouldliketoabsolvethemofanyresponsibilityfortheinformationprovidedhere.Anyerrorsorerroneouscontentissolelythefaultoftheauthor.

Lastly,Thisbookisstilldedicatedtoanyonewhositsthroughmylecturesordesignpresentationsindulgingmydiscussionsaboutdesign,art,culture,food,travelandeverythingelse.

ThanksforbeingpartoftheFamily,

SageRussell2012

Moreteachingandlearningresourcescanbefoundonlineat:

WWW.LIGHTINGTEXTBOOK.COM

Contents

PartI:_TheFundamentalsofLightChapter1TheDesignMentality

Chapter2ThePowerandPurposeofLight

Chapter3MoreImpactwithLessLight

Chapter4AddingLightinLayers

Chapter5PhysicalBasicsofLight

Chapter6PhysiologyofVision

Chapter7TheColorScienceofLightSources

Chapter8ElectricLightSources

PartII:DesigningLightChapter9TexturesofLight

Chapter10ShapesofLight

Chapter11LocationoftheLightSource

Chapter12BuildingLightfromDarkness

Chapter13DevelopingLightingIdeas

Chapter14AShortcuttoConceptsinLight

Chapter15LightingThatWorks

Chapter16DesigningwithDaylight

Chapter17GraphicTools:RenderingandLightMaps

Chapter18LightingUnitsandMeasurements

Chapter19UnderstandingIlluminanceLevels

Chapter20LightingCalculations

PartIII:DeliverablesChapter21DecipheringManufacturers’Literature_andLuminaireCut

Sheets

Chapter22SelectingLuminaires:ABasicFamily

Chapter23Switching,DimmingandControlSystems

Chapter24ThePreliminaryLightingLayout“Redline”

Chapter25LuminaireSchedulesandCutSheets

Chapter26TheLightingPlan

Chapter27LightingLayoutsforResidentialSpaces

Chapter28LightingLayoutsforCommercialSpaces

Chapter29CommonLightingDetails

Chapter30DaylightandElectricLightIntegrationDetails

PartIV:FinalThoughtsonDesignTheFundamentalLightingDesignProcess

GreenDesignandSustainability

DesigningwithNewEyes

AppendicesAppendixAGlossaryofLightingTerms

AppendixBProfessionalOrganizationsandAgencies

AppendixCDescriptiveWordsforLighting

AppendixDDirectoryofContributorsandOtherManufacturers

ThePitch

Lightistrulyadesigner’smedium.Itisamongthemostpowerfultoolswehavetoaffectchangeinhowweperceiveandexperiencetheenvironmentaroundus.Lightbelongsasacontrollabletoolofspacedesign,justasform,scale,andmaterialdo.Lighttranslatesvisionanditisvisionthatgivesusasubstantialportionofourexperiences.

Thisbookdeliversauniquetrainingthatmakesdesigningwithlightanintuitivevisualprocessthatcandeliverawholenewappreciationforthecapabilitiesofarchitectureanddesign.Here,onewillfindaprocedurefordevelopingdesignideasandthevisualtoolsfortranslatingthoseideas.Adesignerarmedwiththistypeofunderstandingwillbeinspiredandwell-equippedtoenrichthedesignedenvironmentthroughthecreativeapplicationoflightingdesign.

Thisknowledgeisforarchitects,landscapearchitects,interiordesigners,plannersandlightingdesignersaspiringtodevelopintuitionandconfidenceindesigningwithlight.Itisthesepeoplewhoareresponsibleforbringingorganizationandemotionalexperiencetotheenvironmentsweinteractwitheveryday.Theconceptsandprocessesputforthinthisbookareintendedtobeimmediatelyusefultoanydesignerwhowantstoincludelightasanallyindesign.

Mygoalinassemblingthisbookistoprovideinformationtothepeoplewhoarepoisedtomakethemostofit.Oftentimes,thosewhohavethebestchanceofapplyingdesignedlighttomaximumeffectaredeprivedofthenecessaryknowledge.Consequently,lightingdecisionsoftenfallbythewayside,andpowerfuldesignopportunitiesaremissed.

Regardlessofthereader’scurrentfamiliaritywithlightingdesign,thisbookwillprovideamoremeaningfulunderstandingoftheroleoflightinthedesignedenvironment.Withinthesepages,onewillfindcreativeproceduresandgraphictechniquesforgeneratingandcommunicatinglightingdesignconcepts.Theresultingintuitionandtoolsetwillhelpthereadermakelightingdesigndecisionswithconfidenceandjoy.Myintentionisnottocreatetechnical

“lighting-super-experts”,butrathertoprovidecreativeconfidenceandaworkingfamiliarityofthepowerandeffectoflightthatwillproveusefulwithanyamountofsupportingtechnicalknowledge.

Ihopetoempowerthosewiththeopportunitytodesignwithlighttogoforwardwithconfidence,layclaimtolightasadesigntool,anduseittoaddimpactandmeaningtotheirdesign.

∼SageRussell,2012

PartITheFundamentalsofLight

Chapter1TheDesignMentality

“Byourverynature,wearealldesigners”Beforewegoontodiscusshowtoapplylightinthedesignedenvironment,wemustlookathowweconsiderdesignandhowwecomeupwithideas.Wemustsolidifyourcreativeprocess.Asdesigners,weareideapeople.Thatisournature;itiswhatpeopleexpectofusandwhatourclientsaskofus.Weareinthebusinessofgeneratingideas.Thistaskseemseasyenoughashumansarenaturallyblessedwithcreativespirit.Thereisanunfortunatetendency,however,forthatspirittobestifledinsomepeopleandnurturedinothers.Atsomepoint,oftenchildhood,apersonistoldthatperhapshe/sheis“justnotartistic”or“notacreativeperson.”Inallcases,thisclaimisfalse.Creativityishumannature.Whenwecallourselvesdesigners,wearetellingtheworldthatwehavedecidedtonurturecreativityanddedicateourselvestothecultivationofideas.

Therearetwoproceduresthatareinvaluabletoanyonepursuingthecreativecapabilitiesofhis/hermind:thecommon“brainstorm”andtheprocessofreverseengineeringdesign.

THEBRAINSTORMBrainstormingisoneofthemostvaluableprocessesinwhichan“ideaperson”canengage.Itisthesimpleprocessofwritingdownanyandallideasthatcometomindwhenthinkingonaspecifictopicorchallenge.Thereisoneandonlyonefundamentalruletoabrainstorm:therearenowronganswersinabrainstorm.Thissimpleruletranslateswelltocreativityanddesignbecausetherearenowronganswersindesign,simplyideasandpossibilitiesthataremoreappropriatethanothers.Thedesignercannotaffordtobecometooattachedtooneseeminglygoodidea.Intheprocessofdesign,ideasareshotdownforanumberofreasons,andthedesignermustpossessaheadfullofotherideaswaitingtobeexpressed.

Foradesigner,thebrainstormisthefreedomtoconjureandcultivateanyandallideasthatcometomindregardingaspecificdesignchallenge.These

ideasareaproductofthatparticulardesigner’sbackground,education,pastexperiences,values,sourcesofinspiration,andbeliefsaboutdesign.Theseideasareasindividualasthedesigner,anditisthisuniquenessthatcompelspeopletoseekoutdesignersforideasandsolutions.

Thenecessaryfirststepofthebrainstormistheprocessofwritingalloftheseideasdown.Creatingalistordiagramofideasgetsthemoutofone’sheadandontopaper.Emptyingtheheadcreatesroomformoreideastogerminateandkeepsthesameideasfromcirculatingandclutteringthemind.Jottingdowntheseideasalsoresultsinapermanentrecordofthem,sothatnonewillbelostinthedarkcorridorsofthebrain.

Figure1.1Asimplewrittenlistofthemesandwordsthatcometomindwhenvisualizingaspecifictopic.Inthisexample,prominent“bigideas”havebeencircled.

Figure1.2Abubblediagramshowstherelationshipbetweenideasastheyprogress.

Theproductsofabrainstormareproofthatweallhavegreatideas.Thededicateddesignerissimplymorediligentincultivatingideas,writingthemdown,communicatingthem,andkeepingtrackofthem.Ifwedon’tallowourselvesfreereigntoconjureideas,andgetthemdownonpaper,theideasarelostforever,victimsofthepowerfulforcesofself-censorshipandself-criticism.Letitbesaidthatinthelandofdesign,thereisnoshortageofskepticsandcriticstotellusthatourideasaretoowhimsical,tooexpensive,tootime-consuming,orunrealistic.Ifweexpectthatthisrefiningofideaswillcomefromoutsideforces,itbecomesveryclearthatwedon’tneedtocritiquetheminternally.Thus,wegoforward,writingdownideas,conceptsandsolutionsasfastaswecanthinkofthem,knowingthatthroughtheprocessofdevelopingdesign,thebestideaswillrisetothetop.

Therewardofthisprocessistheconfidencetoproposeideaswithoutfearofrejection.Whenweknowthatwehavealongwrittenlistofgreatideas,andabrainthatcanconjurenewonesatwill,thenwearemuchmoreproductivewhenengagedwithothersintheprocessofrefiningthem.Weareneitherdismayednordejectedwhenourideasaredeemedunsuitable.Weseecriticismasachallenge,ratherthanathreat.Thiswelcomingoffeedbackand“thickskin”isoneofthemostvaluabletraitsofaskilleddesigner.

Makingaregularhabitofbrainstormingdevelopsthecreativeproductivityandflexibilitythatarethefoundationofadesigner’sconfidenceand

skill.

REVERSEENGINEERINGFROMDESIGNTheprocessofreverseengineeringisexactlyasitsnameindicates.Itisatoolofdissectingsomethingtodiscoverwhatmakesitwork.Take,forexample,aguitarmakerwhotakesapartabeautifulacousticguitartoidentifyexactlyhowthatguitargetsitswoody,slightlyhollowsound.Upondissection,itisdiscoveredthatthesoundistheproductofaveneerofrareSumatranteakwoodbondedtotheinside.Theguitarmakercannowincorporatethissimplefeatureinconstructingguitarsinthefuturewheneverthesamesoundisdesired.How,youmayask,doesthisanecdoteapplytothedesignmentality?Theanswerliesinthebeliefthatasdesignersdealingintherealmofthebuiltenvironment,weareresponsiblefordesigningspacesthatcompelinteractionandelicitemotion.Besidesthebasicfunctionofthespaceswedesign,wecaremostabouthowpeoplefeelandconsequently,howtheybehaveandinteractwithourdesign.

Weexperiencedesignedenvironmentsandthenaturalworldarounduseverydayandthushavetheopportunitytoreverseengineerdesigneveryday.Whatwe,asdesigners,candotomakeuseofthisskillistotakethetimetoidentifyhowwefeelinourenvironmentandwhatisatworktomakeusfeelthatway.Dissectingourexperiencesinthiswayhasthreedistinctsteps:

Step1:Experiencelife

Goplaces,meetpeople,andputourselvesinasmanyengagingsituationsaspossible.Thisactisreallyabyproductoflife,anditissafetosaythatnearlyeveryonedoesthissimplybyleavingthehouseeachday.

Step2:Assesstheemotionaleffect

Thissteptakesalittlemorededication.Itistheexerciseoftakingstockofyourfeelingsoremotionalstateinagivensituationorenvironment.Thisskillisthesortwecreditpoets,artistsandphilosophersaspossessing.Assessinghowonefeelsisnotautomatic,andtherearecertainlypeoplewhogoabouttheirdailylivesneverstoppingtorealizehowanenvironmentaffectsthem.

Step3:Identifythemechanismsresponsiblefortheemotionaleffect

Thissteprequirestakingthetimetoidentifywhataboutthesituationorenvironmentiscausingtheemotionalresponseweareexperiencing.Itisa

mentalstepinwhichonlyafewengage.

Anexampleofthisthoughtprocessmightoccurasfollows:

Anyonecanstandattheedgeofaslowmovingcreekinthewoods.

Anenlightenedpersonmighttakethetimetorealizethesenseofpeace,calm,tranquilityandconnectiontonaturethatispresent.

Itisthedesignerwhotakesthetimetorecognizethatthesefeelingsaretheproductoftheshiftingbreezerustlinginthereeds;theglintandflickerofsunlightonthewatersurface;andtheearthyhuesofgreen,brownandyellows.

Withthisawareness,whenthedesigneriscalledupontocreateanenvironmentthatdeliversafeelingofcalm,tranquilityandpeace,heorsheknowsthatearthytones,naturalmaterials,andaspecificqualityoflightandshadewillprovidethedesiredemotionalresponse.

Theseingredientsdonotneedtobetranslatedliterally,butknowledgeofthemwillbringusonestepclosertoadesignsolutionpossessingdepth,contextandpermanence.

Topracticethisprocedure,wecantakeanypieceofimagery,song,orfilmanddissectittofigureoutwhyitworks.Inmusic,artandfilm,nothingisdonebyaccident,andeachingredientcontributestoaspecificeffect.

Watchafavoritefilmorlistentoafavoritesong.Studythesethingswiththeintentofidentifyingtheemotionsinducedandthenidentifyingthemechanismsresponsiblefortheemotion.Whatbecomesimmediatelyapparentisthatlightquantityandqualityplayadominantroleinhowwevisualizeanenvironment.

TryThis:Afteryouexperiencesapieceofartordesignwiththisgoalinmind,

makeachartonapieceofpaper.Ontheleftsideofthepaper,startacolumntitled“EmotionandFeeling.”Fillthiscolumnwiththemanyidentifiablefeelingsassociatedwiththedesign.Ontherightsideofthispaper,startacolumntitled“MechanismResponsible.”Takethetimetoidentifywhatspecificingredientswereresponsiblefortheemotionsandfeeling.Isitaperspectiveorapointofview?Isitatoneortempoorbeat?Isitaspecificcolor,texture,orqualityoflight?Identifyingtheseingredientsputsthedesigneronapathtocallontheminthefuturetocreateapredictableeffectinhis/herowndesign.

Figure1.4Dissectinganenvironmentgivesonespecificingredientsforuselatertocreateasimilaremotionalexperience.

Ifwecanadoptthehabitofreverseengineeringtheworldaroundus,wecanquicklyhoneourskillsascreativethinkersanddesigners.Oncewehavetakenthetimetoidentifythemechanismsthatworkinanenvironmenttocreatecertainfeelings,wecanusethosemechanismstocreatethesameeffectinourowndesign.Inthismanner,thedesignerbuildsanever-growingtoolboxoftechniquesandingredientsthatcanbeputtousetoelicitapredictableeffect.Thedesignergainstheabilitytotranslatethefeelingsofanenvironmentintotangible,tactileingredientsthatcanbeinjectedintoanysetting.

Aswemoveforwardanddiscussthespecificnuancesandeffectswecanencouragewithlight,letuskeepthesetwotoolsaspartofoureverydaydesignprocess.Ourtechniquesforcultivatingandexpressinglightingdesignideasarequitespecific,butletusalwaysmakeuseofthesefundamentalskills.Designstartswiththeabilitytoconjureideaswithoutself-censureandaconstantdedicationtofiguringoutwhyourfavoriteenvironmentsworkthewaytheydo.Ifwecanincorporatethesetoolsashabits,wewillbemuchbetterpreparedtoprovidetheconstantflowofideasandconceptsthatpeopleexpectofus.

Chapter2ThePowerandPurposeofLight

Becauseourjourneyisoneofenrichingandenhancingourdesignswithlight,wewillfirsttakesometimetoestablishwhylightissuchausefultoolincreatingemotionandalteringourperceptionoftheworldaroundus.Thereisanindoctrinationrequiredsothatwemoveforwardwithanunfailingfaithinthepoweroflighttoaffectdesign.

WHYWESTUDYLIGHTInthebuiltenvironment,itisreasonabletosaythatthemajorityofourexperiencesarevisual.Sound,smell,andtouchcertainlyplayvariousroles,butmostpeoplerelyonvisiontodeliveraverylargequantityofinformation.

Vision,byitsverynature,isaproductoflight.Itistheresultofthecreationoflight,thereflectionoflight,and,ultimately,theabsorptionandtranslationoflightbyourvisualsystem.Logicdictatesthenthatifwewanttohavemaximumcontrolofthedesignedenvironment,wemustbecomeintimatewithlightandlearntomakeitourallyintranslatingdesign.

Lightcanquicklyandpowerfullyaltertheappearanceandemotionaleffectofourdesignedspaces.Adesignercanspendanyamountoftimerefiningthelayoutofaspace,thescaleofaspace,thematerialsandfinishesofaspace.Howeverwithafewsimplestrokes,lightingcanbeappliedtotrulyenhanceorutterlydestroythedesiredeffect.Adesignermayenvisionameditationlodgefashionedfrombamboosheathingwithanaturalriverrockfloor.Thelodgemayhaveheavydarkwoodfurnitureandoiled,bronzehardwareandaccents.Despitetheeffortandattentiontodetail,wecanchangetheemotionaleffectinaheartbeatbyinstallingredstrobelightsandadiscoball.Anextremeexample,tobesure,butthepointisvalid:Ifonewantstochangethemoodofaspace,changethelighting.Ifonewantstochangethescaleofaspace,changethelighting.Ifonewantstochangethecolorofaspace,changethelighting.Onceyourecognizehowmanyaspectstherearetolight,youstarttounderstandthatitservesasanefficient,effective,andpowerfulwaytoaccomplishadesigngoal.

Withjustabasicunderstandingofthecolors,intensities,andtexturesoflight,adesignergainsanunderstandingofwhichtypesoflightwillsupport,andwhichwilldetractfromaproject’sdesigngoals.

BEYONDONANDOFF:THREEFUNDAMENTALASPECTSOFLIGHTLightismuchmorethanwegiveitcreditfor,anditdeservestobetreatedwiththecareofanydesignmedium.Justasadesignertakescareinmakingdecisionsaboutthenuancesandsubtletiesofcolorandmaterial,sotoo,musthe/shetakecareinmakingdecisionsaboutlight.Lightcanbecontrolledtoamuchhigherdegreethaniscommonlyconsidered.Tomakethemostoflight,wemustdefinewhatwecancontrolaboutourlight.Thereareahandfulofpropertiesthatmustbeaddressedinordertomakeawell-thought-outlightingdecision.Everypieceoflightaddedtoanenvironmentshouldbeconsideredintermsofthreebasicproperties:Intensity,Color,andTexture.

LightIntensity:Brightvs.Dark.Intensityisthemostobviousandwellunderstoodaspectoflight.Itisonestepbeyondsimplyonoroff:isthislightdim,orisitbright?Wetendtoassociatelowlightlevelswithmorerelaxed,intimate,personalenvironments.Wetranslatehigherlightlevelstobemoresterile,public,active,andkinetic.Lowlightsituationsoftenencouragelingeringandrelaxing.higherlightlevelscanstimulateactivityandmovement.

Figure2.1Higherlightlevels(left)translateanexposed,publicfeeling.Lowlightlevels(right)translatecalmandprivacy.

LightColor:Warmvs.Cool.Thereareanumberofwaystoalterthecolorofourlightsources,bothsubtlyandovertly.Lightingsourcescanexhibitallmannerofdifferentcolortemperatures,warmorcool,asslightvariationsofneutral.Ourlightsourcescanalsobemodifiedtoexhibitverysaturated,vividcolors.Thesecolorshavevaryingeffectonmood,dependingonaperson’sexperiences,cultureandconditioning.Colorandcolortemperaturecandeterminewhetherapersonfeelscomfortableenoughtolingerinanenvironmentorwhetherhe/sheisdrivenaway.Colorcanimmediatelyaffectmoodandstateofmind.Warmlightingcolors;yellowsandreds,tendtoelicitcalm,relaxationandaslowerpaceofaction.Coolcolors;bluesandgreens,tendtoelicitactivityandalertness.Distinctlysaturatedcolorsgetusedinhigh-design,themedenvironmentstocreatevisualinterestandauniqueemotionalexperience.

Figure2.2WarmLight(left)andcoollight(right)shouldbechosenforthewaytheyrevealthecolorsandmaterialsinaspace,andthemooddesired.

LightTexture:Directionalvs.Diffuse.Textureisperhapstheleastunderstoodorconsideredaspectoflight.Thetextureofthelightweintroduceintoaspacehasadramaticeffectontheoverallfeelingandfunction.Whenwespeakoflighttexture,wearetalkingaboutthephysicalmannerinwhichlightisdeliveredfromasource.Ononeendofthespectrumwehave soft, even, diffuse light that is often the product of luminaires thatincorporate diffusingmaterials.On theother endof the spectrumwehave theharsh, directional light that is the product of luminaires that utilize precisionreflectorsandlensesthatdeliverlightinaspecificdirection.Thinkofanaverageglowingglobe(diffuse)versusadirectedspotlight(directional).

Thesignificantdifferencesbetweenthetwotexturesmanifestinthe

Figure2.3Stronglycoloredlightgrabsourattentionandtransportsusawayfromtheordinary,neutralenvironmentswe

areusedto.

shadowsandtheshapesoflightcreatedbythesesources.

Diffusesourcesproducelightthatoverlapstofillinshadowsandhasill-definedbordersasthelightsprawlsfromthesource.Directionalsourcescreatedistinctshapesoflightwithclearboundaries.Useofdirectionallightgenerallyresultsinharshshadowsandcontrastasthatlightiseitherdeliveredorblockedcompletelybyobjectsandmaterialtextures.

Figure2.4Diffuselight(left)reducesshadowsandencourageslongtermvisualcomfort.Directionallight(right)createscontrastandvisualinterest.

Onceweexpandourthinkingtorecognizethesethreeproperties,westarttogetaglimpseofthedepthofdecision-makingthatisrequiredtoensurethatthelightweareaddingtoaspaceisworkingtowardourdesigngoals.

Whenwereferbacktothenotionthatdesignersareinchargeofencouragingemotion,wecanbegintoseethatforeveryemotionthatcanbedescribed,thereisacorrespondinglightintensity,lightcolor,andlighttexturethatsuccessfullyencouragesthatemotion.Whenwewanttocreaterelaxed,calm,soothingenvironments,weimplementlowerlightlevels,warmerlightcolors,andmorediffusesources.Whenwearedesigningmorekinetic,active,productivespaces,weapplyhigherlightlevels,coolerlight,andmore

directionalsources.Muchofwhatwewillbeaddingtoourknowledgeoflightrevolvesaroundarticulatinglightingdecisionslikethesetoencouragedeeperthoughtaboutthelightweadd.Inthismanner,weutilizelighttoitsfullestpotentialinourdesign.

MAKINGLIGHTINGDECISIONSTHROUGHOUTTHEDESIGNPROCESSAnarticulatedapproachtomakinglightingdecisionsismosteffectivewhenappliedwithintheframeworkofoneofourfavoritemaxims:“Makelightingdesigndecisionsateverystepofthedesignprocess”.Fartoooften,architectsanddesigners“designinthedark”.Theyoftenembarkonapathof“design,design,design”,andoncethespaceiscompletely“designed,”itisthen“litup.”

Thethoughtprocessthatisimplementedinthistextisnearlytheopposite.Adesignershouldlookforeveryopportunitytothinkabouthowlightshouldbeusedinadesign.Lightcancertainlybe“applied”toanalready-designedspace,buttheresultwillneverreachthelevelofgreatnessthatispossiblewhenlightisintegratedintoaprojecteverystepoftheway.Fordesigntotransitiontogreatness,lightinghastobeconsideredateachsignificantdesignjuncture.Thegreatdesignprojectsthatweadmirecomefromallrealmsoftasteandstyle,buttheonethingtheyshareisthoughtfullightingintegration.

Foreverydesigndecision,thereisalightingdecisiontobemadethatcaneithersupportorerodethedesign.

Themorecomfortableadesignerbecomeswithlight,themorelikelythatdesigneristoautomaticallyconsiderlightinthedecision-makingprocess.Foreveryformdecision,scaledecision,materialdecisionandcolordecision,thereisacomplimentarylightingdecision.Iftheselightingdecisionsaremadethroughthedesignprocess,theresultisadepthofdesignthatcannotbeobtainedbysimplypouringlightontoacompletelydesignedproject.

HOWHUMANSUSELIGHTTowarmourselvesuptothenotionoftheimportanceoflight,itisusefultoaccountforsomeofthewayshumanbeingsreactandrespondtolight.Oncewerecognizehowweuselightinourdailylives,wecanstarttoproduceverysophisticatedeffectsthroughourlightingdecisions.Becauseofourlong-standingrelationshipwithlight,ithasthepowertoaffectoursubconsciousinwaysthatnoothermediumcan.Itthissubconsciousrelationshipthatprovides

ourmostpowerfullightingtools.Whenweconsiderhowlonghumankindhasspentexperiencinglight,wecanbegintoappreciateallofthewaysthatlightisutilizedbeyondsimply“seeing.”

Itisimportanttorecognizethatforthevastmajorityofourhistoryhereonearthwe,ashumans,havegrownaccustomedtothesunasourprimarysourceoflight.Inallofitsincarnations-sunrise,sunset,high-noon,shadedanddiffused-thesunisresponsibleformostofourresponsestolight.Thisrelationshipexplainswhywerelyonthelightqualityinourenvironmenttoinformsomanyofourbehavioralcues.

LightasMoodWerelyonlightbothconsciouslyandsubconsciouslytotellusthelevelofactivityandthetypeofmoodweshouldcarryintoaspace.Theseeffectslikelyrelatebacktolightqualitiesthatweassociatewithdifferenttimesofday,aswellaslightqualitiesofdifferentseasons.Asdiscussedearlier,weallhaveaninnateunderstandingofthetypesoflightconducivetoactivityandexcitement,aswellaslightthatencouragescalmandrelaxation.Theselightqualitiescanbeextendedtoencouragemoodsofsadnessandmelancholyorhappinessandjoy.Humansrelyonlighttoinformthemofthetimeofdayandconsequently,themoodandactivitiesthatshouldfollow.Lightqualitymayremindusofseasonsthatcallforcelebrationorseasonsthatcallforworkanddiligence.Thereisextensivestudyofhowspecificwavelengths(colors)oflightaffectourwell-beingandhowlightdeficienciesnegativelyaffectourphysiology.Allofthesetopicsbecomecriticalwhenimplementingmodernelectriclightsourcesandmakinguseofdaylight.

LightasInstructionThroughexperienceandconditioning,humanshavealsodevelopedmovementandlocationresponsesthatwederivedirectlyfromlight.Weuselighttoinstructuswheretogo,whatareastomovetowardandwhatpathstofollow.Wereadtheangleandintensityofsunlighttotelluswherewearegeographically.Designerscanincreaselightlevelstodefineareasthatpeoplebelonginandsubsequentlyleavedarkthoseareasinwhichpeopledonotbelong.Colorsoflightcanbeusedascuestostoporproceed.Flashinglightcanbeusedtograbattentionorwarnpeopleaway.Theseeffectsallrelyonthecontrollableaspectsoflightdiscussedearlier.Tomakeuseofthesepowerfulresponses,thedesignermustalsoconsiderspecificshapes,specificpatterns,andspecificmovementsoflight.

ATTRACTIONTOLIGHT:PHOTOTROPISMThemostpowerfulhumanresponsetolightisthemostsimple:itisthefundamentalattractionthathumanshavetowardlightandlightedspaces.Justlikemothstoaflame,wedrifttowardsareasofbrightness.Thisunconsciousdesireissignificantbecauseitisinstinctual.Itdiffersfromourresponsetomanyotherelementsofdesignthatareaproductoftaste,trendorfavor.Wearetoldthatthehumanaffinityforlightisamechanismofsurvival.Thisinstincthasaname:wecallitPhototropism(Latinforlight-attracted).Thisprimalresponsemeansthatatthemostfundamentallevelofdesign,bysimplyputtinglightintherightplace,wecanhelpdirectpeople’spathofexperienceandencouragetheirinteractionwiththespace.Manyofthelightingeffectswewillemployrelyonthisonesimplepremiseofhumanbehavior.

Figure2.5Whenputtousecorrectly,lightedsurfacesservetomakeway-findingintuitive.

Inordertoappreciatetheeffectivenessofusinglighttoattractpeopleandguidetheirexperience,itishelpfultoinvestigatewhyhumansmayhavedevelopedthistypeofresponse.Onaverybasiclevel,itisaboutvision.Thehumanvisualsystemisveryfinelytunedfortranslatinglight.Asthesayinggoes,apictureisworthathousandwords.Itissafetosaythatseeingisoneofthefastestwaystolearnabouttheworldaroundus.Itisbecauseofthis

dependencythatourbrainsarealwaysencouragingustopursueareasthathavemorevisualinformation,thatis,lightedareas.Thebrainbelievesthatthemorewesee,thebetterourlifeexperiencewillbe.Nodoubt,thereisalsotheresidualbeliefthatthemorewecansee,themorelikelywearetofindfood,shelter,companionship,andthelesslikelywearetobeeatenbypredators.

Whenweinvestigatealloftheseemotionalandbehavioraleffectsthatareuniquetolight,weseethatthereismuchmoretolightthanjustsufficientquantity.Intherealmofarchitectureanddesign,wecandomuchmorethansimplyaddlighttoaspacesothatpeoplecanfunctionandperformvisualtasks.

Throughoutthistext,theknowledgethatwewillbeexploringisbasedonmakingdecisionsaboutwhatwewantlighttodoinaspace.

Anythingweintroduceasadesigningredienthastohavejustificationforbeing,sowejustifylightbyidentifyingthemanybenefitsitservesinanenvironment.Wethenstudythedifferenttypesoflightoverwhichwehavecontrol.Lightingdesignthenbecomestheprocessofconceptualizingwhatlightshouldbeaccomplishinginaspaceandhowandwherethatlightshouldbedelivered.

Chapter3MoreImpactwithLessLight

“It’sallaboutplacement.”Themostimportantawarenessforeffectivelightingdesignisthefocusonwherelightisdelivered.Aswedeepenourunderstandingofhowhumanstranslatelighttovisionandultimatelyexperience,webecomeacutelyawareofhowtomaximizethedesiredexperienceofourdesignthroughcarefulplacementoflight.

Sustainabledesignandaconcernforresourcesareincreasingprioritiesforarchitectureandconstruction.Thistrendhasalreadyledtosignificantlegislationandimplementationofcodesthatcontrolhowmuchelectricitywededicatetoelectriclight.Thisconcernforconsumptionusuallytakestheformofrecommendationsforlightlevelsappliedtotasksandenvironments.Thesestudiesandguidelinesforhowmuchlightisappropriateforspecificvisualtasksareuseful,butdesignersofcomplexspacesarelikelytodealwithfarmorethansimplyvisualtaskperformance.Somespacescanbeeffectivelyaddressedbystudyingavisualtask-likeperformingsurgeryorreadingworkmaterials-anddeterminingtheexactamountoflightappropriateforthattask.Adesignerconcernedwiththeoverallexperience-mood,interaction,andvisualimpactofaspace-musttakeamuchmoreholisticapproachthatinvolvesputtingtherightintensity,colorandtextureoflightontotherightsurfacestocreatemaximumeffect.

Whenweplacelightwithcare,theresultisamoreprofoundstatementlikelycreatedwithlesstotallight.

Thisfocusedapplicationof“specificlightonspecificsurfaces”hasitsfoundationinfourimportantrelationshipsbetweenlightandhumancolorvision:

1.Adaptation:adaptingtobrightordarksituations;2.Brightness:contrastbetweensurfacesandtheirsurroundings;3.Phototropism:attractiontolightedsurfacesandobjects;4.VerticalVision:tendencytolookaroundusratherthanaboveor

below.

RelyingonAdaptationAdaptationreferstotheabilityofthehumanvisionsystemtoperformwellunderdifferentlightlevels.Allofushaveexperiencedthephenomenaofwaitingforourvisualsystemtoadjustfromonelightingscenariotoanother.Whenwewalkfromasunlitparkinglottoadarkenedmovietheater,oureyesandbrainsworktogethertomaximizethequantityoflightenteringourvisualsystem.Whenwetransitionfromthedarktheaterbacktothebrightparkinglot,oureyesandbrainsworktolimittheamountoflightbeingtranslated.Althoughinbothcases,thisprocesstakestime,eventually,oureyesandbrainsadjustsothatweareabletofunctioninbothsituations.Thelightlevelsthatwearedealingwithinthetwoextremesaredrasticallydifferent.Thevariationbetweenlightlevelsunderahighnoonskyandamoonlitnightareontheorderoftensofthousands.Itistrulyafeatofphysiologythatwearecapableofreadingabookinbothofthesesituations.

Thedesignimplicationsofthisadaptationworktremendouslyinourfavor.Becauseourvisualsystemisconstantlyatworkadjusttothesurroundinglightlevels,wecandeducethatexcesslightintroducedintoaspaceloseseffectivenessasourvisualsystemworkstoadaptand“even-out”ourexperience.Thus,wecanlikelygetawaywithfarlesslightinmanyspacesasourvisualsystemwillchangetomakethemostofwhatlightisavailable.

Theseeffectsaremostnoticeableinevenly-lightedenclosedspaces.Aroomfilledwithflat,evenlydistributedlightwillappearverysimilar,nomattertheactuallightlevel,asthevisualsystemadapts.

Adaptationalsotellsusthataspacefullofsurfacesreceivingdifferentamountsoflightwillalwaysexhibitcontrast,nomatterwhattheactuallightlevelsare.

BrightnessthroughContrastBrightnessisacommontermusedtodescribetheperceivedlightedeffectofthesurfacesinourdaytodayenvironments.Brightnessisnot,however,anabsolutepropertyofasurface.Becausethehumanvisualsystemadaptstoeachlightedsituation,brightnessisasubjectivejudgmentmadebyanindividualinaspecificlightingsituation.Itisvaluabletounderstandthatcontrastbetweenobjectsiswhatdefinesvisionanddrivesourbrightnessjudgments.Oureyestelluswhereoneobjectbegins,andanotherendsbecausetheobjectsreflectlightdifferently.Whenwereadabook,thedarkinkreflectslesslightthanthewhitepaper,and

wecandistinguishtheshapesofthelettersonthepage,eventhoughbothmaterialsarereceivingthesamequantityoflight.Asweapplymorelighttothepagesofthebook,thewhitepaperreflectsmorelightandappearsbrighter,whilethedarktextcontinuestoreflectverylittlelight.Anothersimpleexampleisthecornerofanyroom:Inevitably,wecantellwhereonewallmeetstheotherbecauseofthecontrastbetweenthetwosurfaces.Iftwointersectingwallsexhibitedthesamebrightness,ourperceptionwouldbeofonecontinuoussurface.Whenweapplyhigherlightlevelstovisualtasksoraccentedobjects,itisanattempttoimprovevisibilitybyincreasingthecontrastbetweentheobjectsormaterials.Objectsarenotvisiblesimplybecausetheyhavelightcastontothem;theyare“visible”becausetheyreflectlightdifferentlythanthetheirsurroundings.

UsingPhototropismtodrawattentionAsdiscussedinChapter2,phototropismistheunderstandingthathumanbeingsareattractedtolightasamatterofinstinct.Thissimpleinstinctcanbereliedupontodrawattentiontothesurfacesandspaceswithwhichwewantpeopletointeract.Phototropismsuggeststhatdespiteconditioningandexpectation,inaroomfullofdetailedfurniture,intricateflooring,wallcoveringsandtilemosaics,theobjectthatthecasualobserverwillnoticefirstistheshadedtablelampglowinginthecorner.Withthisunderstanding,werealizethatwehavepredictablecontroloverwhereaviewer’sattentionisdrawninourdesignedspaces.Phototropismdictatesthattheeyeoftheobserverwillmovefromthebrightestsurfacetothenextbrightestsurface.Itmeansthatwecanoftenconvinceanobserverthataspaceisbrightbysimplydrawinghis/herattentiontoafewlarge,brightsurfaces.

LightingVerticalSurfacesThethirdtoolofhumanperceptiononwhichwerelyisthepremisethatthehumanvisualsystemisdesignedtotranslatethelightreflectingoffofthesurfacesinanenvironment.Theeyesaren’tabletodomuchwiththehighlevelsoflightthatcomedirectlyfromalightsource.Thus,theperceptionofthebrightnessofaspacehasmoretodowiththelightdetectedfromthesurroundingsurfacesthanthebrightnessofthelightsources.Thisconceptisexemplifiedbyastageperformerunderaspotlight.Thispersonhasalargeamountoflightcastontohim/her,buthe/shestillfeelsliketheyareinthedark.Anotherexampleisasimpleroomwithaglowingchandelierinthemiddle.Thechandeliermayattractattention,butitdoesnotnecessarilymakeaspacefeelbright.

Becauseweareupright,standingcreatures,werelyonthelightreflectingfromtheverticalsurfacesthatmakeupoursurroundingsanddefineourperipheralvision.Inmostofourdaytodayactivities,ourfieldofvisionisfocuseddirectlyinfrontofus.Evenwhenwelookaroundus,weareusingtheupright,verticalsurfacesofoursurroundingstodefineourenvironment.Thefeelingsofconfinementorfreedomandoveralllightqualityaredefinedbytheconditionsofthewalls,horizonsceilings,andskyconditionsaroundus.Theonlytimewelookdownistoassessthesafetyofthepathinfrontofus,sotheonlytimewereallyneedtoapplylightdownwardandimmediatelyaroundusistoilluminatesuchpaths.

Humansdonotdefinebrightnessbythelightlevelonthegroundaroundthem,nordotheydefinebrightnessbythelightfocuseddirectlyontothem.Asupright,mobilecreaturesgearedtolearnfromreflectedlight,humansnaturallyfocusonupright,reflectivesurfacesaroundthemtodefinetheirimpressionofanenvironment.Ifthegoalistocreateanimpressionofbrightness,lightappliedtoverticalsurroundingsismuchmoreeffectivethanlightdirectedontheviewer.

Figure3.1Lightappliedtoverticalsurfaces(left)increasestheperceptionofbrightnesscomparedtothesameamountoflightappliedtohorizontalsurfaces(right).

ASummaryofOurLightingTacticsThevisionsystemwilladapttomakethemostoflowlightlevelsandtomitigateexcessivelight.

Brightnessisasubjectivejudgmentbasedoncontrastbetweenneighboringsurfaces.

Humanbeingsareinstinctivelyattractedtobrightsurfaces,areasandobjects.

Humansgaintheirdefinitionofbrightnessfromtheverticalsurfacesaroundthem.

Thesefourelementsofhumanperceptionworktogethertoformthefoundationofhowwepurposefullyplacelightintoourenvironments.

Withthisbasis,ourdesignapproachbecomesastudyofhowtocreatemaximumeffectbydirectinglightontoafewspecificsurfaces.Thisapproachstartswithidentifyingthesurfacesthatwillbestrespondtolight.Wherecanwecreatelightedgoalstodrawpeoplethroughspaces?Wherecanweenhancetheperceptionofbrightnessbylightingverticalsurfacesandobjects?Wherecanwerelyoncontrastoflightlevelstocreatevisualinterest?Byansweringthesequestions,wewillcreatedynamic,visually-interestingspacesbypaintingspecificpiecesoflightontospecificsurfacestoaccomplishthelightingdesigngoalsofaspace.Thislightingapproachistheveryoppositeofprovidingevenwashesoflighttodefineaspace.

Toaccommodatethespecificplacementoflight,manyofthelightingtoolsavailabletothedesignerarediscreet,architecturally-integratedluminairesthatdeliverafocusedpoolorplaneoflightontoaspecificsurface.Byemployingthesehidden,directionallightsources,wedefineourenvironmentasacollectionoflightedsurfaces,ratherthanacollectionofoverly-brightlightsourcesoraflatfieldofgenericevenbrightness.

Becausewespendsomuchtimeinofficesandclassroomsthattypicallyemployanevenleveloflightthroughout,wecometothinkthatthisdesignisthecorrectorsafewaytolightaspace.However,aswelearntoarticulateourlightinggoals,itbecomesclearthattheonlyreasonspacesaretreatedwiththeseevenlightlevelsissothatapersonmayconceivablysitdownanywhereandperformavisualtaskforanextendedperiodoftime.Becauseofthis,welaunchintoourpracticewiththeunderstandingthatlightisourmediumormoreaccuratelythatlightedsurfacesareourmedium.Thissimplebuildingmethodofdesigningspecificpiecesoflightwillguideallofourdesigns.

THEFUNDAMENTALTWO-STEPPROCEDUREFORLIGHTINGDESIGNThisimprovementinlightingunderstandingcanbedefinedbya2-stepprocedureoflightingdesignthatwewilladopt:Lightingspecificsfirstandaugmentingtheambiencesecond.

Step1:LightSpecificsFirst

Thisstepreliesontakingtimetorecognizewherewewanttoputlight.Wefirstidentifythetasks,accentsandlocalvisualeffectsthatareintegraltoourdesign.Wevisualizeourselveswiththeabilityto“paint”lightontothesesurfacesasifwithapaintbrushorspraycan.

Figure3.2Anunlightedspace(left)withlightmentally“painted”ontoitssurfaces(right).

Figure3.3Howthelightedeffectmightlook(left),Howitmightlookwithanaddedambientingredient(right).

Afterlightingthesespecificsurfaces,westepbackandlookattheoveralllightedeffectofourdesignedspace;weassesstheeffectagainstourprojectorspacespecificdesigngoals,suchascomfort,uniformity,contrastandvisualinterest.Everypieceoflightwedirectontoaspecificsurfacelightsnotonlytheintendedsurface,butgoesontointer-reflect–thatis:bouncefromonesurfacetoanother–toaddasecondary“glow”ofuniformity.Understandingthis“inter-reflectance”iscrucialtovisualizinghowwearebuildinglightintoourspaceoneingredientatatime.

Step2:AugmenttheAmbienceorPerceivedBrightnessItisonlyafterwehaveassessedtheoveralleffectoflightingourspecificsurfacesthatwecandeterminewhetherourspaceneedssupplementallightingtointroduceadifferentspatialambience.Ifwedodetermineaneedforagreateroverallperceptionofbrightness,wenowknowthatlightontothemostvisibleandappreciatedsurface;theverticalsurfaceswillmostefficientlyachievethisgoal.

YOUCANNOTLIGHTAIRThistwo-stepprocedureisinstarkcontrasttotheideaoffirst“fillingup”aspacewithuniformlightonlytogobackattemptingtocreateelementsofvisualinterestthroughadditionalaccenting.Ourdiscussionofadaptationremindsusthatvisionisbasedoncontrast,notabsolutebrightness.Wediscerndetail,notbyhowmuchlightisonanobject,butfromcontrastbetweenoneobjectorsurfaceandanother.Astatuethatistwiceasbrightasthewallbehinditwillgrabourattention,regardlessoftheactualmeasuredlightlevel.Therefore,ifwefloodourspaceswithlightfirst,wewillendupwastingthatmuchmorelighttryingtodrawoutsurfacesandobjectswithinthealreadybrightspace.Ifweinsteadidentifyandpaintlightontospecificsurfacesandobjectsfirst,wesucceedincreatingthecontrastandtherefore“visualinterest”andbrightnessthatweintend.Thiscontrastwillremainintactasweaugmentourdesignwithadditional“fill”or“ambient”light.

Figure3.5The2-to-1accentratio(left)-andthustheperceivedbrightness-remainsthesamewhenlightisaddeduniformly(right).Visualinterestisonlyenhancedwhenthecontrastdifferenceinincreased(below).

Whenthis2-stepprocedureisimplemented,theresultisadesignedspacefilledwithemotionalimpact,engagingvisualinterest,andlogic.Wecreatedesignthattrulyencouragesinteraction.Thislogiccanproveusefulevenforouropenofficespacesandclassrooms,butisexceptionallyeffectiveinourhigh-designinteractiveenvironmentswherevisualimpactandemotionaleffectaretheprimaryprograms.

Themagicofthisprocedureandunderstandingisthatitrequiresnoknowledgeoflightingproductsandtechnologies.Itusesnocalculationsorlightlevelmeasurement.Lightinginthismannerissimplyachangeinperspectiveandunderstandingthatwillallowonetoassesslightedeffectbetterandtobetterdefinethelightingneedsofaspace.

Wewillbuildoffofthisprocedurebyintroducingasystemofdeterminingwherelightbelongsandarticulatinglightinggoals.Thissimple,two-stepprocessoflightingspecificsfirstandthenaugmentingambiencewillremainasthefoundation.

Chapter4AddingLightinLayers

Aswithdesigninganything,lightingdesignisnotnearlyasspontaneousacraftasonewouldwanttobelieve.Likeallgoodartforms,designismuchlessanexplosionofsuddencreativityandmuchmoreaproductofprocedureandunderstanding.Asdesignersconcernedwithlight,welooktoenrichourcraftbyexpandingourpossibilitiestocreateroomforgreatideas.Themaxim“formfollowsfunction”isastrueinlightingdesignasinanydesigndiscipline.Totrulymasterlightingistoestablishjustificationforwhyweaddlighttoaspace.Designmusthaveareasonforbeing,andtocreateopportunityforgooddesign,weelaborateonthereasonsforlightingto“be.”

Wetouchedbeforeontheimportantmentalpracticeofmakinglightingdecisionsthroughoutthearchitecturalandinteriordesignprocesses.Tofacilitatethisgoal,wewillgiveourselvesasmanyopportunitiesaspossibletostopandlookatourdesignwithfresheyes.Ifwebreakupthelightingdesignprocessandfocusononeaspectoflightatatime,wehavemoreopportunitytoponderthespecificpiecesoflightthatcanbeusedtosupportourdesigngoals.

Oneofthebeautiesofdesignisthatthereareno“wrong”answers,simplyideasthatarenotwellthoughtthrough.Ifwestudyourideasoveralongenoughperiodoftime,thegreatideasaresuretorisetothetop.Greatlightingisaproductofassessingdesignneedsatnumerousstepsofthedesignprocess.Poorlightingisoftentheproductoflightingdesignideasappliedallatonce,attheendofaproject.

Totrulygetafeelfortheimportanceoflightintegration,weneedonlyvisualizehowpowerfullightisatchangingtheeffectofaspace.Themoodsofarchitectureareoftensubtle,andlightcanhaveaswiftandpotenteffectondesign.Wemustbekeenlyawareofwhatdesigngoalsarebestfulfilledbylightandwhatlightisresponsibleforinourdesignedenvironment.

Totheseends,thelightingprocedurethatwewillimplementisamethodofarticulatingthereasonsweaddlighttoaspace,andaddressingeachreasonindividually.Thisprocedurehasbeenrefinedandlaidouthereasasystemof

addinglightinfivedistinctlayers

THEFIVELAYERAPPROACHTOLAYERINGLIGHT

Layer1:Lightingtochoreographanexperience

Uselighttocreategoals,pathsanddestinationstoencourageflowandmovement

Layer2:Lightingtodefinemoodandambience

Addintensity,colorandtexturetoelicitemotionandencourageaspecificuseinaspace

Layer3:Lightingtoaccentobjects

Createlightthatdrawsattentionandencouragesinteractionbymakinginterestingobjectsstandoutevenmore.

Layer4:Lightingtorevealarchitectureandshapespace

Applylighttothefeaturesanddetailsofaspacetoenhancespatialeffectsandrevealthemechanicsofstructureandform

Layer5:Lightingfortasks.

Applylighttotaskareastoaccommodatethebasicfunctionsofspace

“Focusattentionandthoughtononelayeratatime”

Inaperfectworld,thedesignerhastheopportunitytolookateachoftheselayersindividually,withamentalpausein-between.Foralightingdesigner,theidealsituationistobecomeabsorbedintheprogramor“brief”ofaprojectbeforeeventhinkingaboutlightingsolutions.Thenextstepistosurroundoneselfwiththeplans,elevations,diagramsandrenderingsthatdefinetheproject.Thedesignerthensetsouttogenerateideasforaddedlightthatmightchoreographanexperiencethroughthespace(layer1).Afterexhaustingthoseideas,thedesignertakesabreak.Thedesignerthenreturnstothedesignandthinksofadditionsoflightthatcontributetomoodandenvironment(layer2).Andsotheprocessgoes,designingwithaspecificpurposeinmind,lookingattheprojecteachtimewithfresheyes.Thisidealisnotalwaysrealistic,buttomakethemostofalayeringsystemofdesign,eachstepshouldbeaddressed

individually.Ifwestareatadesignedspaceandthinkmerelyof“lightingitup”inone

fellswoop,weareboundtocomeupwithgenericlightingsolutionsbasedonutility,habitandfear.Functionistheprimaryobjectiveofanydesignproject,andlightingcanmakeorbreakthefunctionalityofaproject.

Justlikeachefaddsspecificingredientsandseasoningsthroughoutthepreparationofameal,applyingourdesignedlightinlayersgivesusadepthofdesignthatisnotimmediatelyobvious,andcertainlynotpossibleifwetrytoapplyalloftheseideasinonepasstowardstheendofthedesignprocess.

Theselayerswillbeoutlinedheretogiveanimpressionofjusthowmuchcanbeaccomplishedwitheachofthem.Thepowerofeachlayerwillbecomeevidentaswegoontostudythenuancesoflightandhowhumansinteractwithit.Withthelayersystemtoguideourthoughtprocess,lightingideascomeeasilyandwithpurpose.Ourdesignprocessismorecomfortable,andresultsaremuchmorecertain.

ThissystemisthesinglebesttoolIknowofforempoweringadesignerofanyexpertiseleveltotakecommandofhowlightisaddedtothedesignedenvironment.

LAYER1:LIGHTINGTOCHOREOGRAPHANEXPERIENCETochoreographistodirectmovement.Inarchitecture,wefindourselvesresponsibleforencouragingpeopletoflowthroughspaceandinteractinaspecificorder.Thus,theapplicationofchoreographyissimplydetermininghowwewantaviewertomovethroughandinteractwithourdesign.Humansarephototropic.Weareinstinctivelydrawntobrightsurfacesandobjects.Withthisknowledge,weusethepoweroflighttosubconsciouslyconvinceapersontomovetowardaspecificareajustbyplacinglightinthatarea.Whenwewanttoencouragemovementorflow,wecanresorttobluntmethodslikesignageanddirectionalcues,orwecanrelyonthesubtle,butpowerful,humanattractiontolight.

Thepracticeisassimpleaslightingwhatwewantpeopletomovetowardsandleavingdarkwhatwewantthemtomoveawayfrom.Inthismanner,weuselightedend-pointsorgoalstomovepeoplethroughaspace.Weplacelightattheendsofhallsorontotheentranceofabuilding.Welightthefarendofaroomandwelightthecoffeetableinagatheringarea.Wefindwaystouseasingle,lightedsurfacetoattractattentionwherewemightpreviouslyhaveilluminatedanentirepath.Inthismanner,choreographingattentionandflowis

oneofthewayswereducehowmuchlightweintroduceintoaspace.Foreverydirectedmovementthatwewant,weidentifytheonesurfacethatwhenlighted,willencouragethatmovement.Whenwewanttodrawattentionandcreatevisualhierarchy,weidentifythespecificobjectsthatwecanlighttoaccomplishthisgoal.Whenwecombinethisspecificlightplacementstrategywithourknowledgeoftheuprightnatureofhumanvision,wefindthatverticalsurfaces-walls,partitions,furniture,andartfeatures-arethemosteffectivesurfacesforourchoreographypurposes.Suddenly,wefindourspacealreadytakingformwithvisualinterestcreatedthroughidentifyingwhichspecificverticalsurfacesandcentralelementsserveourchoreographygoals.Althoughchoreographyplanningisbutonelayeroffive,onceapplied,wealreadyhaveaspacethatisintuitivelyself-guidingandhasalogicalflow.

Figure4.1Lightinverticalsurfacesandobjectsisaneffectivemeansofencouragingpeopletomovetowardsaspecificgoal.

LAYER2:LIGHTINGTODEFINEMOODANDAMBIENCEThesecondlayerwestudyistheapplicationoflightintoourspaceforthesole

purposeofalteringtheemotionalstateoftheviewer.Itiseasytovisualizehoweasilylightcanchangetheoverallcolor,scale,ortextureofaspace.Wefirstidentifythemoodwewanttocreateinanarea,andthenidentifylightingingredientsthatwillsupportthatmood.Addinglighttoaffectmoodisastudyinthecontrollableaspectsoflightandrequiresdeliberatedecisionmaking.Aneasywaytocreatelightingthatsuccessfullyaffectsmoodistodefineeachlightingeffectintermsofthethreecontrollableattributesoflightthatweidentifiedpreviously:

Intensity:Dimvs.Bright.

Color:Warmvs.Cool(Oranobviouscolor).

Texture:Directionalvs.Diffuse.Whenweusethisawarenesstomakeanintensitydecision,colordecisionandtexturedecisionforeachpieceoflightweaddtoaspace,wecanbesurethatthelightissympathetictothemoodwewanttocreate.

Thegoalofthislayerofthoughtistodefinetheprojectonaroom-by-roomorarea-by-areabasisanddescribethemoodandemotionaleffectwedesireforeachofthesespaces.Agoodpracticeistocreatea“MoodMap”thatlabelstheintendedmoodineacharea,spaceorroomofaproject.Thismapmightdescribespaceswithemotionaldescriptorssuchas“cozy”,“harsh”or“dazzling”.Thesedescriptorsservetoinformourdecisionsaboutthethreecontrollableattributesofthelightthatweapplytothespace.

Thesesubtlecharacteristicsmustbethoughtofforeverypieceoflightthatweintroducetoavoidapplyinglightthatisaccidentallyinconflictwiththedesiredmood.Whenwenoticethat“cool”sourcesaren’tconducivetointimateresidentialsettings,wearesimplyaddressingoneaspect(inthiscasethecolortemperature)thathasnotbeenconsideredcarefully.Whenwecomeacrossexamplesoflightthatworkagainstthedesiredemotioninaspace,itisveryoftenonlyoneofthesethreecontrollableaspects(intensity,color,ortexture)thathasbeenneglected.Therefore,withonlyaminorchange,thelightcouldberemediedtocontributepositivelytothedesiredfeeling.

Thissecondlayerwillgiveyoutheopportunitytomakemeaningfuldecisionsaboutthecorequalitiesoflight.Itwillalsoencourageyoutoarticulatethespecificintentofeachdesignedarea.

Figure4.2.1Intensity,color,andtextureoflightcangreatlyaffectthemoodofaspace.

Figure4.2.2Intensity,color,andtextureoflightcangreatlyaffectthemoodofaspace.

LAYER3:LIGHTINGTOACCENTOBJECTSThethirdlayerwetackleisarguablythemostintuitiveandreadily-recognized.Wearesimplyapplyinglighttoalready-interestingobjectsandsurfacessolelyforthepurposeofmakingthosethingsmorenoticeable.Thephototropicnatureofhumanscanbeusedtodrawhumanmovement,butitisalsoeffectiveonasmallscalebydrawingvisualattention.Byplacingdiscreetshapesoflightontotheobjectsinourspace,wearecreatingalogicthatwilldictatehowaviewer’seyetravelsoverthevisuallandscapeofasinglespace.Wecandictateasubconsciousvisualpathfromanaccentedwallmural,toacrystalchandelier,toaperfectly-appointeddiningtable.Thisorganizationofvisualinterestencouragesavisitortoexperiencetheenvironmentinaspecificorder,takingtimetointeractwiththedesign;asortofchoreographyonasmallscale.

Whenweaccenttheobjectsinourspace,wearealsomakingdecisionsaboutwhattypeoflightisappropriateforthatobject.Thisrequiresanunderstandingofthematerialsusedinourdesignandwhethertheyrespondbettertoparticularintensities,colorsandtexturesofaccentinglight.Ifweareinterestedinrevealingtexture,wewanttousemoredirectionallightatsteeperangles.Ifwewanttoconcealtexture,weusemorediffusesourcesthatscatterlightinmanydirections.Weshouldevenbethinkingoftheshapeofthelightthatwearecastingontoanobject.

Whenwespeakofaccentingobjectstocreatevisualinterestandlogic,wearealsospeakingaboutthedecorativelightsourcesthatweusetoaddfocusandsparkletoaspace.Decorativependantsandwallsconcescanserveaspointsofinterestontheirown.

Theplacementoflighttoaccentobjectsisanotherwaywefocuslightontospecificsurfacesandreducetheamountoflightneededtocreatevisualclarityandfunctioninourdesign.

Figure4.3Distinctpiecesandshapesoflightaddtotheinterestofexistingobjectsandmaterials.

LAYER4:LIGHTINGTOREVEALARCHITECTUREThefourthlayeroflightinginoursystemaddresseslightwhichdefines,accentuates,andarticulatesthearchitecturalformsanddetailsthatwehavetakenthetimetodesignintoourspace.Visionisentirelydependentonlight,soitisreasonabletosaythatthegreatestofarchitecturalconceptsandspatialeffectscanberenderedmeaninglesswithouttheproperapplicationoflight.Withanunderstandingofthepoweroflighttoexpandandcontractspaces;tomakeobjectsappearcloserorfartheraway,weareequippedtomakeveryimpactingdecisions.Revealingarchitecturealsorequiresustothinkabouttheshapeofthelightwearecreating.Itisalsoanopportunitytothinkaboutwherethelightappearstobecomingfrom.Usinglighttoaccentuatearchitecturaldecisionstakestheformoftwodisciplines:lightingtodefinethearchitecturalcharacterandlightingtoaccentarchitecturaldetails.

LightingtodefinespatialcharacterThefirststeptoaffectingarchitecturalperceptionistodecideonaroom-by-

roombasisjusthowwewantaspacetobeconsidered.Wemustdecidewhetherwewantaspacetofeeltallandexpansive,confiningandintimate,wideandsweeping,etcetera.Afterwegotolengthstoplaceourboundariesandobjectsinamannerthatdeliversaparticularfeelingofspace,wecanapplylighttoappropriatesurfacestoenhancethedesiredeffect.

Wecanwashlightontoceilingstodefinetheheightofaspace.Wecanlightthewallsofaspacetorevealtheboundaries,orwecanleavethemdarktoeliminatetheperceptionofconfinement.Theapplicationoflightontoaspecificsetofarchitecturalboundariesandsurfacescarriesadistinctspatialimpact.Wemusttakecareandputpurposeintoourdecisionofhowwetreateacharea.Itisimportanttorecognizethatwherelightoriginatesfromhasasignificantimpactonhowpeopleperceiveaspaceandhowtheyfeelinaspace.Humansarecomfortablyconditionedtotheideaoflightstreamingdownontotheworldfromtheskyabove.Theadventofarchitecturallightingtoolsmeansthatwecantrumpexpectationandcreatelightthatemanatesfromtheground,wall,furniture;anyobjectorsurfacewechoose.

LightingtoaccentarchitecturaldetailsandfeaturesThesecondelementofrevealingarchitectureistoidentifythenuancesandarchitecturalfeaturesthathelpdefinethestructureandlogicofaspace.Wearelookingfortheexpressionsofstructure;thecolumnsandsoffitsthatdefineaspaceorthecoves,coffersandverticesthatdefineshape.Mostofthesearchitecturalfeatureswilljumpoutatusfromourplansandsketches.Wetreatthemmuchthesameaswetreatother“accentable”objects.Theonlydifferenceisthatinadditiontolightingthemjusttodrawattention,wearehelpingtoexpresstheformsandstructurallogicofaspaceandhowthespaceissupported.

Figure4.4Afewwell-placedpiecesoflightadddimensionanddepthtoarchitecture.

LAYER5:LIGHTINGFORTASKSThelastlayerthatwediscussinourcourseoffivelayersisthelightthatweintroducetoaspacestrictlyforthesakeofperformingvisualtasks.Thesetaskscanbeasspecificasreadingpaperworkorassubtleasnavigatingalobby.Wesavethisthoughtprocessforlastbecauseasweapplylighttoaddressallofthepreviouslayers,itislikelythatthelightwillinteractwithourspacetodeliverthelightnecessaryforourvisualtasksaswell.Ifwedesignwithconsiderationtoallofourotherlayersoflight,wewillhavearich,dynamicemotional

experience.Ifourdesignhasfailedtoaccommodateforourtasks,wecanaugmentbyaddingadditionalluminairesorlocalizedtasklighting.However,ifweneglectthemoreethereallayers,likechoreographyandmood,itisunlikelythatwewilleverbeabletoregainthosesubtleaspectsoffunctionality.

Lightingfortasksalsohappenstohaveanenormouswealthofprecedentandinformationavailabletohelpadesignerdeterminewhatlightlevelsareappropriateforspecifictasks.Therearereferencebooksfullofchartsandtablesthatcanbeusedbyanyoneforsolvingtasklightingproblems.

Whatshouldbeavoidedistasklightingservingastheonlytypeoflightconsideredforaspace.Inagooddesignapproach,itismerelyoneoffivelayers,andthelastoneatthat.

Wewillinvestigatethespecificsofprovidinglightfortasksasitisacriticalcomponentofthefunctionalityofaspace.Butitmustneverovershadowthethoughtanddesignoftheotherlayersthattrulyinfuseuniqueexperienceintoourenvironments.

Figure4.5Taskilluminanceshouldconsidervisualcomfortandperformance.

Tobecomecomfortableandconfidentwiththelayersystem,wemustremind

ourselvesthatnoneofthelayersarecompletesolutionsontheirown.Knowingthis,wecanfreeourselvestoaddresslighthowandwherewewantit.Ifweisolateeachoftheselayersasauniquethoughtprocess,wecanstandbackandwatchourspacenearlybuilditselfasacollectionofwellthought-outapplicationsoflightontospecificsurfaces.

Oursuccesswiththismethodreliesonremindingourselves,onceagain,thatlightedsurfacesareourmedium.Allofthelightingredientsweaddthroughthislayeredapproacharepiecesoflightpaintedontospecificobjectsandarchitecturalelements

Additionally,ourunderstandingofperceptiontellsusthatthemostefficientuseofourlightingresourcesislightappliedtoverticalsurfacesandtheuprightaccentedobjectsthatweplacethroughoutourdesignedspaces.

Ifwespendoureffortsdesigningtherightlightontherightsurface,themoretechnicaltaskofchoosinghowtodeliverthatlightwillbeeasierandcanbeexecutedwithconfidence.

Chapter5PhysicalBasicsofLight

Whenwededicateourselvestoincorporatinglightintoourspaces,andclaimitasafamiliarmedium,wealsodedicateourselvestounderstandinghowlightworks.Forourpurposes,wewillsailthrougharelativelysuccinctdefinitionofwhatlightis,howitinteractswiththesurfacesofourenvironmentandhowthisaffectsouruseofit.Anunderstandingoflightfromaphysicalperspectivewillempowerustomakegooddesigndecisionsandavoidtheperilsandpitfallsofmisappliedlight.

LightisamemberofamuchlargerfamilyofphysicalphenomenoncalledElectromagneticRadiation.Inourdiscussion,wewillsimplycallit“radiation.”Radiationisresponsibleformanyphenomenaweencounterinourdailylives.Itisallaroundusallofthetime.X-Rays,Microwaves,RadioTransmissionwavesandevenheatareallformsofradiation.“Light”ismerelyanamewehavedecidedtogivetothetypesofradiationthatweareabletodetectwithoureyes.

LIGHTASRADIATIONRadiationisessentiallypowerand,assuch,hasnomass,nocolor,notaste,andnosmell.Allofthedifferenttypesofradiationtravelaroundourplanet,andtheuniverse,attheverysamespeed.Wecallthisspeed“thespeedoflight,”butitis,infact,thespeedofeverytypeofradiation.Lightjusthappenstobeourfavoritetype.

Theonlydifferencebetweenoneformofradiationandanotherishowfastthatradiationvibratesasittravels.Thusthelightweusetoseediffersfromthemicrowavesusedtoforcookingonlyinhowfastitisvibratingasittravelsthroughspace.Becausethisrateofvibrationistheonlydiscerniblepropertyofradiation,wesymbolizeradiationaslittle,squigglylinesflyingaroundus.Thisallowsustodescriberadiationbythedistancebetweenpeaksandtroughsinoursquigglylines.Thelengthfrompeaktopeakortroughtotroughiscalledthe“wavelength”oftheradiation,anditistheonlysurewaytodistinguishonetypeofradiationfromanother.Inthecaseofvisiblelight,theselengthsarevery,very

small,sotheyareoftendescribedinNanometers.Ananometerissoshortthatittakesonebillionofthemmakeameter.

Figure5.1Radiation,includinglight,isbestimaginedassquigglylinesvibratingatdifferentratesastheytravelthroughspace.

Wedon’tneedtovisualizetheseunits.Weneedonlytoknowthatinscientificcircles,wavelength,oftenexpressedinNanometers,isaperfectlyappropriatewaytodescriberadiation,includingvisiblelight.Figure5.2showstheentireknownspectrumofradiationandthecorrespondingrangeofwavelengthsforthedifferenttypes.Youcanseethat“light”isafamilyofradiationatthe“short”endofthespectrum,thatistosayradiationwhichhasshorterwavelengthsandvibratesrelativelyfast.

Figure5.2Thecompletespectrumofelectro-magneticradiationincludingtheportionwecallvisiblelight.

Generally,wesaythathumancolorvisioncandetectradiationwithwavelengthsasshortas380Nanometersandwavelengthsaslongas770Nanometers.Soitiswithinthisrangethatwehavethe“visiblespectrum”orradiationwecall“light.”Anythingvibratingfaster,orvibratingslower,wenolonger“see.”Theradiationisstillthere;wesimplycannolongerdetectitwithoureyes.

Humansdohavemechanismsfordetectingothertypesofradiation,butcertainlynotwiththeacuityofthe“visiblespectrum.”Infra-redradiation,whichliesjustbeyondthevisiblespectrum,isagoodexample.Humansdon’tdetectitwiththeireyes,buttheydodetectitwiththeirnervesasvariouslevelsofradiant

heat.Wearecommonlytoldthatheatrises,but,moreaccurately,heatedairrises.Heat,itself,canbedirectedwithreflectorsjustlikeotherformsofradiation.

Figure5.3Anarticulationofthewavelengthsofradiationthatconstitutethevisiblespectrum.

Mosthumanshaveanamazingabilitytodistinguishbetweendifferenttypesandcombinationsofvisiblelight.Thearticulationofourvisualsystemisevidentintheplethoraofnamesthatwehavegiventoalloftheselightexperiences.Wenamethemascolors,andthereisnoshortageofsubtlevariationinourcolorexperiences.Itisimportant,however,toremindourselvesthat“color”issimplyanameforanexperience.Lightitselfhasnocolor.Itisonly

whendifferentwavelengthsofradiationreflectoffofsurfacesinourenvironmentandenteroureyethatwehaveanexperiencethatwecannameasa“color.”Henceeverywavelengthofradiationinthevisiblespectrumwillcauseafairlypredictablecolorexperience.Andso,ratherthanargueaboutwhetheranobjectisperceivedasyellowish-orangeor“canaryyellow”,wecouldsimplydescribetheradiationbyitswavelengthinNanometerstoendthedebate.Itisalsoworthnotingthattheacuityofcolorvisionvariesfrompersontopersondependingonhis/herphysiologicalmake-up.Variousformsofcolordeficiencycandrasticallyreducethenumberofuniquecolorexperiencesofwhichapersoniscapable.Studiesshowthatabouteightpercentofmalesandlessthanonepercentoffemalessuffersomeformofcolordeficiency.

EVOLUTIONOFCOLORVISIONDescribingradiation,lightandcolorinthismannerbegsanexplanationofwhyhumanshavecometo“see”thisradiationinthefirstplaceandwhywearesogoodatdiscerningonetypefromthenext.Theexplanationliesinthelogicoflifeonearth.Historically,thesunhasbeentheprimarysourceofradiationhereonearth.Thesunexhibitsaseeminglyendlesscycleofnuclearfusion,whichemitsaveryelaboratespectrumofradiation:essentially,thecompletespectrumasweknowit,fromx-raystoradiowaves.Theatmospherethatblanketsourearth,however,blocksthevastmajorityofthisradiation.Someofthisradiationslipsthrough,andasfaraswecanguess,hasalwaysslippedthrough.Thisbandofsneakyradiationthatactuallymakesittoearth’ssurfaceisabandthatincludesourvisiblespectrumandsomeoftheultra-violetandinfra-redradiationjustbeyondtheendofthe“visiblespectrum”.Colorvisionisanadaptationthathumanshavedevelopedinresponsetoradiationthathasalwaysbeenhere.Wehavehadalongtimeonearth’ssurfacetorefineourabilitytonotonlydetectthisradiation,buttoarticulateveryminutedifferences,justaswecanwithsmellsandtastes.

Thislogicalsoexplainswhywedonotreadilydetectorusealloftheotherformsofradiation;theyweresimplyneverontheearth’ssurfaceforustocareabout.Itisonlytheadventofmodernsciencethathasintroducedmanyoftheseotherformsofradiation–microwaves,x-rays,andradiowaves-toourlives.

Figure5.4Humanshaveevolvedtodetectandusethesmallbandofradiationthatslipsthroughtheearth’satmosphere:visiblelight,ultra-violet,andinfra-red.

Radiationthatreachestheearthinteractswiththesurfacesaroundusinthreeways:

Radiationcanbe“reflected”orbounceoffofasurface.

Radiationcanbeabsorbedbyasurface.

Radiationcan“transmit”orpassthroughasurface.

Itisthroughthesereactionsthatthecomplexspectrumsfromsunlightandelectriclightsourcesbecomedifferentcombinationsofvisibleradiationthatwetranslateintodifferentcolorexperiences.

Despitethecomplexitythatcanbeattributedtothephysicsofradiationplays,thelessonsarefairlybasic:

“Light”isthenameforagroupofspecificwavelengthsofradiationthathappentobedetectedbyoureyes.

Colorisnotapropertyofanobject.Colorisourbrain’stranslationoftheradiationbeingreflectedfromanobjecttooureyes.

BASICLIGHTINGINTERACTION

TERMINOLOGYTomoveforwardandspeakwithclarityaboutthewayslightinteractswithourenvironmentandourvisualsystem,itisimportanttopointoutthatinallcasesoflight,wearetalkingaboutthefundamentalpieceoflight:TheLumen.Lightingsciencemakesthetaskoftalkingaboutlightalittlebittrickybylendingdifferentnamestothephenomenaoflumensoflightinteractingindifferentways.Thespecificsofmeasuringlumensoflightwillbediscussedlaterinchapter18.Fornow,thecriticalknowledgeismerelyabitofvocabulary.

Illuminanceisanexpressionofthequantityoflightfallingontoor“striking”anobject.TheIlluminanceontoasurfacedoesnotnecessarilytelluswhatthatsurfacewilllooklike,asitdoesnotdefinetheamountoflightthatwillreflectoffofthatsurface.Knowingtheilluminancelevelontoanobjectdoes,however,allowustopredictthecontrastthatwillbecreatedbetweenmaterialsofdifferentreflectances.

Exitanceisanexpressionofthetotalquantityoflightleavingasurface.Exitanceiseasytounderstandbecauseitissimplyamatterofcountingupthenumberoflumensoflightthatleaveasourceorsurface.Thissimplicityisalsowhatlimitstheusefulnessofexitanceasadescription.Exitancetellsushowmuchlightisleavingasourceorsurface,butitdoesn’ttellusinwhatdirectionorwherethatlightendsup.

Luminanceisthephenomenaoflightleavingasurfaceataspecificdensityinaspecificdirection.Althoughluminanceisdifficulttomeasure,itisextremelyusefulbecauseitdescribeslightcomingoffofasurfacejustasaviewerwouldexperienceit.Describingtheluminancelevelsofaparticularsituationallowsustovisualizethelightedeffectofthespace.

The safest way to use these terms properly is to get used to the prepositionsrelatedtoeach.ItisappropriatetotalkaboutIlluminance“onto”asurface.Wegenerallyspeakof theExitance“offof”asurface.Wegenerally talkabout theluminance“comingfrom”asurface.

Figure5.5Theinteractionsoflightarealwaysaboutthebasicunitoflight:TheLumen.

Figure6.1Themajorcomponentsofthehuman

Chapter6PhysiologyofVision

Thehumaneye,withallofitsmechanics,deservesaheavybookofitsown.But,forourpurposeswewillfocusonthecomponentsoftheeyethatdetectandtranslatelight.Thesecomponentsinitiatethechemicalprocessthattransmitsinformationtoourbrain,whereitisprocessedintovisualexperience.Tostudythesemechanicsasdesigners,wemustunderstandwhattheeyeandbrainneedtoperformandfeelcomfortableinanenvironment.

Tobetterunderstandtheneedsofourvisualsystem,westartbystudyingsomemechanicalbasicsthatwetouchedonearlier.

AdaptationThistermisthenamewegivetothemechanicsoftheeyeandbrainworkingtocontroltheamountoflightthatenterstheeyeandistranslatedbythebrain.We“darkadapt”whenwewalkintoadarkroom,asthemechanicsofoureyesandbrainsworktomakethemostofwhatlittlelightisavailable.“Brightadaptation”occurswhenwetransitionintoabrighterspaceandoureyesandbrainsworktolimittheamountoflightenteringthevisualsystem.Adaptationoccursunconsciously.Itisworthknowingthatbrightadaptationhappensratherquickly.Darkadaptationcantakeafewminutestooccurcompletely.Forthisreason,wegiveextrathoughttolightlevelswhenwetransitionpeoplefrom

Figure6.2Theflexible“crystallinelens”changesshapetorefractlightdifferentlyastheeyefocusesonobjectsthatarefar

away(left)ornear(right).

brightspacestodarkspaces.

AccommodationThisisafancynamefortheabilityoftheeyetofocusonobjectsatdifferentdistances.Theeyehasflexiblerefractingcomponentsthatchangeshapetobendlightdifferentlywhenweshiftfocusfromacloseobjecttoanobjectfaraway.

STRUCTUREOFTHEEYEThehumaneyeconsistsofanumberofimpressivecomponentsthatperformallofthesecomplextasks.Nearlyallofthesefunctionscanbeunderstoodbyfindinganalogywithacamera.

Theoutermostcomponentoftheeyeballisthecornea,afluid-filledbulgeatthefrontofoureyethatdoesafairamountofgatheringandfocusingoflighttowardsthebackoftheeyeball.Thecorneaalsodoesawonderfuljobofprotectingtheothercomponentsoftheeyeandfilteringoutharmfulradiation.

Behindthecorneaistheiris.Theirisisthecomponentoftheeyethatcarries“eyecolor”andactsasashutterdevice,openingandclosingtocontrolthequantityoflightthatenterstheeyeball.Itistheiristhatisfirsttoactwhenthevisualsystem“adapts”todifferentlightlevels.Thepupilisthenamefortheaperturethattheiriscreates.Soweseeourpupilchangeinsizetoadmitmoreorlesslightasconditionschange.

Behindthepupilistheflexible,shape-changinglensthatisresponsibleforasmall,butcritical,portionofouraccommodation(focusing).Thislensisattachedtomusclesthatcontractandrelaxtooptimizetheshapeofthelenstorefractlightfromfarawayorfromnearbyaswefocusonobjectsatdifferentdistances.

Allofthesecomponentsareworkinginharmonyatalltimestodeliverthe

idealquantityoflighttotheelementsatthebackofoureyeball.Theseelementsmakeuptheretina.Theretinaishometoallofourlight-detectingphotoreceptorscalledrodsandcones.Thedifferenttypesofphotoreceptorsaredistributedinaverypurposefulwaythatcanbebrokendownintothreeareasofinterest.

Theperipheryofourretinaishometophotoreceptorscalled“rods”thatdetectlowlevelsoflight.

Thecentralareaofourretinaiscalledthemaculaandishometoamixofrodsandourmoredetailorientedphotoreceptorscalled“cones.”

Theverycenterofourretinaiscalledthefovea,anditishomeexclusivelytocones.Becauseconesaresocriticalfortranslatingdetailandcolor,thefoveaisslightlyconcavetomaximizethesurfaceareaavailable.Thedensityofconesatthefoveaallowsforgreaterdetailandcolorperceptionatthecenterofthefieldofvision.Itisthiscentermostareaoftheretinatowardswhichalloftheothermechanicsoftheeyeballareworkingtodirectlight.

Theconesandrodsarethecriticallightdetectingcomponentsoftheeye.Tounderstandhowthetwodifferentsystemsworktocontributetovisionindifferentlightsituations,wewillexpandonthemhere.

RodsRodsarethephotoreceptorsthatpopulatetheouterperimeteroftheretinaandareresponsibleforourso-called“peripheralvision”

Rodsareverylargeandverysensitivetosubtlelightchangesandmotion.

Rodsareactiveinlowlightlevels.Wecallthese“scotopic”situations.

Rodspopulatetheperipheryoftheretinaandpartsofthemacula.TheFovea(centerarea)oftheretinacontainsnoRods.Thereisonlyoneclassofrods,andtheyallcontainthesame

photopigment.ThisphotopigmentiscalledRhodopsinandismostsensitivetoradiationwithawavelengthof504Nanometers.Thiswavelengthofradiationwouldtranslatetothecolorexperience“blue-green”tonormalcolorvision.Becauseallofourrodshavethesamesensitivityandrespondtolightthesame,theyonlytranslatevalueinformation.Thusinlowlightlevel,“scotopic”

situations,ourrodstranslateonlyajudgmentofbrightordarktothebrain.Scotopicvisionsituations,therefore,appearmonochromatic(one-colored).

ConesConesarethephotoreceptorsthatpopulatethecentralareasofoureyeandareresponsibleforallofourhighdetailandcolorvisionfunctions.Conesareorganizedintothreedistinctclasses,andeachclasscontainsadifferentchemicalphotopigment.Thedifferentpeaksensitivitiesofthedifferentclassesofconesmakecolordistinctionpossible.Understandinghowlightisdetectedbythedifferenttypesofconesandtranslatedtothebrainisnecessarytounderstandingcolorscienceandmakingappropriatelightsourcedecisions.

Conesareactiveinhighlightlevels.Wecallthese“photopic”situations.

Conespopulatethecentralpartsoftheretina.Themaculaisprimarilymadeupofcones,andthefoveaatthecenterofourretinaisexclusivelymadeupofcones.

Conesareresponsibleforourcolorvisionandaresmallinsizeinordertotranslatedetail.

Therearethreedifferentclassesofcones,eachnamedforthephotopigmentchemicalthatitcontains.Thesethreephotopigmentseachhaveapeaksensitivitytoadifferentwavelengthoflightandarenamedforthewavelengthtowhichtheyaremostsensitive.Theseuniquesensitivitiesarewhatmakediscerningcolorpossible.

Our“R”orRedConescontainthephotopigment“erythrolabe,”whichismostsensitivetoradiationofwavelength580Nanometers.Notsurprisingly,thiswavelengthonitsownwouldelicitthecolorexperiencewecall“red.”

Our“G”orGreenConescontain“chlorolabe,”whichismostsensitivetoradiationofwavelength540Nanometers.

Our“B”orBlueConescontainthephotopigment“cyanolabe,”whichismostsensitivetoradiationofwavelength450nanometers.

PhotopicColorVisionfromourConesThekeytounderstandingconesandrodsisinvisualizinghowthese

photoreceptorsworktogethertotransmitinformationtoourbrain,whereitisthentranslatedintovision.

Figure6.3Approximatesensitivitiesofthethreeclassesofcones.

Figure6.3showstheentirespectrumofvisibleradiation(onitsside).Youmayrememberthatontheshortendofthespectrum(380Nanometersinwavelength),wehaveradiationthatelicitsthecolorexperience“violet.”Ontherightsideofthediagramisthelongendofthevisiblespectrum(radiationofwavelength780Nanometers)whichisradiationthattranslatesweperceiveasthecolorexperience“red.”Ontheleft-handaxisofthechartisasimplemeasurementofquantityorintensity.Thethreesensitivityspectrumsofthethreetypesofconesareoverlaidontothediagram.Asexpected,thepeaksensitivitiesofeachclasscoincidewithradiationtypesthatdeliverthecolorexperiencewewouldexpect.Themosteffectivewaytovisualizetheworkingsoftheconesistopictureeachclassofconesasanindividualpersonorgroupthatcastsavoteofintensitybasedonhowmuchoftheirfavoriteradiationtheydetect.

Asanexample,ifwecouldisolateaspecificwavelengthofradiation,inthiscase520nanometers,wecouldpredicthoweachclassofconeswouldvotebasedonwherethelineofthewavelengthintersectseachofthethreesensitivitycurves(seefigure6.4).WeseethattheRedconesvote4,theGreenconesvote7,andtheBlueconesvote1.Thesethreevotesformthethreedigitnumberthatistransmittedtothebrainforprocessing;inthiscase“4-7-1”.Thebraintranslateseachunique3digitcodeasauniqueexperience.Tokeepthemstraight,wenametheexperiencesascolors.Intheeventthatourclassesofconesalldetectthe

samequantityoftheirfavoritelight,theyallvotethesame,andthenumbersenttothebrainlookslike“3-3-3”or“5-5-5”.Inthiscase,thebrain’stranslationisaneutralvalue,someshadeofgrayorblackorwhite.

Figure6.4Theeffectofanisolatedwavelengthofvisiblelightcanbedeterminedbyidentifyingwhereitintersectsthesensitivitycurves.

Farmorelikelythanafewisolatedwavelengthsoflightisagroupofmanydifferentwavelengthsthatmaybereflectingoffofanobjectorcomingfromalightsource.Inthecaseofabroadspectrumlikethis,wefindtheintersectionsofallofthedifferentwavelengthsandconsideranaveragevaluethatrepresentsthem(seefigure6.5).Inthisfashion,everyimaginablecombinationoflightcanbeboileddowntoavotefromeachoftheclassesofphotoreceptorsandtransmittedasathree-digitnumbertothebrain.Thethreedigitsarewhatmakecolorspaceathree-dimensionalplacewithsomanypossiblecolorexperiences.

Figure6.5Evenaverycomplexspectrumistranslatedbythephotoreceptorsasasingle3-digitnumber.

Althoughthewavelengthcharacteristicsoflightareabsolute,thedetectionoflightandtranslationofcolorarefarmoresubjective.Everyperson’svisualsystemhasslightlydifferentpeaksensitivitiesanddifferentrangesofdetection.Thereareindividualswhodetectcertainwavelengthsoflightthatotherpeopledonot.They,therefore,havecolorexperiencesthatsomepeoplemayneverhave.

Thismodelofcolorvisionleadstotheunderstandingthatthesensationof“color”ismerelythebrainstranslationoftheretina’sdetectionofdifferentquantitiesofdifferentwavelengthsoflight.Thishasimportantramificationsinthatwecanartificiallycreateanycolorexperiencewewantthroughanengineeredcombinationofmanydifferentwavelengthsoflight.

ScotopicVisionfromourRodsIfwecanvisualizetheinteractionofourcones,understandinghowrodsworkisverysimple.Inthecaseofourrods,thereisonlyoneclass,onephotopigment,and,therefore,onlyonevote.Theinformationthatistransmittedtothebrainisasinglenumber.Becauseofthis,low-level“Scotopic”visionisamonochromaticexperience.Thebrainisbeingfurnishedwithonlyenoughinformationtomakeavaluejudgment:simplydarkorlight.

Figure6.6Allrodsaresensitivetolightinthesamemanner.Thus,theytranslateonlyavaluejudgment.

THETROUBLEWITHWHITELIGHTThisscienceneedstobemostthoroughlyconsideredasitrelatestoso-called“whitelight.”Withtheadventofmodern,highly-engineeredelectriclightsources,wehaveharnessedtechnologythatallowsustocreatelightsourcesthatcanappearasapleasingversionofneutralwhenvieweddirectly,yetrendercolorsverypoorly.

Figure6.7showsthatifwecreatealightsourcethatemitsjusttherightwavelengthof“blue”lightandjusttherightwavelengthof“orange”light,ourconeswillsendathree-digitnumbertoourbrainthatwillbetranslatedasneutral.

Figure6.7Theperceptionofneutralfromalightsourcecanbecreatedthroughacombinationofasfewastwowavelengthsoflight.

Figure6.8Theperceptionofneutrallightismorecommonlytheproductofawidevarietyofvisiblewavelengths.

Whatisinherentlydangerousisthatwhenourbraindetectsa“neutral”light

source,wearetemptedtobelievethatthislightsourcewillaccuratelyrenderallofthepotentialcolorsintheenvironmentaroundus.Butifwecreatedthelightsourceillustratedinfigure6.7,itwouldaccuratelyrenderonlytwocolors;therestwouldbemuddledandgray.Wewouldsuccessfullyhavecreatedasourcethatappearsperfectlyneutraltotheeye,butrendersonlyorangesandblues.Forthisreason,adesignershouldavoiddescribinglightassimply“white.”Tospeakaccuratelyoflightsources,wemustdiscusstwodistinctproperties:

1. Thecompletenessofthespectrumofalightsourceor“ColorRenderingIndex,”

2. Thebalanceofspectrumoflightsourceor“ColorTemperature.”

Chapter7TheColorScienceofLightSources

Likeallcolorexperiences,“white”orneutral,isrelativelysubjective,andpeoplemayexperienceitslightlydifferently.Inadditiontothevariationinindividualcolorsense,therearetwootherfactorsthatcontributeto“white”beingadangeroustermtolabelalightsource.

Thefirstofthesefactorsisasimplephysicalshortcomingofphotoreceptors.Ourconesrelyonchemicalphoto-pigmentstocausethechemicalreactionthattranslatesvision.Whenweexhaustthesupplyofphoto-pigmentstheconescannolonger“vote.”Thistemporaryexhaustioniscalled“bleaching”ofthephotoreceptorsandisthereasonthatafterstaringatasaturatedcolorforalongperiodoftime,weseethe“inverse”ofacolorwhenwelookaway.

Thesecondshortcomingisbasedonourbrains’habitofignoringrepetitiveinformationthatitdeemsoflittleuse.Yourbrainisadeviceofefficiency,andifitfeelsthatarepetitivesignalisbeingignored,itwillstopsendingit.Inthismanner,asyoustareatanobject,yourbraingrowsboredoftellingyouthattheobjectiscolored.Thebrainstartstoignorethesignalssentbyyoureye,andyourperceptionoftheobject’scolorbeginstoshifttowardsneutral.Moreappropriately,yourbrainisdecidingthatthecolorofthatobjectisthe“newwhite,”and,thus,everyothercolorisjudgedfromit.

Thesefactorstogethermeanthatanobjectappearstobemostsaturatedwithcolortheinstantwelookatit,andfadesasourconesrunoutofphoto-pigment.Thissubjectivityalsomeansthatwecandomucharguingaboutthecolorofanobjectorlightsource.Wehavealreadypointedoutthatwecaneliminateargumentaboutcolorbylabelingindividualcolorsbytheircorrespondingwavelength.Hereweareinterestedinapplyingthissimplicitytolightsources.Wespecificallycareaboutthelightsourcesthatwerelyontorevealthecolorsoftheworldaroundus.Inanattempttolimitconfusionandargument,weinsistondescribingtwouniquepropertiesofeverylightsource:ColorRenderingIndexandColorTemperature.

ColorRenderingIndex:

Thistermdescribesthecomplexityorcompletenessofthespectraloutputofalightsource.

ColorTemperature:

Thistermdescribesthecolorthatalightsourceappearstotheeyeduetoanimbalancedspectraloutput.

COLORRENDERINGINDEXColorrenderingindexisrathersimpleinprincipleandexpression.Thecolorrenderingindex,orCRI,ofalightsourceisexpressedasanumberrangingfrom0to100,where100isaspectraloutputthatcontainstheentirevisiblespectrumand,therefore,rendersallcolorsaccurately.Ifalightsourceemitseverywavelengthinthevisiblespectrum,thenthematerialsinanenvironmenthavetheopportunitytoreflectallofthosewavelengthstotheeye,and,thus,expressallofthepotentialcolorintheenvironment.

ThelowertheCRIvalue,thefewerdistinctwavelengthsthesourceemits.Therefore,fewerpotentialcolorexpressionscanbereflectedfrommaterialsintheenvironment.Whenwegoontoinvestigatevariouselectricallightsources,wewillseethatcolorrenderingcapabilities(andcorrespondingCRIvalues)varygreatlyfromsourcetosource.Thisvarietyisofhugesignificancetothedesigner.Sincedesignersareresponsibleformakingmanycriticalmaterialandcolordecisions,itisimperativethattheyareawareofthepossibleshortcomingsofthelightsourceunderwhichtheyaremakingtheirdecisions.Manyapersonhasbeenshockedtofindthattwomaterialsthatlooktobethesamecolorunderaspecificelectriclightsourcelookutterlydifferentunderdaylight.Daylightrepresentsacompletespectrumand,therefore,hasaColorRenderingIndex(CRI)of100.

Incandescingsourceslikethecommon“lightbulb”andhalogensourcesareengineeredtoalsoemittheentirevisiblespectrum,sotheyalsohaveaCRIof100.AbadfluorescentsourcemayhaveaCRIof60.WewilldiscussthespecificCRIvaluesofvariouselectriclightsourcesinchaptereightwhenweinvestigateeachsourceindividually.Sufficeittosayforgeneralunderstandingthatthefollowingguidelinescangetusthroughthesystem:

ColorRenderingIndices(CRI)inthe60’sand70’sarerelativelyincompleteandareunacceptableformakingcriticalcolordecisions.

Figure7.1ColorRenderingIndex(CRI)ofdifferentlightsourcesexpressedfrom0to100.

CRIvaluesinthe80’sdoareasonablejobofrevealingcolors

CRIvaluesinthe90’srendercolorsveryaccuratelyandareappropriateforcolorcriticalenvironments.

CORRELATEDCOLORTEMPERATUREThisisamethodofdescribingtheapparentcolorofalightsourcethatisverynearlyneutral.Whenalightsourceappearscoloredtooureye,itisduetoanunbalancedspectraloutput.Ifasourceemitslittleornogreenlight,itmayappearreddishor“warm.”Asourcemayalsoappear“warm”orreddishifitemitseverycolor,butemitsahigherproportionofred.

ColorTemperaturesareexpressedinDegreesKelvinorsimplyKelvins(becauseTheKelvinscaleisabsolute,itneedsnounits).

Thereasonthatweexpressthiscolorappearanceasatemperatureisaresultoftheexperimentingthatledtothescale.Thecolortemperaturescaleisexpressedasthecolorsthatablackbodyradiatorexhibitsasitisheatedtoextremetemperatures.Ablackbodyradiatorisakintoafancyblockofironthatwon’tmelt.Asthisfancyblockofironisheatedtohightemperatures,itbeginstoglow.Thefirstcolorthattheironblockwillglowisadull,deepred.Ifheatedfurther,thesameblockofironwillbegintogloworangeandthenyellow.Experimentsshowthatifheatedevenhigher,thecolorexhibitedbythisblockofironwilltravelallthewaythroughthecolorspectrum.Thus,thenextstopisgreen,onwardtoblue.Thepaththatthiscolortransitionmakesisnotlinear,so

Figure7.2Therangeofcolortemperaturesusedtodescribecommonelectriclightsources

thegreenhappenstobevery,verypaleandis,forourpurposes,consideredacolorlessneutral.

Theglowingredcoloroftheironoccursatatemperatureofabout1800Kelvins.Withthislogic,whenalightsourceexhibitsthisreddishcolor,ratherthancallitreddish,wedescribethelightsourceashavingaColorTemperatureof1800Kelvins.Inthissystem,orangeoccursatabout2500Kelvins,followedbyyellowatabout2800Kelvins.Followingtheprogressionoftemperatureandthecolorspectrum,keepinginmindthatweusethepalegreenasourneutral,theColorTemperaturetranslationsfollowthetableinFigure7.2.

Wemostoftenusethissystemofcolordescriptionforourengineeredlightsourceslikefluorescentlamps,LightEmittingDiodes,andHighIntensityDischargelamps.Thesecolorassociationsareonlyapproximationsanddifferinmeaningfromsourcetosourceandevenbrandtobrand.Thisleavesplentyofroomfordiscrepancy,butthebasicsofColorTemperaturetodescribetheslightcolorofengineeredsourceslikefluorescentremainsuseful.

2500Kelvins:warm

3000Kelvins:neutral

4100Kelvins:cool

Itisworthnotingthatwiththeseengineeredsources,thecolortemperaturedescriptionhasnorelationshiptotheoperatingtemperatureofthesourceitself.However,whenwediscussincandescentorhalogenincandescentsources,colortemperaturehasmoremeaning.Becausetheselight

sourcesaretheproductofheatingametalfilament,thecolortemperatureexhibitedisrelatedtothetemperatureofthefilament.Whenweheatanincandescentfilamentto2800degreesKelvin,wegetlightthatwewoulddescribeasthe“color”2800Kelvins(warm).

WhereourengineeredsourcescausedifficultyiswhentheyarenotlabelednordescribedbytheirColorRenderingIndex,ornumericColorTemperature.Unfortunately,manyconsumergradefluorescentlightsourcesandLED’sarelabeledwithmarketablenameslike“daylightwhite”or“designerwhite.”Thesenamesgivenorealhintastothecolortemperaturetoexpectandcertainlytellnothingofthecolorrenderingindex.Thus,theseproductsshouldbeavoidedwhencolorrenderingandsourcecolorarecritical.

KnowingtheColorRenderingIndexandColorTemperaturepropertiesofalightsourceisnecessaryforgainingafullunderstandingofalightsource’scapability.ItisreasonabletosayColorRenderingIndexisthemoreimpactingofthetwo.Ifasourceemitsacompletespectrumofvisiblelightandrevealseverycoloraccurately,itisreallyamatterofpreferenceastowhetherthatsourceneedstoappearwarmorcool.Thisisjustlikedaylightwhichchangescolordrasticallyfrompalesunrisetodeepsunset,butisalwaysusefulforrevealingcolor.Conversely,ifalightsourcerevealscolorspoorly,itisoflittlesignificancewhetherthesourceitselfappearswarmorcooltotheeye.Manyunsatisfactorylightingsituationscanberemediedbyimplementinglightsourceswithabettercolorrenderingindex.Veryfewlightingproblemscanbesolvedjustbyaddressingcolortemperature.

Tomakecompletelightingdecisions,itisnecessarytounderstandandspecifyboththeColorTemperatureandColorRenderingIndexofalightsource.

Chapter8ElectricLightSources

Atthecoreofeveryelectricluminaireisthelampthatactuallyconvertselectricityintoradiantlightenergy.SincethecommercialsuccessofthestandardIncandescentlampin1879,modernsciencehasdevelopedanumberofwaystoelectricallycreatelight.Eachtechnologyhasprosandconsthatshouldbeunderstoodbythedesignerinterestedinmakinglightingdecisions.Justasitisimportanttounderstandtheprioritiesandprogramofthedesignjob,itisnecessarytoknowwhichlightsourcesaregoingtoservethosepriorities.Thetopicoflightsourcetechnologyhasbecomemorecomplexastechnologieshaveprogressed.Whenweconsiderhowlonghumanshavereliedonthesunastheprimarysourceofillumination,itiseasytounderstandwhyelectriclightsourceselectionissocriticalandwhyourvisualsystemstruggleswiththecolorrendering,colortemperatureandglareissuespresentedbymanyofournewer,technologicallyadvancedsources.

Wewilldiscusseachofthesetechnologieswiththeintentofunderstandinghoweachperforms,andwhereeachshouldbeusedornotused.“Lamp”isthepropernameforwhatmostpeoplecalla“lightbulb.”Inourdiscussionwecareaboutvocabularyasmuchasanythingelse,sowewillrefertooursourcesaslamps.

Let’ssummarizeourworkingknowledgeofthedifferentlightsourcetechnologiesbyidentifyinganddiscussingthepropertiesthatdefinetheirsuitabilityforaspecificlightingchallenge:

InitialCost:Howexpensiveisthistypeofsourcetopurchase?

OperatingCost:Theexpenseofprovidingelectricity,maintainingandreplacingthesource.

ColorRenderingIndex:CRI(onourscaleof1to100.)Arepresentationof“completeness”ofvisiblespectrumprovidedbythesource,andthushowwelliswillrendercolorsinthedesignedenvironment.

ColorTemperature:ExpressedindegreesKelvinorKelvins;indicatestheperceivedcolorofthesourceitselfasaproductofanimbalancedspectraloutput.Roughlycategorizedaswarm,neutralorcool

Ballast,TransformerandDriverRequirements:Manysourcesrelyonspecializedelectronicormagneticequipmenttoconvertstandardlinevoltageelectricitytosomethingmoresuitableforthesource.Thesedevicesareoftenbuiltintegraltothelamp,integraltotheluminaire,orareremotelymountedwithinaspecificdistanceofthesource.Oftentheymustbeinstalledsuchthattheyareaccessibleformaintenanceorreplacement.

Dimming:Manysourcescanbesimplydimmed.Othersrequireacarefulmatchingofdimmingcontrollersspecifictothesourcetype.Someelectriclightsourcescannotbedimmedatall.

Instanton/off:Manysourcesrequiretimeto“warm-up”topresentfulllightoutput.Somesources,whenturnedoff,mustbeleftofffora“re-strike”timeperiodbeforetheycanagainbeswitchedon.

“Directability”:Anindicationofhowfocusedthelightleavesthesource.Somelampshaveopticalreflectorsbuiltintothem.Othersourcesrelyonluminairestoopticallycontrolanddirectlight.Theabilitytofocuslightfromasourceisrelatedtothesizeofthesource.Thesmallerthelightsource,theeasiertoharness,controlanddirectit.

Efficacy:Afancywordforefficiency;thisisanindicationofhowwellthetechnologyconvertselectricitytovisiblelight.Mostelectricity“wasted”inanelectriclightsourceisconvertedtoheat,whichmustbeconsideredinitsownright.Efficacyisexpressedaslumensoflight“out”forwattsofelectricity“in”orsimply“lumensperwatt”

LampLife:indicateshowlongalightsourceprovidesaworkingpercentageofitsinitiallightoutput.Thisishelpfulforselectingandplanningasthelabortoreplacealampisoftenmorecostlythanthelampitself.Itisgoodpracticetoreplacelampsinbulkbeforetheyactuallyfail.Lamplifeiscommonlyexpressedinthousandsofhours.Acommonassumptionisthat1000hourstranslatestoroughly1yearoftypicaluseresidentiallyand3000hourstranslatestoayearofcommercialuse.Theseassumptionsassumeaboutthreehoursorninehoursofuseperday(respectively).Adjustmentsshouldbemadeaccordingly.

Figure8.1Theworkingcomponentsofstandardincandescentlightsources

Temperaturerequirement:Someelectriclightsourceshaveparticulartemperatureconcerns.Manyfluorescentsourcesfunctionpoorlyincoldenvironmentsandmoreefficientlyinwarmenvironments.

HeatGenerated:Electricityinalightsourcenotconvertedtovisiblelightisoftenconvertedtoheat,whichmustbeconsideredforsafetyconcernsandforadditionalcoolingloadneeds.

NoiseGenerated:Bewarethatmanyelectriclightsourcesandtheiraccompanyingequipment(drivers,ballast,transformer)cangenerateunwantednoise.Thisawarenessandconsiderationiscrucialforinteriorenvironments.

STANDARDINCANDESCENTSOURCESCheap,hotandinefficient;standardincandescentlampsareusedforsoft,diffuseblobsofwarmlightthatrendercolorswell.StandardIncandescentsourcesrepresentaverybasictechnologythathaschangedlittleinthe100-plusyearssinceitsrefinement.Figure8.1illustratesthebasicworkingcomponentsthatenablethesesourcestofunction.Verysimply,electricityispassedthroughanengineeredmetalfilament.

Aswithmanymaterials,themetalfilament“resists”theflowofelectricity.Thisresistancecausesfriction,which,inturn,becomesheat.Oncethisresistanceandsubsequentheatbecomegreatenough,themetalfilament“incandesces”;itgivesoffradiantenergyinabroadspectrumthatincludesthevisiblespectrum.Understandingthattheradiantenergygivenoffalsoincludesahugequantityofheat(infra-redradiation)explainsmanyoftheundesirablepropertiesandinefficienciesofincandescentsources.Itisworthnotingthatmanycountrieshaveintroducedlegislationtophaseouttheuseofincandescentlightsources:TheEuropeanUnionin2009,RussiaandCanadain2012,TheUSandChinain

2014.Checkwithlocalandnationalregulationsbeforeconsideringthesesourcesforuseonyourproject.

ThePropertiesofIncandescentSources:InitialCost:cheap!

…Dirtcheap.Thisistheprimaryreasonincandescentsourcesaresocommon.Thesmallpricetagcompelsustoreachforincandescentlampsdespiteourknowledgeortheirinefficiencyandshortlamplife.

OperatingCost:Expensive;Incandescentsourcesareinefficientandshort-lived.Theyconvertonlyabout1/3rdofthequantityofinputelectricityintovisiblelight.Theremaining2/3rdsleavesasheat.Incandescentsourcesareexpensivetoelectrifyandrequirefrequent,costly,labor-intensiverelamping.

ColorRenderingIndex:100(great);Thefilamentoftheincandescentsourceisengineeredtoincandesceinamannerthatdeliverseverywavelengthofvisibleradiation.Thiscompleteoutputspectrumcanrevealallofthecolorsthatthesurfacesinanenvironmenthavetooffer.Thisdesirablecolor-renderingabilityisanotherreasonwearesoreluctanttomoveawayfromthesesources.

ColorTemperature:warm;Incandescentsourcesactuallyoperateatthetemperaturethatcorrespondstotheircolortemperature.Standardincandescentfilamentsareheatedtoabout2800degreesKelvin,sothewarm,yellow-orangelightgivenoffbythesourcecanbedescribedas2800Kelvins.Thiswarmthisanotherreasonweseemtobeattractedtothesesources.Thewarmcolortemperaturetranslateswellinintimate,relaxedenvironments.

BallastandTransformerrequirements:None;Incandescentsourcesrequirenospecialcomponentstooperate.Linevoltageelectricityissimplydriventhroughthefilament,whichheatstoapointofincandescing.

Dimming:CheapandEasy;

Incandescentsourcescanbedimmedsimplybyloweringtheamperage(quantity)ofelectricitythatispushedthroughthem.Thiscanbeaccomplishedwithasimplewallboxdimmerthatcanbeinstalledinplaceofmostcommonlightswitches.

Instanton/off:Yes;Incandescentfilamentsheatuptoincandescenceveryrapidlyaselectricityisappliedtothem.Forourpurposes,wewillconsideritasinstant.

Directability:Poor;Incandescentsourcesareverylargetoaccommodatetherelativelylargefilamentwithin.Generally,thelargerthesource,themoreinefficientitistogatherupthelightanddriveitoutinaspecificdirectionthroughtheuseofopticalcontrol.Thinkofbuildingareflectoraroundacommon“lightbulb”toaccentasculpture,andyoubegintogetthepicture.

Efficacy:VeryPoor(10LumensperWatt);Incandescentsourcesdomuchmoretodeliverheatthantheydolight.Thisresultsinalargequantityofwastedelectricity.Incandescentsourcescreateabout10lumensoflightforeverywattofelectricityputintothem.

LampLife:Poor;Anothersignificantdrawbackofstandardincandescentsourcesisthefrequencywithwhichwereplacethem.Incandescentsourcesareexpectedtohavealamplifeofabout1000hours.Usingourestimates,thistranslatestoanywherefromthreemonthstooneyearofregularusebeforethesource“burnsout.”Asincandescentlampsoperate,themetalfilamentisheatedsothatisliterallyboilsaway.Asthefilamentboilsaway,itbecomesthinandbrittleand,ultimatelybreaks,causingfailure.

Temperaturerequirements:None;Incandescentsourcesoperateequallywellinanyreasonabletemperaturecondition.

HeatGenerated:Lots;Incandescentsourcesemitmoreinfra-redradiationthanvisiblelight.Theyaretrulyheatlampsbynature.Theycanbeexceptionallyhot

Figure8.2Commonshapesofstandardincandescentlightsources.

tothetouchandmustbeconsideredfortheheatdamagethycandotoneighboringmaterialsaswellastheadditionalheatingloadtheyrepresentinthedesignedspace.

NoiseGenerated:Some;Incandescentsourceshaveatendencyto“buzz”whentheyaredimmeddown.Thisgenerallycomesfromthefilamentbuzzingduetovibrationaselectricityflowsthrough.Incandescentsourcesarefairlysilentunderfull-poweroperation.

Incandescentlampsareinexpensivetopurchase,rendercolorswell,haveapleasingwarmcolorcast,andareeasytodim.Theyare,however,wildlyinefficient,produceatremendousamountofheat,andareshort-lived.

Weuseincandescentsourceswhenwearetryingtocreatesoft,diffuse,warmfloodsoflight.Incandescentsourcesaregoodfordistributinganevenquantityofwarmlightinalldirections.Occasionally,webuildreflectorsaroundincandescentlampstocreatedownlightsandaccentluminaires,butthelargenatureofthesourcemakesthemill-suitedforthistask.Incandescentlampsareoftentheheartofdiffusingluminaireslikefloorlamps,tablelamps,anddecorativesconces.Thelimitinsizeandwattageofincandescentsourcesalsolimitsthesizeofapplication.Theselampsareusuallysuitedtosmallerenvironmentsandlow(10’-0”andunder)ceilings.ConsideringthescheduledphasingoutofincandescentsourcesandtheemergenceofsuitablealternativesintheformofcompactfluorescentandLEDtechnology,thereisdwindlingjustificationforspecifyingincandescentsourcesonaproject.

HALOGENINCANDESCENTSOURCESSmallandhot,Halogensourcesdeliverclean,crisp,easily-directedlightthatisusefulforcreatingfocusedshapesoflight,accentsurfacesandobjectsorfortwinklinguseasbarelampsforvisualinterest.Calledbymanynames,Halogen,QuartzHalogen,TungstenHalogen,wearetalkingaboutalightsource

Figure8.3Theworkingcomponentsofhalogenincandescentlightsources.

thatisessentiallyarefinedversionofthebasicincandescentlamp.Halogenincandescentsourcesarenamedforthehalogengasthattheycontainandthequartzouterbulbthatsurroundstheirfilament.Bothoftheseadvancementsallowthefilamentinthesesourcestooperateatahighertemperature.Thishasthesurprisingbenefitofallowingthesourcetorunmoreefficientlyandalsoextendsthelifeofthelamp.Theotherbenefittheseadvancementsprovidetothedesignerisasmallersourcepackagewhichcanmoreeasilybefocusedanddirectedviaopticsandreflectors.Figure8.3showstheworkingcomponentswiththeexpectedsimilaritiestostandardincandescentsources.

HalogenIncandescentsourcesarebasicallyarefinedversionofstandardincandescent;theyofferhighercolortemperaturesdescribedasnearlyneutralpaleyellow.Theselampsofferlongerlamplife,greaterefficacy,andasmallerpackagethatcanbebetterdirectedtoaccentandlightspecificobjects.Halogenincandescentsourcesarestillrelativelyinefficient.Itisworthinvestigatingcontemporaryceramicmetalhalide(CMH)andLEDsources,whichhavebeenfashionedintosimilarlampshapestoprovidesimilar,“directable”effectsatmuchgreaterefficacy.

ThePropertiesofHalogenIncandescentSources:InitialCost:Moderate;

Halogensourcesaremoderatelyexpensivetopurchase.Thisexpensecomesfromthecostofthetechnologyandbecausetheyarelesscommonthanthestandard“lightbulb.”

OperatingCost:Expensive;Althoughmoreefficientthanstandardincandescent,Halogensourcesarestillwastefulandstillshort-livedwhencomparedtosourceslikefluorescent,LEDandHighIntensityDischarge(HID).

ColorRenderingIndex:100(great);Halogensourcesalsorelyonheatingfilamentstoapointofincandescing.Thesefilamentsaredesignedtoemitaspectrumthat

includesallofthevisiblewavelengthsthatobjectsinourenvironmentmayreflecttooureye.

ColorTemperature:warmtoneutral;Thehigheroperatingtemperatureofhalogenincandescentsourcescreateslightthatexhibitsahighercolortemperature.Thefilamentisheatedtoabout3000degreesKelvinand,therefore,createsapaleyellowishlightthatwecandescribeas3000Kelvins.

BallastandTransformerrequirements:Some;Manyhalogenincandescentsourcesareengineeredtooperateatalowervoltagethaniscommonlydeliveredtoelectricalcircuits.These“lowvoltage”sourcesrequireatransformerto“transform”theelectricityfromstandardlinevoltage(120voltsintheU.S.,220voltsinmuchofEurope)toalowervoltage(commonly12voltsor24volts).Thesetransformerscanbeassmallasacandybar,butmustalwaysbeconsideredastheymustbeinstallednearbyandmustbeaccessible.

Dimming:CheapandEasy;Justlikestandardincandescentsources,halogenincandescentsourcescanbedimmedwithsimplewallboxdimmers,whichregulatethequantityofelectricitydeliveredthroughthefilament.Itisimportanthowevertomatchthedimmingequipmenttothespecifictransformertype(electronicormagnetic)ifatransformerisinuse

Instanton/off:Yes;HalogenIncandescentfilamentsheatuptoincandescence,andthusgiveofflightnearlyinstantaneously.

Directability:goodtoexcellent;Oneofthemostnotableby-productsofHalogentechnologyistheabilitytobuildasmallerlamparoundasmallerfilament.Thesesmalllampsareidealforbuildingintoprecisionreflectorsthatdriveoutlightinasingledirection.Thesmallsizeisthereasonhalogenincandescentlampsaresocommonlyusedforaccenting,stagelighting,andprecisionfloodlighting.Manyhalogenincandescentlampsarebuiltwithintegralopticsandreflectors.

Efficacy:Poor(15LumensperWatt);

Whenfirstdeveloped,Halogenincandescentsourceswereheraldedforbeingfiftypercentmoreefficientthanstandardincandescent.ComparedtosourceslikeLEDandceramicmetalhalide,whichbothoffersimilarlampshapes,thisnumberisnowlessthanimpressive.

LampLife:mediumtogood;ThehighertemperatureofHalogenIncandescentlampscreatesasituationinwhichthemetalofthefilamentrecycleswithinthelamp,thus,extendinglamplifesignificantly.Halogensourcesgenerallylastabout3000hours,butcanbeengineeredtolastaslongas10,000hours(aslongas10yearsbyourresidentialassumptionof1000hoursperyear)

Temperaturerequirements:None;Halogenincandescentsourceswilloperatewellinanyreasonabletemperaturecondition.

HeatGenerated:Lots;Halogenincandescentsourcescreateasignificantamountofheatthatmustbeconsideredforsafetyaswellasaddedheatloadtoaspace.

NoiseGenerated:Some;Halogenincandescentsources“buzz”whentheyaredimmeddown.Inadditiontothebuzzofthefilament,somehalogensourcesrelyonmagnetictransformerswhichcanalsocreatenoise.

Halogenincandescentlampsaremoderatelyexpensivelampsthat,likeincandescent,areratherinefficientandcreateexcessheat.Weusehalogensourceswherewewanttheexcellentcolor-renderingcapabilitiesandthenearlyneutralcolor.Halogensourcesareverysmall,sotheycanbeincorporatedintosmallerluminairesandintoprecisionaccentingluminairesthatdriveoutadirectionalbeamoflightforaccentingspecificsurfacesandobjects.AdvancementsinLEDandceramicmetalhalidetechnologyhaveresultedinlampshapesthatprovidethesamedirectablelightashalogenincandescentsourceswithmuchgreaterefficacies,increasedlamplifeandsuitablecolorrenderingindices(CRI).

FLUORESCENTLAMPSEfficientandversatile,fluorescentlampscreatediffuselightthatcanhavemanydifferentcolortemperaturesanddifferentcolor-rendering

Figure8.4Commonshapesofhalogenincandescentlamps.

capabilities.Fluorescenttechnologyhascomealongwaysincethedaysofflickering,humming,bluelight.Themostsignificantaspectoffluorescentlamptechnologyisthevastrangeofcolortemperaturesandcolorrenderingcapabilities.Consequently,caremustbetakeninspecifyingthem.Ifadesignerdoesnotspecifytheparticularcolortemperatureanddesiredcolor-renderingindexofafluorescentsource,theproductdeliveredcanbeverysurprisingandlessthandesirable.

Fluorescentlampsworkthroughaverynovelmanagementoftechnologybasedonphosphorescence.Figure8.5showsthecomponentsthatareatworkinallfluorescentlamps.Long,linearfluorescentlampsandtwisty,compactfluorescentlampsareallbasicallyhollowglasstubesfilledwithvaporizedmetal.Whenthis“cloud”ofmetalvaporisexcitedbyabombardmentoffreeelectrons,itgivesoffalimitedspectrumofmostlyultra-violetradiation.Themagicofthetechnologyisthewhitepowderycoatingofmineralphosphorsthatlinetheinsideoftheglasstube.Thesephosphorsglowbytranslatingthelimited-spectrum,ultra-violetradiationintoamuchbroaderspectrumofvisiblelight.Thequalityandmake-upofthephosphorcoatingiswhatdeterminesthecolor-renderingpropertiesandcolortemperatureofthelamp.Thisphosphorcoatingcanbeengineeredtodeliverlightthatexhibitsanyversionofcoolorwarm:bluish,violet,pinkish,orange-ish,yellowish,etc.Usingelectricitytoexcitethemetalvaporandthetranslationmadebythephosphorcoatingareefficientprocessesthatcreateverylittleheat.

Fluorescentlampsalsorequireadevicecalledaballastthatstartsthelampandstabilizestheelectricitydeliveredtothelamp.Theseelectronicormagneticdevicesrangeinsizeandmustbelocatedinornearthefluorescentluminaire.

Figure8.5Theworkingcomponentsoffluorescentlightsources.

ThePropertiesofFluorescentLightSources:InitialCost:Moderate;

Fluorescentlampsgetlessexpensivetopurchaseastheybecomemorecommonplace.Therearealsomanygovernmentfundedprogramsthatsubsidizefluorescentlampstoencouragetheiruse.CommoditylampsliketheT-8canbequiteinexpensive.Thoughdesirablecolortemperaturesandcolorrenderingpropertieswilldrivethecostup.

OperatingCost:Cheap;Betweenthehighefficiencyandlongtimebetweenrelamping,thesesourcesareamongthemosteconomicaltooperate.

ColorRenderingIndex:70-95(moderatetogood);Thevariationsinphosphortechnologyallowfluorescentlampstobeengineeredtorendercolorswell.Unfortunately,farmorecommonareversionsthatdon’t.Generally,bettercolorrenderingindex(CRI)willmeanamorecostlylamp.Itisalwaysadvisabletoseeaworkingsampleofaspecificfluorescentlampwhenconsideringitforuseonaproject.

ColorTemperature:Variable.Warmtocoolandeverythinginbetween;Fluorescentlampscanbeengineeredtoexhibitanycolordesired.Whatiscriticaltounderstandisthatthecoloralampappearstooureyedoesnecessarilyindicatehowwellthatlampwillrendercolors.Fluorescentsourcesgenerallyhaveaslightcolorcastthatmaylookoddwhencomparedtoincandescentandhalogensources.Itis

alwaysadvisabletoseeasamplepriortoconsiderationonaproject.

BallastandTransformerrequirements:Yes;Allfluorescentlampsrequireaballasttooperate.Theballastcanbebuiltintotheluminaireormountedremotely.Somefluorescentlamps,likethoseintendedtoreplacescrew-inincandescentlamps,havetheballastbuiltintothem.Ballastsoperateeithermagneticallyorelectronically,anditisworthwhiletospecifyelectronicballastsformostuses.Magneticballastsareresponsiblefortheflickering,humming,andbuzzingthatareassociatedwithfluorescentlamps.Electronicballastsaresmall,light,quiet,startnearlyinstantly,andaremoreefficient.

Dimming:yes…butcostly;Manyfluorescentsourcescanbedimmed,butthisrequiresalamp-specificdimmingballastand,oftentimes,aspecifictypeofdimmingswitch.Itisadvisabletogetacontrolsspecialistorlampmanufacturer’srepresentativeinvolvedwhendesigningdimmablefluorescentlighting.

Instanton/off:Yes(withanelectronicballast);Anelectronicballastwillallowafluorescentlamptostartnearlyinstantly.Magneticallyballastedlampstendtoflickerandstutterwhenturnedon.

Directability:Poor;Becauseoftheirlargesize,fluorescentlampsarebestusedforadiffuseglowoflightandarehardtodirectasaccents.Fluorescentluminairestendtobequitelargetoaccommodatethelargerreflectorsandoptics.

Efficacy:Excellent(70Lumensperwattaverage);Fluorescentlampshavebeenrefinedtobeexceptionallyefficient.Rangingfrom50to100lumensperwatt,theselampsconsumeaslittleas1/10ththeelectricityofincandescentlampswhileprovidingthesamequantityoflight.Bewarethathigh-efficacylampsmaycompromiseotherfeaturessuchascolorrenderingindex(CRI)orlamplife.

LampLife:Excellent;Fluorescentlampsaredesignedtolastanywherefrom10,000to

hoursto30,000hours-anywherefrom10to30years-betweenrelamping.Itisworthnotingthataluminairemayfailduetoballastsfailureratherthanlampfailure;Checkboth.

Temperaturerequirements:Preferwarmth;Fluorescentlampsoperatebetterinwarmenvironmentsandactuallygetbrighterastheywarmthemselvesup.Fluorescentlampsoftendon’tworkincoldenvironments,socareshouldbetakenwhenspecifyingthemforsuch.

HeatGenerated:Verylittle;Efficienttechnologymeansthatverylittleelectricityisconvertedtoheat,buttheselampsstillbecomewarmtothetouch.

NoiseGenerated:Some;Lampswithmagneticballastscanclickandbuzz.Electronicballastscanalsohumslightly.Lampslabeledas“high-output”canalsogiveoffasignificantamountofnoise.

Figure8.6Commonshapesofcompactfluorescentlamps.

Figure8.6.5Commonshapesoflinearfluorescentlamps.T-12’sareoldertechnology,T-8’sarethemostcommon,andT-5’sarenewertechnology.

Fluorescentsourcesrepresentanefficientwaytoproducesoft,glowinglightakintothediffusetexturewewouldgetfromanincandescentsource.Theyaregoodforthesamediffuseblobsoflightand“general”areailluminance.Theselampslastanexceptionallylongtime.Fluorescentlampsrequirecareinspecifyingbecauseofthevarietyofcolortemperaturesandcolor-renderingindexvaluesavailable.ItisnecessarytospecifybothCRIandcolortemperaturewhenusingfluorescentlamps.

Wemostcommonlyusefluorescentlampsforlarge,openareaslikeclassroomsandopenofficeworkspacesthatneedaconsistentlevelofdiffuselightthroughout.Weusefluorescentlighttowashupontoceilingsorinslotsandcovestowashdownwalls.Likeincandescentlamps,itisdifficulttoharnessthelightoftheselargelampsandfocusitasaccentlight.Withtheincreasingpopularityoffluorescentsources,theirdisposaliscomingunderscrutiny.Fluorescentlampscontainaverysmallamountofliquidmercury.Checkwithyourlocalagenciesforanyspecialregulationsgoverningpurchase,specificationordisposaloffluorescentlamps.

Figure8.7Theworkingcomponentsofhigh-intensitydischarge(HID)lightsources.

HIGHINTENSITYDISCHARGE(HID)LAMPSThishighwattage,highoutput,efficientsourcerangesinusefromstreetlightstoretailaccent.Mostnotably,theyallrequiresomewarm-uptimeandarenoteasilydimmable.HighintensitydischargelampsrepresentalargefamilythatincludessourceslikeHighPressureSodium,MetalHalide,andCeramicMetalHalide.WewillfocusourdiscussionontheCeramicMetalHalidefamily,asthistechnologyproducesrelativelycompletecolorspectrumsthataresuitableforcolorcriticalenvironments.ThetechnologybehindHIDsourcesreliesoncreatinganarcofelectricityinanenvironmentofmetalvapor.ItisfairtoconsiderHIDsourcesasacompressedversionoffluorescenttechnologyjustashalogensourcesareacompressedversionofstandardincandescent.LightfromHIDsourcesdoesnotrelyonphosphorstotranslatelight,sothelightcolorandrenderingcapabilityareproductsoftheblendofmetalsthatmakeupthevaporinthelamp.Allofthisoccursinthearctubeofthelamp,aselectricityispassedbetweenelectrodes.Figure8.7showsthecomponents.

ThePropertiesofMetalHalide,CeramicMetalHalide(CMH)andotherHighIntensityDischarge(HID)lamps:

InitialCost:High;Theselampsrepresentalotoftechnologypackedintoasmallpackage.Theyarealsofairlyuncommonandthereforearerelativelyexpensive.

OperatingCost:Cheap;Likefluorescent,theselampsareefficientsotheyconsumerelativelylittleelectricityandhavelonglamplivesrequiringless-frequentmaintenanceandrelamping.

ColorRenderingIndex:70-90(moderatetogood);StandardmetalhalidelampshaveCRIvaluesinthe70’sor80’s.CeramicmetalhalidecanhaveCRIvaluesinthe90’sandcanprovidepleasingcolorrenderingproperties.OtherHIDsources,likehighpressuresodiumandmercuryvapor,havenotoriouslypoorcolorrenderingpropertiesrepresentedbyCRIvaluesof30to50.

ColorTemperature:warmtocool(pinktogreen);Metalhalidelampstendtohaveagreenishorbluishcastregardlessofthecolortemperaturerating.CeramicmetalHalidelampstendtohaveapinkishorvioletcast.AllHIDsourcesshouldbesampledpriortospecificationonaproject,especiallywherecolorrenderingiscritical.

BallastandTransformerrequirements:Yes;HIDsourcesallrequireanelectronicormagneticballasttooperate.Electronicballastshavedesirablefeatureslikeimprovedefficiencyandlessnoise.

Dimming:seldom;ThedimmingofHIDsourcesisavailable,butcanbequitecostly.Alampmanufacturer’srepresentativeshouldbeconsultedifdimmingofHIDsourcesisbeingconsideredforaproject.

Instanton/off:No!ThemostnotabledownsideofHIDsourcesisthattheyallrequiretimetowarmup.Thistimeisshrinkingastechnologyadvances,butcanbeanywherefrom30secondstofiveminutes.Forthisreason,theselampsareprimarilyusedwheretheywillbeleftonforlongtimeperiods.WhenspecifyingHIDsources,theyshouldgenerallynotberelieduponforinstant-onoperation.

Directability:Goodtogreat;HIDsourcesarecompactbynature(relativetotheirlightoutput).Manyofthesesourcesareputintolampshapessimilartohalogensources.TheHIDarctubecore-wherethelightisactually

Figure8.8Commonshapesofhigh-intensitydischarge(HID)lamps

generated-isquitesmallandsocanbeeffectivelyfocusedanddirected.

Efficacy:Excellent(70-100Lumensperwatt);

HIDcoversabroadarrayofsourcetypes,butallofthemhaveverygoodefficacies.Sourceswithgoodcolorrenderingcapabilitieslikeceramicmetalhalidehaveefficaciesonthelowerend(70lumensperwatt),butlesscolor-consideratesourceslikehigh-pressuresodiumhaveefficaciesashighas120lumensperwatt.

LampLife:Good;HIDsourcesareratedtolastanywherefrom10,000hoursto30,000hours;anywherefrom10to30yearsbetweenrelamping.

Temperaturerequirements:none;HIDsourceswillworkequallywellinmostanytemperaturecondition.

HeatGenerated:Relativelylittle;HIDsourcesareefficientanddon’tcreatemuchinfra-redradiation,butthelargewattagesavailablemeanthatthelittlebitcanadduptobequitehot.HIDlampsalsoproduceafairamountofUVradiation.HIDlampsimplementanoutershieldtocontainthis,butlampsshouldbediscardedifthisouterglassisevercompromised.HIDsourcesshouldalsobescrutinizediftheyaretobeusedtoilluminate

Figure8.9Theworkingcomponentsoflightemittingdiode(LED)lightsources

UV-sensitivematerialsorproducts.

NoiseGenerated:Some;LargerHIDlampshaveballaststhatcanclickandbuzz.Evennewer,smallerHIDsourcesthatuseelectronicballastscanhaveaslighthum.ItissafestnottoconsiderHIDsourcesinspaceswhereextremequietisrequired.

HIDsourcesareundergoingconstantrefinement.ThecurrentgenerationofHIDsourcesisfocusedonceramicmetalhalidetechnology,whichoffersgreatcolor-renderingcapabilities.ThesesourcesareengineeredtocomeinsmallpackageslikethePARlamps,MRlamps,and“T”lamps,usuallyassociatedwithhalogensources.HIDsourcesarefindingtheirwayintohotels,casinos,andretailoperations.Theystill,however,requirewarm-uptimeandarerarelyeversilent.AworkingsampleofanyHIDsourceshouldbesampledormocked-uppriortoinclusiononaproject.

LEDSOURCESLED’s,orLightEmittingDiodes,havetrulycomeofageandarerapidlybeingrefinedtoreplacemanypreviouslypopularelectriclightsources.ApplicationsformallytheterritoryofhalogenandincandescentsourcescannowbesolvedwithLED’s.WhatwasonceusedastheindicatorlightonhomeapplianceshasevolvedintoanearlyfullspectrumsourceusedforRed-Green-BlueColormixingcapabilitiesandasaneutralsource-bothdirectableanddiffuse-fortasksandaccents.LEDtechnologyisbasedonelectrifyingadiodethatemitsasinglewavelength(color)ofradiationdependingonthecompoundofthediode.Togainabroaderspectraloutput,thesediodesarematedwithphosphortechnologyinthesamemannerasfluorescentlamps.Thesediodesaretinysothatinaclusterofmanydiodes,eachdiodecanhaveuniqueopticalandcolorproperties.LEDsourceadvancementsareleadingtoLEDsourcesthatare

larger,moreefficientandpossessmoredesirablecolorrenderingproperties.LEDsourcesareveryheatsensitiveandcommonlyfailduetoheatbuildup.LEDsourceapplicationsshouldalwaysbeconsideredfortheirabilitytodissipateheat.

TheGeneralPropertiesofLightEmittingDiodeSources:

InitialCost:VeryHigh;LEDsourcesarethecuttingedgeoftechnology,and,assuch,theyareexpensivetobuy.Likeallthingseconomic,priceshavedroppedandwillgrow.continuetodosoasvolumeandpopularity

OperatingCost:Cheap/moderate;

LEDsourcesaregaininggroundasveryefficaciousmeansofcreatingelectriclight.Pairthiswithamazinglamplife,andyouhaveaverylowoperatingcost.Thecatchisstillthecostofreplacementwhentheproductdoesfail.BecausemanyLEDsourcesareintegratedintolampmodules,arraysornearlycompleteluminaires,replacementcostandeffortareoftensimilarto

Figure8.10Commonshapesandconfigurationsoflightemittingdiodes(LED’s).

replacinganentireluminaire.

ColorRenderingIndex:70-90(moderatetogood);LED’shavenowmadetheleaptousefulnessasneutralsourceswithgoodcolorrenderingproperties.Generally,costsincreasewithincreasedcolorrenderingindices(CRI),butsuitablecommodityproductsareincreasinglyavailable.LEDsourcesarealsocommonlyusedforsaturatedcolorsandcolormixingapplications.LEDsourcesdorequirecarefulscrutinywhenintendedforcolorcriticalsituations.Itisadvisabletoviewaworkingsampleofaparticularproductbeforespecifyingitforaproject.

ColorTemperature:Variable(Cooltoneutraltowarm)LEDproductsclaimtoprovidecolortemperaturefrom2800Kupto5000K.Tohavefaithinthecolortemperature,itisimportanttoactuallyseesamplesofLEDproductsbeforespecifyingthem.

BallastandTransformerrequirements:Yes;LEDsourcesrunatoddvoltages,andmostrequireaproprietarytransformer(oftenreferredtoasadriver)thatmaybebuiltintegraltothesourceormayneedtoberemotelymountedinanaccessiblelocation.

Dimming:Yes;LED’scanbedimmed.Thedimmingpropertiesaregenerallyaproductofthedriverortransformertechnologyandmustbespecifiedassuchfromthemanufacturer.

Instanton/off:Yes;LEDsourcesaretrulyonoroff,withnowarminguptime.

Directability:Great;LEDsourcesaredirectionalbynature,sotheycanbecontrolledwithlensesandsmallscaleoptics.AtrickiertaskisgettingLEDsourcestodiffuseevenly,butthistoocanbeaccomplishedvialensesanddiffusingmaterials.

Efficacy:Good(50-90Lumensperwattasofthisprinting);LED’sundergosomuchdevelopmentthattheirtrueefficacyisamovingtargetandshouldbeconfirmedpriortoeachjob.BemindfulofspecifyingproductsjustbecausetheyareLEDsourceswithout

confirmingtheefficacyasLED’smaynotalwaysbethemostefficacioussolution.

LampLife:GreatAsofthisprinting,LEDsourcearemarketedashavingconservativelamplivesinthe50,000to80,000hourrange.Thistranslatesto50to80yearsdependingonuse.Ofnote:LED’stendto“fadeaway”ratherthansimply“burnout”sotheyshouldbereplacedonascheduleratherthanoninstinct.LED’sarealsoveryheatsensitive.Exposuretoexcessheatorimproperheatdissipationsituationscansignificantlyreducelamplife.

Temperaturerequirements:AvoidheatLEDsourcesarecommonlymatedtosignificantheatdissipatingtechnology.Caremustbetakentoallowspaceforventilationandheatdissipation(manufacturersmayevenspecifyventilationrequirements).ExcessheatwillsignificantlyreducethelamplifeandreliabilityofanLEDsource.

HeatGenerated:RelativelylittleLEDsourcesconvertmostinputelectricityintovisiblelight,butthesmallamountofheatcanaddup,akintofluorescent.Dissipatingtheheatiscritical,regardlessofthequantity.

NoiseGenerated:NoneBothLEDsourcesandtheelectroniccomponentsthatdrivethemoperateveryquietly.

LED’sareeverywhereandgaininggroundfast.Thishasresultedinstandardizedlampshapes,connectiontypesandmoreavailability.Ubiquityalsoresultsinlowercosts.LED’saresuitablecandidatesfordirectableaccentapplications,arealighting,andsmallandmediumscalediffuseapplications.LEDlightsourcesarealsousefulascontinuouslinearsourcesforcovesandslotsandforcoloredorcolor-changingapplications.ManysuitableLEDproductsareavailableforretrofittingexistingincandescent,halogenandfluorescentinstallations.ItisadvisabletotakecareinresearchingandsamplingLED’stofindproductssuitableforaproject.Themajordrawbacksaretheinitialcostandsensitivitytoheataswellasthelackofstandardizationacrossdifferentbrands.LED’sareavailableasretrofitlamps,dedicatedmodules,continuousarraysandcompleteluminaires.ItisadvisabletosourceLEDproductsfrommanufacturerswithatrack-record,whocanbereliedupontostandbehindtheproduct.Itisalso

advisabletoseekproductsthatfollowsomeformofstandardizationandhavealampmodulethatcanbereplacedwithoutreplacinganentireluminaire.Bewareofnoveltyproductsfrommysteriousmanufacturersandbeawareofthehiddeninefficienciesofmodulereplacementanddisposal.

LAMPNAMINGLOGICOneofthemorehelpfulelementsoflamptechnologycomesinunderstandingthenamingconventionthatisusedtodescribetheshapeandsizesofcommonelectriclamps.

Mostlampsaregivenadescriptioncodeof2or3lettersfollowedby2or3numbers.Inmostcases,thelettersaresomemannerofdescribingthelampshape,andthenumbersareamannerofdescribingthesize.

Figure8.11Mostlampnamesdescribethelampdiameterin1/8”increments.

LampSizeThesizingoflampsisverysimple,ifnotutterlylogical.Commonelectriclampssizesareindicatedbyatwo-numbercodethatdescribestheirsizein⅛”increments.Bythislogic,ourcommonlightbulb,whichinlightingcirclesisreferredtoasanA-19lamp,is ”indiameteror2-⅜”indiameter.ThismeasurementturnsouttobeaccurateaswegodownthelinefromsmalllampslikeMR-16lamps( ”or2”indiameter),tolargerPAR-38lamps( ”or4-¾”indiameter).Figures8.11and8.12illustrateafewexamplesofthesesizecodes.

LampShape

Thesystemfordescribingtheshapeasacodeisalittlemorevaried.Inevitably,thetwoorthreelettersleadingalampcodearemeanttogivesomeliteralindicationoftheshapeofthelamp.Astrollthroughthefamilyillustratessomeexamples.

A-lamps,whichincludetheA-19(commonlightbulb),A-21,andA-23,arenamedsuchthat“A”standsfor“arbitrary.”Thisispresumablyduetoitsirregularshape.

Nextinthelineageofdirectionalityareso-called“R”lamps,likeR-20,R-30,andR-40.Inallofthesecases,Rstandsfor“reflector,”presumablytodescribethegenericsilverbackingcommonoftheselamps.

Figure8.12Commonsizesofthearbitraryshaped“A”lamp(left)andreflector“R”lamps(right).

WethenencounterourPARlamps,likeourPAR-20,PAR-30,andPAR-38.PARstandsforParabolicAluminizedReflectorandreferstotheengineeredparabolicreflectingsurfacebuiltintoeachoftheselamps.

Figure8.14Commonsizesofparabolicaluminizedreflector“PAR”lamps.

WhenwediscussMRlamps,liketheubiquitousMR-16andthesmallerMR-11andMR-8,theMRstandsforMultifacetedReflector;averyhighly-engineeredreflectingdevice.

Figure8.15Commonsizesofmultifacetedreflector‘’MR”lamps.

T-lampstendtobe“tubular”inshape,asisthecasewithourlinearfluorescentT-8andT-5lamps.T-lampscanrefertosmaller,tubularhalogenorHIDlampsaswell.

Figure8.16Commonsizesoftubular(T)lamps.

Theparadeofnamesandcodesgoeson,butthelampsmentionedaboverepresentmostofwhatwerunintointheworldofarchitecturallighting.

LAMPCODESFORCOLORRENDERINGINDEX(CRI)ANDCOLORTEMPERATUREItisimportanttopointoutthatlampstrulyarethecoreofallofourlightcreatingdevices.Thedesignindustryputsmuchfocusonluminairesandtheirbehaviorsandaestheticappeal,butattheheartofeveryelectriclightcreatingdeviceisalampofsomesort.Itisperhapsmorevaluabletodedicatebrainspacetoknowingaboutlamptechnologiesandpropertiesthantoclutterone’sheadwiththeglutofluminaireliteraturethatcirculates.Lamptechnologytendstochangeslowerthanluminairetechnology,andthereisaninherentlogictothewaylampsaredesigned,marketed,andmanufactured.

ThekeytosuccessfullyspecifyingtherightlampiscaringtremendouslyaboutColorTemperatureandColorRenderingIndexpropertiesofthelamp.Rememberthatoncewestepoutsideofstandardincandescentandhalogenincandescentsources,sciencecancookupanycolorandcolorrenderingpropertiesdesired.Asperourearlierdiscussion,itisimperativetoboillampsdowntotheirtwoprimarypropertiesofconcern:

ColorRenderingIndexorCRI(from1-100)

ColorTemperature(inDegreesKelvinorKelvins)

Luckilyforus,mostengineeredelectriclightsourceslikeHIDandfluorescentaredescribedbyathreedigitcodethatisstampedrightonthelamporlamppackaging.ThisthreedigitcodecontainsinformationindicativeofboththeColorRenderingIndexandColorTemperature.

ThefirstnumberintheseriesindicatestheColorRenderingIndexorCRI.Ifthe3-digitproductcodestartswitha7,theCRIofthatproductisinthe70’s.Ifthecodestartswithan8,theCRIisinthe80’s.A9indicatesaCRIinthe90’s.Wetendtogivemoremerittothecolor-renderingcapabilitiesofourfluorescentandHIDsources,andsowecanassesstheCRIcodelikethis:

7=CRIinthe70’s:Thisisacceptable,butshouldbeusedonlyinnon-colorcriticalenvironments.

8=CRIinthe80’s:Thisistypicalandreasonabletouseinmostday-to-dayapplications.

9=CRIinthe90’s:Thisisverydesirableforcolorcriticalenvironments,butalsorelativelyexpensive.

Thesecondcomponentofthecodeliesinthelasttwodigits.ThesetwonumbersareindicativeoftheColorTemperatureindegreesKelvin.Thesystembreaksdownlikethis:

28=ColorTemperatureof2800K=warm(imitatingthecolorofincandescentsources);

30=Colortemperatureof3000K=neutral(imitatingthecolorofhalogensources);

35=ColorTemperatureof3500K=slightly-cool;

41=ColorTemperatureof4100K=cool;

50=ColorTemperatureof5000K=very-cool;

Figure8.17MostfluorescentandHIDproductsarelabeledwithathreedigitcodeexpressingcolorrenderingindexandcolortemperature.

Keepinmindthatcolortemperaturesarereallymeaningfulonlyasguidelineswithinafamilyofproducts.Onebrandof2800Kfluorescentlampmaynotlooklikeanotherbrandof2800Kfluorescentlampandwillcertainlynotlooklikea2800KMetalhalidelampnortheincandescentlampitistryingtoimitate.

SourceEfficacyEstimatesIdentifyingsourcetechnologieswiththeirgeneralefficaciesorefficienciesisausefulandoftenneglectedpieceofinformation.Insomelightingdesignguides,itisarecommendedpracticetodesignappropriatelightlevelsforspacesbasedonawatts-per-square-footdensityofinstalledluminaires.Thispracticetendsto

betacticallydeficient.Designinglightonapowerdensitybasisisignorantofthedifferentefficaciesofthedifferentsourcetechnologies.Itcanleadtouninspireddesignsofflat,evenilluminancelevelswheretheymaynotbewelcome.TheclosestthingtodesigningtoadensityistheLumenMethodCalculationwhichrecommendslightdensitybasedonlumenspersquarefoot(wewilldiscusscalculationmethodsinChapter20).Forthetimebeing,wewillintroduceabasicsetofnumbersthatwillpaintanapproximatebutusefulpictureofhowthemostcommonelectriclightsourcescomparetooneanotherintermsofefficacy(lightoutcomparedtoelectricityin).Asdesignprogresses,itisadvisabletoknowtheefficacyofthespecificproductbeingconsidered.Forschematicplanningphasesandbasiccomparisons,theroughapproximationsforthesourcetypesbelowcanbeused:

Standardincandescentefficacy=10lumensperwatt(lpw);

Halogenincandescentefficacy=15lumensperwatt(lpw);

FluorescentandHIDefficacy=70lumensperwatt(lpw);

LEDefficacy=50-90lumensperwatt(lpw);

Thissimpletableshowswhywetendtogroupallofourhigh-efficacysourcestogether.Italsoillustrateswhyfluorescent,HIDandLEDsourcesaresodesirablewhencomparedtotheefficaciesofincandescentandhalogenproductsthattheycanreplace.Ifyoucanmakeamentalnoteofthesefournumbers,youwillhaveaninvaluablefoundationforvisualizing,estimating,andcalculatinglightingeffects.

Allofthesepropertiestogethergivetheuserfairlygoodinsightintomakinglampdecisions.Lampliteratureisalso,thankfully,morestraight-forwardthanthatofluminaires.Bygraspingthebasicconceptsofcolorrendering,colortemperatureandefficiency,oneismuchbetterpreparedtomakedecisionsaboutsuitablesourcesforaccomplishinglightinggoals.

PartIIDesigningLight

Chapter9TexturesofLight

Textureisoneofthemostneglectedconceptsoflight.Italsohappenstobeoneofthemostusefulfordesignersdesiringaquickintuitiveknowledgebaseformakinglightingdecisions.Thisunderstandingallowsonetovisualizeanddescribethevarioustexturesoflightthatwemightpaintontooursurfaces.Youwillrecallthatthebasicspectrumoflighttextureincludes“soft”,diffuselightontheoneend,anddirectional,focusedlightontheotherend.Oncewecanidentifyhowourvariouslampandluminairetechnologiesdeliverthesevarioustextures,wecanmakeinformeddecisionsfromthestartofthedesignprocess.

DIFFUSELIGHTWhenwetalkaboutdiffuselight,wearetalkingaboutlightthatleavesasourceequallyatallanglesand,assuch,reflectsoffofthesurfacesofanenvironmentatallangles.

Figure9.1Diffusesourcesdeliverlightevenlyinmanydirections.

Thislightisusuallytheproductoflargeglowingsourceslikeincandescentglobesandfluorescenttubes.Wecandiffuselightevenfurtherbyplacingdiffusinglenseslikefrostedglassandacryliconourlightsource,asin

thecaseofdecorativependantsandsconces.Diffuselightfillsinshadowsand,therefore,reducestheappearanceof

texturechanges.Weusethislighttorenderpeopleasitisflatteringandforgivingoftexturalimperfections.Weusesoft,diffuselighttocreatecomfortable,intimateenvironmentswherewewantlong-termvisualcomfort.Diffuselighttendstobeevenlight,whichreduceseyestrainthatcomesfromhigh-contrastenvironments.Diffuselightalsoworkswellfortaskenvironmentsbyeliminatingshadowsand,again,reducingcontrastthatcauseseyestrain.

Figure9.2Diffusesourcescanbefurtherdiffusedtodeliverevensofterlight.

Diffuselightappliedastheonlyingredientcanbecomeboringandvisuallyun-interesting.Whenaspaceisfilledwitheven,diffuselight,thereislittlevisualinteresttodirecttheorderthatyouexperienceaspace.Diffuselightcanalsocauseauniquetypeofeyestrainthatcomesfromhavingtoolittlecontrast.Overlongperiodsoftimeinpurelydiffuseenvironments,theeyetendstostraintopulloutdetailandfindvisualacuity;oftendescribedasan“under-water”feeling.

DIRECTIONALLIGHTDirectionallightistheproductoflampsandluminairesthathavepurpose-builtreflectorsthatharnesslightfromasourceandpushitoutinasingledirection.

Figure9.3Directionallamps(left)anddirectionalluminaires(right)utilizereflectorsandopticstodeliverlightinacontrolledmanner.

Thiseffectisoftenaccomplishedwithanengineeredluminaire,orsimplywithinthelampitself.Directionallightisnotablydeliveredinashapethathasdistinctboundaries.Ourdirectionallightsourcescreatepoolsandbeamsandscallopsoflightthattendtobebrightestinthecenter,andfadetoaclear-cutborder.Thesesourcesarecommonlythefirstingredientconsideredinourdesignprocess,astheyareabletodeliverspecificpiecesoflighttospecificsurfacesandobjectsinourspace.Thelightarrivesfromonedirectionandhasatendencytoreflectoffofobjectsinonedirection.Hence,directionallightcreatesdistinctshadowsbetweenlightanddarkand,therefore,introducescontrastthatshowsoffmaterialtexture.

Figure9.4Diffuselightsources(top)hidetextureandlimitcontrast.Directionalsources(bottom)createshadows,contrast,andvisualinterest.

Weusedirectionallightsourcestocastaccentontoart,objectsanduniquearchitecturalfeatures.Directionallightmakesobjectsglowandmakesmetalsandglassshimmerandsparkle.Itisthesesourcesthataddvisualinterestandhierarchytoenvironmentsbycreatingobjectsandsurfacesthataredistinctlybrighterthantheirsurroundings.Thecontrastcreatedbydirectionallightcan,however,becomeuncomfortableoverlongtimeperiods.Excessivecontrastcausestheeyetoconstantlyre-adaptwhenlookingfrombrightelementstodarkelements.Directionallightisalsoundesirableformanytaskssinceexcessiveshadows(oftenfromapersonorhis/herownhand)canobscurethetaskonwhichyouaretryingtofocus.

DESIGNINGWITHDIFFERENTLIGHTTEXTURESThefundamentalsofmakinggoodluminaireandlampdecisionsareassimpleasidentifyinglightsourcesbythetypeoflighttheydeliver.Thediagrambelowexhibitswhatwewillconsiderasthefourlevelsoflighttexture,rangingfrom

directionaltodiffuse.

VeryDirectionalLightAtthedirectionalendofthespectrum,wehavereflectordrivenlampslikehalogenMRlampsthathaveprecisionengineeredreflectorsthatdrivelightout.Thislightisperfectforaccentingartanddecorativeobjects,butcreatesglareandcontrastthatmaybeunsuitableforlightingasocialgatheringspace.WecanalsocreatethisdirectionallightwithaccentluminairesthathaveprecisereflectorsaroundasmallhalogenorHIDsource.ManyLEDsourcesalsoprovideverydirectionallight.Wecancomparethislighttotheharshnessofdirectsunlight.

Figure9.5Effectsofverydirectionallight(left)areoftentheproductoflampsandluminairesthatincorporateengineeredreflectorsandsmallsources(right).

DirectionalLightSlightly-softerdirectionallightcanbecreatedwithPARtypelamps.Theselampsalsohaveareflector,butincorporatediffusinglensesandless-preciseopticsthatcreateaslightlymorediffusequalityoflight.PARlampsarebuiltaroundsmallHalogenorHIDsources.WecanalsocreatethisqualityoflightbyplacingdiffusingfiltersinfrontofMRtypelamps.Thislightisperfectlyfunctionalforpaintinglightontoart,gatheringareasandarchitecturalfeatures;itisacceptabletosomeforcreatingevenlevelsoftasklight.Itissimilartothequalityofunfilteredskylight.

Figure9.6Effectsofdirectionallight(left)areoftentheproductoflampsorluminairesthatincorporatelesspreciseopticsandreflectors.

DiffuseLightTowardsthesofterendofthespectrumareluminairesthatusereflectorstoharnessthelightofdiffuselamps.Whenwetakeanotherwisediffuseincandescentlamporfluorescentlampandbuildalargereflectoraroundit,theproductisasubtlewashorpoolofslightlydiffuselight.Wealsogetthislightfromourfamilyofincandescent“R”lampsthatarelittlemorethanacommonlightbulbwithagenericreflectingsurfacebuiltintotheback.Diffuselightisunsuitedformakinganaccentstatement,butdeliversanicequalityoflightforgatheringareasandtasksituations.Wemightlikenthiseffecttothesoftlightofdaylightdiffusedthroughsheercurtains.

Figure9.7Theeffectsofdiffuselight(left)areoftentheproductofdiffuselamps(right)andluminaires

withengineeredreflectorsandlargersources(right).

VeryDiffuseOntheverydiffuseendofthespectrum,weconsiderglowingsourcesthatputoutlightineverydirectionandoftenincludediffusingmaterialstoencouragethespreadoflight.Wegetthislightfrombareincandescentandfluorescentlamps.Wealsocreatethislightwithdiffusingsourceslikeshadedtablelamps,floorlamps,diffusingpendantsandsconces.Thisislikethelightwegetonacloudy,overcastgrayday.Diffuselightissuitableforfillinganentireroomwithahomogenousglow,butiscertainlynotusefulforaccentingobjects.

Figure9.8Effectsofverydiffuselight(left)areoftentheproductofluminaireswithdiffusersanddiffusesources(right).

Withthesefourtexturescommittedtoourintuitiveknowledgebase,adesigneriswell-preparedtoarticulatethequalityoflightenvisionedforaspace.Onceyougetusedtotheideaofmakingatexturedecisionaboutlight,youwillwonderhowyouevergotbywithoutdoingso.Thedesignerwhocanvisualizeanddescribedifferenttexturesofdiffuseanddirectionallightcanalsoidentifylightsources,lampsandluminairesthatarenotgoingtomeettheneedsofthedesign.

Chapter10ShapesofLight

Thenextingredientinourintuitiveunderstandingoflightisthearticulationofshapesoflightthatweaddtoourdesignedspaces.Itisimpossibletodelivervisualinterestinaspacewithoutmakingdistinctstatementsthroughtheshapeoflightandlightedsurfaces.Theeasiestwaytounderstandthedifferentshapesoflightistoidentifythefollowingthreecategories:poolsoflight,planesoflightandglowingobjects.

POOLSANDPIECESOFLIGHTMostofourdirectionalsources–lampsandluminaireswithengineeredreflectorsandoptics-emitbeamsoflightthatdeliversomewell-definedshapeoflightontotheobjectsweilluminate.Theseshapesoflightcanhaverelativelysoftbordersorwelldefinedboundariesbetweenlightanddark.Weusetheseshapesto“spotlight”orcastshapesoflightontospecificobjectslikeart,sculpture,furniturepieces,andconveningareas.Creatingdistinctpiecesoflightcertainlyaddsvisualinterest,butcaremustbetakentonotoverusethetreatment.Lightshapestendtocomeacrossasartificialandcontrived,astheyarerareinthenaturalworld.Poolsanddistinctpiecesoflightcanalsobreakupotherwisehomogenoussurfaces.Wallsandlargerectilinearshapescanbecomevisuallychaoticwithtoomanyappliedpiecesoflight.Whennotusedwithrestraint,thesedefinedpiecesoflightcangivegalleries,restaurantsandotherenvironmentsan“over-done”appearance.

Figure10.1Distinctpoolsoflightaddvisualinterestandcontrast,butcanbecomeoverwhelmingorvisually“noisy.”

PLANESANDLINESOFLIGHTWehaveavastarrayofcontinuouslinearsourcesthatareusefulforcreatinglonglinesoflightthatfollowthelonglinesofourarchitectureandmaterials.Linearsources,usedproperly,allowanentiregeometricsurfacetoglowevenlyandcanenhancethewaytexturesandmaterialsareperceived.Slotsandwashesoflightbleedacrosssurfacesandcreateshapesoflightverysimilartowhatwemightencounterfromdaylightdeviceslikeskylights,lightwellsandwindows.Wetendtohaveanaffinityfortheseshapesbecausetheydeliverasenseofconnectiontothenaturalskylightandsunlighttowhichweareaccustomed.Geometricshapesoflightcanreinforcetheshapeandformofrectilineararchitecturalsurfaces.Uniformshapesarealsogoodcandidatesformitigatingthehigh-contrasteffectofstrongaccentlighting.Theyareagoodtoolforbalancingambientglowina“too-contrasty”space.

Figure10.2Planesandlinesoflightcanharmonizewitharchitectureandarereminiscentofnaturaldaylight.

GLOWINGOBJECTSGlowingobjectslikependants,sconcesandshadedlampsmakeupthelastshapeweconsider.Wecalltheseself-containedpiecesoflightart“self-luminous”sources,andwedistinguishthemfromthearchitecturally-integratedlightsourcesthatweusetocreatepoolsandplanesoflight.Themostcertainthingthatwecansayofself-luminoussourcesisthatwemustusethemwithcare.Whenwecombinedecorativeintriguewithbrightness,theresultisanobjectthatdrawsimmediateattentiontoitself.Theseglowingobjectscanbeusefulforinstructingvisualflowandencouragingwayfinding,butifwetrytousethemasourprimarysourcesoflight,weendupwithoverlybrightdecorationthatworksagainstourlightinggoals.Oncetheseglowingsourceshaveattractingone’sgaze,theeyesadapttothebrightness,sothespace,asawhole,isconsequentlyperceivedasdarker.Itisgoodpracticetousethesesourcesinconjunctionwithluminairesthatdirectlightontosurfaces.Thiscombinationofeffectsallowsustouseourdecorativeluminairesatlowerlevelsforthevisualeffectwetrulydesirewithouthavingtorelyonthemtocreatebrightnessinaspace.

Figure10.3Glowingsourcesserveasvisualinterest,butcanoverpoweraspaceandbeasourceofglare.

Addingaconcernforshapetoourlightingdecisionsgivesusonemorespecificingredientformatchinglightapplicationtothefunctionofourspace,andtheshapeofourspace.Wecannowidentifyhowwewanttoaddlightsothatitharmonizesandemphasizesthegeometry,scaleandmaterialsofourdesign.Designingwithshapesoflightalsohasaprofoundeffectonthemoodandfeelingthataspacetranslates.

Chapter11LocationoftheLightSource

Thelastfrontierofdecisionmakingaboutaddinglightisdesigningwherethelightappearstobecomingfrom.Itisimportanttoponderthisdecisionbecauserecenttrendsandtechnologieshaveledtothemisconceptionthatalllightingdevicesbelongintheceiling,washinglightdownontothegroundbelow.Tomakethemostofourlightingresources,wemusttaketimetoinvestigatealloftheotherwaysofdeliveringlightthatwecanconceive.Manysuccessfullightingdesignsare,indeed,basedonceiling-mounteddownlightsastheyarecertainlyaversatilewaytodeliverpiecesofarchitecturallight.Wewillstriveforinnovation,however,byopeningourmindtothevarietyofmethodsfordeliveringlight.Itisagoodpracticetoinvestigateuncommontechniques,first,toavoidthetendencytomigratebacktowardsthegenericmeansofrecesseddownlights.

LIGHTFROMTHECEILINGONTOWALLSThequickestchangewecanmaketothegenericdownlightingtacticistouselightsourcesthatcanbeaimedtodirectlightontotheverticalsurfacesofaspace,ratherthansimplystraightdown.Thesepiecesoflightgoalongwaytoincreasetheoverallperceptionofbrightnessinaspace.Verticallightingalsoexpandsaspaceandshowsoffthearchitecturalboundaries.

Figure11.1Lightingverticalsurfacescreatesadistinctimpressionofbrightness.

LIGHTINGFROMTHEGROUNDUPWARDWecanimplementlightsourcesthatrecessintothegroundorfloorplaneandcreatebeamsoflightthatwashthewallsandcastpoolsoflightupontoceilingsandcanopiesoverhead.Thistacticdeliversauniquelightqualitythatisrareinthenaturalworld,wheredaylightfromaboveisthenorm.Upwarddirectedlightcancontributetotheperceptionofheightandverticality.Itcanalsocreateamoreintimatefeelingifthelightfurtherrevealstheceilingabove.

Figure11.2Lightingupwardfromthegroundisatonceunusualandcreatesauniqueenvironment.

LIGHTINGFROMTHEWALLUPWARDThesesourcesaremountedtothesurfaceofawallorregressedintoawallandcastlightupontotheceilingplaneabovethem.Lightontotheceilingplaneopensupaspaceandincreasestheperceptionofvolume.Abrightceilinglendsafeelingofopennessbymimickingabrightskyabove.Theevenlightfromaglowingceilingissometimesallthelightneededforasimpleenvironmentwherelittletaskoraccentlightingisnecessary.

Figure11.3Lightingfromthewalltotheceilingaddsvolumeandheighttoaspace.

Figure11.4Lightingbackontothewallcreatesbrightnesswithoutglare.

LIGHTINGFROMTHEWALLBACKONTOTHEWALLWehaveavastarrayofdecorativeandfunctionalluminaireswithshieldedsourcesthatpaintlightbackontothewalltowhichtheyaremounted.Thesedifferfromourpurely-decorativesconcesinthattheywashlightontothewall,ratherthansimplyglow.Thistreatmentoflightisusefulwhereceilingorfloormountedluminairesarenotanoption.Theseluminairescanbemountedinrowsandpatternstohelptheflowofalongspaceorcorridor.

LIGHTFROMSLOTSANDCOVESONTOWALLSANDCEILINGSThesearethearchitecturallyintegratedlinesoflightthatcreateevenwashesanduniqueglowsontoentiresurfacesofaspace.Theseshapesoflightgoalongwaytoenhancethegeometryofspace.Thelong,cleanlinescanshowoffthejointsandconnectionsofstructure.Linesoflightalsodoagoodjobofmimickingthecleanlightwereceivefromdaylightopeningslikeskylightsandlightshelves.

Figure11.5Slotsoflightfromabovecreatebrightnessontoverticalsurfacesandarereminiscentofdaylight.

SUSPENDEDGLOWINGSOURCESGlowingsourcesaddahazeoflighttoourspacesandadistinctfocalpoint.Theymustbeappliedwithcaretoavoidglareandgenericfloodsoflight.Thesesourcesareoftenthecrowningelementsofvisualinterestthatweapplyafterourotherlightingneedshavebeenmet.Thereareenvironmentswhereasingle,well-placedglowingsourcecansolvemostofourlightingneeds,buttheyaremoreoftenmisusedtodrawattentionandleaveaspacefeelingdark.

Figure11.6Glowingpendantsactasfocalpoints,butcanalsodelivercontrolledlightupanddown.

LOWLIGHTINGONTOTHEFLOORLocalizinglightontothefloorplanecanbeaccomplishedwithluminairesthatmountlowonthewall.Theseso-called“steplights”areusuallyconsideredforlightingstairs,buttheyarejustaseffectiveindeliveringlightontothefloor

plane.Theseluminairestypicallyrecessintothewallandworktogetthelightsourceclosertothesurfacebeinglighted.

Figure11.7Low,wall-mountedarealightskeeplightdownwhereitisneeded.

Thegoalofconsideringasimplelistoflightingapplicationslikethisistoavoidtherepetitiveandstaticenvironmentthatistheproductofover-usingrecessedlighting.Certainly,acomplexspacecanbelightedentirelywiththerightadjustable,ceiling-mountedluminaire,butifwestartbyexperimentingwithideasofunusuallightapplication,wearemuchmorelikelytoinnovate.Theresultcanbeaspacewithatrulyspecialanduniquedesigncharacter.Therearecertainlynumerouswaystodeliverlightotherthanthemannerswehavelisted,butifwecanaddthesedistinctmethodstoourintuition,wewillbemuchmorelikelytoconsiderthemaswedesign.

Chapter12BuildingLightfromDarkness

Withournew-foundintuitionforthetexture,shapeandoriginoflight,wecanfurtherexpandonourdecision-makingprocesstomakesurethatweareconsideringallofouroptionswhenaddinglighttoaspace.Ifweconsidereachoftheseaspectseverytimewelooktoaddlighttoourdesign,wecanbesurethatthelightwillsupportwhatweareattemptingtoconveythroughthedesign.Theconvenientaspectofthisintuitiveknowledgeisthatitdoesn’tyetrequireknowledgeoflightlevels,calculations,orluminairetechnologies.Wearestillsimplyaddressingthelightitselfandhowthatlightwillinteractwiththesurfacesofourdesignedenvironment.Aslongaswecanvisualizelightandcommunicatedesignideasforit,wecanfindawaytoimplementit.Ourexpandedlistofthecontrollableaspectsoflightnowlookslikethis:

Lightintensity:Brightvs.Dark;

LightColor:Warmvs.Cool;

LightTexture:Directionalvs.Diffuse;Wenowhaveavisualunderstandingofwhattexturemeansandwhattypesofsourcescreatethesetextures.

Lightshape:Poolsoflight,Planesoflight,Pointsoflight;Wecannowmakedecisionsabouthowwematchtheshapeoflighttotheshapeofourarchitecture,surfacesandobjectswithinaspace.

Lightorigin:Whereisthelightcomingfrom?Thinkingbeyondbasicdownlighting,wearemorelikelytocomeupwithlightingsystemsthataretrulycomplementaryofthedesignedspace.

BUILDINGLIGHTFROMDARKNESS

Aneffectivementalexerciseforenhancingthedesignprocessistostepbackandapproachaspaceasacollectionofsurfacesthatcanreceivelight.Thisprocesscanbebrokendownintotwosteps:seeinganenvironmentasacollectionofsurfacesandseeingthosesurfacesforthematerialsofwhichtheyaremade.

SeeingourenvironmentasacollectionofsurfacesOncewehaveadoptedallofthesubtletiesoflightingdesigndecisionsintoourintuition,wearereadytostartplacinglightwithmeaning,conviction,andtruerelationtothedesigngoalsofourproject.Thehelpfulprocessformakinglightingadditionstoourenvironmentistotakewhatweknowaboutourarchitectureandsurroundingsandvisualizethisenvironmentasacollectionofsurfacesindarkness.Fromthisstartingpoint,wepictureourselveswiththeabilitytopaintlightontothespecificsurfacesthatmakeupthespace.

Themoreweknowabouttheuseandlayoutofaspace,thebetter,butthisvisualizationcanbedonewithonlythewalls,floorandceilinginourmind.Wepictureourselvesplacinglightontoeachsurfacebecausethisisexactlywhatallofourarchitecturalluminairesaredesignedtodo.Alloftheengineeredreflectorsandprecisionlampshavebeentweakedandrefinedtogiveustotalcontrolofdeliveringlightexactlywherewewantit.Wecanplacelightontoawall,ontoatable,ontoapieceofart,upontotheceiling,anywherewefeelthelightbelongs.Aspacevisualizedintotaldarknessisablankcanvaswaitingforlightingdesign.Thedesignercanimaginepaintinglightontosurfacesasifwithabrushorspraycan.One-by-one,surfacesarelightedinthismanneruntilthe

Figure12.1Thementalprogressionofvisualizingaspaceasacollectionofsurfacesandpaintinglightontosurfacesoneby

one.

desiredlightingeffectbeginstoemerge.Figure12.1illustratesthementalprocessofvisualizingdarknessandaddinglightonesurfaceatatime.

SeeingsurfacesforthematerialsthatmakethemOncewehaveestablishedthementalpictureofourenvironmentasthesurfacesthatmakeitup,wetakethenextstepandvisualizethematerialsthatmakeupthesesurfaces.Thisiswhereweimplementourintuitiveknowledgeofmatchinglighttexture,colorandintensitytothespecificmaterialswithwhichwearebuilding.

Texture:Thinkofthematerialtextureandwhetheritshouldberevealedourconcealed.Organicstone,concreteandwoodmaybenefitfromdirectionalsourcesthatshowoffthesubtletexturesbycreatingshadowthroughgrazingandsteepaimingangles.Imperfectwallsormaterialsintendedtoappearsmoothandflawlessmaybenefitfromdiffusesourceslocatedfarfromthematerial.

Color:Thinkofmaterialcolorandwhatcolorlightsourcewillcomplementit.Cool-coloredmaterialscanbeemphasizedbycoolsourceslikecoolfluorescent,metalhalideandLED’s.Warmer,richermaterials,likewoodandwarmstone,benefitfromwarmsourceslikeIncandescent.Keepinmindthatwarmfluorescentsourcesoftenappearwarmtotheeye,butactuallydoapoorjobofrenderingwarmmaterials.Mockupanycriticalsituationswherethesourceneedstocomplementthecolorofthematerial.

Intensity:Thinkofmaterialfinishandwhatlightintensityissuitable.Oftentimes,lightcoloredsurfacesneedverylittleadditionallighttomakethemstandoutasbrightsurfacesandfocalelements.Darkermaterials

mayrequireconsiderablymorelighttoserveasfocalpoints.Somedarksurfacesreflectsolittlelightthattheymaynotbeworthlightingatall.

Shininessorspecularityofamaterialshouldalwaysbeconsidered.Shinymaterialsrespondtolightbyreflectinganexactimageofthesourcethatislightingthem.Thiscanbedesirableasinthecaseofaccentingjewelry,glasswareandothershinyproducts.Largearchitecturalsurfacesofglassormetalmay,however,reflectundesirableglareorreflectthelightsource.Suchsurfacesmaybebetteroffappliedwithlittleornolight.

Thismentalprocessofvisualizingaspacein-deptheffectivelydrawsoutlightingconceptsandideasthatwillenhanceanenvironment.Takingjustafewmomentstobreakaspacedownintoitsconstituentmaterialsandsurfacesmakesiteasiertoaddressthespecificnuancesofeachlightingaddition.Thisthoughtfulnessleadstoadesignedenvironmentwithlightingapplicationsthatrespondtoeachsurfaceandperfectlysupportthedesignintent.

Figure13.1Atypicalresidentialbedroom.

Chapter13DevelopingLightingIdeas

Whenweconsidertheprocessanddecision-makingthatwecannowapplytoourlightingdesign,webegintoseethestepsinamorearticulatemanner.Ifabused,thiscanleadtolightingdesignthatisoverlycomplicated.Ifwemakedecisionscarefully,however,theresultwillbeauniquesynergyoflightandmaterialinspacethatmeetsthegoalsofourprogramandbecomestheframeworkoftrulygreatdesign.

Take,forinstance,acommonresidentialbedroom.Ifweuseourknowledgetodeterminewherelightactuallybelongsinthespace,wecanveryquicklyestablishanumberofappropriateapplications.Wecanconsideranyorallofthe“FiveLayer”approachthatguidesourdesign.Wemaythinkofchoreography,mood,andaccent,orwemaythinkonlyofvisualtasks.

Considerthefollowingapplicationsoflightinthisspace:

Accentingartonthebedwalltoprovideavisualfocus;

Lightontothevanityfortasksandrenderingfaces;

Lightontobookshelvestoreadtextandhighlighttheobjects;

Lightatthebenchatthefootofthebedtoaccommodatedressing.

Figure13.2Onewaythespacemightberenderedtoshownumerouslightingoptions.

Nowconsideralloftheapplicationsoflightthatwehavearticulatedandconsiderthemostcommonlyseenmethodtosolvealloftheseproblems:asingleluminaireinthecenteroftheroom.

Figure13.3Atypicaleconomy-mindedlightingsolution.

Supposethisluminaireisasimplerecesseddownlight.Whichofthesegoalsarebeingaddressed?Nearlynone,asthelightissimplypusheddowntothedarksurfaceofthefloorinthemiddleoftheroom.

Supposethisluminaireisasurfacemounteddecorativedish.Nowwhichofouridentifiedapplicationsareweaddressing?Perhapsnonedirectly,butitcouldbearguedthatwearecreatingsomeamountoflightonnearlyeverysurface.Henceinaverygenericmanner,itmaybeasuitablesolution.

Now,whatifwearticulateandplaceluminairestospecificallyaddressallthatwehaveidentified?

Webegintoseewhatlightingdesigncanlooklike,thoughsuchasolutionmaybeoverlycomplexandabitself-indulgent.Theeffortandexpenserequiredtoinstall,electrifyandmaintainsuchasolutionwouldbeexcessive.Additionally,thelightingsolutionmaybetoospecificandcustomizedtothecurrentlayoutanduseofthespace.Inspacesofthistypeourlightingsolutionsmayneedtobemoreuniversalandflexible.

Itiseasyenoughtoselectfromamongthesolutionsthatwehaveidentifiedtocomeupwithareasonableblendoffunctionandversatility.

Ifwestartexperimentingwithcombinationsoftheeffectsandapplicationswehaveidentified,weareboundtorefineouroptionsintothe

Figure13.4Anexampleofanover-developedsolutionforthespace.

exceptionalsolutionsthatwillsupporttherestofourdesign.

Figure13.5Examplesofafewprudentlightingsolutions.

Theprocesswehavejustwalkedthroughisoneforaverycommonandmisunderstoodspace.Thissamemethodologycanbeappliedtoalloftheenvironments,largeandsmall,thatwewilldesign.Wehaveallowedourselvestorelyonourintuitionandbrainstorminafashiontoidentifylightinggoalsandthenthemethodsforimplementingthem.Nomatterhowcomplexourspaces

andenvironmentsbecome,lightingdesignissimplyamatterofusingdesignknowledgetodeterminewherelightgoes,whatkindoflightitis,andhowtogetitthere.

Ifwelookcarefullyatthestepsabove,wewillseethatwearegivingourselvestheopportunitytoapplyallofourprocedure:

Wethinkspatiallyandseeourroomasacollectionofsurfaces.

Weidentifyspecificobjectsfirstandvisualizelightonthosespecifics.

Weconsiderthefivelayersoflight(choreography,mood,accenting,architectureandtasks.)

Weconsiderthecontrollableaspectsoflight(intensity,color,texture,shape,origin)

Weconsiderallofthewayswecandeliverthelightweareafter.Allthewhile,weareconsideringtherealworldaspectsofefficiency,

economy,maintenance,flexibility,andanyotherfactorsthatmaybearealityforthistypeofspace.Wemaygoontosolvelightingchallengeswithcosteffectiveluminariesorhigh-efficiencysources,butsincewehavealreadyidentifiedwherelightwillgo,theintegrityofthedesignsolutionwillstayintact.Bydesigningwithlight,ratherthanattachingourselvestospecificluminariesoraspecificlayoutortactic,wecanrespondtothechangingprogramoftheproject.Decidingwherelightbelongsaffordsustheconfidencetodealwithchangesinbudgetorschedulethatmightotherwisederailadevelopedlightingdesign.

Withathoroughknowledgeofourdesignrequirements,andanintimacywiththeenvironmentwearedesigning,allweneedisthewillingnesstobethoughtfulwithlight,andourintuitionwilldotherest.

Thisgivesusgreatconfidencetoexploreallofourideasandlightingdesigngoalswithoutanextensiveknowledgeofspecificluminaires,specificlightlevelsorcomplexlightingcalculations.

Chapter14AShortcuttoConceptsinLight

Beforedelvingintospecificapplicationsoflightintypicalspaces,itiswellworthexploringlightingapplicationconceptsinabroadersense.Thestrengthoflightingdesignliesinhowtheindividualdesignerapplieshisorherknowledgeoflightingcauseandeffect.Ratherthanpresentacollectionofgenericlightingsolutionsforgenericspaces,thefollowingchapterrepresentsaportfoliooflightingconceptsthatcanbeappliedtomanyspaces.Confidenceinmakingdesigndecisionscomesfromexperienceandfamiliarityorfromthegenuinebeliefthateveryoptionhasbeenconsidered.Therearenoshortcutstofamiliarityandexperience,butthefollowingvisualconceptscanhelplayafoundationthatwillstrengthenadesigner’sabilitytoconceptualizeandinvestigatenumerouslightingoptions.

Forthemajorityofdesigners,thegoalisnottograspeveryshredoflightingknowledgepossible.Thegoalsaremorepracticalandfocused:visualizationandcommunication.

Adesignermustbeabletovisualizelightingeffects.

(Thisisthereasonwepresentlightasvisualconcepts.)

Adesignermustbeabletocommunicateanddescribethelightthathe/shedesires.

(Thisiswhyweemphasizelightingvocabularyandgraphiccommunication.)

Ifadesignercanvisualizelightandsuccessfullycommunicatelightinggoalstoothers,thereareconsultantsandexpertswhocanassistthedesignerinbringingthoselightingideastoreality.

Theimagesanddescriptionspresentedherearetargetedtowardsthishypothesis.Byprovidingvisualconceptsofwhatlightcando,thedesigneris

lefttodecidewheretheseingredientsarebestputtouseinthedesign.

“LIGHTAWALLANDLIGHTANOBJECT”Thisbasicconceptcanbeimplementedineventhesimplestspaces.Itisapplicableatanyscaleforanyarchitecture.Thelargeverticalsurfacetowhichyouapplylightwilldefinethebrightcharacterofyourspace.Itwillcontributetoyourmoodandthearchitecturaleffectofthespace.Theobjectthatyoufocuslightonwillcreatevisualinterest,likelyaccommodatetasks,andwillorganizeandchoreographyourspace.Figures14.1and14.2showspaceslightedgenericallybesidethesamespacewiththistacticapplied.

Figure14.1Agenericlayout(top)yieldsaflatqualityoflightinaseatingarea.Lightingaverticalsurfaceandafocalobject(bottom)createsperceivedbrightnessandvisualinterest.

Figure14.2Agenericlayoutappliedtoadiningarea(top).Amorefocusedapproach(bottom)createscontrastandmood.

MOVELIGHTTOTHEPERIMETEROneofthesimplestwaystotransformaspaceistoapplylighttothewallsandotherverticalsurfaces.Whenweconsiderthebare-boneslightingtacticofplacingagroupofrecesseddownlightsinthecenterofaroom,weneedonlychangeourtacticslightlytogetgreatereffect.Thoughtlesslyplacingluminairesinthecenterofaspaceisapooruseoflightresources.Bysimplyshiftingthelocationoftheseluminaires,lightispaintedontothehighverticalsurfacesthatdelivertheperceptionofbrightness.Thissimpleshiftisaneffectiveexampleofusingthesameluminairesinadifferentwaytomakeanimpactingdifferenceonhowaspacefeels.Observehowdifferentthesebasicspacesfeelasaresultofthisshift.

Figure14.3Lightdirecteddownward(left)cancreateacave-likeeffect.Thesameamountoflightappliedtoverticalsurfaces(right)addstotheperceivedbrightness.

CHOREOGRAPHHALLSANDCORRIDORSPassagewaysareoftentreatedwiththesamethoughtlessapplicationofregularly-spacedluminairesmarchingdownthecenterofthespace.Theseluminaireslosemostoftheirlightintothedarkfloorsurfaceanddolittletoorganizethespaceorcreatebrightness.Ifweuseourlighttoaddresstheverticalsurfaces,wecancreatebothvisualinterestanddefiniteway-findingbycreatinglightedgoals.Wecanexperimenttoidentifythelightedsurfacesthatcreatethemoodandeffectweareafter,but,invariably,thebestuseofourlightwillnotbeonthefloor.Asinglepieceoflightattheendofahallwayisoftenmorecompellingthananentirerowofrecesseddownlights.Consideralsowhathappenswhenweimplementasymmetriclightingorevenalinearslotoflightdownoneside.Lightingthewallofahallwaycreatesacontinuouslightshapethatencouragesflow.

Figure14.5Lightdirectedupwardontoanoverhangorceilingcreatesanencompassingenvironmentoflight.

Figure14.4Alightedgoalandalightedsurfaceareallthatareneededtomakeacorridorattractiveandfunctional.

UPLIGHTOVERHANGSANDCANOPIESWallsandverticalsurfacesaren’ttheonlysurfacesthathaveaprofoundeffectonourspaces.Wecancreateadominatingpresenceandaltermoodbywashinglightupontotheceilingsandcanopiesinourspace.Lightingtheceilingoverheadcanmakepeoplefeelsafer,canexpandspace,andcanlendasenseoflightnesstoanenvironment.Usingourlightingresourcesinthismannercanoftendeliverdramaticeffectwithverylittlelightused.

SLOTS,COVESANDLIGHTSHELVESThelasttwodecadeshavetrulyseemed“theeraoftherecesseddownlight”.Becauseofthistrendwehavegottenveryusedtotheideathatscallopsoflightandpoolsoflightarethepropershapestoaddtoourspace.Moreandmore,thegeometryofcontemporaryarchitectureseemstopairbetterwithlinearplanesof

light.Spacesthattendtobecomevisuallyclutteredcanbeorganizedbyapplyinglightaslargegeometricstatements.

Largecleangeometricshapesoflightlendourdesignsthesameclean,efficientfeelingasourcontemporaryarchitecture.Slots,coves,andlightshelvesareallexamplesofarchitecturalfeaturesthatcanconceallightsourcesthatcreatethelarge,glowingshapesthatdefineourperceptionofbrightnessinaspace.

Figure14.6Spacesusuallytreatedwithpoolsoflighttakeonnewfeelingwhenlightedwithlinesandplanes.

LIGHTINGTHROUGHGLASSLightingglasscanbeunderstoodbyrecognizingthatasatransparentmaterial,wecannotlightglassitself.Lightdirectedtowardglasseitherpassesthroughorreflectsdirectlyback.Becauseofthisproperty,ifthereisnothingtoseebeyondapieceofglass,theglasswillsimplyactasamirror.Thishastwoimportantdesignconsequences.

First,itisworthnotingthatluminairesplacedclosetowindowstendtoreflectadirectimageofthebrightsourcerightbackatus.Forthisreasonitisgoodpracticetoavoidplacinginteriorluminairesrightnexttoglassandwindows.Secondly,itmeansthatourbestchanceofdrawingattentionthroughglassistocreatebrightsurfacesandobjectsbeyondtheglass.Thisleadsustolightexteriorfeaturestodrawattentionthroughglassopenings.Italsoleadsustowashlightontoexteriorevesandoverhangsjustbeyondourwindows.

SUPPLEMENTINGDECORATIVELUMINAIRESHopefully,itisclearthroughallofourdiscussionsthatglowingdecorativesourcesoflightarenotidealstand-alonetoolsforourversionofintegratedarchitecturallightingdesign.Decorativeluminairesdohaveanimportantplaceinourlightingtoolvocabulary,but,ontheirown,theytendtobesourcesofglareandleavearoomgloomy.Tomakebetteruseofthesedecorativeluminaires,weneedtosupportthemwithmoredirectionalluminairesnearby.Whenwehaveconcealedsourcesthatwecanusetoplacespecificpiecesoflightwherewewant,wearefreetouseourdecorativesourcesatlowerlightlevelsforthesubtlevisualeffectsandmoodeffectswedesire.

Figure14.8Providingdirectedaccentlightfreesupglowingsourcestoserveasdecoration.

DIRECTIONALDECORATIVELUMINAIRESInordertoavoidtiptoeingarounddecorativelightingelements,ithelpstobedeliberateinthetypesofdecorativeluminairesspecified.Itisusefultodrawacleardistinctionbetweenself-luminousglowingsourcesandshieldeddecorativeluminairesthatdirectlightbackontonearbysurfaces.Luminairesthatappearasglowingbrightspotstendtobeoverlyself-servinganddon’talwayssupportthe

spaceasawhole.Decorativeluminairesthatdirectlightcanbeusedlikeourotherarchitecturallightsourcesforlightingsurfaces.Foreveryglowingdecorativependant,wallsconceandfloorlamp,thereisprobablyaversionoftheluminairethatshieldsthesourceanddirectsthelightontothesurfacesofthespace.

Figure14.9Decorativeluminaireslikethelinearpendantshownherecanbedesignedtoprovidefunctionallightfortasksandambience.

Theideaspresentedherearejustahead-starttowardfamiliarityofthewayslightcanbeeffectivelydeliveredtoaddemotionandexperiencetoourdesignedenvironments.Withadedicationtodissectingdesignedenvironments,thedesignerwillsteadilybuildarepertoireoflightingideasandconceptsthatwillworkforhim/her.Asthisknowledgebasegrows,itisahelpfulpracticeforadesignertopinpointwhatworksandwhatcouldbechangedtoimprovetheinteractionoflightinthespaceshe/shevisits.

Therearefewabsolutesindesign,andevenfewerinlightingdesign,buttheimagesandconceptsdiscussedinthischaptershouldencourageyoutothink

abitdeeperaboutwhatoptionsareavailableandshouldgetyoutoquestionthestatus-quosolutionsthatgetappliedtosomanyspaces.

Chapter15LightingThatWorks

Thedeeperourfamiliaritywiththebasicsoflightingscienceanddesign,themorewecanlearnfromlighted,designedenvironmentsallaroundus.Taketimetoinvestigatedesignandarticulatewhatelementsofdesignareresponsibleforthewaythingsarefunctioning.Eachofthefollowingimageshasidentifiablelightingelementsthatplayastrongroleinthedesignasawhole.Thereisasayinginlightingdesignthat“Goodlightinggetsaspacenoticed,andbadlightinggetsitselfnoticed.”Thisspeakstothepowerofarchitecturally-integratedlightandwarnsustobecautiouswithourdecorativelightingelementsandstrongly-themedlightingstatements.

Thesurestwaytocreateapredictableeffectistointegratesomethingthathasbeensuccessfullyimplementedbefore.Butadesignermustbesurethathe/sheisimplementingsomethingbecauseitworksandisdesired,notsimplybecauseitisacommonly-usedsolution.

Thefollowingimagesareaccompaniedbynumbereditemsthatpointoutthekeylightingelementsineachscenario.Thescenariosfocusonintegratedlightingthatiswellthought-outandsupportstheneedsandgoalsofeachspace.

DaylightResponsiveOfficeSpace

1. Localizeddirecttask/accentluminairesateachworkstationfortargetedtasklighting

2. Subtledirectlinearlightingcastdownwardprovidesuniform,low-levelglowontohorizontalsurfaces

3. Indirect,linearuplightcastontohighlyreflectivesuspendedceilingsurfaceprovidesperceivedbrightnessandinter-reflectedglowontohorizontalandverticalsurfacesthroughout.

4. Daylightresponsivemechanicalshadingtobalancedirectanddiffuseddaylightcontribution

High-endRetailShowroom

1. Continuouslinearsourcesilluminateverticalperimetertodefineboundaryandcreateperceivedbrightness

2. Concealed,adjustableaccentluminairescastlightontospecificexhibitobjectsandchoreographpaththroughspace.

Museum/GallerySpace

1. Poolsofincreasedlightlevelsmovetheeyefromoneimportantobjecttothenext

2. Slender,indirectsourcesfilltheceilingvolumewithdiffuseambientlight3. Directionalluminairesprovideaccentlightonartandverticalsurfaces4. Indirectuplightrevealsthevolumesandshapesofthevaultedceilingsystem

5. Thecombinationofdirectional,accentlightanddiffuselightprovideforlong-termvisualcomfort

High-EndRetailDisplay

1. Combinationluminairesintheroomcenterprovidebothcomfortablediffuselightandaimableaccentlightforvisualinterest

2. Adjustableaccentluminairesinrunningslotsprovidepunchontothedisplayedobjects

3. Planesoflightineachdisplaynichedefinethespaceandcreatetheperceptionofbrightness

4. Glowinglinesoflightinthedisplaynichesdefinethedepthandformofthespace

ContemporaryHigh-endDining

1. ContinuouslinearLEDlightingtocastambientglowandverticalbrightness

2. Adjustablehalogenaccentluminairestocastdistinctpoolsoflightondiningtables

3. Adjustablehalogenaccentluminairestoaccentwallpaneling,provideadditionalverticalbrightness,anddepthofspace.

Contemporary,CasualLounge

1. Uplightandreflectivesurfacesdefinetheentryofthespace,whiledarkermaterialsandlightdirecteddownwardprovidemoreintimacyandalowerscaleinthediningarea.

2. Recesseddecorativedownlightsprovideatwinkleontheceilingandapooloflightformoodandaccentdownatthetask.

3. Thebrightverticalsurfaceskeepthespacebright,sothelightingisfreetobeappliedonlywherenecessary.

Chapter16DesigningwithDaylight

Sustainabilityandenergyconcernshavebroughtdaylightdesignandintegrationtotheforefrontofthelightingdesignpractice.Localcodesandincentiveprogramshavesignificantlyopenedupthedaylightdiscussion.Alightingdesignerisnowexpectedtohaveamuchbroaderunderstandingnotonlyofgooddaylightingpractices,butofspecificcodeandincentivecompliancerequirements.Thistrenddrivesprojectstoconsiderdaylightingfactors-buildingorientation,glazing,shadingstructuresandlandscaping-farearlierinthedesignprocess.Thisleadstoearlierlightingdesignerinvolvement,makingdaylightingyetanothertopicinwhichthelightingdesignershouldbecomeanexpert.

Whenwetalkabouttheimportanceofmakingdecisionsaboutwherelightwillgoandhowlightwillinteractwitharchitecture,wearetalkingaboutthecontrollableaspectsofdaylighting,aswellaselectriclight.Themostcriticalcomponentofdaylighttorememberisthatasasource,itishugelyintense.Assuch,themisuseofdaylightcanbeamazinglydetrimentaltoaproject.Forthisreason,daylightdesignisprimarilyastudyincontrol.

Therearenumeroustextsdiscussingthefine,technicalaspectsaswellasthemorephilosophicalsideofthesunasalightsource.

Wewillfocushereonbasicsthatcanproveusefulasintuitiveknowledge.Alsopresentedhereisafundamentalprocedurethatwillencourageyoutothinkthroughallofthefactorsanddecisionsthatwillleadtosuccessfuluseofdaylight.

Daylightcanbeassessedandcontrolled,and,assuch,itdeservesthesametypeofdesignscrutinythatweapplytoelectriclight.Weshouldapproachourspaceswiththeintenttovisualizeoureffectsanddeterminewhatsurfacesandobjectswillbenefitfromtheadditionofdaylight,justaswedowithelectriclight.

OBVIOUSBENEFITSOFDAYLIGHT

Aprimaryaspectofdaylightsystemsistoconsiderthebenefitsthatmayserveyourdesign.Inordertoactuallymakeuseofthesebenefits,thedaylightsystemsweintegratemustbeaswell-conceivedasourelectriclightsystems.

Firstandforemost,daylightisameansofproducinglightwithouttheconsumptionofelectricityorotherfossilfuels.Thisisahugebenefittoallmannerofprojectswheresustainability,minimalmaintenanceandenvironmentalconcernarepartoftheprogram.Daylightconsumesnoelectricityandalsoeliminatestheneedforchanginglamps.Daylightcanalsobeharvestedwithrelativelylittleheatgain,whichmeansthatwecanreduceourneedfortheelectricityassociatedwithairconditioningandcoolingthatoffsetsheatcontributedbyelectriclight.

Daylightisalsoaspecialsourceoflightbecauseofourlongstandingrelationshipwithit.Whenweconsiderhowlonghumankindhashadonlydaylight(andoccasionalfirelight)asalightsource,itiseasytoimaginewhywehaveaspecialfondnessforit.Daylightconnectsustothenaturalworldandbringsusintocontactwithawayoflifeforwhichwearereadilyequipped.Smallquantitiesofdaylightstaveoffdepression,allowustosynthesizeVitaminD,andcaninvigorateourspiritandenergylevel.Certainformsofdaylightalsohavetheuncannyabilitytodeeplyrelaxus.

Daylightisinherentlydynamicandchangesthroughoutthecourseofthedayandtheyear.Thisfactorbenefitsournaturalrhythmsandstimulatesouractivemind.Oneofthemostdepressingaspectsofpoorly-executedelectriclightisthestatic,unchangingnature.Daylightisdynamicbynature,soevenasmallamountcanhaveahugeimpactontheinterestandstimulatingeffectofanenvironment.Thechangesindaylightqualityaresoeffectiveinencouragingdifferentmentalstatesthatmanyelectriclightsystemsstrivetomimicsimilarchangesintextureandcoloroverthecourseofaday.

FLAVORSOFDAYLIGHTInordertovisualizeandimplementtheintegrationofdaylightintodesign,itishelpfultocategorizetwotypesofdaylightsystems:FunctionalDaylightandDaylightAccenting.

FunctionalDaylightisthecarefulintroductionofdaylightintoaspacetoservetaskandspatial-definingfunctions.Thisisgenerallydiffuse,evenlightthatcanaccommodatelongtermvisualcomfort.

Figure16.1Controllingdaylightthroughdiffusionorshading(left)turnsitintoatoolforsolvinglightingchallenges.Directsunlightcomponents(right)areusefulforimpactandinterest.

DaylightAccentingisamoredramaticandobvioususeofdaylighttoinspirecertainmoodsandcreatedistinctvisualinterest.Thesefeaturesmaybeintegratedintohigh-designspaceswhereemotionalimpactisthepriority.

Thesetwotypesofdaylightareaccomplishedthroughdistinctlydifferenttypesofsystemsandhaveverydifferenteffectsonourenvironments.Therearesystemsthatintroducebothsimultaneously,butwhenwevisualizeadesigneffect,itisimportanttoidentifyourtargetanddistinguishbetweenthetwo.

COMPONENTSOFDAYLIGHT(TEXTURES)Theotherbasicintuitionthatadesignershouldcarryisthedistinctdifferenceinlightqualitythatisobtainedfromthedifferentcomponentsofdaylight.Daylightentersourspacesinanumberofdifferentwaysandtakesondifferenttextureaccordingly.Justaswedistinguishbetweenthedirectionalbeamofanaccentluminaireandthesoftdiffuselightofaglowingglobe,webreakdownthecomponentsofdaylightintothreetextures:DirectSunlight,SkylightandDiffusedSunlight

Directsunlightis,arguably,theleastusefulasafunctionallightsource

andmosthazardoustodesign.Lightreceiveddirectlyfromthesunisexcessivelybrightandleadstosituationsofglareandunacceptablecontrast.DirectsunlightcanalsointroduceheatandUVradiationthatcandamagematerialsandfabrics.Ascreaturesofreflectedlight,sunlightintooureyesoroffofabrightsurfaceintooureyesissimplytoobrightforourvisualsystem.

Skylightistheproductofsunlightdiffusingandscatteringthroughvariousstatesofouratmosphere.Skylighttakesonmanydifferentqualitiesdependingontimeofday,timeofyear,weatherandatmosphericconditions.Fromclearblueskylighttosoft,diffusecloudydaylight,mostformsofskylightsuitourvisualsystemwellasasustainedlightqualityforlongdurations.(Thisisnosurprise,givenourlonghistorywithskylight).

Diffusedsunlightistheproductofintroducingsunlightintoourspacesafterithasinteractedwithsomesortofdiffusingmaterial.Oncewehavepassedsunlightthroughtintedorfrostedmaterials,wegainamuchmoremanageablesourceoflight.

SITELAYOUTANDMASSINGThedynamicnatureofthesunandskydemandthatweconsiderthedaylight-harvestinggoalsforaprojectveryearly.Thefirststepinrecognizinghowtomakeuseofdaylightistoidentifytheopportunitiesbasedontheproject’sorientationandproportions.

Thereareafewquickrulesofsolargeometrythatwillhavesignificantimpactonthepotentialusesofdaylightonadesignjob.Daylightissimpleatitsheart,andtherelationshipcreatedbyprojectorientationisequallysimple.

Architecturallayoutandmassingmustbeconsideredwithdaylightimplicationsinmind.Heightandwidthofformsandfacadesgreatlyaffectthesurfaceareaavailablefordaylightingopportunities.Glazingmustbeconsideredforitsdaylightimplicationsandnotsimplyforitsviewconsiderations.Solarorientation,sightlinesandsolarshadowlinesshouldalsobeinvestigatedindecidinghowandwheretolocateaproject.

Figure16.2Themassingofastructurewilldeterminetheopportunitiesforvariousformsofdaylightharvesting

LatitudeThecloseryouaretotheNorthandSouthPoleoftheearth,thelowerthesunwillbeinyourskythroughouttheyear.Withoutburdeningourselveswithsolargeometry,wecansafelysaythataprojectontheequatorhasthepotentialforthesuntobedirectlyoverheadmuchoftheyear,whileaprojectintheArcticwillneverseethesunhighinthesky.

Figure16.3HighLatitudesandsummermonths(left)meanahighsunangleandshortshadows.Lowlatitudesandwintermonths(right)meanalowsunandlongshadows.

CardinalOrientation

Thesunrisesintheeastandsetsinthewest.Spacesfacingthesedirectionshavethepotentialfordirectsunlightexposureinthemorningsandeveningsofeveryday.

Figure16.4Inthenorthernhemisphere,thesunwillreliablyarcacrossthesouthsky,castingshadowstothenorth.

SeasonalSunAnglesDaylightalsohasapredictabledynamicbehavioroverthecourseoftheseasonsinayear.Thesunwillridehigherintheskyinthesummermonthsandwillridelowerinskyoverthewintermonths.Thismeansthatwithalittlestudying,wecandesignphysicaloverhangsandshadingdevicesthataffectdaylightdifferentlythroughouttheyear.

Figure16.5Awelldesignedoverhangcanshadehighsummersun(left)andallowinlowwintersun(right)

NorthLight/SouthLightLivinginthenorthernhemispheremeansthatthesunwillalwaysarcacrosstheskytothesouth.Thismeansthatsouthfacingspaceshavethepotentialfordirectsunlightallday,whilenorthfacingspaceswillreceiveexclusivelyskylight.(Thisprincipleisobviouslyreversedforthoselivinginthesouthern

hemisphere.)Itisgoodpracticetocreateasimplediagramoftheprojectsitein

referencetothecardinaldirections.Thiswillgivethedesignerguidanceastowherehe/shecanusecertaintechniquesandwheretowatchoutforpotentialproblems.

Itisalsohelpfultodrawtheelevationsoftheprojectsiteinreferencetosolaranglesandthestructuresthatmayshadedaylightingopportunities.Dosomeresearchonthesolaranglesthatoccurattheprojectlatitudethroughtheyeartogainaspecificunderstandingofthesunlightvariance.

Figure16.6Asimplemapofwhattypesofdaylightcanbeexpectedonaprojectinthenorthernhemisphere.

Whenitcomestoactuallyimplementinganddesigningdaylightsystemsintoaspace,itpaystothinkthesolutionsandconceptsthroughallsunpositions.Visualizenotjusttheidealsituations,buteverypotentialsunangleconditiontowhichthedesignwillbesubjected.Thinktheprojectthroughmorningandnight,sunnyandcloudy,andwintertosummer.Fartoomanydaylightideasareconceivedinonedimensionandaresuccessfulonlyontheonedayayearwhenthesunandtheprojectareperfectlyaligned.

DAYLIGHTSYSTEMSThenextstepinmakingdaylightdecisionsistodeterminewhattypesoflightcharacterwillservethedesignintent.Thecontrollableaspectsofintensity,color,texture,shapeandoriginarejustasvalidwithdaylightastheyarewithelectriclight.Daylightsystemscanbelumpedintotwobasiccategories:sidelightand

top-light.Wethenidentifythetechnologiesandgeometriesthatweusetocontrol,modifyandenhanceeach.

SidelightSystemsCommonwallwindowsaretheclearestexampleofsidelightenteringaspace.Sidelightsystemsareuniqueinthemanywaysthattheycantransformdaylightintoausefulform.Ifwereceivedirectsunsidelight,wemustconsiderdiffusingtechniquesliketinting,frosting,andfritting.Sidelightingsystemsareeffectivehighuponverticalsurfacestoimpartaglowthatlightsupceilingsandwallstotranslatevolume.Sidelightsystemscanalsobedesignedwithgeometryinmindsothatdifferentcomponentsofsunlightandskylightaredelivereddifferentlythroughtheyear.Thesesystemscanincorporateoverhangsandshelvestoshadedirectsunlight.Figures16.7through16.11illustratevarioussystemsforharvestingandcontrollingsidelight.

Figure16.7Sidelightingdaylightsystems:Overhangingsoffit.

Figure16.8Sidelightingdaylightsystems:Lightshelf.

Figure16.9Sidelightingdaylightsystems:Lightmonitor.

Figure16.10Sidelightingdaylightsystems:Clerestorywindow.

Figure16.11Sidelightingdaylightsystems:Verticalshading.

Top-lightSystemsMostdesignedspaceshaveaccesstohighangleddownwarddaylight,regardlessoforientationandneighboringstructures.Daylightfromabovecanbeshapedmuchliketherecessedluminairesweusesomuch.Highdaylightiseasyto

incorporateintolong,linearslotsandcleanplanes.Theguidelinesforsuchsystemsarethesameasanydaylight:

Directsunlightshouldbediffusedandcontrolled;

Skylightiswelcomedandeasiertoputtouse;

Studyofsolargeometryanddiffusingmaterialsarethekeytogooddaylighttextures.

Figures16.12through16.14illustratevarioussystemsforharvestingandcontrollingTop-light.

Figure16.12Toplightingdaylightsystems:Skylight.

Figure16.13Toplightingdaylightsystems:Bouncedskylight.

Figure16.14Toplightingdaylightsystems:Shieldedskylight.

LIGHTCONTROLTECHNIQUESThelastingredienttomakinguseofdaylightisanunderstandingofthetechnologiesthatweusetoalterthelighttextureswereceive.

DiffusingDiffusingdaylightcanbeaccomplishedthroughtheuseoftranslucentacrylic,frostedglassandahostofotherslightlyopaquematerials.Thistreatmenttendstocreateasoft,eventexturesimilartoskylightonacloudyday.

TintingTintingisthesimpleactofreducingthetransmittanceofatransparentsubstrate.Tintingfilmsandlaminatescomeinavarietyofcolorsandareoftenmirrored.Inmanycasestheyreceivemixedreviewsastheyimpartastrangesortofgloomyordarkperceptionoftheoutsideworld.

FrittingFrittedmaterialsareotherwisetransparentmaterialswithlinesetchedorembeddedinthem.Goodfrittingcanactlikeaseriesofminiaturelightshelvesorlouvers,usinggeometrytoreducethetransmissionoflightatcertainangles.Badfrittingbehavessimilartodiffusingmaterialsorprismaticlenses.

DaylightatWorkThereare,ofcourse,situationswheretheraw,unbridledeffectsofnatural

daylightareexactlywhataspaceneeds.Whendaylightisusedasanaccentfeature,thechallengeisofteninstudyingexactlywhattypeofsystemismosteffective.Daylightforthesakeofenergyconservationisanoblecause,buttherearejustasmanyvalidemotionalandexperientialreasonstoworkdaylightintoyourdesign.Manyofthemostamazingnaturalanddesignedspaceshangmuchoftheirgreatnessontheinclusionofdaylight.Theetherealconnectionweholdwithdaylightmakesitapowerfulingredientthatcanturnanotherwisesterileenvironmentintoatrulymovingexperience.

INTEGRATINGWITHELECTRICLIGHTWhetherourdaylightingingredientsarefunctionaloraesthetic,itisnecessarytoconsiderhowtheycansubstituteorworkinharmonywithelectriclight.Indesignapplicationsitisworthinvestigatinghowaparticulardaylighteffectcanberecreatedwithelectriclight,orvice-versa.Itallowsaspacetohavesimilarlighttexturesinvaryingskyconditionsthroughoutthedayandtheyear.Considerhowshelves,slots,covesandcofferscanbefittedwithcomponentsofbothelectriclightanddaylight.Consideralsothedecisionsthathelpthetwosystemsworkinharmony:intensity,colorandshape.

Intensity:

Technologyallowsustorespondtothedaylightwearereceivingbyautomaticallyreducingtheintensityofthecomplementaryelectriclightsystem.Photocellscansendsignalstodimorstepdowntheoutputleveloftheelectriclightsystem.Photocellscanalsoactivateshadingsystemsinthecaseofexcessdaylight.Ifyourgoalistousedaylighttoreduceorreplaceelectriclight,athoroughstudyoftechnologieslikephotocells,dimmers,andtimeclocksisinorder.

Color:

Coordinatingdaylightusewithelectriclightalsodemandscarefulconsiderationofthecolortemperaturesoflightthatarebeingintroducedtothespace.Thecolorofbothskylightandsunlightareentirelyvariable.Skylightcanrangefromthepaleblueofaclearmorningtothemurkycoolofacloudydaytothevioletsandpinksofasunset.Directsunlightcanvaryfromawarmglowtoabrilliantorange.Both,however,seemtohaveanuncannyknackforshowingofftheunnaturallookofthecolorsofourelectricsources.Becausedaylightcomponentsbynaturehaveperfectcolor-renderingcapabilities,theytendtoshowoffthedeficienciesofour

electricsystems.Electriclightcanlookveryunnaturalwhenitisshownupbydaylight.Becauseofthegreatvarianceofdaylight,itisnotsuggestedthatyourelectriclightsourcesnecessarilytrytomatchthecolortemperatureofyourdaylightingingredients;itissimplyonemorefacetoflighttoconsider.

Shape:

Integratingdaylightandelectricelementstogetheralsorequiresconsiderationoftheshapeoflight.Daylighttendstobedeliveredinlong,cleanpiecesandplanes.Ourlong,linearelectricsourcescandoagoodjobofharmonizingwiththeseelements.Daylightcanalsobedeliveredincleandirectionalbeamsandpoolswhenproducedbysmallaperturesanddeviceslikesolarlighttubes.

Thepointistotakecontrolofdaylightandexpandconceptsofwhatcanbeaccomplishedwithit.Almostanysourceofelectriclighthasaproperdaylightcounterpart.Theresponsibilityissimplytoinvestigatethepossibilitiesandthinkthrougheverydesigndecision.

Somecommondaylightintegrationdetailscanbefoundinchapter30

HAZARDSOFDAYLIGHTForallofitspowerandcharm,itisimportanttorememberthattherearedistincthazardsofdaylightappliedimproperly.Keepattheforefrontofyourmindtheperilsthatcanbefallaspacewithpoorly-controlleddaylightcontributions.

HeatGainsUnmitigateddirectsunlightgenerallycontributesafairamountofheat,inadditiontoexcessivelight.Therearelow-emissivityglassesandcoatingsthatcantransmitvisiblelightwithouttheheatcontribution,butthesearenotcommonplace.Ifyouwantdirectsunlight,yougetheat,oryoumakeuseoftheseexpensiveglazingtechnologies.

GlareandContrastSunlightisanobviousculprit,creatinglighthundredsoftimesbrighterthanourbrightestelectricsources.Asatasklight,directdaylightissimplytoobright.Asanaccentlight,sunlightcanstillcauseglareandcontrasttowhichthehuman

visualsystemsimplycannotadapt.Skylightanddiffusedsunlightcanalsopresentproblemswhennotcarefullyconsideredwiththematerialreflectances,colors,andvisualcriteriaofaspace.

DamagetoArt,FabricsandOtherMaterialsSunlightanddaylightcontainaquantityofultravioletradiationthatwilldeterioratedyes,inks,pigmentsandtheintegrityoforganicmaterials.GlazingblocksallbutasmallquantityofUVradiation,buteventhissmallquantityhasdamagingeffectsovertime.

ExcessiveWindowLightDaylightwindowsarenotnecessarilyviewwindows.Windowsplacedforclearviewsoftheexteriorenvironmentshouldalwaysbeconsideredforthedaylightthattheywillreceive.Fartoooften,glazingisdesignedforviewswithnoconsiderationfortheintrusionofdaylightthatwillresult.Daylightsystemsshouldbedesignedindependentofviewwindowsandviceversa.Simplewallglazingcancertainlyservebothpurposes,butcarefulstudyandconsiderationarenecessary.

DAYLIGHTASACONTROLLABLEELEMENTThebottomlineisthatsunlightandskylightarecontrollable,predictablesourcesoflightthatcanbeusedtosatisfytheneedsofallofourfivelayerswhenimplementedproperly.Therearedaylightingredientstoservetheneedsofwayfinding,mood,accenting,spatialrevelationandtasks.

Thekeyistotakecontrolofdaylightanddesignsystemsthatuseit.Evensimplewallwindowsdeservetheconsiderationofdiffusingcurtains,blindsandshadingdevices.Daylightshouldneverbeanaccident,norshoulditbeneglected.Likemanyotheraspectsoflight,fearkeepsdesignersfromconfidentlyimplementingdaylight.Daylightissuchanelementalmaterialthattherearenumeroussimplewaystosuccessfullyputittouse.

Unlikeelectriclightdevices,therearefewproductcatalogsthatillustratedaylightsystems.Gooddaylightuseisoftentheproductofuniquesituationsandafairamountofexperimenting.Ifyoucomeacrossanapplicationthatyoulike,takenote,sketchit,andstartacollectionofdaylightsystemsthatyoucandrawfromthenexttimeyouneedtoleanonthesublimecharacterofsunlightandskylight.

Iamastrongbelieverintheuniquemoodandvisualattractionof

daylight.Igotogreatlengthstostudytheopportunitiesforintroducingskylightanddiffusesunlightintomyenvironments.IthinkthisaffinityissostrongthatItendtodesignmyelectricallightingsystemstomimictheintensity,shapeandtextureofcontrolleddaylightsystems.Thisalsoofferstheadvantageofseamlessintegrationbetweenelectriclightanddaylight.Despiteallofthecautionencouragedregardingdaylightintegration,rememberthatalittlebitofdaylightcangoalongwaytowardsapositiveeffectinthedesignedenvironment.

Figure17.1Lightingsymbolsonaconstructiondocumentdoverylittletodescribehowthespacewilllook,feel,orfunction.

Chapter17GraphicTools:RenderingandLightMaps

Wementionedearlierthatthedesigner’sabilitytovisualizelightingideasisonlyoneofthenecessaryskills.Inordertoimplementlightingdesign,thedesignermustalsobeabletotranslatethoseideastootherdesignersandultimatelybacktothemselves.Communicatingideasisnecessaryforworkingthroughchallenges,gettingfeedbackandassistance,thinkinginnovatively,and,foremost,beingfreetothinkcreatively.Foradesigner,representingideasvisuallyisthefastest,clearestwaytogetthoseideasoutofone’sheadandintothedesignprocess.Thecredothatalightingdesignershouldadoptcanbestatedassimplyasthis:

“DRAWYOURLIGHT.”Fartoooften,peopleseelightasaproductofluminaires,andthey,

therefore,designbystaringataspaceplanandplacingsymbolsthatrepresentluminaires.Thisprocessinevitablyyieldsrepetitious,staticsolutionsofhabit.Thelittlecirclesandsquaresymbolsdolittletoexplaintousoranyoneelsehowlightisbehavinginthespace.Inourdesignprocessweshouldvownevertodesignbydrawinglightingsymbolsstraightaway.

Thefirststepinexpressinglightideasistographicallyrepresentlightaslight.Wedrawthislighthowweenvisionit,andwhereweenvisionit.Weidentifythesurfacesandobjectsthatwewantbright,andwedrawbrightnessontothem.Remember:lightingdesignisnothingmorethanthesuccessfulapplicationofthemostappropriatetypeoflightontothemostappropriatesurface.Ifwecanmakeahabitofexpressingourideasthroughdrawinglight,wecanheaddownamorethoughtfulandprogramresponsivepathofdesigningthatwillyieldmoreinspiredandinnovativedesigns.

Drawinglightontosurfaces,objectandspacesrequiresonlythesimplestoftools.Ayellowcoloredpencilcanrepresent“light”initsmostgenericform.Withthissinglecoloredpencil,wecansketchlightontoarchitecturalelevations,sections,plansandperspectives.Wecanprintoutimagesandsketchontothem.Wecansketchlightontoourownhand-drawnscribbles.Imakeahabitofcarryingaroundasmallarmyofyellow,coloredpencilssothatassoonasalightingideacomestomind,Icancommunicateitimmediatelywithoutalotofbigwordsandhandwaving.Whenonedrawslightontoplansandsketchestheeyesoffellowdesigners,clientsandpeerslightupwithcomprehensionandunderstanding.Iknowofnoeasiertoolforcommunicatinglightideas,andsothiswillbeourfirst.Icallthisprocessofexpressinglightthroughgraphics“LightMapping”

Figure17.2Alightmapdetailexampleofacontemporaryresidence.

Figure17.3Alightmapexampleofanentirefloorofaresidence.

Figure17.4Alightmapexampleofanelevationofacentralbarareainacasino.

Ourdesignprocessshouldalwaysrevolvearoundadimensionalunderstandingofourenvironmentsasawhole.Arecommendedpracticeistocommittoispinningup,displaying,andsurroundingoneselfwithallthatcanbeknownabouttheprogram,surfacesformsandspacesofaprojectbeforestartingtodesignlightingforit.Beingsurroundedbyvisualrepresentationsofmaterialconceptboards,elevations,section,plansanddimensionalmodelsallowsthedesignertorenderlightingideasinalldimensionsandtounderstandtheramificationsoflightingdecisionsandconcepts.

CREATINGLIGHTMAPSThemostbasicformofalightmapissimplywhateverarchitecturalorenvironmentalinformationthedesignerhasavailablewithlightinggraphicsappliedontop.Afterwehaveexhaustedalloftheinformationwehaveavailableandhavemadelightmapsofalloftheelevations,sectionsandperspectives,wesetoursightsoncreatingalightmappedplan.Thelightmappedplancanbebasedonafloorplan,furnitureplanorceilingplan.Thissimple,graphictoolwillhelptocommunicatelightideasandwillserveasaroadmapwhenwemove

forwardandlayoutourlightingequipment.Whenwegotosolvelightingchallengesandidentifylocationsandtypesofluminaires,agood,light-mappedplanwillsolveitself.Inanidealdesignworld,thereistimeenoughtocreatelightmapstoaddressseparatelyeachoftheFiveLayersofLightthatwehaveidentified.

TheKeystoSuccessinCreatingaLightMap:Thinkonlyintermsoflight.Don’tworryaboutpracticality,constructibility,luminairelocation,oreventheluminaireitself.

Thinkaboutthequalityoflightandwhereitgoes

Focusonsurfacesandobjectsandhowtheyreceivelight.

AddingtotheImpactofaLightMapWhenwesetouttotranslatelightinginformationonplanintwodimensions,itisimperativethatwekeepourmindopenandourideasfresh.Wecanaddrenderingtechniqueslikeadditionalcolorsandpatternstorepresentdifferentlightingtechniques.Itisoftenhelpfultographicallydistinguishbetweendirectionalaccentlighting,diffuselighting,lightcastupontoceilingsandlids,aswellasvariationindesiredcolorcasts.Figure17.5illustratesafewideasforwaystorepresentlighting.Itisoftenhelpfultocreatealegendonthelightmapthathelpstranslatethedifferentapplicationsoflight.

Figure17.5anexampleofalegend(left)usedtoclarifycolorsandpatternsusedonalightmap(right).

Withthesesimpletools:Ayellowpencil,anorangepencil,andsomeimaginativepatterns,adesignercantranslateawealthoflightingconceptsinplan.

Asonecanseefromtheprecedingfigures,thegoalistotrulyrepresentlightwhereitendsup.Moretothepoint,werepresentthesurfacesthatreceivethelight.OurLightMapplanbecomesamapofspecific“lightingevents,”onespecificlightingconceptafteranotherclearlyidentified.

DescribingLightInordertocreateLightMapsthatcantrulystandontheirowntotranslate

informationtoothers,weaddarticulatedescriptionstothegraphicsofourlighting“events”.Describinglightdoesn’tneedtobeastudyinpoeticsandsuperlatives.Wearesimplyclarifyingwhatitisthatlightisdoing.Thebetterourdescriptions,thelesswehavetorelyonspecializedgraphicstogetourideasacross.Lightingdescriptionsarelikearchitecturalnotes;theyneedbedetailedonlyenoughtogetinformationacrossclearly.However,evenabriefdescriptionisbetterthantheambiguityofnodescriptionatall.Takeprideindescriptionsoflightanddolethemoutgenerously.Thereisaruleindesignthatsays:“Whenindoubt,createanote.”Wewilltranslatethisguidelinetobeoneofourmottosingraphicsandcreatinglightmaps:“Whenindoubt,addadescription”.

Tohelpforgetherightlevelofinformationintoalightingdescription,I

recommendconsideringthefollowingelementsthatareincludedinagooddescription:Color,texture,andintensityofthelight;

Howthelightaffectsmood;

Howthelightinteractswiththesurface.

Ifalightingdescriptionincludestheseelements,itwillbethatmucheasierforotherdesignerstounderstandtheintentofthedesign.Itwillalsobeeasiertosolvelightingideasandselecttheluminairesthatwillbringtheideatolife.AlistofusefullightingdescriptorsisincludedinappendixC.

Figure17.6Descriptionsoflightingintentareacrucialsteptowardsdefininglightingchallenges.

ItisgoodvisualpracticetostudyenvironmentsthatfeaturegoodlightingdesignandimaginehowonewouldrepresentthemgraphicallyasaLightMap.Thisanalysisreallyshowsofftheideathatitisthesurfacesreceivinglightthatdefineaspace.Figure17.7and17.8showimagesoflightedspacesandhowtheymighthavelookedasLightMapsduringthedesignprocess.

Figure17.7Acontemporarykitchen(below)canbequicklyrepresentedinalightmap(above).

Figure17.8Alivingroom(below)canbequicklyrepresentedinalightmap(above).

CREATINGLIGHTMAPSFORALL5LAYERSInthe“5-layerProcess”wehaveatoolthatcreatesmaximumopportunityforgerminatinglightingconcepts.Inthe“LightMap”,wehavetheultimatetoolforefficientlyandclearlytranslatinglightingconceptsandgoals.Thecombinationofthetwocanresultintheultimateprogramspecific,thoroughly-articulated,well-communicatedlightingdesign.AsdiscussedinChapter4,theidealdesignprocessinvolvesthinkingintermsofonelightinglayeratatime.TheLightMapprocesscanbebrokendowntoaccommodatethis.AgoodpracticeistorenderLightMapsforeachofthefivelayersonseparatesheetsoftranslucentvelumortracepaperthatcanbeoverlaidonone-anotherforcomparisonandcoordination.Let’sreviewtheFiveLayersofLightasweaddressedtheminChapter4:

1. Lighttochoreographanexperience;2. Lighttoaffectmood;3. Lighttoaccentobjects;4. Lighttorevealarchitecture;

5. Lightfortasks.

AslightingideasevolveonaseriesofLightMaps,particularlightingeventswillservemanypurposesacrossourfivelayers.Thiswillpointoutlightingeventsthatareabsolutelycriticalandwillalsohelpidentifylightingthatisperhapsexpendableornotasnecessaryfortheoverallsuccessofaproject.LightMappinginlayersallowseachlightingredienttobeassessedandre-assessedasthedesignevolves.

Layer1:LightMappingChoreographyAgoodfirststeptoimplementwhencreatingalightmappedplanistoshowlightforthesakeofchoreographingapathofexperienceforavisitor(thefirstofourfivelayersfromchapterthree).Choreographybenefitsgreatlyfromthelightmappingprocessbecauseitrequiresalargescaleoverviewoftheproject.Thechoreographystepisaquickandsimpleapplicationoflightonjustafewlargesurfacesorobjectsinspacetocreatedistinctdestinationsthatserveaslightedgoalsforpeopletomovetowards.Thechoreographyintentcanbefurtherclarifiedbyaddingsymbolstorepresentthelocationofapersoninteractingwiththespace.Figure17.9showsthesesymbolsasblueconesindicatinggoalsfordirectingtheattentionandmotionofavisitor.Thisprocessofcreatingapathhelpstoidentifywhatitisthatshouldbelightedinordertodrawapersonthroughthespace.Lightcanberenderedontoonesurfaceafteranotherinsequencetomaphowthelightedsurfacesencourageapersontoflowthroughthespace.

Figure17.9Conesofviewanddescriptionsexplainhowweintendtouselighttoleadavisitorfromonespacetothenext.

TheadditionofdescriptionstofurtherarticulatethegoalsofthechoreographylightingingredientsroundsoutthisfirstphaseofLightMapping.

Layer2:LightMappingMoodandEmotionalEffectCreatingalightmapofdesiredmoodandemotioninaspacecanbeas

simpleasidentifyingdescriptivemoodwordsforeachspaceorareaofaproject.This“MoodMap”canbecreatedbydrawingborderstodefinespacesofuniqueuseandlabelingeachwithafewdescriptiveterms.Thinkintermsoftheoverarchingprojectmoodaswelleachindividualspace.Projectgoalsmaycallforspacestoimpartavarietyofmoods;calm,welcoming,relaxed,professional,sterile,cold,etc.Thegoalistothentranslatethesemooddescriptorsintovariouseffectsorcharacteristicsoflight.Themooddescriptorswillinformdecisionsaboutintensity,color,texture,shapeandoriginofthelight.

AswitheachoftheFiveLayers,itisadvisabletoapplyeachlightmapasaseparatesheetoftranslucentvelumortracepaperoverthepreviousLightMapsinastackingmanner,soadesignercanseewheredifferentlightinggoals

overlapandsupportone-another.

Layers3,4and5:LightMappingVisualInterest,ArchitecturalDefinitionandTaskLighting

OnceLightMapshavebeencreatedtosuccessfullyrepresentchoreographyandmood,theLightMapprocessisimplementedfortheremainderofthelightingthoughtlayers.Thethird,fourthandfifthlayersidentifiedintheFiveLayerProcessshouldideallybestudiedandrenderedontoalightmapindividually.Asadesignergainsexperiencewiththeprocessesandtools,itmaybecomesecondnaturetotacklemanylayersatonce.

Howevertheprocessisarticulated,thedisciplineisalwaysfocusedonthetwocorehabitsofvisualizinglightedsurfacesandobjects-notluminairesandlamps-anddrawinglighttocreatevisualrepresentationsofconcepts.TheLightMapprocesscanbeimplementedmanydifferentways,butthefinalresultshouldbeavisualrepresentationofaprojectshowingallofthelightthatwillbeadded.

Awell-executedLightMapprocesswillcreateavisualroadmaptowhichlamps,luminaires,controlsandotherlightingsolutionscanbeeasilyappliedto“solve”thedesiredlightingevents.Beforemovingon,taketimetoreviewalloftheaspectsoftheprojectprogramandwhethertheyhavebeenthoroughlyaddressedbytheseconceptandgraphicprocesses.EffortspentontheLightMapprocesswillpayoffinspadesasdesigndevelopmentrapidlymovesintothe“solution”phaseoflightingcalculationsandequipmentselectionandplacement.

Figure17.10Acompletedlightmapofaresidentialfloor.

Thegoalofthelightmapistocommunicateideastoothersandtocreateavisualmapoflightthatwillhelptomakeluminairedecisionseasier.Ifthelightmapisthorough,withbold,cleargraphicstorepresentlight,itsetsthedesignerupnicelytomoveforwardandmakequickworkoflayingouttheluminairesthatwillcreatethelightingevents.

Chapter18LightingUnitsandMeasurements

Uptothispoint,wehavemanagedtoexplorethedepthsoflightingdesignconceptandapplicationwithouthavingtoburdenourselveswiththespecificsoflightingscienceandthesystemsofunitsandmeasurementsthatgowithit.Inordertospeakknowledgeablyaboutlightingeffectsandlightingsolutions,itisnecessarytohaveabasicunderstandingoflightlevelsandhowtheytranslatevisually.Inordertoengageinthisdiscussion,wemustfirsttakealookatlightingscienceandsomeofthefundamentalbuildingblocksoflightingmetrics.Thiswillhelpusnotonlycommunicateourlightingideasmoreprecisely,butwillalsoallowustorecognizeappropriatetoolsandtacticsastheyarepresentedbyothers.

Whenwegoontodiscusslightlevelsindesign,wealmostalwaysrefertothelightingunitofthefoot-candle.Afoot-candleisameasurementofIlluminancecastontoasurfaceinaspace.Theunitofthefoot-candleis,indeed,basedonthelightproducedontoanobjecta“foot”awayfromaveryspecialcandle.Wehoweverarenotreallyconcernedwithwhatafoot-candleis,butratherwhatdifferentilluminancelevels,expressedinfoot-candles,looklike.Let’sstartwiththebasics.

IT’SALLABOUTTHELUMENLightcomesinpieces,oratleastweconsiderthatitdoesformostofourscienceandstudy.Scientistscallthesetinypiecesoflightphotons,andtheyexhaustivelystudyallofthewaysthatphotonsinteractwiththephysicalworld.

Inlightingscience,wearenotjustconcernedwithlightgenerically;weareconcernedwithhowthesepiecesoflightaffecthumanvision.Ourvisualsystemismoresensitivetosometypesoflightthanothers,sowemeasureaunitoflightenergyasitaffectsthesensitivityoftheconesandrodsinthehumaneye.Wecallthesemodifiedpiecesoflight“lumens.”Thelumenisthebasisofalllightingstudy,andwecanalwaysbesafetalkingaboutlightintermsoflumens.Westudythreecommonwaysthatlumensinteractwiththe

environment:Westudythenumberoflumensontoor“striking”asurface;calledilluminance

Westudythenumberoflumensoffoforleavingasurface;calledexitance

Westudylumensoflightleavingasurfaceorsourceinaspecificdirectionwithaspecificdensity;calledluminance

Whenwetalkaboutlightingeffects,wegenerallytalkaboutlightdensity,and,thereforewetalkabouthowmanylumensareactingperarea.Anunfortunatepartoflightingscienceisthatwehavecomeupwithdifferentnamesforthemeasurementsoflightinteractingindifferentways.Figure18.1showsthethreeinteractionsaslumensoflightstrikeandreflectoffofasurface.

Figure18.1showsthatilluminanceandexitancearebothmeasurementsoflightdensity;specifically,ameasureoflumenspersquare-foot.Thedifferencebetweenthetwophenomenaissimplywhetherthelightisstrikingasurface(illuminance),orleavingasurface(exitance).

Luminance,however,isamorethoroughmeasurementofhowdenselylightisleavinginaspecificdirection.

Tocompletelyunderstandthenuancesofthesethreemethodsofmeasuringlight,wewillelaborateonthemhere.

Figure18.1Thetwocommonwaysweconsiderlightinteractingwithsimplesurfaces.

Illuminance:

Illuminanceisthemeasurementoflumensoflightstrikingontoasurface.

Illuminanceismeasuredandexpressedinfoot-candles(FC).

1foot-candleistheequivalentof1lumenoflightdistributedevenlyontoa1squarefootsurface.

Figure18.2Diagramofonefoot-candle(densityoflightontoasimplesurface).

Exitance:Exitanceisthemeasurementoflumensoflightleavingasurfaceorsource.

Exitancesimplyaccountsforthetotalnumberoflumensleavingandgivesnoinformationaboutthedensityordirectioninwhichthelightisleaving.Theexitanceofareflectivesurfaceistheilluminanceontothatsurfacemultipliedbythereflectanceofthesurface.Ifasurfaceis50%reflective,theexitanceoffofthesurfacewillequalhalfoftheilluminanceontothesurface.Inthecaseofalightsource,theexitanceisthesheernumberoflumensthatthelightsourceiscreatingandemitting.

Exitanceisseldomusedtodescribelightlevels,butunderstandingitisusefulforvisualizinghowlumensinteractwithsurfacesandobjects.

Luminance:Luminanceisthemeasurementofaspecificdensityoflumensoflight

Figure18.3DiagramofCandle-power(densityoflightleavingalightsource

leavingasurfaceorsourceinaspecificdirection.Itdescribeslighthowanobserverexperiencesitandexplainsourinstinctiveundertandingtheintensityoflightonasurfacediminishesasthatsurfacegetsfurtherfromthelightsource.

Luminanceismeasuredandexpressedincandelaspersquaremeter(CD/sq.M).

Inordertounderstandwhatluminancerepresents,itisnecessarytounderstandwhatacandelarepresents.

Thecandelaistheunitoflightdensity.Itisausefulwaytoexpresshowdenselylightleavesasourceorsurface.Onecandelaistheequivalentoflightleavingasourcewithadensityofonelumenper“steradian,”ofsphericalarea.Asteradianisacontouredareamadeofaportionofasphere.Theareaofasteradianissuchthattherearealways4Π(fourpi,or12.56)steradiansinanysphere.Thusinthecaseofaspherewitharadiusof1ft.(andthusatotalsphericalsurfaceareaof4Π),eachsteradianis1sq.ft.inarea.Asaspheregrowslarger,thesizeofasteradiancarvedfromthespheregrowslargerexponentially.Figure18.3showstwodifferentspheresandonesteradianofareacarvedoutofeachofthem.Becauselightspreadsoutsphericallyasitleavesitsorigin,thesamenumberoflumenspassesthrougheachsteradiandespitetheareadifference.But,anobjectoffixedsizereceivesfewerandfewerlumensasthedistanceincreasesandlightspreadsout.

Thiscandelaoutputisveryusefulfordescribingdirectionallightsourceslikeaccentluminairesthatdirectfarmorelightforwardthanofftothe

side.Knowingthecandelavaluethatcomesfromthecenterofanaccentluminaireisusefulforcalculatingtheilluminancelevelthatwilloccuratapointonasurfaceorobjectduetothatspecificluminaire.

Thenatureofthecandelameansthattheluminancevalueexhibitedbyalightsourceorsurfacediffersbasedontheanglefromwhichthesourceorsurfaceisbeingviewed.Itisluminancethattheeyedetectsandusesasthebasisfordecisionsaboutsourceorsurfacebrightness.

Althoughwehavecraftynamesforalloftheseinteractionsandtheirunits,themostimportantandcommonly-encounteredinlightingdesignisilluminanceexpressedinfoot-candles.Thisexpressionoflightontoobjectsiseasytomeasureandhelpsustounderstandthelevelsofcontrastwecancreateinanenvironment.Illuminancevaluesontoasurfaceareindependentofthecolororreflectanceofthesurface,soanilluminancevaluealonedoesnotindicatehowanobjectwilllook.Ablackobjectandawhiteobject,sidebysideonatable,maybeexperiencingthesameIlluminancelevelfromtheluminairesabovethem.Thedrasticdifferenceinappearancebetweentheobjectsisaproductoftheirreflectance.Tosuccessfullyvisualizeasituation,wemustbetoldthereflectanceoftheobjects(valuesandcolors),aswellastheIlluminancelevelontotheobjects.Thisgivesusenoughinformationtointerpolatetheexitancefromtheobjects.Ifwealsoknowthetextureofthebooksandhowtheywilldirectreflectedlight,wecanestimatetheirluminance,whichismuchmorecloselyrelatedtoourdescriptionofobject“brightness.”Itisworthnotingthatallofthesemeasurementsoflightdonotdictateobjectivelyhowbrightasurfacewillappear.Brightnessisajudgmentmadebyaviewerandisdependentontheadaptationoftheviewerandthecontrastoftheenvironment.

Inallthreeofthesecasesoflightingmeasurement,wearetalkingaboutlumensinteractingwithobjects,soifallelsefails;itisalwayssafetodescribelightaslumens.

Chapter19UnderstandingIlluminanceLevels

Lightismostcommonlydescribedbyhowmuchwedetecttobeleavingasurfaceandstrikingoureyes.“Brightness”isagenerictermforthisphenomenon.Oddly,inlightingdesignstudy,wemorecommonlydescribethequantityoflightstrikingasurface.Veryoftenthisisbecausewearediscussinglightquantitiesastheyareneededtoperformvisualtasks.Thesevisualtasksinvolvematerialsofvariousreflectancesthatcreatecontrast.Thisquantificationoflight“onto”asurfaceiscalledIlluminance.Andwhenwegetscientificaboutquantitativelightingstudy,ourdiscussionswillrevolvearoundmeasurementsandexpressionsofilluminance.Therefore,wewillcommonlyexpresslightlevelsintermsoffoot-candles(theunitofmeasuringIlluminance)incident“onto”asurface.

ThestudyofspecificquantitiesoflightdesiredisanaturalprogressionoftheLightMapprocess.Whenwestartaddressingeachindividuallightedsurface–especiallyaccentedsurfaces(Layer3),ortasksurfaces(Layer5)–wewillneedtoidentifyspecificilluminancelevelsthatwewanttoprovidesothattheseaccentedsurfacesstandoutfromtheirsurroundingenvironmentandsothatthetasksurfacesreceiveenoughlighttoperformthevisualtaskathand.

ILLUMINANCELEVELINTUITIONThereisawealthofpublishedinformationaboutwhatspecific

illuminancelevelsareappropriatetoprovideontosurfacestoaccommodatedifferenttypesofvisualtasks,andmanypeopleusetheseguidelinesasthebasisoftheirdesign.Adheringtoprescribedilluminancelevelsfortasksandneglectingthelightingeffectofawholespacecan,however,leadtoaveryone-dimensionalexperience.

Becauseweareafteramuchmoreholisticapproachtoourdesign,weareinterestedinanintuitiveabilitytovisualizedifferentIlluminancelevelsandwhattheyrepresent.Thoughprescribedilluminancelevelsarereallyintendedonlyto

beconsideredforaspecificsurface,adesignercanputIlluminancelevelstogoodusebyutilizingthemtodescribetheoverall,ambientglowofaspacewheremanysurfacesareexperiencingasimilarilluminancelevel.Thisistechnicallyanabuseoftheintentionofilluminancelevelprescription,butissuchausefulwayfordesignerstocommunicatelightingintentionthatwetaketheliberty.Whenonedescribesanentirespaceasexhibitingan“average”illuminancelevel,onemustaccountforcontrast,accent,andareasofhigherandlowerlightlevelswithinit.

Assembledhereisashortlistofilluminancelevels(expressedinfoot-candles)thatcanhelpadesignertovisualizewhatthesedifferentlightlevelscanmeantoadesign.Asyouconsidereachspacetype,closeyoureyesandvisualizethespacedescribedifitwerelightedfairlyevenly.Whatyouarevisualizingonthesurfacesofthespaceislikelytheilluminancelevellisted.Rememberthisisnotalistofrecommendations,butratherareferenceforvisualizing.DesignedSpace illuminanceLevelFullMoonLight 0.1Foot-candleExteriorParkingLot 1.0Foot-candleDim,romanticrestaurant 5.0Foot-candlesComfortableLivingRoom 10-15Foot-candlesResidentialden/study 20-35Foot-candlesClassroom/OpenOffice 50-70Foot-candlesLaboratory/ExamRoom 100Foot-candles

ItisuncommontolightanentireinteriorspacetoIlluminancelevelsbeyond100foot-candles.Oncewestartdealingwiththesehigherilluminancelevels,weareusuallytalkingaboutlightthatwouldbeappliedtosmallareasoflocalizedtask.Wemayprovide200foot-candlesoflightontoanoperatingtableoranaccentedobject,butitisunlikelythatwewouldlightanentirespacetothislevel.

ADDINGILLUMINANCEVALUESTOALIGHTMAPKeepingtheselightlevelsinmindwhiledesigninganddiscussinglight,willprovidealloftheintuitiveknowledgeneededtoengageindiscussionsoflightlevelsforbasicspaces.Withjustthissmallamountoffamiliarity,onecanstartaddingthesevaluesastargetsforspecificsurfacesandwholeroomeffectsin

designedspaces.Thesuggestedprogressionofdesignistolabelthesewholeroomand“specificsurface”IlluminanceleveltargetsasapartoflightmapLayer5(SeeCh.4).Illuminancelevelsarebestusedtodescribethequantityoflightcastontoasurface,buttheycanalsobeusedtogiveanimpressionoftheoverallambientglowthatonemayperceiveinaroom.Thiscanbeputtousebymentallywalkingthroughthedesign,roombyroom,determiningtheoverallambientglowthatisdesiredforeachroom.

Figure19.1Addingambientilluminanceleveltargets(shownhereingreen)helpstorefinedesigngoals.

Inresidentialsettingsthisprocesscanbehandledveryeasily.Forspaceslikeresidencesthatdon’thavetosupportcriticaltasks,itissafetousealimitedrangeofilluminancevaluesbetween5and35Foot-candlesastargetsforwholeroomambience.Youcanreferencethetableabovetoseethatthesevaluescovermostofthemoodsandenvironmentswetrytocreateinaresidentialsetting.Theseilluminancelevelscanalsoserveastheoverallambientglowforspaceslikerestaurants,galleries,hospitalityandmuseums.Formoretaskorientedspaces,likeopenofficeareas,classrooms,civicandconferencespaces,averageilluminancelevelsinthe35to55Foot-candlerangetendtobecommon.Whenvisualtasksareacriticalcomponentofthelightingdesignprogram,adesignerisadvisedtoconsultmoretechnicalreferencematerialforIlluminancelevel

recommendationsontospecifictasksurfaces.Theilluminanceguidelinesaboveareagrosssimplificationofatopicthat

encompassesmuchstudyandengineering.Forourbasicunderstandingandabilitytovisualize,thesenumberswillsuffice.

Itisimportanttorealizethatwholeroomilluminancelevelsarejustreferencetargetsoffwhichtobuild.Thehopeisthatallofthespecifictaskandaccentlightingthatgetsaddedtothespacewillinter-reflecttocreatethisglow.Ourdesignprocedureinnottocreateanambientlightlevelfirst,andaddaccentortaskaffectslater.

Wedefinelightinggoalsforspecificsurfacesandobjectsfortaskandaccentfirstandthenassesstheeffect.Onlyafterwehavedonethis,dowedesignlightingintendedtoincreaseambientlightlevelsorperceivedbrightness.

AsilluminanceleveltargetsfindtheirwayontotheLightMap,designerswillfindtheirlightingdesignfallintoplacemucheasier.

LIGHTINGFORVISUALINTEREST:THE“2X”RULEAsdesignersprimarilyinterestedinaddingimpactandemotiontoourenvironments,muchofwhatwelightareaccentedsurfacesandobjectsthatmuststandoutfromthesurfacesaroundthem.Whenwepaintlightontoobjectswiththeintentofdrawingattentiontothem,itishelpfultoidentifyspecificlightleveltargetstomakesuretheimpactofdesignstaysintact.

Nowthatwehaveabasicunderstandingofwhatilluminancelevelsmean,wewillintroduceausefulrule-of-thumbfordesigningaccentandfeaturelighting.Wecallthisrulethe“2times”contrastrule,andweuseitfrequentlyforcreatingaccentsandvisualinterest.Theruleisbasedonfundamentalvisionsciencethattellsusthatanobjectmustbetwiceas“bright”asasurfaceadjacenttoittoappearnoticeably“brighter”.Whenwelightanobjectorsurfacewiththeintenttomakeit“pop”orserveasafocalelement,weimplementasimpleversionofthistheorybyilluminatingtheaccentedobjectwithatleasttwiceasmuchlightasthesurroundingenvironment.Thissimplifiedsolutionofaddressingonlytheamountoflightcastontoanobjectignoresthereflectanceandcoloroftheobject,butitisagoodstartingpoint.Therearemorecomplexramificationsofthisrulethathavetodowithobjectcolor,andreflectance,butforourdesignpurposes,wecansafelyrelyonthebroadversionofthisrule.Generally,themorelightwecastontoasurface,thegreatertheaccentedeffect.

Theotherendofthecontrastrulecomesfromthedesiretonotcreatetoohighalevelofcontrastthatmightbetranslatedasglare.Toavoiduncomfortable

glareandexcesscontrast,weavoidlightinganobjecttobemorethan5timesasbrightasthesurroundingenvironment.

Sothe“2times”contrastrulereallybecomesthe“2to5times”contrastrule.Wesaythatforcreatingvisualinterestindesignedspaces,wewanttolightourobjectstobetwiceasbrightastheirsurroundings,butnotmorethan5timesasbright.Weaccommodatethisinaverysimplifiedmannerofilluminatingobjectstotwotofivetimestheilluminanceofthesurroundingenvironment.

Theeffectsofthisrulecanbewrittenontothelightmaptofurtherclarifythelightingdesignintent.Theprocessisassimpleasidentifyingtheobjectsandsurfacesonewantstouseasfocalelementsineachspace.Becausethedesignerhasalreadyassignedadesiredambientglowtothesespaces,he/shehasanilluminancevaluetouseasthebasisforthe“2to5times”contrastrule.Mentallywalkthroughthedesign,spacebyspace,andidentifyobjectsandlabelthemwithatargetaccentilluminancelevel.

Anexamplemightbeadiningroomwherethedesignintentioncallsforaminimumambientglowofthespacetobearound10foot-candles.Usingthe2to5timesrule,weseethatouraccentedobjectsshouldbeilluminatedtolevelsbetween20and50foot-candles.The“2to5times”rulerequiresthatwehavefirstestablishedanambientilluminancelevelwithwhichtowork.Thisiswhywewentthroughtheprocessoftargetingoverallambientilluminancelevelsforthewholespace.Thesetwosimplestepsofdefininganambientglowforaspacefirstandthenusingthatasthebasisforaccentsarequickandeffective.

Figure19.2Establishingambientilluminanceleveltargets(ingreen)allowsadesignertogobackanddefineareasofheightenedlightlevels(inpink).

Howwewillactuallygetthelighttherecanbeworkedoutlater.Fornow,wearesimplyaddingmoreinformationtoourLightMaptomakeitincreasinglyeasierforustolocateandselectluminaires.

IESILLUMINANCELEVELCRITERIAAmorespecificwaytoarriveatilluminanceleveltargetsforspecifictasksandcriticaleffectsistousethewell-establishedsystemputforthbytheIlluminatingEngineeringSocietyofNorthAmerica(IESNA).TheIESNAisascientificbodydedicatedtothestudyoflightinganditseffectsonhumanvisualperformance.TheIESNAhascommittedsignificantresourcestothestudyofilluminancelevelsontotasks.

RememberthatIlluminancelevelsaredescriptionsofhowmuchlightweareputtingontoanobject.Illuminancelevelsdon’taccountforreflectanceorhowlightwillleaveasurface.Thislimitstheirvalueintryingtodescribehowasurface,objectorspacewilllook.

Illuminancelevelsareexceptionallyusefulwhendeterminingappropriatelightlevelsfortasks.Thisworksprimarilybecausevisualtasksinvolveobjects

withknownreflectances.Ifweknowthereflectanceofthematerialsinvolvedinatask,itissafetoprescribeaquantityoflightthatshouldbecastontothetasktocreatethenecessarycontrast.Reading,forexample,involvesdarktextonlight-coloredpaper.Aswecastmorelightontoareadingtask,thelight-coloredpaperreflectsmorelightbackatus,whilethedarkinkcontinuestoreflectverylittle.Inthismanner,thecontrastbetweenthetwoincreases.ThisisthefundamentalbasisforthelonglistofIlluminancevaluesthattheIESNAprovides.TheIESNApublishesabookthatcategorizesavarietyoftasksarticulatedwithavarietyofmaterials.Foreachofthesetaskandmaterialcombinations,theIESNAprovidesarecommendedIlluminancelevel.IESNAliteraturecanbeorderedfromwww.iesna.org.

TheIESNArecognizesthattherearemanyfactorsthatdictatewhatisappropriatelighting.AnothersignificantaspectoftheIESNAilluminanceselectionprocedureistheassessmentofthedesignedspaceandconsiderationforalloftheothervisualperformanceissuesthatmustbeaddressed.Thisincludesconcernslikecolorrendition,evenness,andglare.Itishelpfulforadesignertodevelophis/herownlistoflightingissuesandconcernsliketheonepresentedinFigure19.3.Ratingtheimportanceofeach-onascaleofonetoten,say-canaddevenmorevaluetosuchalist.

Figure19.3Alistoflightingconcernsthatshouldbeconsideredforeveryproject

TheIESselectionprocedurecancertainlyhelpadesigneravoidunder-lightingcriticalsituations,butitisreallyintendedasaproceduralguideforvisualtasks(thefifthlayerofour5-layersystem).

Forvisualeffect,aesthetics,mood,andspatialorganization(The

remainingfourlayersfromour5layersystem),intuitionandexperiencewillserveusbetterthanexactnumbers.Thisisthereasonwehavegonetogreatlengthstovoyagethroughathoughtprocessthatleadstounderstandingandintuition,beforedivingintoquantification.Illuminancevaluesareawelcomelevelofinformationtoaddtoourdesignintent,buttheyareonlyonepartofamuchbiggerpicturethathasitsfoundationinvisualizationandgraphicrenderingoflightingconcepts.

Remembertovisualizelightingeffectfirstandthendrawanddescribethelightingeffect.Onlyifthedesignerfeelstheneedtofurtherarticulatedoeshe/sheneedtomoveontospecifyingtargetIlluminancelevels.Weaddthesevaluestoourlightmaptoclarifyourintentandmaketheselectionandplacementoflightingequipmenteasier.Iftargetingaspecifictaskoraccentlightleveldoesnotservetoprogressourdesign,itisnotworthtakingthetimetoidentify.

Chapter20LightingCalculations

Itisimperativebeforedelvingintotheworldoflightingcalculationstostepbackandrememberthereasonforusingcalculationsindesign.Weusecalculationstohelpusarriveatspecificsolutionstocriticallightingchallenges.Ifacalculationwillhelpusselectaluminaire,andapplythatluminairetocreatethelightingeffectweareafter,wewelcomeit.Itisimportantnottorelyoncalculationstooheavilyastheyaremerelyasupplementtogoodlightinginstinctandexperientialknowledge.Itisalsoimportantnottoassumethateverylightingelementwearedesigningcanbenefitfromperformingacalculation.

Lightingcalculationscanassistusinselectinglampsandluminaireswhenwearetryingtoobtainaspecificlightlevel.Lightingcalculationsalsohelpuspredictthelightingeffectwemaygetfromaspecificlightingscenario.

Wewillinvestigatetwolightingcalculationmethodsthathelpusintwotypesoflightingsituations:LumenMethodCalculationsandPointCalculations.

LumenMethodcalculationsareusedfordeterminingaveragelightlevelsinlarge,openareas.

PointCalculationsareusedfordetermininglightlevelsataspecificpointonanobjectorsurface.

Thesetwocalculationscoverthetwoendsofthedesignspectrum:broad,spatiallightlevelsandminute,point-specificlightlevels.

Tounderstandhowwemakeuseoflightingcalculations,wemustfirstinvestigatemorespecificallythewaywecountandmeasurelight.

Inthecaseofbothtypesofcalculations,wewillbeusingIlluminanceasourmeasurementoflightlevel.Illuminanceis,ofcourse,themeasureoflightfallingontosurfaces.Specifically,illuminanceisthemeasureofthenumberoflumensthatarefallingontoasquarefootofarea,whichisthedefinitionofafoot-candle,theunitofmeasurementofilluminance.Afoot-candleisonelumenoflightreceivedevenlyoveranareaof1squarefoot.

Figure20.1Onelumenontoaonesquare-footarearepresentsonefoot-candleofilluminance

Figure20.2Tenlumensontoa10square-footareaisalsorepresentsonefoot-candleofilluminance

LUMENMETHODCALCULATIONSFORLARGE,OPENAREASThelumenmethodofcalculatinglightlevelsisreallynotacalculationall,butratheranextrapolationoftheunitdefinitionofthefoot-candle.Whenwedissectthefootcandle,weseeitissimplyameasurementoflightdensityinlumenspersquarefoot.

1Foot-candle=1Lumen÷1squarefootor

1FC=1Lm÷1sq.ft.

Therefore,wecangeneralize

Illuminance=Lumens÷area(insquarefeet)orwecanexpressitasmathematicalabbreviations

E=Lms÷A(sq.ft.)PuttingthistogethertellsusthattocalculatetheIlluminancelevelontoasurface,wesimplycountupthenumberoflumensfallingontothatsurfaceanddividebytheareaofthesurface.Inthecaseofawholeroom,thatsurfacewouldlikelybethefloor,oranimaginaryworkplaneabovethefloorattaskheight(oftenassumedtobe30”).Abasicsituationwherewewanttopredictlightingeffectmaylooklikeexample1.

LumenMethodExample1:SolvingforIlluminancelevelImaginearoomthatis10’×15’,with5downlightsplacedevenlyaroundtheroom.Eachdownlightemits1000lumens.Ifweimaginethatall1000lumensfromeachluminaireenduponthefloorofthespace,whatilluminancelevelcanbeexpectedontothefloorinthisroom?

Figure20.3A10’by15’floorlightedby5downlights.

Weknowthatthesolutiontoaproblemlikethisistosimplycountupthelumensthatmakeittothesurfaceinquestionanddividebytheareaofthesurface.Usingthebasicequation

Illuminance=Lumens÷areaor

E=Lms÷AWepluginthevaluesweknow.Theareaoftheflooris

A=10’×15’=150squarefeet.Thetotalnumberoflumensthatmakeittothefloor“Lms”

1000Lumens×5downlights=5000lms.Sotheequation

E=Lms÷Abecomes

E=5000Lms÷150sq.ft.or

E=33.3Lmspersq.ft.or

E=33.3Foot-candles(Similartotheilluminancelevelwemightpictureonthedeskofahomeofficeorlibrary).

LumenMethodExample2:SolvingforLumensorLuminairesNeededWetendtousetheLumenMethodCalculationmorefrequentlyforfiguringouthowtodeliverlighttoprovideadesiredilluminancelevel.Inthesecases,weusethissameequationflippedaround.

Illuminance=Lumens÷Areabecomes

Lumens=Illuminance×Area

ormorespecifically

Lumensneeded=Illuminanceleveltarget×Area(insquarefeet)

Abasicsituationwhereweneedtosolvealightingchallengemaylooklikethistwo-partprocess:Giventhesame10’×15’room,wewouldliketolightthefloortoanaverageilluminancelevelof60foot-candles.Howmanylumensneedtomakeittothefloorsurface?

Figure20.4Howdowedeliverthedesiredilluminanceleveltoa10’by15’floor?

Weuseourbasicequation

Lumensneeded=Illuminancetarget×Areaorsimply

Lumens=Illuminance×Areaor

Lms=E×AWepluginthevaluesweknow.

Ourilluminancetargetis

E=60foot-candles.Ourareais

A=10’×15’=150squarefeetSotheequation

Lms=E×Abecomes

Lms=60fc×150sq.ft.or

Lms=9000LumensWeneedtointroduce9000functionallumensoflightontothefloortogettheaverageilluminancelevelweareafter.

Howdowegetthose9000functionallumensontothefloor?Weneedtodeterminewhatquantityandtypeofluminairecanaccomplishthisgoal.Hence,thecalculationhastwoparts.Inordertoanswerthequestionofhowmanyluminairesweneed,weneedtoknowthelumenoutputofthoseluminaires.Forthisreason,mostluminairemanufacturersprovidecut-sheetsthatprovidethisinformation.Forthisexample,wewillassumethatwehavefoundaluminairethatemits550lumensandthatalloftheselumenswillmakeittothefloorinthespace.

Ifweweretousealuminairethatprovides550Lumensontothefloor,howmanyluminaireswouldweneedtoevenlyplaceinthespace.Thisquestiontranslatestoasimpleequation:

Luminairesneeded=Lumensneeded÷Lumensperluminaire

Wesolvethisbyplugginginwhatweknow

Luminairesneeded=9000Lumensneeded÷550Lumensperluminaire

soouranswer

Luminairesneeded=16.36getsroundedupto

Luminairesneeded=17Sowehavedeterminedthat17ofthesespecificluminairesspacedevenlyinthe150square-footspacewillyieldusthe60foot-candlesofaverageIlluminanceontothefloor.

LumenMethodRealityChecksWhenweperformlumenmethodcalculationsforcriticalsituations,itisimportanttoaddintwofactorsthatmakeourcalculationsmuchmorerealistic.Thefirstofthesefactorsisasafetyfactor,or“maintenance”factorcalledthelightlossfactor,or“LLF.”Thesecondfactoristhecoefficientofutilization,or“CU.”

LightlossfactorLightlossfactorisawaytoaccountforthefactthatthelightperformance

ofourlampsandluminaireswilldeteriorateovertimeforanumberofreasons.Thelightlossfactoraccountsforlampsgettingdirtyandthusemittinglesslightovertime.Italsoaccountsforlossinperformanceofballastsandtransformersoverthelifeoftheluminaire.Thereisanarticulatemethodofcalculatingeachofthesecontributingfactors,butitiscommontouseanindustrystandardgenericvalueof0.85foralightlossfactor.Thismeansthatweperformcalculationsexpectingonly85%ofthelightfromourlightingsystemtobeworkinginthespaceasthesystemages(Inexceptionallydirtyspaceswedeterminethisvaluemorecarefully).Thisassumptionpushesustodesignnotforhowwewantasystemtoperformondayone,butratherforhowwewantthesystemtoperform2or3yearsdowntheroad.Justasanarchitectover-designsthekeystructuralelementsofabuilding,thelightingdesigneroverdesignstomakesurethataspacewillperformasintendedwellintothefuture.

CoefficientofutilizationTheotherwaytobringthesimplelumenmethodcalculationcloserto

realityistoaccountforhoweffectivelytheluminairesareworkingwiththesurfacesofthespacetodeliverlighttothetargetsurfaceinquestion.Ifweareconcernedwiththelightlevelonafloorplaneandweareimplementinganindirectlightingsystemthatdeliverslightupwardontotheceilingwhereitthen

isreflecteddownward,itissafetosaythatsomeofthatlightwillbeabsorbedbytheceilingandwallsandlostbeforeitmakesittothefloor.Indeed,itisrarethatthemajorityofthelightfromaluminaireisdirectedimmediatelyontothesurfacewithwhichweareconcerned.Itisalsoimportanttoaccountforthegeometryandreflectancesoftheroomsurfaces.Roomsurfacegeometryandreflectancewilldeterminehoweffectivelylightinter-reflectstoreachthesurfaceinquestion.Weaccommodateforluminaireorientation,roomgeometryandsurfacereflectancebyincludingafactorthattakesintoaccounttheserelationshipsineachspecificsituation.Wecallthisfactorthecoefficientofutilization,orCU.TheCUisexpressedasadecimalnumberorapercentagetorepresenthoweffectivelyourlightingsystemisbeingutilized.Themoredirectlyourluminairesarebeingutilizedandthemorefavorablethegeometry,thehighertheCU.Insituationswherelighttakesaveryindirectpathtothesurfaceswearecalculating,theCUislower.

Figure20.6LightdeliveredwithahighCoefficientofUtilization(left)andlightdeliveredwithalowCoefficientofUtilization(right).

Thereisaverytediouswaytoaccuratelycalculatethecoefficientofutilizationthattakesintoaccountroomgeometry,surfacereflectancesandluminaireplacement.Forourpurposes,wewillrelyonafewballparknumbersthatwillsimplyaddtotheusefulnessofourlumenmethodcalculations.Likethelightlossfactororanyothersafetyfactor,weincludethesenumbersinourcalculationstomakesurethatweareoverdesigningandaccommodatingfornon-idealconditions.ThelistbelowshowsCoefficientofUtilizationvaluesthatwouldbeappropriateinacalculationwhereweareconcernedwithanilluminancelevelonthefloororahorizontalworkplane.Thevaluesalsoassumethatthespaceinquestionconsistsoffairlyreflectivesurfaces:

LumenMethodCalculationswithSafetyFactorsBothofthefactorsdiscussedheresimplygetinsertedintoourequationstoconvinceustousemorelightor,conversely,toexpectlesslightfromourlampsandluminaires.

Thiscreatesamoreaccurateandusefulequationforpredictinglightingeffect.Withtheadditionofthelightlossfactorandthecoefficientofutilization,ourlumenmethodcalculationgoesfrom:

Illuminance=Lumens÷Areato

Illuminance=(Lumens×LLF×CU)÷AreaOurformulafordetermininghowmuchlightweneedtointroduceintoaspacegoesfrom:

Lumensneeded=Illuminancetarget×Areato:

Lumensneeded=(Illuminancetarget×Area)÷(LLF×CU)

Oftentimes,whenweareafteraverybasiccalculationandwedon’twanttonumericallyincludethesetwofactors,werefertothelumensinourequationas“functionallumens,”thatis,lumensthatweknowarebeingutilizedtoputlightontothetaskwithwhichweareconcerned.Inthismanner,wecanusethebasicversionsofourequations,withoutthesafetyfactors,butdescribeourresultsintermsofhowmany“functionallumens”wewouldneed,orhowmany“functionallumens”weareproviding.

Regardlessofwhetherweusethesimplifiedequations,orwhetherweincludethetwosafetyfactors,itisimportanttorecognizewherelumenmethodcalculationsareviable.Inorderforan“averageilluminancelevel”tobemeaningful,thespaceorsurfaceinquestionmustactuallyhavean“averageilluminancelevel.”

Sothelumenmethodcalculationisreallyonlyvalidforlarge,openareaswithevenlightinglayouts.Thismeansthatifwehaveaspacewheretheluminairesareconcentratedanddirectedtoonearea,knowingthattheaverageIlluminancelevelontheflooris25foot-candlestellsusverylittlesincewecanplainlyseethattheroomisexceptionallybrightinoneareaandverydarkinanotherarea.

Goodcandidatesforlumenmethodcalculationsareopenofficespaces,classrooms,sportsarenas,warehouses,publichallways…anyrectangularspacewithanevenlayoutofluminairesandfewobstructions.

Whenweareinterestedinlightingeffectsontoobjectsandspecificsurfaces,weusetheotherformofcalculation:thepointcalculationmethod.

THEPOINTCALCULATIONMETHODWhenweareinterestedinilluminancelevelsthatexistataveryspecificpointonasurface,weuseasimplecalculationthattakesintoaccounthowthedeliveryoflightspreadsoutasthedistancebetweenthelightsourceandtheobjectincreases.Wegenerallyusethiscalculationforconsideringobject,accentandtasklightlevelsthatareaproductofafewspecifically-placedluminairesthataredirectingtheirlightimmediatelyontothesurfaceinquestion.Becauseofthis,thepointcalculationmethodrequiresthatwebeabletoatleastestimatethelocationofourlightingequipmentinreferencetothesurfaceandthedistanceandaiminganglebetweenthetwo.Oneofthemostcommonsituationstousethepointcalculationisinaccentingartworkorotherobjectsofinterest.

Theequationweuseforthepointcalculationmethodis,again,notreallyanequationatall,butratheranexpressionbasedontheunitdefinitionofthecandela.Candelasareameasurementoflightdensityexhibitedfromaspecificsourceinaspecificdirection.Candle-power(expressedinCandelas)isaverycommonwaytodescribethewaylightleavesdirectionalluminaires.

Whenweconsideraglowingglobe,itisfairlyobviousthatthesourcedistributeslightevenlyineverydirection.

Figure20.7Acandeladistributiondiagram(left)foradiffusesource(right).

Architecturalluminaireslikedownlights,accentluminaires,spot-lightsandwall-washershaveopticsandreflectorsthatdrivelightinaveryspecificmanner.TheCandle-powermeasurementfromaparticularluminaireisameasureofthelightdensitythataluminaireproducesinaspecificdirection.

Figure20.8Acandeladistributiondiagram(left)foradirectionalsource(right).

Therereallyisnowaytoestimatethecandelavaluescomingfromalightsourcebyobservingthesource,sothisinformationmustbegiventousbythemanufacturerofthelamporluminaire.Luminaireliteratureoftenincludesacandeladistributiondiagram.Thisdiagramgivesspecificcandelavaluesthatoccurdirectlybeneathasourceandatvariousangles.

Figure20.9Literatureforahigh-performanceluminairemayprovideacandeladiagram.

Pointcalculationsusuallyinvolveverydirectionalluminairesthatcreatepoolsorspotsoflight.Inthesesituations,wecanusuallycountonthehighestconcentrationoccurringatthecenterofthepooloflight.Thecandelavaluefromthiscenterpointhasaspecialdesignation:wecallitthe“CenterBeamCandle-Power”orCBCP.SomeluminaireandlampliteraturewillforgoacomplexcandeladistributiondiagramandsimplypublishthisCBCPvalue,assumingthattheuserisconcernedwiththebrightareaoflightatthecenterofthebeam.

Figure20.10Thehighestcandelavaluefromalightsourceiscommonlyfoundatthecenterofthelightoutput.

Thepointcalculationmethodisbasedontheprinciplethatlightspreadsoutasittravelsawayfromasource.Thisspreadoflightisexemplifiedbythepooloflightcreatedbyadirectionalluminaire.Asthedistancefromthesourceincreases,thepooloflightgetslarger,butalsogetsless“bright”becausethesamequantityoflightisspreadoutoveralargerarea.Usingthisprinciple,wecandeterminetheilluminancelevelataspecificpointbyknowingthecandelavalueofthesourceinthatdirectionandthedistanceandaiminganglefromthesourcetothepoint.Candelasareanexpressionoflightdensityorlumensperareawheretheareaisapieceofsphericalspace(seech.18).Themostimportantstepinputtingthepointcalculationequationtouseisdeterminingthedistancevalue“D”fromthesourcetotheilluminatedpointinquestion.Thisvaluemustbedeterminedandalwaysexpressedinfeetbeforeitissquaredintheequation.Theequationforastraightforwardpointcalculationlookslikethis:

Illuminance=Candelavalue÷Distance2(distanceinfeetsquared)

Or

E=CD÷D2

Theequationisbestunderstoodthroughasimpleexample.

PointCalculation:Example1:Supposewehaveanaccentluminairerecessedintoa10’-0”ceilingdirectlyaboveaplatethatisonatableat3’-0”abovethefloor.Ifthataccentluminairehasacenterbeamcandlepower(CBCP)of10,000candelas,whatilluminancelevelcanweexpectatthebrightestpointontheplate?ThisisbestexpressedasadiagramasinFigure20.11.

Figure20.11Pointcalculationsarecommonlyusedinsituationsinvolvingonesourceandoneobjectofinterest.

UsingourbasicPointCalculationequation

Illuminance=Candelavalue÷Distance2or

E=CD÷D2

pluginthevaluesweknow:center-beamcandelavalueofthesource

CD=10,000Candelasdistancesquared:The“Distance”isthedistancethelightmusttravel.Inthiscase,itisthemountingheightoftheluminaire(10ft.)minustheheightofthetable(3ft.)

D2=7feet,squared=49squarefeet(theunitsgetsquaredtoo,whichrepresentsthetranslationof

distanceintosurfacearea)Ourequationbecomes

Illuminance=10,000CD÷49sq.ft.Or

Illuminance=204Foot-candles.

Thisisahighilluminancelevel,butcertainlywithinreasonforanobjectwearetryingtoaccent.Itisalsoimportanttonotethatthisilluminanceleveloccursonlyatthebrightcenterofthepooloflightontheobject.

Wetendusethiscalculationmorefrequentlytodeducewhattypeofcandelavalue(andthereforesource)weneedtoaccomplishacertainlightingtask.Anexampleofsuchasituationmaylooklikeexample2

PointCalculation:Example2:

Supposewehaveanaccentluminairerecessedintothesame10’-0”ceilingdirectlyabovethesameplatethatisonatableat3’-0”abovethefloor.Ifwewanttoilluminatethatplateto150Foot-candles,whatkindofcenterbeamcandlepowervaluewouldweneedfromtheluminaire?Thediagramisthesame,butweusetheflippedversionourbasicequation

Candelavalueneeded=Illuminanceleveldesired×distancesquared

Or

CD=E×D2

Wepluginwhatweknow:

illuminancedesired

E=150Foot-candles

distancesquared

D2=7feetsquared=49sq.ft.

andoursolutionbecomes

CD=150FC×49sq.ft.

or

Candelavalue(typicallyCBCP)needed=7350Candelas.

Ofcoursethesecondpartofthistypeofsituationisfiguringoutwhatsortoflamporluminaireisgoingtoprovidethiscandelavalue.Wemayevendecidetousetwoluminairesinwhichcaseweneedonlyhalfofthecontributionfromeachofthem.Tofindaspecificluminaireorlamp,wesimplylookatthevariouscandelavaluesproducedbydifferentlightingequipment.Inthecaseofluminaires,thecandelavaluesarerepresentedintheformofadistributiondiagram.

Figure20.12Candeladistributiondiagramsforvariousversionsofabasicdownlight.

Whenweareusingoneofourmanyaccentinglamps,likeanMR-16orPARlamp,thecandelavaluewillusuallybeexpressedasthecenterbeamcandlepower(CBCP),tuckedinwithahostofotherinformation.

Figure20.13AccentlampliteraturecommonlydescribestheCenterBeamCandle-powervaluesofafamilyoflamps.

Pointcalculationsbecomemuchmoreusefulandslightlymorecomplicatedwhenweconsidersituationsinwhichtheobjectwearelightingisnotperpendiculartothelightsource.Inthesesituationswemustincludeabitofgeometryinourcalculationtobemoreaccurate:Ifweareaimingthelightsourceatanyangleotherthanperpendiculartothesurfacebeinglighted,weknowour“pool”oflightspreadsoutandisthereforeless“intense”.Thisisexemplifiedbytheshapethe“pool”oflighttakeson.Astheaimingangleisincreased,acircularpooloflightbecomesanelongatedandwidened“scallop”oflight.

Wemodifyourpointcalculationequationtoaccommodateforhowthegeometrywillspreadoutthelightintensity:

Candelavalueneeded=(Illuminanceleveldesired×distancesquared)÷cosineoftheangle

TheangleinquestionistheanglecreatedbetweentheaiminglineoftheluminaireandalineperpendiculartothesurfacebeinglightedasdisplayedinFigure20.14.

or

CD=(E×D2)÷cosineofangle.or,ifweusetheequationtosolveforilluminanceontotheobject,weusethis

E=(CD×cosineofangle)÷D2

Anexampleofthissituationmightlooklikeexample3

PointCalculation:Example3:Supposewehaveanaccentluminairerecessedintoa10’-0”ceilingaimedtolightacollectibleplaterestingonapedestal3’-0”fromthefloor.Toaccenttheplate,theluminaireisaimedatanangle.Aimingtheluminairecreatesanangleof30degreesbetweentheaiminglineoftheluminaireandthelineperpendiculartotheplate.Ifwewanttoilluminatetheplateto100foot-candles,whatkindofcenter-beamcandelavaluewouldweneedfromtheluminaire?

Figure20.14Apointcalculationusedtodeterminehowtolightanobjectwhenanaimingangleisinvolved.

Weusetheversionofourequationthataccountsforlightingatanangle

Candelavalueneeded=(Illuminanceleveldesired×distancesquared)÷cosineoftheangle

or

CD=(ExD2)÷cosineofangleWepluginwhatweknow:

illuminancedesired

E=100Foot-candlesWeusesimpletrigonometrytodeterminetheDistancesquared

D2=8.1feetsquared=65sq.ft.Cosineofangle=cosineof30degrees=0.87

Oursolutionbecomes

CD=(100FCx65sq.ft)÷0.87

Or

Candelavalueneeded=7471Candelas.

Throughthisexamplewecanseethatlightingatananglereducestheeffectivenessofthelightsourceimmensely.Thismakessensewhenweconsiderhowthegeometryaffectstheshapeandsizeofthepieceoflightcreated.Ratherthanadefinedcircleor“pool”oflight,theaimingangleresultsinalong,wide“scallop”.

Itisimportanttorecognizethatthischapterpresentssimplecalculationsthatignoreanyinter-reflectedlight.Inthesesituations,itisassumedthatallofthelightbeingmeasuredcomesdirectlyfromtheluminairesinquestion.

Onceadesignergetsthehangofthebasicprinciplesofthesetwotypesofcalculations,he/shewillbegintogainaninstinctforwhereeachcanbeuseful.Asmentionedbefore,itisequallyimportanttorecognizewherecalculationswillnotbenefitthedesignorhelptocreateagoodlightingsolution.Calculationsaremerelytoolstosupportandrefinethelightingconceptsthatonedrawsupashe/sheworksthroughthemoregraphicalandimaginativeprocessesthatwenowassociatewithlightingdesign.

Allofthetoolswehaveexploredthroughthissectionaregearedtowardsbringingustoapointwherewearereadytopreparedrawingsthatwilltranslateourlightingconceptsintoaconstructibleproject.Thevisualizing,thearticulating,thesketching,thedrawing,thedescribing,andthecalculatingarealltoolstomakethejobofselectingtheappropriatelightingeasier.Thenextlogicalstepistouseallofthecreativeandcalculativeinputtocreatethedrawingsanddetailsthatwillallowtheprojecttobebuilt.

PartIIIDeliverables

Chapter21DecipheringManufacturersLiteratureandLuminaireCutSheets

Beforewecanhopetomakeintuitivedecisionsaboutselectinglightingequipmenttosolveourlightingchallenges,wemustdedicatesometimetounderstandingwhattypesofluminairesareavailabletous.Lightingproducts,likemostspecificationdesignproducts,haveawealthofinformationpublishedaboutthemtohelpthedesignerdeterminewhichproductismostappropriate.Inadditiontoprintedcatalogsandwebsites,mostlightingmanufacturersemployalocalrepresentativetoservicetheneedsofthedesigner.Thisrepresentativewilltakethetimetoexplainwhyaparticularpieceoflightingequipmentmayormaynotsuitonesneeds.Themanufacturer’srepcanalsogivepricinginformationandindicateshippingleadtimesfortimesensitivejobs.Oneofthebestthingsdesignerscandotopositionthemselvesforgoodlightingknowledgeistocontacttheirlocallightingmanufacturer’srepresentativeagency.

Lightingliteraturecomesinallshapesandsizesandalllevelsofusefulness.Manufacturerspublishwhattheycall“cutsheets”tolistthevariousfeatures,optionsandcapabilitiesofalightingproduct.Firstandforemost,aproductcutsheetshouldgiveusanideaofthesize,functionandoverallappearanceofaproduct.Beyondthesebasics,thelevelofinformationprovidedbyvariousmanufacturersvariesgreatlyfromveryvaguetoverydetailed.Generally,themoretechnicallyinclinedtheluminaire,themorearticulatetheinformation.Someofourmoreexoticdecorativeluminairesprovideverylittleinformation.Inordertolearntodecipherthesemanufacturerscutsheets,wewilllookatafewexamplesandlearnhowtoidentifythekeypiecesofinformation.

Thecomplexandcrypticnatureoflightingmanufacturers’cutsheetsshouldnotpreventadesignerfromtakinguplightingasadesigntool.Ifadesignercandevelopconfidenceintheabilitytogatherinformationfromthesecut-sheets,he/shewillbewellarmedtomakeconfidentluminairedecisions.Theabilitytodeciphermanufacturers’cutsheetsisabsolutelynecessaryforproperlyspecifyingandorderinglightingequipment.

Thefollowingisalistoffeaturesthatthedesignershouldbeabletoidentifyfromacutsheetandputtogethertocreateacompleteluminaireproductnumber.Asthedesignerreadsaboutthepiecesofinformationthathe/sheislookingfor,referbacktothesamplecutsheetinFigure21.1.

PHYSICALBASICSThefirstimpressionofaluminaireshouldbeitssize,shapeandfunction.Itshouldbereadilyapparenthowandwherethisluminairewouldbemounted(surface,recessed,wall,ceiling,etc.).Iftheluminaireisrecessedintothewallorceiling,thecutsheetshouldquicklyconfirmwhethertheluminairewillfitintothespaceavailable.Oneshouldalsogetanimpressionofhowtheluminairewilllookinthespace.

Figure21.1Atypicalarchitecturalluminairecutsheet.Inthiscase,arecessedadjustableaccentluminaire.

ThecutsheetshownforreferenceinFigure21.1isforasmalladjustableaccentluminaireandincludesallofthevariousreflectorsandthevarioushousingsthatcanaccommodateit.Thisisarecessedadjustableaccentluminaire.Uponfirstglance,itshouldbeobviousthatthispieceofequipmentrecessesintotheceilingplane.Weshouldbeabletoidentifythelamplocatedwithintheluminaire,andtheangleofthelampshouldhintthatthisisanadjustable/aimableluminaire.Theotherpieceofinformationthatshouldjumpoutatusisthesheersizeofasimpleluminairelikethis.Thisrecessedaccentluminaireisagoodexampleofhowlargetheseluminairescanget.Ifwelookatthecutsheet,weseethattherearethreedifferentsizesofhousingavailablefordifferentusesofthisluminaire.

MountingStyle:Doesthisluminairerecessintotheceiling?

Doesthisluminairemounttothesurfaceofawallorceiling?

Doesthisluminairemountfromapendantorcanopy?

ThecutsheetinFigure21.1showsthreedifferenthousingtypesfordifferentconstructiontypes.Recessedluminairesoftenhavemultiplehousingoptionstoaccommodateinsulated(IC)andnon-insulated(Non-IC)plenumsituations,whichwewilldiscussbelow.

LuminaireSizeandHeight:Whataretheluminairedimensions?

Howwilltheluminairedimensionsworkinourspace?

Ifthisisarecessedluminaire,willitfitintoourceiling,wallorfloorassembly?

TheluminaireshowninFigure21.1hasanapertureofabout4”,whichisrathersmall.Therearethreehousingsavailableforthisluminaire,rangingfrom8”inheight,to11”inheight.Allthreehaveasimilarfootprintof14”x10”.Thesephysicalbasicsbegintoshowwhyitissoimportanttocoordinate

recessedluminairelocationswhenbuilding.

Aesthetics:Whatarethecolorsandfinishesavailable?

Whattrims,diffusersandaccessoriesareavailable?

ArecessedluminaireliketheexampleinFig21.1hasrelativelylittleaestheticimpressioninthespace,buttherearedecisionstobemadenonetheless.Forrecessedluminaires,wemustdecideonthecolorofthereflectorconeabovetheceilingandthetrimringthatrestsatceilinglevel.ThecutsheetinFigure21.1showsthatweneedtomakeacolorspecificationforeachofthesecomponents.BecausethisluminaireholdsanMR-16lamp,wecanalsospecifyanytypeofcoloredlensordiffusinglenstosoftenthelight.

Lightsuitability:IstheluminaireICrated(Suitableforinsulatedceilings/plenums)?

Istheluminairelistedfordamporwetlocations?

Doestheluminairedeliverthequality,color,andtextureoflightthatweareafter?

Istheluminaire/lampdimmable?

Isthesourceinstanton/off?

Doestheluminairecreateexcessiveglare?

Istheluminaireaimable/adjustable?

TheluminaireinFigure21.1isreallynothingmorethanaholderforanMR-16lamp.Assuch,thelampisgoingtodictatemostofthelightdeliveryproperties.TheMR-16lampisalowvoltagehalogenlamp,soweknowthatitisinstantonandoff,iseasilydimmable,andisaverydirectionallight.

ICratingisacommonissuethatcomesupwithrecessedluminaires.ICratingstandsfor“InsulationContact.”Itisaratingthatindicatesthattheluminairehousingiscoolenoughtobeincontactwithfiberglassandbattinsulation.Weencounterthisinsulationmostcommonlyonresidentialprojects,

sowhendesigningforaresidence,itisalwaysprudenttodetermineiftheluminairesneedtobeorareICrated.

LampandElectricalBasics:Aretheremultiplelamp/sourceoptions?

Doestheluminairerequiremultiplelamps?

Whataretheluminairevoltageoptions?

Whataretheluminairewattagelimitations(Maximumwattage)?

Doestheluminairerequireaballastortransformer?

TheluminairehereacceptsMR-16lampsupto75wattsforthenon-IChousingandupto50WattsfortheICversion.TheICratedhousinglimitslampwattagetolimitpotentialheat.BecausetheMR-16lampisa“lowvoltage”source,weknowthattheluminairerequiresatransformer.Inthiscase,thetransformerisintegraltotheluminaire.Often,aluminairewillnotincludeatransformer,andaremotetransformerwillberequired.

LightOutputPerformance:Whatisthelumenoutputoftheluminaire?

Whatistheefficacy/efficiencyoftheluminaire?

Whatisthedistributionshapeoftheluminaire?

Doesthecutsheetprovideadistributiondiagram?

Howwouldwedescribethelightdistributionshape?Spot,flood,accent,wash,spread,glow,diffuse?

TheluminaireinFigure21.1willhavethepropertiesoftheMR-16lampweputintoit.MR-16lampscomeinalldifferentbeamspreadsandcandeladistributions.Becausethelampdefinesthelightoutputproperties,wecanprobablylearnmoreaboutthisluminaire’slightperformancefromthelampmanufacturer’sliteraturethanwecanfromtheluminairecutsheet.

Regardlessofhowthoroughorlackingtheliteraturethatisavailable,

rememberthebasicsthatwillgetusmostofthewaytowardstherightproduct:Howisthisluminaireinstalled(Recessed,surface,wallmountetc.)?

Whattypeoflamp/sourcedoesthisluminaireuse?

Doesthisluminairerequirearemotedriver,transformerorballast?

Whatarethedimensionsoftheluminaire?Ifadesignercansuccessfullyanswertheprecedingquestionswhenfacedwithaluminairecutsheet,thenhe/shehasaverygoodchanceofselectingappropriatelightingequipment.Justsimplyknowingthattheinformationissomewhereonthecutsheetgivesusgreaterhopeandconfidencewhenweareporingoverluminairecatalogsandwebsites.

Chapter22SelectingLuminaires:ABasicFamily

Everylightingprojectisentirelyunique,andoverthecourseofadesigncareer,onemayfindoneselfbecomingmoreproficientandfamiliarwithcertaintypesofenvironments.Timeandtime,again,projectsituationscallforthesamestylesandtypesoflightingequipment.Forthisreason,wewilllookatafamilyofthe“workhorse”luminairesthatcommonlyappearonluminaireschedulesforresidential,high-designcommercialandhospitalityprojects.Obviously,lightingdesignprojectsspanabroadspectrum.Therearedesignerswhowillneverhaveneedforanyoftheproductsmentionedhere.Butthesetoolsseemtobeversatileenoughtobeusefulasafoundationforeveryone.Technologies;sources,efficaciesandcoderequirementsareconstantlychanging,sobesuretostayuptodatewithadvancementswithinthesebasicfamilies.Whenindoubt,hoponlineorcallyourlocalmanufacturer’srepresentativeforuptodateinformation.Andremember:Itisalwaysadvisabletoseeaworkingsampleofaluminairepriortospecifyingitonaproject.

THEBASICLUMINAIREFAMILIES

The4-inchApertureRecessedDownlightTherecesseddownlightis,nodoubt,oneofthedarlingsofthearchitecturallightingworld.Thislittledeviceshowsupasnothingmorethanaholeintheceilingandcastsfairlydirectedlightontoasurfacebelow.ThesmallversionofadownlightwillusuallyholdanMR-16low-voltagelamporaline-voltagePAR-20lamp.Thereareeven4”aperturedownlightsthatholdcompactfluorescentlamps,ceramicmetalhalide(CMH)lampsandofcourseLED’s.Thissmallaperturedownlightwillgenerallybeusefulinceilingsupto9’-0”high.Bewarned,however,thatbytheirverynature,downlightsarefairlyrestrictive.Becausetheyplacelightdirectlydown,theydonotallowforpreciseaimingontoverticalsurfacesorspecificobjects.Forthisreason,manydesignerseschewthe“fixedaim”downlightaltogetherandinsteaduserecessedadjustableaccent

luminaires(Seefollowingpages)Somecommonly-specified4”aperturedownlightsaremadebyLightolier,Prescolite,Leucos,Deltalight,Prima,CapriandJuno.Belowarecutsheetsandimagesofthistypeofluminaire.

Figure22.1.14”aperturehalogendownlightfromDeltalight.

Figure22.1.24”apertureLEDdownlightfromErco.

Figure22.1.34”aperturehalogendownlightfromPhilipsLightolier.

Figure22.1.4Anapplicationfeaturing4”aperturedownlights.

The6-inchApertureRecessedDownlightThe6inchdownlightbehavesinthesamewayasitssmallercousin,butitgenerallycontainsalargerlampformorerobusteffects.Ifyouaregoingtousea

6”apertureluminaire,makesureyouaregettingenoughlighttojustifythelargeraperture.Lookfora90W-150WPAR38halogenlamp,70W-150WT6ceramicmetalhalidelamp,or2500-lumenLEDmodule.Generally,theselargerdownlightsareautilitarianwaytogetlightontothehorizontalplanefromceilingswithrangingfrom10’-0”to30’-0”inheight.

Figure22.2.16”apertureLEDdownlightfromErco.

Figure22.2.26”aperturedownlightfromPhilipsLightolier.

Figure22.2.3Anapplicationfeaturing6”aperturedownlights.

The4-inchand6-inchRecessedAdjustableAccentTherecessedadjustableaccentissimplyadownlightthatcanbeaimed.Itsversatilitymakesitoneofthepreferredworkhorsesofthelightingdesigner.Thisluminairecanbeusedlikeatheatricallightingdevicetodirectadefinedpieceoflightontoanysurfaceatwhichitisaimed.Formanyapplications,therecessedadjustableluminairecanactasanaccent,awall-wash,orsimplyasageneraldownlight.Theycanbediffusedwithlensmediatoprovidelightthatvariesfromdramaticandharshtosoftandflattering.Theseluminairesareparticularlyusefulfor“painting”piecesoflightontothespecificobjectsandsurfacesthatwehaveidentifiedonourlightmaps(seech.17).Somesimpleprojectspacescanbelightedalmostentirelywithrecessedadjustableluminaires.Itiswellworthspecifyinganadjustableluminairethathastheaimingmechanismrecessedabovetheceilingplane,ratherthantheall-toocommon“eyeball.”Somewell-knownmanufacturersofadjustableaccentsincludeErco,Zumtobel,andRSA,aswellasthosebrandsmentionedinthedownlightfamily.

Figure22.3.14”apertureadjustable-accenthalogenluminairefromErco

Figure22.3.24”apertureadjustableaccenthalogenluminairefromPhilipsLightolier

Figure22.3.34”Apertureadjustable-accentceramicmetalhalide(CMH)luminairefromPhilipsLightolier

Figure22.3.44”apertureadjustable-accentLEDluminairefromErco

Figure22.3.56”apertureadjustableaccenthalogenluminairefromPhilipsLightolier.

Figure22.3.66”Apertureadjustable-accentceramicmetalhalide(CMH)luminairefromPhilipsLightolier

Figure22.3.76”apertureadjustable-accentLEDluminairefromErco

Figure22.3.8Anapplicationfeaturingadjustableaccentluminaires

TheMillworkDownlightInevitably,therecomesaneedforaverysmallversionofanadjustableaccentordownlight.Aswehaveseen,themajorityofrecessedluminairesfeaturelargehousingstocontainheat.Thereare,however,recessedproductsthathavereducedhousingsandaresuitableforbuildingintocabinetry,millworkandarchitecturaldetails.SomecommonlyusedproductsareavailablefromPrimalighting,DaSallighting,andArdeelighting.

Figure22.4.1Millwork“pucklight”LEDluminairefromDasal.

Figure22.4.2millwork“pucklight”halogenluminairefromDasal

Figure22.4.3millwork“pucklight”halogenluminairefromPrima

Figure22.4.3Anapplicationfeaturingmillwork“pucklight”luminaires

TheDirect-burialor“In-grade”FloorLuminaireThisfamilyofluminairesmountsdirectlyintothegroundorfloorofaspaceandcastslightupwardsontowalls,columns,andcanopiesabove.Itisessentiallyarobustdownlightmountedupside-down.Becauseitgoesintheground,theseluminairesmustbedurable,watertightandmustbeconsideredfortheamountofheattheycreate.Theymustbeconsideredfortheirdepthandthetypeofflooringorground(wood,earth,stone)intowhichtheycanbemounted.Theyalsoneedtobelocatedverycarefullyastheirinstallationisnotoriouslylaborintensive.Directburialluminairesarealsoavailableinadjustableversionssothattheycanbeaimedtowashlightontoaspecificsurface.Implementingtheseluminairesisonewaytointroduceauniquelightcharacterintoaspace.SomecommonlyspecifiedversionsofthistypeofluminairearefromLumascape,Lumiere,Hydrel,Kim,andDeltalight.

Figure22.5.1Direct-burialhalogenuplightfromDeltalight.

Figure22.5.2Smalldirect-burialLEDindicatoruplightfromErco.

Figure22.5.3Direct-burialhalogenuplightfromErco.

Figure22.5.4Direct-burialLEDuplightfromErco.

Figure22.5.5Direct-burialcompactfluorescent(CFL)uplightfromErco.

Figure22.5.6Anapplicationfeaturingdirect-burialuplights.

TheWallMountedUplightor“WashLight”Theseluminairesareoftenmountedoncolumnsandotherverticalsurfacestoaccenttheverticalsurfaceanddirectlightupwardsontotheceilingorlidabove.Theyareusefulforaddinganambientglowandaccentinguniqueceilingarchitecture.Theseluminairescanbesurfacemountedtoprojectfromasurface

orcanrecesstocreatea“holeinthewall”effect.Theseluminairesareavailableinnumerousdecorativestylesorcandisappeartohavealmostnoimpressionatall.Somecommonly-specifiedversionsofwallsurfacemounteduplightsarefromWinona,ElliptiparandInsight.SomewallrecessedversionsaremadebyBelfer,Energie,EuroliteandDeltalight.

Figure22.6.1WallmountedhalogenuplightfromDeltalight.

Figure22.6.2DecorativewallmounteduplightfromDeltalight.

Figure22.6.3Wall-mountedcompactfluorescent(CFL)uplightfromErco.

Figure22.6.4Wall-mountedceramicmetalhalide(CMH)uplightfromErco.

Figure22.6.5Wall-mounted“holeinthewall”uplightfromErco.

The“GlowingDisc”AreaLightOftentimesanafterthought,somesortofsurfacemountedarealightshouldbeconsideredforsmallspacesorutilityareas.Toooften,thesesmallspacesarelefttorecessedluminairesthatdirectmostoftheirlightingeffectdownward,leavingthespacedarkandcave-like.Asimpledishorslightlydecorativedisccan

providelightontotheceilingandwallsaswellasdownward.Somecommonly-specifiedversionsarefromTechlightingandEurekalighting.

Figure22.7.1Glowingsurfacemountedcompactfluorescent(CFL)arealightfromDeltalight

Figure22.7.2GlowingsurfacemountedLEDarealightfromEureka

Figure22.7.3Glowing,surface-mountedarealight(CFLandLED)fromTechLighting

TheResidential-GradeDownlight:CompactFluorescent,LEDandLEDRetrofitWithenergyconsumption(efficacy),lamp-lifeandlongevityofdesignrisingontheprioritylist,eventhesimplestofresidentialprojectsarebeingpushedtowardsnon-incandescentsources.Thelightingprograminresidentialspacesisoftendrivenbygreaterconcernforcolorrendering,warmcolortemperatures,minimizingglareandcreatingsofterlighttexturesthroughtheuseofdiffusinglenses.Recessedluminairesforresidentialprojectsmustcommonlyprovideaninsulatedceiling(IC)ratedhousing(seechapter24).Thesecriteriaalladduptoafairlyspecializedproduct,worthyofitsownfamily.Commonly-specifiedhigh-efficacy,residentialluminaireareavailablefromLightolier,Iris,andCapri.

Figure22.8.1Compactfluorescent(CFL)downlightfromErco

Figure22.8.2Compactfluorescent(CFL)downlightfromPhilipsLightolier

Figure22.8.3LEDdownlightfromPhilipsLightolier.

Figure22.8.4AdownlightLEDretrofit/lampreplacementfordownlightsfromCree.

TheContinuousLinearLEDLuminaireLong,continuouslinesoflightarefairlycommondesignfeatureincontemporaryenvironments.Thediminutivelinearsourcesthatcreatetheseshapesoflightcanbesmallerthan1”x1”inprofileandareoftenflexibleandcanbecuttoanylengthinthefield.Theseluminairesoftenoperateatlow-voltagesthatrequirearemotetransformeror“driver”.Theseluminairescanserveincoves,slots,niches,andevenasundercabinetluminaires.Manymountintoslenderchannelbrackets.Someevenmountwithsimplestickytape.Somecommonly-specifiedversionsofthistypeofluminairearefromTivoli,Solavanti,ColorGlo,andTokistar.

Figure22.9.1LinearLEDsourcefromSolavantiLighting.

Figure22.9.2LinearLEDsourcefromTokistar.

Figure22.9.3Anapplicationfeaturingcontinuouslinearsourcestouplightceilingbeams.

FluorescentContinuousSourcesForlargerormoreutilitarianlinearapplications,fluorescentsourcesoftenprovetobeagoodsolution.Theseluminairesincorporatelinearorcompactfluorescentlampsmountedend–to-endtocreateacontinuouseffect.Thiscanbeaccomplishedwithsomethingassimpleasabarelamp,ortheluminairemayhaveareflectortodirectlight.Thesesourcesarecommonlyusedincommercialandthemedenvironmentsincoves,slots,andbacklightapplications.Somecommonly-specifiedversionsofthisluminairearefromBelfer,Bartco,TivoliandTokistar.

Figure22.10.1LinearfluorescentstaggeredstripfromBartco

Figure22.10.2ContinuouscompactfluorescentsystemfromBelfer.

Figure22.10.3CompactfluorescentstaggeredstripfromBartco.

Figure22.10.4LinearfluorescentstripfromLightolier.

Figure22.10.5ModularlinearfluorescentsystemfromDeltalight.

Figure22.10.6Anapplicationfeaturingcontinuouslinearfluorescentsources.

Low-LevelSteplightThelow-levelarealightor“steplight”isasuperbtoolfordeliveringlightdirectlyontoagroundplane.Toooften,whenadesigncallsforlightontothefloor,luminairesareplaceduphigh,and,consequently,lightiswasted.Steplightscandeliverfocusedlightingforsafetyonpathwaysandstairs.Steplightssucceedindeliveringacontrolledpooloflightthatdoeslittletodisturbtheexistinglightedenvironment.Largerversionsofthislow-levelarealightareusedinlargersettingsforilluminatingseatingareasorexteriorareasboundbylowwalls.

Figure22.11.1SmallaperturehalogensteplightfromDeltalight.

Figure22.11.2Largeaperturecompactfluorescent(CFL)steplightfromErco.

Figure22.11.3SmallLEDindicatorsteplightfromErco

Figure22.11.4Anapplicationoftypicalsteplights

Thissmallfamilyofluminairesisbynomeanscomprehensive.Itgivesbutaglimpseofsomeofthemorecommonwaystodeliverlightontothesurfacesofourdesigns.Therenumeroustoolsfordeliveringlight,butatthecoreofdesign,wearestillsimplydealingwithshapesoflight,coloroflight,textureoflight,wherethatlightgoes,andhowitgetsthere.Choosingarchitecturalluminairesshouldbeanexerciseinselectingtoolstodeliverlightingeffectsthathavealreadybeenidentifiedthroughthedesignprocess.Rememberthatmanyluminairesareoftennothingmorethanlampholders.Adesignershouldbeabletorecognizewhenthelampisdoingmostoftheworkandwhentheluminaireismoreintegraltothedeliveryoflight.Hopefully,thisrepresentationofsomemorecommonlightingtacticswillbroadenhorizonsasthedesignermovesontoactuallylayoutandspecifylightingequipmentforhis/herdesign.

Chapter23Switching,DimmingandControlSystems

Designinglightingcontrolsystemsisanartandscienceinitsownright.Consideringhowthelightingelementsinaspacewillbecontrolledisanintegralpartofcompletingthelightingdesignthoughtprocess.Thereisasignificantchasmbetweensimple,wall-mountedswitchesandthewhole-building,computer-basedcontrolsystemsthatallowfortremendousflexibility.

Sustainabilityinitiatives,incentivesandcodeshavemadelightingcontrolsincreasinglyimportantandconsequentlycomplex.Alightingdesignerisexpectedtopossessanintimateknowledgeofcurrentcodes,incentivesandsustainabilitypracticesaswellasthetechnologiesavailable.Constantresearchandstayinguptodatewithtechnologiesandpracticesisamust.Onamoderndesignproject,documentationandtroubleshootingofthelightingcontrolsystemcanconsumeasmuchtimeasthatofthelightitself.Butcontrolsneednotbecomeunwieldy.Onceadesignerisfamiliarwiththebaselinerequirementsoflocalcodesandthebestpracticesemployedbyotherdesigners,meetingcoderequirementsandimplementingpractical,usefullightingcontroltechnologycanbecomesecondnature.

Thekeytomakinguseofthesetechnologiesistomakedecisionsaboutthespecificfunctionalitytheprojectneeds.Designofthecontrolsystemsshouldbetreatedsimilarlytodesigningthelightitself.Theeffectsofdimming,mixing,fadingandtimingfunctionsarethecomponentsthatcompletealightingapplication.Lightingcontrolsystemsshouldbechosenwithaconsiderationforhowtheycansimplifytheproject.Whenlightingcontrolsareaddedasameanstoprovidemoreoptionsandinfiniteflexibility,unwieldychaoscanbetheresult.

TYPICALSWITCHEDLIGHTINGCIRCUITSTomakesenseofthebenefitsandfeaturesofthevariouslevelofcontrolsystem,itismosthelpfultounderstandhowbasicin-line“lightswitches”workto

controlthedeliveryofpowertoluminaires.

Figure23.1Elevationdiagramoftypicalelectricaldeliveryforlighting.

Inatypicalelectricalset-uplikethebasicresidenceinFigure23.1,electricalservicefromtheutilityisconnectedtodistributionpanelstypicallylocatedinautilityareaontheproject.Fromthesedistributionpanels,theelectricityissplitintobranchcircuitsthatrunouttothereceptacles(plugs)andthevarioushard-wiredluminairesontheproject.Theonlywaytointerruptpowertothesedeviceswouldbetophysically“open”orinterruptthebranchcircuitthatconnectsbacktothepanel.Tocontrolpowertoluminaires,thistakestheformofsimplewallmounted“lightswitches”.Thelightswitchiseitheron(closed)andpasseselectricitytothelightingdevice,ortheswitchisoff(open)andelectricityisnotdelivered.Theimportantthingtovisualizeistheflowofelectricityfromthepanel,totheswitch,andthenontotheluminaire.

WALLMOUNTEDLIGHTINGCONTROLDEVICESTherearealsoanumberofwallmounteddevicesthatcanaddhelpfullevelsoffunctionalitytoalightingdesignwithouttheexpenseandcomplexityofacompletecomputer-basedlightingcontrolsystem.

DimmersDimmersaredevicesthatcontrollightingintensity.Commonincandescentdimmerssimplylimitthecurrentofelectricity.Low-voltagesources.LEDsourcesandfluorescentsourcesoftenrequireadedicateddimmermatchedtothesourcetype.Wallmounteddimmersarecommonlyavailableandserveinplaceofatypical“lightswitch”.Increasingly,dimmingdevicesarerequiredbycodeforlightingapplicationsthatinvolveincandescentorhalogenincandescenttechnology.Theyarecommonlyusedinresidentialprojectsandareanincreasinglypopularmeansofcontrollinglargefluorescentapplicationsinspecialcommercialspaces,eventspacesandconferencerooms.Attheirsimplest,dimmerscurtailelectricitywastebygivingtheusercontroloverthedesiredlightquantity.Dimmerscanalsobepairedwithdaylightsensorstoreduceelectriclightlevelsinresponsetoavailabledaylight.

Figure23.2TwoversionsoftypicalwallmounteddimmersfromLutron.

TimerSwitchesAtimerisasimplelightswitchthatkeepsalightingload“on”forasetamountoftime,andthenautomaticallyturnsitoff.Manytimersoffertheabilitytomodifyorprogramthetimerfunction.

TimeClocksAtimeclockisadevicewithmechanicalorelectronicmeansofkeepingtime.Theyareoftenmountedclosertoanelectricalpaneltocontrolentirecircuitsof

Figure23.3Anexampleofatypicalwallmountedoccupancysensor

lighting.Thetimeclockallowslightingfunctionstoautomaticallyoccuratspecifictimesthroughouttheday.Sophisticatedtimeclocksmayalsoknowthetimeofsunriseandsunsetthroughtheseasonsaswellasdaylightsavingschanges.Controllinglightingthroughatimeclockallowslightingfunctionstobeprogrammedtoreliablyactivateatcertaintimesofdaythroughouttheyear.Timeclocksareoftenafirstlevelofsophisticationoncommercialprojectsastheyreducewastedelectricitybyassuringthatlightingapplicationsdon’taccidentallyremain“on”afterbusinesshours.Manytimeclocksmeetthebasiccontrolrequirementsofmanylocallightingcoderequirements.

OccupancySensorsOccupancysensorsdetectpeopleandactivitythroughheat,motion,soundorobstruction.Thesecontroldevicescanoftenbeprogrammedtocomeonandturnoffmanuallyorautomaticallywhentheydetectapresence.Manylightingefficiencycodesrequirethatthesedevicesbeusedtoautomaticallyswitchlightsoffifoccupancyisnotdetected.Theyareoftenusedtoturnoffaportionoftheluminairesinalargeareatomeetcoderequirementsaddressing“uniformlightreduction”targets.Theyareavailableasintegraltotypicalwall-mountedswitches,orasstand-alonedevicesforcontrollingentirelightingcircuits.

INTELLIGENTLIGHTINGCONTROLSYSTEMSTheincreaseinenergycoderequirementsandsustainabledesignincentiveshadmade“wholeproject”controlsincreasinglypopularandfeasible.Besidesfinetuningoflightingeffect,theyallowimplementationofmanyenergysavinginitiatives(occupancyresponse,daylightresponseandtimeofdayresponse)inacomprehensivepackage.Mostofourmoresophisticatedlightingcontrolsystemsdeviatefromthesimple“switching”modelinanimportantmanner.Whenanintelligentcontrolsystemis

Figure23.4AtypicalSceneControlleror“Keypad”

employed,powerisdeliveredfromthedistributionpaneltoanearbyintelligentlightingcontrolpanel(wewillcallitthe“lightingpanel”).Electricitythenflowsdirectlyfromthe“lightingpanel”totheluminaires.Thismeansthattheprimarycontrolofelectricityflowingtoaluminaireistheintelligentlightingpanelitself.Intheset-upshowninFigure23.5,individualcontroldeviceslikemulti-buttonkeypadssendasignaltothelightingpaneltellingittodeliverelectricitytotheluminaire(ornotto).Thebiggestbenefitofthistypeofdesignisthatcontroldevicescansendasignaltothelightingpaneltotellittooperateanyluminairethatisconnectedtothelightingpanel:Abuttononakeypadinthekitchencantellthelightingpaneltoactivatethelightsinthelaundryroom;akeypadnexttothebedcantellthelightingpaneltoturnoneveryluminaireinthehouse.Thistypeoflightingcontrolscenariocanbeidentifiedasthreeparts:

1.Theintelligentlightingcontrolpanel(usuallyonlyoneperproject);

2.Thecontroldeviceslikemulti-buttonkeypadsthatreplacecommonlightswitches;

3.Thegroupsofluminairesthatwewanttocontroltogether(called“lightingloads”or“lightingzones”).

Thefunctionanddesignofthesystembranchesoutfromthisbasicconcept.Thelightingloadsgetspecificnames(ormorelikelyaddressnumbers),andweprogramthelightingpaneltorecognizethesenamesoraddresses.Wethenprogramtheindividualcontroldevicestosendtheappropriatesignaltothelightingpanel.

Figure23.5Elevationdiagramofelectricaldeliveryforanintelligent“whole-project”lightingcontrolsystem.

Inaset-uplikeFigure23.5,wewouldprogramthetopbuttonofakeypadtosendasignaltothelightingpaneltosendpowertoaloadintheroom.Inthisfashion,wecanprogramthebuttonsonakeypadtocontroldifferentlightingloadstodifferentintensitiestocreate“scenes.”Whenthistypeofcontrolsynchronizationisdistributedthroughoutanentireproject,wecallita“wholebuilding”lightingcontrolsystem.

Somewell-knownmanufacturersofintelligentlightingcontrolsystemsincludethefollowing:

LC&D,Lutron,Litetouch,Vantage,andCrestron.

LocalizedControlPanelsLightingcontrolintelligencedoesnothavetoberemotelylocatedasinFigure23.5.SmallercontrolsystemscanbelocatedtoincorporateonlytheluminairesinasingleroomasinFigure23.7.Thesesmaller,localcontrolsystemsusuallycontroluptosixlightingloadsandcanbeconnectedtocontroldevicesanywhereintheroom.Atypicalsituationmaybeanauditoriumorahometheaterwherenumerouslightingloadsinaspaceneedtobecontrolledfromnumerouslocations.Thelocalcontrolsystemcanreducethenumberoftraditionalwall-mountedlightswitchesusedandcanadddimmingandscene

creatingabilities.Anormal“switched”lightinglayoutforaspacemaylooklikeFigure23.6.Inthiscase,thewallsconces,wall-washluminaires,steplights,andpendantsareeachcontrolledbyalightswitch.Alocalcontrolsystemwouldbeinstalledinplaceofthelightswitches.Thegroupsofluminaireswouldnowbeconsidered“lightingloads,”andeachwouldbeconnectedbacktothelocalcontrolsystem.

Figure23.6Usingstandardlightswitchestocontrolcomplexspacescanleadtoanover-abundanceoflightswitches.

Figure23.7Alocalized“wholeroom”controlsystemcanreduceclutterandconfusion.

Thelocalcontrolsystemwouldhaveasetofvisiblebuttonsthatwouldbeprogrammedtoturnonthevariouslightingloads.Wecankeeptheprogrammingsimpleandprogrameachbuttontocontrolonelightingload,orwecanprogrameachbuttontoactivateasceneofmultiplelightingloadsatvaryinglightlevels.Wecanalsoinstallothercontroldevicescapableoftellingthelocallightingcontrolsystemtoactivatethesamescenes.Figure23.7showshowaspacemightlookwhensuchasystemisimplemented.Theselocalsystemscanoftenberetrofitintoexistinglightingsituations.Acommoncandidateisaroomthathasfourorfivewallswitchesinonelocation.Ratherthanfusswitheachswitch,thelocalcontrolsystemreplacesalloftheswitchesandopensupthepossibilityofprogrammingscenesanddimminglevelsandactivatingthemwithasinglebuttonpress.

Somecommonmanufacturersofsmall,localizedlightingcontrolsystemsincludethefollowing:

Wattstopper,

Lutron“GrafikEye”,and

Crestron.

Thesetypesoflocallightingcontrolsystemscanalsobelocatedfarfromthelightingloadsthattheycontrol.Inmanycommercialprojects,asimplelocallightingpanelisusedonlyforitsbuilt-intime-clockandall-onandall-offfunctions.

Allofthedevicesdiscussedhereareintendedtoaddtothefunctionalityofalightingdesignandincreasinglytotacklethetwolargestelectricitywasters:Lightinginadvertentlylefton,andexcessivelightingwithnolocalcontrolforreducingit.Withouttheconsiderationofthesetechnologies,oneislivinginaworldoflightswitchesonthewallthatmustbemanuallyturnedonandmanuallyturnedoff.Adesignershouldconsiderhoweachlightingadditionwillbecontrolledandwhetherthesecontroltechnologieswillprovideabenefit.Itishighlyadvisedthatadesigneremploytheassistanceofalightingcontrolmanufacturers’localrepresentative,whocanassistinspecifyingcomponentsforthesesystems.

Thevariouslevelsofcontrolcapabilityarethecrowningtouchonthelightingdesigninaspace.Acarefulconsiderationofcost,complexity,andconveniencewilldictatetheappropriatelightingcontrolsystemforeachdesign.

Chapter24ThePreliminaryLightingLayout“Redline”

“Thepreliminarylightinglayoutiswhereourdesignconceptsstarttobecomebuildable.”

Nowthatwehavebeenintroducedtoavocabularyofluminairetypes,applications,andcontrolmethods,wearereadytomoveforwardinourdesign.Thepreliminarylightinglayoutistheintermediatestepbetweenlightingconceptsandlightingdrawingsusedforconstruction.Itisanevolvinglayoutoflightingluminairelocationsthatgivesthedesignertheopportunitytoponderandselectlightingequipmentandfine-tunethelocations,applicationsandcontroloftheseluminaires.Thispreliminarylayoutisoftenreferredtoasa“redlinelayout”becauseluminairelocationsandnotesareoftenmarkedinredpencilandundergonumerouschangesandtweaksbeforethedocumentisfinalized.Theredlinelayoutiswhereourgraphics,descriptionsandcalculationsaretranslatedintoindividualsymbolsthatrepresentspecificpiecesoflightingequipment.Creatingthe“Redline”preliminarylayoutisbasicallytheprocessof“solving”theconceptuallightmapthathasbeencreated.Aclear,well-executedlightmapwithnotesanddescriptionsshouldprettymuchsolveitself,leavingthedesignerwiththesimpletaskofmatchinglightingequipmentandlocationstothealready-documentedlightingapplicationsasindicatedonthelightmap.

Figure24.1Theprocessofmarkingideas(hereinred)fortheplacementofspecificlightingequipment.

Thetwosignificanttasksthatareaccomplishedthroughthis“redline”layoutarethelocatingandselectingofluminaires.Thesedecisionswillformthebasisofthefinalconstructiondocuments-theLightingPlan,LuminaireScheduleandLuminaireCutSheets-thatwillmakeourdesignbuildable.

Thereareveryfewrulesforthegraphicsandsymbolsusedinlayingoutpreliminarylightingintent.Thegoalissimplytoclarifythelocationsandtypesofluminairestobeusedinthedesign.Ifsymbolsalonecannotsuccessfullytranslateideas,additionalnotesandcommentscanbeusedtoprovidemoreinformation.Luminairemountingdimensionsandmountingheightsarealsoausefuladdition.

THEPRELIMINARYLUMINAIRESCHEDULEAsadesignergoesthroughtheredlinelayout,theywillponderoverthetypesofluminairesthatwillsolvetheparticularlightingchallengestheyhavemappedout.Whiletheyarecreatingthispreliminarylayout,theyshouldbesimultaneouslycreatingtheroughdraftoftheirluminaireschedule.Asluminairesymbolsareplacedtorepresentlightingequipment,theyshouldbegivenluminaire“type”labels-uniquenames-thatwillserveasthecoordinationbetweenthelightingdrawingandtheluminaireschedule.Thepreliminary

Figure24.2Identifyeachuniqueluminairewitha“type”labelassoonasitisdrawnintothespace.

luminairescheduleshouldbearunninglistofluminairestobeused.Thelistshouldindicateatleastthenameor“type”labelandadescriptionforeachluminaire.Thissimplestepwillkeepadesignerfromrepeatingluminairetypesandwillstreamlinetheluminaireselectionprocess.

Theluminairetypelabelsneedtobeuniquetoeachluminairethatendsupbeingusedonthejob.

Itisadvisabletoaddluminairetypesanddescriptionstothepreliminaryluminairescheduleassoonasthereisevenaglimmerofthoughtaboutwhattheluminairewillbe.Thissimplestepwillbuildthescheduleincrementallyandkeepaclearrecordofthedifferentequipmentasthedesignergoesthroughselectinglightingequipmentto“solve”thelightingapplicationsindicatedontheredlinelayout.

Figure24.3Acompleted“redline”layoutshowsideasforallluminairelocationsandapreliminaryluminaireschedule.Eachlightingapplicationisinformeddirectlybythelightmap.

The“redlinelayout”shouldactasalinkfromthegraphicsanddescriptionsofthelightmaptotheprecisionandclarityofthedraftedlightingplanfromwhichtheprojectwillbebuilt.Theredlinelayoutgivesthedesignertheopportunitytomoveluminairesandexperimentwithdifferentsolutions.

Chapter25LuminaireSchedulesandCutSheets

Themostimportantsupportdocumentsthataccompanyalightingplanaretheluminairescheduleandcutsheetsthatillustrateexactlywhatlightingequipmentisrequiredtobringthelightingplantolife.Allofthedeliverabledocumentsmustbeaccurateanderrorfree,butthisholdsespeciallytrueforthescheduleandcutsheets,astheywillinformtheorderingoflightingproducts.Oncomplexprojects,architectsandengineerscreatespecificationdocumentsthatarticulatethespecificnuancesofeveryproductandmaterialthatisnecessaryfortheconstructionoftheproject.Theluminairescheduleandcutsheetsaretheclosestalightingdesignergetstotrue“specification”.Assuch,thesedocumentsthatmustlistproductsaccuratelyandcompletely.Theluminairescheduleisthedocumentthattheelectricalcontractorwillusetoprice,orderandinstallthelightingequipment.Thismeansthataslighterrorincatalognumberordescriptioncanaffectthebudgeting,deliveryandinstallationofeveryinstanceofaparticularluminairetype.Thetwosecretstoathoroughluminaireschedulearetogetstartedearly(asdiscussedinChapter24),andtocheckandre-checkthescheduleandcutsheetsforerrors.Bynow,readershaveseenenoughmanufacturers’literaturetoknowthatthecatalognumbersforlightingproductscanbecomeratherlengthyandcomplex.Asimpletypocancauseaproducttobedeliveredinthewrongsize,thewrongcolor,ornotatall.

THELUMINAIRESCHEDULEThesampleluminairescheduleshowninFigure25.1includesmostofthepertinentinformationonewouldneedtoprovideforaproject.Eachcategoryhascriticalinformationthatmustbepresentedinamannerthatmakesthingsclearandobvious.Thecontentsofthevariouscategoriesofinformationarediscussedhere.

Heading

Thefirstpieceofinformationthatshouldgoonaluminairescheduleisthenameoftheprojectandthedatetheschedulewascreated.Withsomanyprojectsgoingonatonce,andsomanychangesbeingmadetoluminaireselections,thislabelingensuresthatthoseinvolvedwiththeprojectarereferringtothecorrectdocument.Theheadingshouldalsoincludethenameofthefirmorindividualpreparingthedocumentsothatthoseinvolvedintheprojectknowwhomtocontactwithquestions.

LuminaireTypeLabelsLuminairetypelabelswillconnectalloftheluminairesymbolsonthelightingplantothespecificpiecesofequipmentthattheyrepresentasdefinedbytheluminaireschedule.Designerscanusewhatever“type”logicmakessensefortheproject.Oftenatwoorthreedigitoralphanumericcodeisemployed.Tokeepluminaireselectionsclear,itisadvisabletogiveauniquetypetoeveryvariationofeverypieceoflightingequipment.Evenifthevariationissimplyalens,lamptype,orfinishcolor,itshouldwarrantauniqueluminairetype.

LuminaireManufacturerThisindicateswhotheproductismadebyandwherespecificquestionsregardingmounting,installationandelectrificationshouldbedirected.Besuretolistthetruemanufactureroftheproduct,notathirdpartyvendorwhoissupplyingtheluminaire.

Figure25.1Theluminairescheduleliststheinformationacontractorneedstopriceandorderalloftheluminaires.

CatalogNumberThemostimportantpieceofinformationtoaccuratelylististheproductcodethatwillbeusedtopriceandordertheequipment.Thecatalognumberisusuallyfulloflettersandnumbersthatindicatespecificfinishes,colors,mountingstyles,andotheroptions.Anysmallerrorsincatalognumberwillcomebacktocauselargerproblemsduringconstruction.

LampSpecificationThescheduleshouldincludeinformationonthequantityandtypeoflamprequiredfortheluminaire.Sometimesitwillbenecessarytolistaspecificlampproduct.Othertimesitwillsufficetolistthedesiredwattageandsourcetype.Itisalwaysgoodpracticetomakesurethatthelampspecificationprovidesinformationaboutcolor-renderingindex(CRI)andcolortemperature(CCT)toensurethatasuitableproductisused.

VoltageTherearemanyvoltagesthatservicelightingprojects.120voltsiscommonlinevoltageforresidencesintheUS,butitcannotbeassumed.Largercommercialprojectsandprojectsthathouseheavymachineryoftenuse277Voltsastheprimaryvoltage.Theluminairesspecifiedforaprojectmustbedesignedtooperateatthevoltagethatwillbeprovidedonthejob.Thisisoneofthefirstpiecesofinformationthatshouldbeconfirmedwiththeelectricalengineerorcontractoronthejob.Luminairesthatuselow-voltagelampstypicallyrequireelectricitydeliveredat12or24volts.Theselowvoltagesgenerallyrequirethatatransformerbeintegraltotheluminaireorlocatednearby.

MountingstyleThispieceofinformationwillhelpanelectricalcontractorpreparethesitefortheluminairewellbeforeitarrives.Itcanalsoheadoffanymajorconflictswithbuildingconditionsandspaceconstraints.

LocationsThissimpledescriptionofwheretheluminaireisactuallyusedontheproject

willsavehoursoflookingforluminairesymbolsonthelightingplanlater.

NotesThisareaisforanyadditionalclarificationinformation.Themostcommonnotesthatshowuponaluminaireschedulearerelatedtoballastsandtransformersthatneedtobeprovided,IChousingrequirements,andwet-listingdesignations.Thisistheplacetoputinformationthatisessentialtothesuccessfulinstallationoftheluminaire.

Rememberthatallofthisinformationwillservethedesignerandtheelectricalcontractoronthejob.Theelectricalcontractorisanecessaryallyonalightingdesignjobandeffortsputtowardsclarifyingthecontractor’sjobwillbenefitthedesignprojectasawhole.

LUMINAIRECUTSHEETSTotakethejobofprovidingclearinformationastepfurther,alightingdesignerincludesjobspecificcutsheetstoaccompanytheotherconstructiondocuments.Thesesheetsareusuallysomeformofthemanufacturers’luminaireliteratureputintoaformatthatwillbenefitthelightingdesignproject.Manymanufacturersincludeblankspacesontheirliteraturesothatdesignerscanturnthemintojobspecificcutsheetsveryeasily.

Figure25.2Amanufacturer’scutsheetoftenprovidesspacefortheinclusionofproject-specificinformation.

Liketheluminaireschedule,cutsheetsareadirectlinkbetweenthesymbolsand“type”labelsonthelightingplanandaspecificpieceoflightingequipment.Agoodcutsheethelpsacontractorbecertainthattheluminairethatisabouttobeinstalleddoes,indeed,belong.Itisagoodideatoincludeonthecutsheetinformationdirectlyfromtheluminaireschedule,suchascatalognumberandlampinformation.Somemanufacturers’literaturewillshowmultipleluminairesoroptionsonthesamepage.Inthesecases,isitveryhelpfulforthedesignertohighlightordrawattentiontothespecificpieceofequipmentbeingspecified.Figure25.3isacustomizedcutsheetmadeforaspecificjob.Themanufacturer’sinformationwassimplydownloadedfromawebsiteand

insertedintotheblankcutsheet.Itiscertainlyworthadesigner’stimetodevelopablanktemplatethatservesthispurposewhileprovidingprojectspecificdesigninformation.

Figure25.3Acustomluminairecutsheetcreatedbythedesignerforaspecificproject

Chapter26TheLightingPlan

Thedraftedlightingplanisthefinalizedconstructiondocumentthatwillbeusedonthejobsiteforthelocationandinstallationofalllightingrelatedequipment.Thelightingplanisaformally-draftedconstructiondocumentthatmustprovidespecificinformationclearlyenoughtoallowacontractortoactuallybuildthedesign.Aproperlightingplanisatoolforconstruction;itisnotatoolfordesign.Atthispointadesignerismerelytranslatinginformationfromahighly-evolvedlightmapandredlinedpreliminarylightinglayout.Thedraftedversionissimplyafinalizeddrawingthatclarifieseverythingandfacilitatestheconstructionprocess.Afinaldraftedlightingplanwillideallyshowallofthelightingequipmentonajob;lightinginstalledintheceiling,lightinginthewalls,lightinginfloors,millworkandniches.Ifadevicecreateslight,itshouldshowuponthelightingplan.Itisadvisabletonotuseareflectedceilingplanasthebasisforalightingplanaslightingequipmenttypicallyhasmuchmorerelationshiptofloorandfurnitureconditionsthantoceilingconditions.Apreferablemethodformanyjobsistostartwithafurnitureplanandaddpertinentceilinginformationtocreateasuitablearchitecturalbackground.Thefinallightingplantrulyisatoolforthebuilder.Remember:Theconstructionphaseofaprojectiswhereactuallightingequipmentwillbepriced,purchasedandinstalled.Itisbyfarthecostliestphaseofaproject.Errorsandmiscommunicationsareequallycostly.Thejobofthefinallightingplanistoeliminateanyopportunitiesforconfusion,mistakesormisunderstandings.Thereisplentyofroomtotweaktheformulaandaddorsubtracttomakethelightingplanworkforeachindividual,butthefollowingingredientsrepresentthe“must-have’s”

LuminaireSymbolsThesecanbeofanydesign.Theycanrelateliterallyorlooselytotheshapeoftheluminaire.Itisencouraged,however,todraftthesesymbolstorepresentthe

actualsizeoftheluminaireifoneisdraftingaplanat¼”=1’-0”or⅛”=1’-0”scale.Ifoneisdraftingaplanataverysmallscale,itisadvisabletosizethesymbolssothattheyareclearlyvisible.Figure26.1presentsasamplelegendofcommonly-usedluminairesymbols.

LuminaireTypeLabelsThereisplentyofroomtoinventconvenientandhelpfulwaystotagluminairesonthelightingplan.Thesafestandsimplestistoputtheluminairetypenexttoeverysingleoccurrenceofeveryluminaireonthelightingplan.Moretechnicallyorientedlightingplansmayincludeinformationlikewattageandsourcetype,butforabasiclightingplan,clarityofluminaire“type”andtheabilitytoreferencealuminairesymbolbacktotheluminairescheduleisparamount.

COMMONLUMINAIRESYMBOLS

Figure26.1Commonluminairesymbolsusedondraftedlightingplans

Figure26.2“Type”labelsortagsarecrucialforreferencingadraftedsymboltoaspecificluminaireontheluminaireschedule.

NotesDon’tbestingywiththeapplicationoflightingrelatednotesontheplan.Ifthereisanyambiguity,clarifyitwithanoteinplainlanguage.Whenwerelyonasingleplantoshowluminairesinceilings,walls,andmillwork,notesareimperativeforclarifyingwhereapieceofequipmentactuallybelongsandwhatitisdoingthere.Asimplenoteattheendofaleadercansavenumerousphonecallsandcoordinationheadaches.

DimensionsPlacementoflightingequipmentisarelativelyexactscience,soitispreferabletonoteexactlocationsofluminaireswithcleardimensions.Luminairesforaccenting,wallwashing,linearslotsandcovesallmaywarranttheadditionofdimensionsthatreferbacktonearbyarchitecturalelements.

ControlIntentThelightingdesignerisalsoresponsiblefortranslatingwhichluminairesarecontrolledtogether(turnedon,turnedoffanddimmed)andwherethatcontroltakesplace.Mostlightingcontrolintenttakestheformofarcsconnectingluminairestowallswitchdevicesornumbersandletterskeyedtowall-switchdevices.ControlintentcangetalittlemorecomplexwhenweintegrateintelligentcontrolsystemsandscenecontroldevicesascoveredinChapter23.

Figure26.3Notesandleaderclarifyanyambiguities.

Figure26.4Dimensionsensurethatluminairesareimplementedproperly.

Figure26.6Asimplelegendcanhelpclarifyvariouslightingrelatedsymbols.

Figure26.5Numberedlightingcontrolzonesandkeypads(left)taketheplaceoftraditionalswitchingsymbols(right)whenacontrolsystemisimplemented.

LuminaireScheduleorLegendIfonehasthemeans,itishelpfultoincludetheentireluminairescheduleasadrawingsheetthatgetssubmittedalongwiththelightingplan.Thisclaritywillensurethatthisinformationisalwaysavailable.

Inadditiontotheluminaireschedule,abasiclegendliketheoneshowninFigure26.6canbehelpfultoexplainsomeoftheothersymbolsusedonalightingplan.Itiscommonpracticetocreatealegendthatclarifiesnotonlyluminairesymbols,butcontrolsdevicesanddetails.

DetailCallouts.Manylightingapplicationsaresimplytoocumbersometobeunderstoodinplan.Whenthisisthecase,wedeveloplightingdetailsthatshowspecificconstructionsituationsanddimensioninaveryprecisemanner.Thesedetailswillusuallyoccupyadedicateddrawingsheet.Numerousexamplesoftypicallightingdetails

appearinChapter29.

Figure26.7(exampleofdetailcallout)

Aswithanyotherconstructiondrawing,properformattingwilladdthefinishingtouchesthatwillgetthelightingplantherespectitdeserves.Theconstructiondocumentsthatcomeoutofthestudioaretheonlyproductthatmuchoftheprojectteamgetstosee.Developmentmaterials-sketches,renderingsandlightmaps-canleadtogreatdesign,butitisallfornaughtiftheconstructiondocumentsarenotcomplete,correctandeasytouse.Intheend,theconstructionofaprojectreliesheavilyonthesefewblackandwhitedrawingsandhoweasytheyaretotranslateintoabuiltenvironment.

Figure26.8Acompleteddrawingsheetofalightingplanforacommercialproject,includinglightingdetailsandtitleblock.

Figure26.9Acompletedlightingsheetforaresidentialproject,includinglegendandnotes.

Chapter27LightingLayoutsforResidentialSpaces

Thefollowingchapterincludeslightingtacticscommonlyfoundintypicalresidentialspaces.Thepointoftypicallayoutsisreallyjusttolendsomefamiliarityandajumping-offpoint.Everyprojecthasuniqueprogrammingcriteriathatmustbethoroughlyunderstood.Itisgoodpracticetodissectanyandalllightinglayoutsthatonecomesacrosstogainafamiliaritywiththevarioustechniquesavailable.Thelightinglayoutsinthischapterareannotatedtodescribewhatlightingprinciplesareatwork.Takesuch“typical”layoutswithagrainofsalt.Regardlessofhowmanytimesthesamespaceislightedinthesamemanner,italwaysbehoovesthedesignertoinvestigatealloftheavailablelightingoptions.

Layout1LightingaResidentialDiningRoom

Aresidentialdiningroomisagoodopportunitytomakeuseofdifferenttexturesandintensitiesoflight.Aformaldiningroomhasveryfewcriticaltasks,solightingdecisionscanfocusonenvironmentaleffect.Likemanyrooms,thefundamentallightelementsofadiningroomaretheverticalsurfacesthatwilldefinethebrightnessofthespaceandtheaccentedobjectsthatwillcreatevisualinterestandaddauniquecharacter.Softness,warmth,andintimacyareusuallythedesiredqualities.Thesecanbeaccomplishedthroughuncommontactics,suchasuplightingfromthefloororwalls,aswellasmoretraditionalpendants

andrecessedluminaires.Eveninitssimplestform,diningroomlightingshouldbemorethanasingledecorativependant.Attheveryleast,luminairesshouldbededicatedtopaintinglightontothetableandverticalsurfacestoallowabalancingactbetweentaskandambientlightlevels

CommonFeatures1.Recessedadjustablehalogenluminairescastlightontotheobjectsthatadornthebackwall.2.Anincandescentorfluorescentdecorativependantcanserveasthemainfocalelementinadiningarea.Itservesasaglowingobjecttodrawattentionandultimatelycongregatearound.Decorativeelementsareattheirbestwhentheyarefreetobedimmedtoanappropriatelevelforambienceandmood.3.Recessedadjustablehalogenluminaires(ideallywithdiffusinglenses)atthetableprovidelightforeatingandrenderingthefacesofthediners.Implementingtheseluminairesfreesupthedecorativependanttoserveonlyasambienceanddécor.4.Incandescentorcompactfluorescent,Wall-mounteddecorativesconcesor,betteryet,wall-mounteduplightsaddalayerofdiffuselight.5and6.Additionaladjustablehalogenluminairespaintpoolsoflightontotheotherimportantobjectsintheroomandcreatemorevisualinterestthroughcontrast.7.Walldimmersoralocalizedlightingcontrolsystemcanbeusedtocontrolanyloadsthatcanbedimmed.Theflexibilitythatdimmingaddstoaspacewillfacilitatethecreationofdifferentevironmentsfordifferentmoodsanduses.

AddressingLayersChoreography:Thedecorativependantservestoanchorthespaceandcreatea

cleardrawandareaforgathering.Thelightedcharacterofthebackwallwillserveasthevisualgoalcompellingavisitortomovetowardsthespace.

MoodandAmbience:Multipletexturescanbecreatedbyimplementingvariousdiffusingsources.Wall-mounteduplightslendasoftness,andthedecorativependantcontributestothemoodandatmosphereAccenting:Crisppiecesofaccentlightcastontoartorfurnitureobjectsprovidevisuallogicandinterestthroughcontrast.Abrilliantpooloflightontothesurfaceofthetableitselfwillservetoaccenttheobjectsonthetableandcreateabright

planeinthespace.RevealingArchitecture:Wallmounteduplightsaddvolumecontributetoanall-

encompassingglowthatexpandsthespace.Thecentralpendantcanalsocastlightupwardtoilluminatetheceilingabove.

TaskLighting:Dedicatedrecessedadjustableluminairespaintpoolsoflightontothesurfaceofthetableaswellasthebuffetoranyothertask-relatedfurniture.Therecessedluminairesandpendantatthediningtablealsoservetoilluminatethefacesofthediners.

Layout2LightingaResidentialKitchen

Theresidentialkitchenisaplacenotonlyforfoodpreparation,butsocializingandgathering.Thekitchenislandoftenbecomesamulti-purposetasksurfaceusedforstudyingandquickdining.Theprogramforsuchaspaceiscertainlynotpurelytaskdriven.Lightingingredientsshoulddrawpeopletothespaceandcontributetothemood.

CommonFeatures

1.6”aperturerecesseddownlightshelptocreateanaboveaverageilluminancelevelthroughoutthespacesothattaskscanbeaccomplishedanywhere.Thesecouldbeincandescent,halogen,orcarefully-selectedcompactfluorescentluminaires.2.Under-cabinetluminairesprovidelocalizedtasklightingoncountertops.Thesecouldbelinearincandescent,linearhalogen,linearfluorescentorindividualpucklights.3.Incandescentorcompactfluorescentdecorativependantsdirectlightontotheislandtasksurface.Theyshoulddirectlightdownwardinadditiontosimplyglowing.4.Asmallaperturerecessedadjustablehalogenluminaireorfluorescentdownlightcanaugmentlightlevelsoverthesinkarea.5.Switchestoactivatetaskspecificlightingcanbelocatedneartheareatheyserve.

AddressingLayersChoreography:Decorativependantsovertheislandcanserveasafocalpoint

andapointofgatheringtodrawpeopleintothespace.Lightingtheverticalsurfacesofthebackwallscanalsohelpcreateaninvitingatmosphere.

MoodandAmbience:Thegloworsparkleofthedecorativependantscanservetoreducethescaleofthespaceandcreateamoreintimatearea.Sourcesshouldalsobewarmincolortemperaturetocontributetoaninvitingfeeling.

Accenting:Lightwasheddownthefaceofcabinetrycancreatevisualinterestandhierarchy.Adistinctpooloflightontotheislandsurfacecanalsoserveasthebrightcenterpieceofthespace.

RevealingArchitecture:Thependantsovertheislandservetoreducethescaleandbreakupthevolumeofthespace.Theundercabinetluminairescancreateabandoflightthatbreaksupthesurfacesofthebackwall.

TaskLighting:Under-cabinetluminairesservetoputlightdirectlyonthetasksurfacewhereitisneeded.Smallpendantscasttasklightingontothetasksurfaceoftheisland.Thesetwoapplicationseliminatetheneedtocreatetasklevellightingthroughoutthespace.

Layout3LightingaResidentialBathroom

Evenasimplebathroomshouldbetreatedwithcaretocreateaspacethatservesallofthefunctionalneedswhilecreatinganenvironmentforlong-termcomfort.Lightingtheverticalsurfaceswilldramaticallyimprovetheperceptionofbrightness,andafew,well-placedaccentscanaddsomesparkleandelegancetothespace.

CommonFeatures1.Diffusedecorativesconcesatthevanityarethefirstlineofdefenseformakingthespacefunctionalandinviting.Evenwithtoday’senergyconcerns,itisworthworkingtofindawaytostickwithincandescentorhalogensourcestoensuregoodcolorrenderingandpleasingcolortemperature.2.Asmallaperturerecessedhalogenluminairecanserveasadditionalvanitylightingtoaccenttheareaandprovideadditionaltasklight3.Additionalrecessedadjustablehalogenorfluorescentwallwash

luminairescanpaintlightontoart-workorsimplyilluminateverticalsurfaces.Lightacrossfromthevanitycanreducecontrastbycreatingaluminousbackgroundforlookingatone’sselfinthemirror.4.Afanandlightcombinationunitisareasonablewaytodedicatelighttothetoiletarea.5.Theshowerortubshouldhaveitsowndedicatedsourceoflight.Thisincandescentorfluorescentluminairemustbesuitableforuseinwetareas.

AddressingLayersChoreography:Evenasimplebathroomshouldhaveareasofbrightnessto

determineavisualorder.Self-Luminoussconcesandapoolofaccentlightatthevanityserveasthebrightcore.

MoodandAmbience:Diffusedecorativesconcesatthevanityservetodefineasoftmood.Lightontothebackwallandatthetoiletcreateaheightenedlightleveltomakethespacemoreinviting.

Accenting:Recessedaccentluminairescancreatepoolsoflighttoshowoffthevanityhardware,artonthewalls,andeventhetoiletitself.

RevealingArchitecture:Glowingwallsconceshelptovolumizethespace.Eventherecessedluminaireintheshowercanaddtotheperceiveddepthofthespace

TaskLighting:Thevanityisacriticaltaskarea,wherelightsourcesshouldbechosenfortextureandcolorrendering.Lightingatthevanitymustprovidesoft,diffuselightfromaboveandbelowwithexcellentcolor-renderingcapabilityforrevealingfaces.Theevenqualitiesofvanitylightingcanalsobeenhancedbyusinglight-coloredsurfacestoreflectlight.Theshowershouldalsogetadedicatedlightsourcetoaidinalloftheimportanttasksrelatedtokeepingclean.

Layout4LightingaResidentialBedroom

Theresidentialbedroomisagoodexampleofaspacewithfewdrivingtaskcriteria,butplentyofneedforversatility.Thelightingsysteminabedroomneedstobeabletocastlighteffectivelyontotasks,likedressingandreading.Allofthelightingingredientsneedtocontributetothegenerallyinvitingandcomfortablefeeling.Thebedroomcansurvivewithafewlightedverticalsurfacesandafewaccentedobjects.Additionsofdecorativelightoruplightcanbeimplementedtoaddvolumeandwarmthtothespace.Thevariouslightingloadsshouldbeindependentlycontrolledsothatdifferentmoodscanbecreatedfordifferenttimesofdayanddifferentuses.

CommonFeatures1.Asurface-mountedglowingdishservestocastaquantityofdiffuselighttoallreachesofthespace.Thisluminaireisagoodplacetointegratefluorescentlamps.2.Recessedadjustablehalogenluminairespaintlightontoartworkandtheverticalsurfacesofthespaceaswellasareasfordressingortheheadofthebedforreading.3.Wallmountedhalogenorfluorescentuplightscastlightontotheceilingtoexpandthespace.Theseluminairesareagoodplacetointegratefluorescentlamps.4.Adedicatedincandescentorcompactfluorescentfloorlamporrecessedluminaireprovidesamplelightingforreadingandcreatesanattractivenookforrelaxing.5.Linearfluorescentluminairesmountedtothebacksideoftheclosetheadercanbeactivatedbyadoorjambswitchtoturnonwhenevertheclosetisopened.Theluminairesareoutofsightandlendaniceglowfornavigatingthecontentsofthecloset.

AddressingLayersChoreography:Washinglightontoartandthebacksurfacesoftheroomhelpsto

drawintheeye.Accentingthereadingnookcreatesaninvitingareaofrespite.Theglowingtablelampsandfloorlampalsocreateobjectsthatdrawattentionandcreatehierarchy.

MoodandAmbience:Wall-mounteduplightsbrightentheceilingandcreateanopen,invitingspace.Theglowinglampsandthecenterglowingdishcontributetotheintimatefeeling.Thewarmthofincandescentsourcesorcarefully-selectedfluorescentsourceswillcreateadesiredmood.

Accenting:Recessedaccentluminairescastpoolsoflightontoartwork,readingareasandthevariousfurnitureelementsinthespace.Eachservestoaddvisualinterestandcontrasttothespace.Thedecorativelampsalsoaddabitofsparkle.

RevealingArchitecture:Accentluminairespaintlightontothebackwallstogiveaperceptionofdepth,whilethewall-mounteduplightsandcenterglowingdishwashlightontotheceilingsurfacetoexpandthespaceandreducethefeelingofconfinement.

TaskLighting:Readinginbedisaccommodatedthroughrecessedadjustableluminairesortypicalbedsidetablelamps.Thevanitydeskordresseralso

receivesdedicatedtasklightfromabove.Closetsbenefitfromdedicatedluminairessothattheydonotdependontheambientlightfromthebedroomitself.

Layout5LightingaResidentialLivingRoom

Theresidentiallivingroomseesfrequentuseandaccommodatesanumberofdifferentactivities.Theprimaryprogramcallsforaspacethatisinvitingandcomfortableforlongspellsofsocializing.Thelightingingredientsshoulddonatemultipletexturesoflight;directionalaccentstocreatevisualinterestandobviousareasofactivity,aswellasdiffuselightthatlendssoftambienceforlongtermvisualcomfort.Thelivingroomshouldalsobecapableofprovidinglow-levelambientlightingfortelevisionviewing.Thevariouslightingloadsshouldallbeindependentlycontrolledsothatthespacecanservethevariousfunctions.

CommonFeatures1. Recessedadjustablehalogenluminairesbalancelightbetweenthesurface

ofthecoffeetableandthesocialseatingarea.2. Wall-mountedhalogenorfluorescentuplightscreatevolumeandinvitingsoftness.Theluminairesprovidealowlevelofambientlightwithoutcastinglightdirectlyontothetelevision.

3. Small-aperturerecessedadjustablehalogenluminairesaccentthehearthofthefireplacetocreatevisualinterestandachoreographicgoal.

4. Recessedhalogenluminairespaintlightontothevariousfurnitureandsecondarytaskareasinthespace.

AddressingLayersChoreography:Lightcastontothefireplaceactsasafocalelementtodraw

attention.Poolsoflightontothecoffeetablecreateanattractiveareaforgatheringandsocializing.

MoodandAmbience:Wall-mounteduplightscastsoft,warmlightontotheceilingtocreateanenvelopingcomfortablespace.Distinctpoolsofaccentlightontowallobjectsandfurnitureservetobrightenupareasandcreatea“lived-in”feeling.

Accenting:Recessedadjustableluminairespaintlightontothefireplace,artandfurnituretocreatevisualinterestandhierarchy.

RevealingArchitecture:Accentedverticalsurfacesservetoexpandtheperimeterofthespace,whileupwarddirectedlightaddsvolumeandanevenly-lightedambientatmosphere.Lightpaintedontothecoffeetableandfireplacekeeptheattentiondownatahumanlevel.

TaskLighting:Recessedluminairespushlightdownontothecentralareaforreadingandrenderingfacesforsocializing.

Chapter28LightingLayoutsforCommercialSpaces

Commercialspacestendtobeareaswherevisualtaskstakepriority.Thisdoesnot,however,precludetheirneedforthoughtfulapplicationoflightforthesakeofemotionalstate.Itisincreasinglycommontofindworkspacesthatrecognizetheimpactthatenvironmentalcomforthasonproductivity.Workenvironmentsalsocommonlysupportmultipleuses,servingworkersastheymovefromcomputertaskstophysicallayouttasks,filing,readingandwriting.Themostsuccessfulworkenvironmentsarethosethatkeepaspacefreshbyaccommodatingdifferentlightingfeelingsthroughoutaworkday.Task-focusedlightingtoo-oftentakestheformofauniformtextureofdownwarddirectedlight.Theadditionoflightingingredientsthataltermoodinaspaceandrevealthearchitecturecangreatlyimproveuponanotherwisedrabandlifelessenvironment.Rememberthatthelayoutsherearejustsomecommontactics.Asuccessfullightingdesignisathoughtfullightingdesignwheretheprogramofthespaceisconsidered,alongwithallavailablelightingoptions.

Layout1LightingOpenOfficeSpace

Openofficespacesoftensufferundertheuniformtreatmentoftasklightdirecteddownward.Themonotonyofthesinglelighttexturecancauseeyestrainandmentalfatigue.Theinclusionofmultiplelighttexturescanimprovethelong-termcomfortofsuchspaces.Lightingtheperimeterofopenofficespacesalsoworkswonderstocreateaspacethatfeelsbrightandlively.Officelightingsystemsmustalsobedesignedtominimizevisiblelampsandglarethatcaninterferewithcomputerscreensandsensitivetasks.Workspacesthatare

computer-focusedmayevenbenefitfromaloweroverallambientlightleveltoavoidahazyreflectioninthescreens.Spacesthataremoreconcernedwithdiversityoftasksandinteractionwithdocumentsandgraphicmaterialsbenefitfromchangeablelightingeffectsandemphasisonthecolor-renderingcapabilitiesofthelightsources.Integratingdaylightharvestingaddsanadditionallevelofcomplexitytothesituation.

CommonFeatures1.Linearfluorescentpendantsdistributelightupontotheceilinganddownward.Thecombinationoftexturesavoidsanoverlydiffuseexperienceandeliminatesvisibilityofbarelamps.Theluminairesaremounted18”to24”fromtheceilingtoallowlighttospreadevenlyovertheceilingplane.2.Recessedfluorescentwallwashluminairesmounted18”to24”fromthewallcreateabrightverticalsurfacetoenhancetheperceptionofbrightnessinthespaceanddefinetheperimeter3.Localizedfluorescentorhalogenundercabinettaskluminairesateachworkstationprovideadirectionalsourcetopunchthoughtthehazeofthegeneraloffice-widelight.Thetasklightcanalsobeselectedtoprovideimprovedcolorrendering.Theseluminairesareindependentlycontrolledbyeachworkspaceoccupant.4.2’×2’or2’×4’acousticalceilingtilesareacommonfinishincommercialspaces.Thesetilesoftenrestrictthelayoutortypesofluminairesthatcanbeusedinthespace.Anindirectlightingsystemmustconsiderthereflectanceoftheseceilingtiles.

AddressingLayersChoreography:Longlinesoflinearfluorescentluminairescreateapatternthat

directsanalreadysymmetricspace.Arowofrecessedwallwashluminairescreatesanadditionalbrightverticalsurfacetodrawattentionthroughthespace.

MoodandAmbience:Individualworkstationshavethebenefitofmoredirectional,colorrendering,localizedtasklightingtopunchthroughthediffuselightingcreatedbypendant-mountedindirectluminaires.Fluorescentlampswithgoodcolorrenderingindices(80+)providereasonablyaccuratecolorrendition.Colortemperatureisselectedtocomplementthecolorpaletteofthematerialsandfinishes.

Accenting:Wallwashluminairesprovideapunchoflightontotheverticalwallsurfaces.Localtasklightingprovidesdirectionallightateachworkstation.

RevealingArchitecture:Longlinesofindirectlinearfluorescentluminariescomplementthelinearnatureofthelay-inceilingtilesandthearrangementoftheworkstations.Luminairesaremountedperpendiculartothelongaxisoftheroomtoavoidanoverly-long,bowlingalleyeffect.

TaskLighting:Linearfluorescent,direct-indirectpendantscreateacombinationofdiffuseanddownward-directedlightforlong-termvisualcomfort.Localizedtasklightingateachworkstationaccommodatescriticaltasksandprovidesimprovedcolorrendering.

Layout2LightingaPrivateOffice

Aprivateofficeservesasanareaofindustryandanareaofrespite.Itmustplaythepartofaworkstationwhilealsoservingasameetingroomandthinkingenvironment.Thelightingsystemsmustbeversatiletocreatevaryingenvironmentaleffects.Atypicalprofessionalmayspendmoretimeinaprivateofficethananyotherspace.Differentlighttexture,brightverticalsurfaceandcontroloverindividuallightingzoneshelptoserveallofthesefunctions.

CommonFeatures1.Well-designed2’×2’fluorescenttroffersprovideadirectionaldownlightcomponentandadiffusespreadofarealight.Recessedindirect

2’×2’luminairesmightalsoprovideadesirablelighttexture.2.Compactfluorescentwallwashluminairesaroundtheperimeterdefinethespaceandaddtotheperceivedbrightness.

AddressingLayersChoreography:Awashoflightonthebackwalldirectsattentionthroughthe

space.Heightenedlightlevelsonthedesksurfaceandotherfurnishingsprovidevisualinterestandhierarchy.

MoodandAmbience:Multipletexturesareachievedthroughthecombinationofmoredirectwallwashluminairesanddiffuselinearfluorescenttroffers.The2’×2’troffersinthisspacecreateadownwarddirectedlightcomponentthathasdirectionalanddiffusequalities.

Accenting:Wallwashluminairescanservetoaccentartonthewalls.Thedirectionalcomponentofthetrofferscastsacrisplightontothedesksurfacebelow,creatingalightedcenterpiecetotheroom.

RevealingArchitecture:Thewallwashluminaireshelptoexpandtheperimeterofthespacebybrighteningtheverticalsurfaces.

TaskLighting:Diffuseanddirectionlighttexturescombineoverthedeskareatoprovidecomfortablelightingforvisualtasks,aswellasconversingwithcolleagues.

Layout3LightingaConferenceRoom

Corporateconferenceroomsserveasareasofcongregationthatbringcolleagues

togethertodiscussbusinessandbuildcamaraderie.Thesespacesalsoactasthecallingcardthatdefinestheimageofthebusinesstooutsiders.Conferenceroomsserveamultitudeofusesfrombusinessdealingstopresentations,luncheonsandvideoconferencing.Thelightingsystemsinaconferenceroomshouldbedynamicandeasytocontroltocreatedifferentlightingenvironments.Theluminairesinaconferenceroomalsotendtohaveanaestheticappeal,fittingoftheimagethatthecompanywantstoconvey.

CommonFeatures1.Adecorative,direct/indirectpendantcastslightupintothecoffervolumeanddownontotheconferencetableandthefacesoftheoccupants.2.Staggeredlinearfluorescentstripsserveasanuplightingcovetofillthecofferwithlightthatinter-reflectstocastdiffuselightintothecoreofthespace.3.Compactfluorescent,recessedwall-washluminairesaddthenecessaryperimeterbrightnesstosoftenthespaceandincreasetheperceptionofbrightness.4.Acousticceilingtilesmaydictatethelayoutofsomeluminairesandmustbeconsideredforhowtheywillreflectlightbackintothespace.

AddressingLayersChoreography:Theconferencetableis,appropriately,theobviousorganizing

elementofthespace.Linearfluorescentpendantsoverheadserveasbrightobjectstodrawattention,aswellastolighttheconferencetable.Aceilingcovesystemcreatesabrighthaloabovethisgatheringarea.

MoodandAmbience:Themultipletexturesoflightcreateareasofdistinctgatheringimportance.Thesoftuplightofthecoveandthebrightnessofthependantsandthelightedtablecreateasenseofseverityandimportance.Perimeterlightinghelpstolightenthemoodwhennecessary.

Accenting:Thependantsandthetablesurfacearethenotableelementsofvisualinterestandorganization.Thewallwashluminairescanalsoservetoaccentartworkorgraphicsonthewall.

RevealingArchitecture:Wallwashluminairesservetodefinetheperimeterofthespacewhilethecentralcovecreatesheightandafocalelementtoanchorthespace.

TaskLighting:Varioustexturesareatworktoprovidedifferenttypesoflightat

theconferencetableforreadingtasks,aswellasrenderingoccupants.Conferenceroomsintendedforvideoconferencingneedadditionallayersofcontrollablelighttorenderoccupants,aswellasbalanceoutthebrightnessofthebackground.

Layout4LightingaReceptionArea

Areceptionareaisoftenthefirstpointofcontactforanoutsideranddefinesmuchoftheidentityofafacilityandacompany.Thesespacesmustbe,atonce,welcomingandcomfortable,nottomentionimpressiveandintriguing.Definingdistinctzonesofusewithinthereceptionareahelpstoorganizethespacebycreatingpointsofspecificinteraction.Seatingareas,displayareas,andtaskareasalldeserveuniquelightingcharactersandtheirownphysicalspace.Decorativeelementsandattentiontocorporatesignageworkwonderstoenhancetheappeal

ofreceptionareas.Lightsourcesshouldalsobechosenwithconcernforcolorrenderingandcolortemperaturesthatarecomplementarytothecolorpaletteandmaterialsinvolvedinthedécor.

CommonFeatures1.Incandescentorfluorescentdecorativependantsaddsparkle,reducescaleandputlightontothetasksurfacebelowthem.2.Compactfluorescent,recessedwallwashluminairespaintlightontothebackwallandanysignagethatmaybethere.3.Incandescentorfluorescent,decorativependantsdrawvisitorstotheseatingarea,creatingvisualinterestandreducingthescaleofthespace.Alittlebitofdecorativecharactergoesalongwaytocreateawelcomeenvironment.4.Recessed,fluorescenttrofferscancreateavolumeofdiffuselightingnecessarytoenliventhetransitionfromoutsidetoinside.Recessed,indirectluminairescanbespecifiedtoprovideacombinationofdiffuselightwithoutthesterile,corporatefeelingoftraditionalparabolictroffers.

AddressingLayersChoreography:Apatternofrecessedluminairescreatesbrightnessontothefloor

thatsurroundsanoccupantinbrightnessuponentry.Lightpaintedontothebackwallservesasthevisualgoalanddrawsvisitorsthroughthespaceorintothespaceiftheentryhasglassdoorsorwalls.Arowofdecorativependantscanalsocreateavisualcurtainthatstopsprogressatthepointofinteractionwiththereceptionist.Wallwashluminairesandpendantsalsodrawattentiontotheseatingareasontheperiphery.

MoodandAmbience:Multiplelighttexturesliven-upthespaceandcreateawelcomingexperience.Lightpaintedontothewallsincreasestheperceptionofbrightness.Pendantsaddahumanscaleandatouchofsparkleandacomfortablediffusequalityoflightattheentrypoint.

Accenting:Recessedwallwashluminairesplacelightontotheartandgraphicsontheverticalsurfaces.Decorativependantscatchtheeyeandpushlightdownontofurnitureandhorizontalsurfacesaspointsofvisualinterest.

RevealingArchitecture:Lightontothebackwalldefinesthelengthofthespacewhilelightedverticalsurfacesexpandtheperimeter.Decorativependantsdropspecificareasdowntoahumanscale.

TaskLighting:Accentedsignageonthebackwalllendscorporateidentity.

Pendantsdrawlightontothereceptionsdeskandtheseatingareatables.

Chapter29CommonLightingDetails

Toimplementlightingdesignthattranscendsthestatus-quoyetisstillconstructible,afairamountoftimeandeffortmustbeputintorefiningtheconstructiondetailsofeachlightingapplication.Manylightingeffectsaretheresultofprecisionandsubtlety.Withouttheproperconsiderations,unusuallightingapplicationscanbecomesourcesofglareorsimplywastedelectricity.Tounderstandwhatispossiblewithlight,itisimportantthatadesignerhaveafairunderstandingoftypicalconstructionmethods.Everyprojecthasuniqueconditionswhichwillaccommodatecertaintypesoflightingintegrationbetterthanothers.Knowledgeofissuessuchasplenumspace,framingconstructiontypeandwallthicknesswillaffectlightingoptions.Rememberthateveryprojectisunique,andthedetailspresentedhereareforreferenceonly.Besuretocoordinatewiththedesignteamtodeveloplightingapplicationsthatwillworkforthespecificproject

Awallorceiling-integratedcoveisagreatwaytovolumizeaspacebycastinglightupontotheceilingplaneabove.Thiskindofcleanshapeoflightcanharmonizewellwiththegeometryofthespaceandlendasoft,envelopinglight.Covescanbeimplementedwithavarietyoflinearsources,includinglinearfluorescent,linearincandescentandlinearLEDsources.

KeystoSuccess:Socketshadowthatoccurswhereluminairesbuttagainstoneanotherisacommonproblem.Considerwhetherthelighthasroomtospreadout,orwhethertheluminairesshouldbestaggeredtooverlapandeliminatethesedarkareas.Geometryofthecoveshouldcreateanopeninglargeenoughforlighttoleave,aswellasformaintenanceoftheluminaires.Cove-specificluminairesexist,whichincorporatereflectorsandopticsthatdrivelightoutofacoveinaveryefficientmanner.

Covegeometryshouldbedesignedtoeliminatethepossibilityoflampvisibility.

Wallslotsintegratecontinuouslinearsourcesconcealedanddirecteddownwardtocreateawashofbrightnessontheverticalsurfacesofaspace.Thesebandsandplanesoflightcanbreakupaspaceandaddtotheperceptionoflightnessbydisconnectingthewallsfromtheceiling.

KeystoSuccess:Socketshadowthatoccurswhereluminairesbuttagainstoneanotherisacommonproblem.Considerwhetherthelighthasroomtospreadoutorwhethertheluminairesshouldbestaggeredtooverlapandeliminatethesedarkareas.Geometryoftheslotshouldcreateanopeninglargeenoughforlighttoleaveaswellasformaintenanceoftheluminaires.Cove-specificluminairesexist,whichincorporatereflectorsandopticsthatdrivelightoutofaslotinaveryefficientmanner.Slotgeometryshouldbedesignedtoeliminatethepossibilityoflamp

visibilityConsiderthematerialsandcraftsmanshipofthewallbeinglighted.Becauseoftheirgrazingnature,wallslotstendtoshowoffimperfections.Bewareofspecularorshinywallsurfacesastheytendtoreflectimagesofthelamp.

Undercabinetlightingisagoodwaytolocalizetasklight.Thiscanbeaccomplishedwithavarietyofsourcetypes,butcolorrenderingandcolortemperatureshouldalwaysbeapriority.

KeystoSuccess:Undercabinetlightingshouldbeaccomplishedwithasolidfrontluminaireorincludeafasciaorpropergeometrytoeliminatethepossibilityoflampvisibility.Undercabinetsystemscanincludelocalswitchingatthetasklocationormaybecontrolledfromtypicalwallswitchlocations.Undercabinetsystemscanutilizeluminairesassmallas1”×1”linearincandescentormorerobustpucklightsandlinearfluorescentsources.Iflinearfluorescentlampsareusedforundercabinetlight,theyshouldbespecifiedwithgoodcolorrenderingandcolortemperatureinmind.

Considerthelocationforthetransformerthatisrequiredforthelowvoltagesourcescommonlyused.

Suspendedsoffitpanelsandfloatinglidsaregoodwaystoreducethescaleofspaceandcastavolumizinglightupward.Suchsystemscanbeverysimplestructurallyandcanmakeuseofcommonsourceslikelinearfluorescentstrips.Withtheadditionofinexpensivecolorfilters,adroppedlidcantransformthemoodandspatialeffectofaspaceverythoroughly.Droppedsoffitscanserveastheanchorforseatingareas,officeworkstationsandretaildisplays.

KeystoSuccess:Considerthegeometryandlocationoftheluminairestoeliminatethepossibilityoflampvisibility.Considerthematerialabovethesoffit.Itshouldbereflectiveenoughtospreadthelightbackintotheroom.Specular(shiny)surfacesshouldbeavoidedastheywillreflecttheimageofthelampsorluminaires.Thesuspensiondistanceshouldbeconsideredtoensurethatlighthasroomtointer-reflectwithinthespace.Luminaireplacementshouldbestudiedtoensureevenlightingwithoutapparentstripesorhotspots.

Backlitwallsandlargeglowingpanelsaddalightnessthattranscendstypicallyconstructedspaces.Thechallengewithlargescaleapplicationsisachievinganevenplaneoflightthattrulyappearstobeself-luminous.

KeystoSuccess:Amplespacebehindthebacklitpanelmustbeavailableforlighttodiffuseevenly.Maintenanceandaccessmustbedesignedintothepanelsystem.Thediffusingpropertiesofthepanelmaterialwilldictatethegeometryandluminairelayout.Besuretomock-uptheapplicationwiththespecificmaterialthatwillbeused.

Millworkintegratedlightingcreatesaverydistinctandattentiondrawingdisplayelement.Thistypeoffeatureiscommonlyusedforretaildisplayandfoodandbeveragedisplay.

KeystoSuccess:Considertheheatoutputofthelightsourceandhowitwillaffecttheobjectbeinglighted.Subtlechangesinsourcelocationwillaffectthelightqualityandshouldbestudiedandmocked-up.Displaylightingcanbeaccomplishedwithasinglelineoflight;bothtopandbottomlight,individualpucklightsoracombinationoftreatmentsasshownhere.Considerthelocationforthetransformerthatisrequiredforthelow-voltagesourcescommonlyused.

Chapter30DaylightandElectricLightIntegrationDetails

Someofthebestlightingdetailsarethosethatcombinetheeffectsofdaylightandelectriclightsources.Thehumanaffinityforthequality,colorandtextureofdaylightcrossesovertoelectriclightapplicationsthatcanmimicthesesametraits.Wellthought-outdetailsthatmanagetofusethetwotogethercancreateremarkablelightingeffectsthatcandefineaspace.Thesedetailshaveadynamiccharacterthatwillchangethroughthecourseofadaywhilemaintainingadesirableeffect.

Iftheelectriclightcomponentcanbeputonadimmer,aphoto-sensorthatdetectsvariationinlightlevelscanbeimplementedtocontroltheexactquantityofelectriclightbeingcontributedtoaugmentthedaylight.Suchsystemsensurethattheelectriclightisnotwasted.

Typicalskylightscanbeaugmentedwiththeadditionofupward-directedlightsources.Theelectriclightsystemcanbeascomplexasashelforcovesystemorassimpleassurfacemountedluminairesthatcastlightupward.Underdaylightconditions,sunlightwilldiffusethroughtheskylightmaterial.Whenactivated,theelectriclightwillwashup,fillingthevolumeoftheskylightandreflectingbackintothespace.

KeystoSuccess:Considerthediffusingmaterialoftheskylightasitmayreflectanimageoftheelectricluminaires.Considerthegeometryandlocationoftheluminairestoeliminatethepossibilityoflampvisibility.Consideraccessibilityandmaintenanceoftheelectriclightsystem.Considerswitchingordimmingoptionsandphotosensorstoregulatethecontributionoftheelectriclightsystem.

Alightmonitorisaperfectcandidateforelectriclightintegration.Ashelforcovesystemcanbeintegratedtocastlightupwardontotheceilingsurfaceofthemonitor.Theelectriclightwillwashup,fillingthevolumeofthemonitorandreflectingbackintothespace.

KeystoSuccess:Considerthediffusingmaterialofthemonitorasitmayreflectanimageoftheelectricluminaires.Considerthegeometryandlocationoftheluminairestoeliminatethepossibilityoflampvisibility.Consideraccessibilityandmaintenanceoftheelectriclightsystem.Considerswitchingordimmingoptionsandphotosensorstoregulatethecontributionoftheelectriclightsystem.

Aceilingslotisagreatwaytoharvestdaylightandistheperfectcandidateforelectriclightintegration.Thecleanplaneoflightcreatedbythedaylightcanbeseamlesslycomplementedbythesameshapeandtextureofelectriclight.Asimplefasciatoconcealtheelectricsourceisallthatisneeded.

KeystoSuccess:Considerthediffusingmaterialofthedaylightslotasitmayreflectanimageoftheelectricluminaires.Considerthegeometryandlocationoftheluminairestoeliminatethepossibilityoflampvisibility.Consideraccessibilityandmaintenanceoftheelectriclightsystem.Considerswitchingordimmingoptionsandphotosensorstoregulatethecontributionoftheelectriclightsystem.

Evensimplewindowscanbeusedtoharvestdaylightwhentheyarefittedwithadiffusingmaterialtocontrolthelightcontribution.Duringdaylightconditions,aclean,diffuselightfiltersin.Duringelectriclightoperation,lightwashestheinteriorsurfaceofthediffusingwindowandreflectsasoftglowbackintothespace.

KeystoSuccess:Considerthediffusingmaterialofthediffusingwindowasitmayreflectanimageoftheelectricluminaires.Considerthegeometryandlocationoftheluminairestoeliminatethepossibilityoflampvisibility.Consideraccessibilityandmaintenanceoftheelectriclightsystem.Considerswitchingordimmingoptionsandphotosensorstoregulatethecontributionoftheelectriclightsystem.

PartIVFinalThoughtsonDesign

TheFundamentalLightingDesignProcess

LIGHTINGDESIGNINANUTSHELLThefollowingshortcutswillservetojogyourmemoryandactasachecklistforthethoughtprocessesandproductionprocessesthatyieldgooddesignandimplementation.

TheDesignDevelopmentProcess

BrainstormanddevelopconceptsTheControllableAspectsofLight(Ch.5)Intensityoflight

ColoroflightTextureoflightShapeoflightOriginoflight

Lightingtechniques(Ch.9,10,11,14)Graphicdevelopment(TheFiveLayerProcess)

LightMapchoreographygoals(Ch.17)LightMapremainingdesigngoals(Ch.17)IdentifyandlabelIlluminancelevelcriteria(Ch.19)

TheSpecificationandRefinementProcess

Conceptrefinement

LightingCalculations(Ch.20)RedlineLightingLayout(Luminairelocations)(Ch.24)Selectluminairetypes(Ch.21,22)Downlights,Adjustableaccentluminaires,Flooruplights,Wall-mounteduplights,Linearsources,Low-

levelsteplights

TheFinalConstructionDocuments

Luminaireschedule(Ch.25)

Luminairecutsheets(Ch.25)Draftedlightingplan(Ch.26)

GreenDesignandSustainabilitySustainabilityhasmovedwell-uptheprogramformanyoftoday’slightingprojects.Thisevolutionwillonlyaccelerateaselectricityandothermaterialsbecomemoreexpensive.Allpartiesinvolvedinthebuildingprocessnowrealizethatgooddesignmeans“green”designandlightingisrecognizedasakeycomponentofthis.Thelightingdesignerisabsolutelyexpectedtobeanexpertintheimplementationofcurrentstandardsofbestpractice.Luminaires,lamps,andlightingcontrolsallcontribute.Softerenvironmentalissueslikelightpollutionandlighttrespassaddyetanotherlayerofknowledgeandexpertise.IntheUnitedStates,roughly1/3rdoftheelectricityweconsumeisforelectriclighting.Thisisahugepercentage,andmeansthatevensmallimprovementsintheapplicationoflightcanmeanlargereductionsinourconsumptionofelectricity.Youmayliveinamunicipalitywhereenergyconservationcodesarewrittenintobuildingcodesandcertaincriteriamustbemetinordertogetabuildingpermit.Alllightingdesignersshouldresearchandinvestigatetheorganizationsthataretakingtheinitiativetosuggestandmandateprogressive,energyefficientlightingdesign.CaliforniaStateEnergyCodeTitle24 energy.ca.gov/title24ASHRAE90.1 aashrae.orgUSGBCincludingLEEDProgram usgbc.orgSavingsbyDesign savingsbydesign.comInternationalDarkSkyAssociation darksky.orgEnergyStar energystar.govUSDepartmentofEnergy energy.gov/savingsDSIRESolarIncentives dsireusa.org

Butremember:Someconservationrecommendationstaketheformofveryclinicalmethodsforreducingtheconsumptionofelectricitythroughdraconianlimitsonsourcetypes,connectedloadandcontrolrequirements.Manyguidelinesandcodesarebasedona“lightingpowerdensity”(watts-per-

square-foot)prescriptionthatisbasedontheusetypeofeachprojectspace.Rememberthatyourintuitionofwherelightbelongsinaspaceandyourunderstandingofhowtoaccomplishmorewithlesslightarethefoundationofyourabilitytocreateimpactingdesignwithminimallightwaste.Themoreyourelyonbrightnessthroughcontrastandvisualinterest,themoreyouwillfindyourselfusinglesslightthroughgooddesignwithouthavingto“reduce”oreliminatedesignideas.

Putlightwhereitbelongs,decidewhatlightedsurfaceswillcontributebesttoyourlightinggoals,andyouwillbewellonyourwaytoconservativedesignthroughconsciousplacementoflight.

DesigningwithNewEyesRememberthatasdesigners,weareultimatelyresponsibleforhowpeoplefeeland,therefore,interactwiththebuiltenvironmentaroundthem.Therearenumerouslessonstobelearnedfromclassicaldesign,aswellasthenaturalworldallaroundus.Lookattheworldwithdesigner’seyes.Alwaysbeonthehuntfortoolsandtechniquesthatyoucanuseinyourdesigntoimpartaspecificfeelingorfunction.

Lighthasimmensepower.

Architecturalprojectsarerarelyrecognizedasgreatwithouthavingsuperbly-executedintegrationoflight.Manygoodprojectsuselightasanafterthought,buteverygreatprojecthaslightingthoughtattheverycore.Thereisno“right”lightingjustasthereisno“right”design.Thereisonlydesignanddesignedlightthatarewellthought-outandthatwhichisnot.Ifyouknowyourspace,youknowmorethanenoughtogettoworkplacinglightontothesurfacesandobjectsthatwillenhanceyourdesign.Thetoolspresentedherearesimplywaystogetyoutobettervisualizeanddrawlight.

“Ifyoucanconceiveofideasandcommunicatethemtoothers,youareeightypercentofthewaytogreatdesign.”

Hopefully,themoretechnicalaspectsofimplantingtheseideaswillserveyouasyousolveyourownlightingchallenges.

Designisastateofmind.Atruedesignercandesignanything.Itistheknowledgeofareliable,creativedesignprocessesthatwillgiveyouconfidenceintheformofabottomlesswellofgreatideasthatjumpfromyourmindontopaper.Letthoseideasout.Writethemdown,sketchthemup.Dowhateverittakestoemptyyourheadofconceptstocreateroomfornewones.Thereisnoneedtoself-censoryourcreativeideas.Thereisawholeworldouttherethatwillhelpyouweedthroughyourthoughtsandfilteroutthebestofthem.

Goodluckindesigningandneverstopobservingandlearningfromtheenvironmentaroundyou.

AppendixAGlossaryofLightingTerms

AAccommodation:Thefunctionofthedynamiccomponentsoftheeyetofocus

onobjectsatdifferentdistances.Adaptation:Thefunctionoftheeyeandbrainworkingtogethertooperate

undervaryingamountsoflight.Adjustable(Luminaire):Describesaluminairethatincludesmechanicalmeans

toaimlightoutputinaspecificdirection.Ambientlight:Adescriptionofthelightqualitythatdefinestheoverall

experienceofaspace.Aperture:Anopeningcutintoaformorsurface.Oftendescribestheopeninga

recessedluminairecreatesintheceilingBBacklighting:Thetacticofplacingalightsourcebehindanobjectortranslucent

surface.Thiscreatesaneffectofsilhouettingsolidobjectsorcreatingaluminousplanefromatranslucentmaterial.

Baffle:avisualcontroldevicethatmountstothefaceofalightsourcetocontroltheanglesatwhichthelightsourceisdirectlyvisible.

Ballast:AnelectronicormagneticdeviceusedtocontrolelectricitytostartandoperatefluorescentandHIDlightsources.

CCandela(CD):aunitmeasurementoflightdensityfromalightsourceor

reflectiveobject.1Candelaistheequivalentonelumenoflightemittedevenlyfromaportionofsphericalsurfaceareacalledasteradian.

Candlepower:anexpressionofluminousintensityfromalightsourceexpressedinCandelas.

CandlepowerDistributioncurve:Agraphicalrepresentationofthelightintensityleavingalightsourceinspecificdirections.

CenterBeamCandlepower(CBCP):Acommonly-usedexpressionofluminousintensityfromthecenter-mostareaofalightsource.(Thisis

typicallythemostluminousareaofalightsource)Choreography:thedirectionofmovementandpathofexperienceofanindividualinthedesignedenvironment.

Chromaticity:Thelevelofsaturationevidentinacoloredmaterialorcoloredlightsource.

CoefficientofUtilization(CU):AfactorusedinlumenmethodcalculationstoexpresshoweffectivelylightisbeingdeliveredfromaluminairetothesurfaceinquestionColorRenderingIndex(CRI):Anexpressionofthecompletenessofthespectraloutputofalightsource.Indicateshowaccuratelyalightsourcewillrevealcolorsinthelightedenvironment.Expressedonascalefrom1to100:thehigherthenumber,themorecompletethespectraloutputandthemoreaccuratethecolorrendition.

Colortemperature:Amannerofdescribingtheapparentcolorofalightsource.Commonlyusedtoexpressthecoolorwarmcolorofasourcethatdeviatesfromneutral.ExpressedindegreesKelvinorKelvins(K)D

Daylight:Ageneralreferencetothequalityoflightreceivedfromthesunasitdiffusesthroughtheatmosphereoftheearth,includingbothdirectsunlightanddiffusedskylight.

DiffuseLight:LightwhichisscatteredinalldirectionsinrelationtoitssourceDiffuser:Lensmaterialusedtoscatterthelightoutputofasourceinall

directionsDimmer:Alightingcontroldevicethatvariestheelectricitydeliveredtoa

luminairetocontroltheoutputoflight.DirectionalLight:Lightthatleavesasourceinasingledirectionthroughmeans

ofreflectorsoropticalcontrol.DirectBurial(Luminaire):Aluminairethatresidesprimarilyinthegroundor

floorstructureofaspaceandcastslightupward.EEfficacy:Usedinlightingasanexpressionofhowwellalightsourceconverts

electricityintoradiantlightenergy.ExpressedasLumensoflightperWattofelectricityforLumensperWatt(L/W)Exitance:Anexpressionofthelightquantityleavingareflectivesurfaceinalldirections.

FFlood(Light):describeslightcastinaconfidedmannedoverabroadareaasa

resultofinteractionwithopticsandreflectors.FluorescentLamp:Alightsourcetechnologythatreliesontheexcitementof

phosphorstoconvertalimitedspectrumofradiationintoamorecompletespectrumofvisiblelightFoot-Candle(FC):The(English)unitof

expressingandmeasuringlightfluxontoanobject,where1Foot-candleistheequivalentofonelumenoflightarrivingevenlyontoasurfaceareaof1squarefoot.

GGlare:Excessivebrightnesscreatedbyanunshieldedlightsource.Also

describesthereflectionofbrightobjectsvisibleinaspecularsurfaceGrazing:Thetacticoflightingasurfaceatasevereanglefromanearbylightsource.TendstospreadlightoveragreatdistanceandrevealtextureH

Halogenlamp:Alightsourcetechnologythatreliesonanincandescingfilamentwithinapressurizedenvironmentofhalogengas.

HighIntensityDischarge(HID)Lamp:Alightsourcetechnologythatreliesonanarcofelectricitypassedbetweenelectrodestoexciteanenvironmentofvaporizedmetal.IncludessourcessuchasMercuryVapor,HighPressureSodiumandMetalHalide.

IIlluminance:Anexpressionoflightquantityincidentontoasurface.Expressed

andmeasuredinFoot-candles(FC)(Englishunit)orLux(LX)(SIunit).In-grade(Luminaire):(Seedirectburial)Incandescentlamp:Alightsourcetechnologythatreliesonradiantenergy

emittedfromametalfilamentresistingaflowofelectricity.IndirectLight:lightdistributedafteritreflectsorinteractswithashielding

surfaceInter-reflection:Theproductoflightinteractingwiththeobjectsandsurfaces

ofaspace.LLamp:ThegenerictermforanengineeredlightsourceLampLife:Anexpressionoftheexpectedoperatinglifeofalightsourceexpressedinhours.Light:Electromagneticradiationthatstimulatesthevisualsystemofatypical

human.LightEmittingDiode(LED):ALightsourcetechnologythatrelieson

electricitypassedthroughasolidstateelectricaldevicethatemitsasinglewavelengthofradiation.

LightLossFactor(LLF):Asafetyfactorusedinlightingcalculationsthataccommodatesforthelossoflightproductionofaluminaireovertimeduetodirt,ballastdepreciationandlumenoutputdepreciationLightMap:Theauthor’stermforavisualdocumentthatexpresseslightingintentthrough

coloredgraphicsonanarchitecturalfurnitureorfloorplan.Louver:Abladedshieldingdeviceimplementedinaluminairetoreducethe

visibilityofabarelampLumen:anexpressionofradiantenergyfluxasitimpactsthehumanvisual

system.Luminaire:Adevicethatcontrolsthedeliveryoflightthroughthemanagement

ofelectricityandtheinclusionofballasts,transformers,opticalelements,reflectorsandarchitecturalmountingmechanisms.

LuminousFlux:Thetotalquantityofvisibleradiantenergythatleavesalightsourceinalldirections.ExpressedinLumens.

Lux(LX):TheSIunitofexpressinglightfluxincidentontoasurface(illuminance)

OOccupancysensor:Devicethatimplementsheat,soundandmotiondetectionto

determinewhetheraspaceisinuse.PPARLamp:Lampshapethatutilizesaparabolicaluminizedreflectortodeliver

controlleddirectionallight.CommonlyassociatedwithHalogenandMetalHalidesourcesPhotometry:Thescienceofmeasuringlightoutputdistribution,patternsandeffectsfromlightsources.

RRecessedLuminaire:Aluminairethatresidesprimarilyintheplenumabove

theceilinglineofaspace.Reflectance:Anexpressionofthepercentageoflightincidentontoasurface

thatinturnleavesthesurface.ReflectedCeilingPlan(RCP):Anarchitecturalplanthatshowsthecontents

anddetailsofanarchitecturalceilingsystemasitwouldappearifviewedfromwithinaspace.

Re-strikeTime:Anexpressionofthetimerequiredforalightsourcetocooloffbeforeitcanbereignitedafteraninterruptionofpower.CommonlyusedinreferencetoHIDsources.

SSconce:Awall-mountedlightingdevicecommonlyassociatedwithadecorative

character.SeasonalAffectiveDisorder(SAD):Ahumanphysiologicalcondition

associatedwithinadequateexposuretovariouswavelengthsoflightcontainedindaylight.

Soffit:Anarchitecturalfeatureofgeometryaddedtoaspacethroughbuilt-up

constructionSolarGeometry:Thepredictablemovementofthesuninthelocalsky,dueto

theearth’srotation,revolutionanddeclination.Specular:Descriptionofamaterial’sabilitytodirectlyreflectlightimages.

Commonlyexpressedas“shiny”.Spot(Light):Describesdirectionallightdeliveredinaconfinedbeamasaresultofinteractionwithopticsandreflectors.StepLight:Aluminairethattypicallyrecessesintothelowerportionofawall

forthepurposeofilluminatingstairs.Steradian:Aunitofsphericalareasuchthatanysizesphereconsistsof2π

Steradians.Usedinmeasuringluminousintensity(seeCandela).TTransformer:anelectromagneticdevicethataltersthevoltageofelectricity

deliveredtoalightsource.Translucent:Thedescriptivepropertyofamaterialthatallowslighttopass

throughbutaltersthedirectionofthelight,resultingindiffusion.Transmission(oflight):Thepassageoflightthroughvariousmaterials.Transparent:Thedescriptivepropertyofamaterialthatallowslighttopass

throughitwithminimalrefractionorchangeofdirection.Troffer:Descriptionofluminaires,commonlyofarectangularnature,that

utilizelinearfluorescentlampstodeliverauniformlighttexture.WWarm-upTime:Referencetothetimerequiredforalamptocometofulllight

output.CommonlyusedinreferencetoHIDlightsources.Wash:Describeslightdeliveredinanevenfashionacrossalargesurface.Watt:Unitofexpressingandmeasuringelectricalworkpotentialinacircuitasa

productofpotentialvoltageandamperage.

AppendixBProfessionalOrganizationsandAgencies

ProfessionalandEducationalOrganizationsAmericanInstituteofArchitectswww.aia.orgAmericanLightingAssociationwww.americanlightingassoc.comAmericanOptometricAssociationwww.aoanet.orgAmericanSocietyofHeating,RefrigerationandAir-ConditioningEngineerswww.ashrae.orgAmericanSocietyofInteriorDesignerswww.asid.orgAmericanSocietyofLandscapeArchitectswww.asla.orgAmericanSolarEnergySocietywww.ases.orgIlluminatingEngineeringSocietyofNorthAmericawww.iesna.orgInternationalAssociationofLightingDesignerswww.iald.orgInternationalCommissiononIlluminationwww.cie-usnc.orgInternationalDarkSkyAssociationwww.darksky.orgInternationalInteriorDesignAssociationwww.iida.org

NationalCouncilforInteriorDesignQualificationwww.ncidq.orgNationalCouncilonQualificationsfortheLightingProfessionswww.ncqlp.orgNationalLightingBureauwww.nlb.org

PublicationsArchitecturalLightingMagazinewww.archlighting.comLightingDesign+ApplicationMagazinewww.iesna.org/lda/iesnalda.cfmMetropolisMagazinewww.metropolismag.comMondoArcMagazinewww.mondoarc.comProfessionalLightingDesignMagazinewww.via-verlag.com

SearchToolsElumit(Lightingsearchandspecificationtool)www.elumit.comDesignguide.comwww.designguide.comLightsearch.com(Lightingproductsearchtool)www.lightsearch.com

ConferencesLightfairInternationalwww.lightfair.comProfessionalLightingDesignConventionwww.pld-c.orgTheArcShowwww.thearcshow.com

AppendixCDescriptiveWordsforLighting

BoldBrilliantConfinedContrastyCrispDramaticDreamyDiffuseDirectEffervescentEphemeralEvenExoticExpansiveFocusedGleamingGlimmeringGlowingHarshIntenseLiquidMuddyMurkyOozingRadiantRestrainedSharpSmooth

SoftSparklingSprawlingSubtleTheatricalUnderstatedVividVoluminous

AppendixDDirectoryofContributorsandOtherManufacturers

SpecialThankstothefollowingmanufacturerswhoweregraciousenoughtofurnishreproductionsofliterature,technicaldataandimages.Withoutthismaterial,thepagesofthistextwouldnotbenearlyascolorful.

ArdeeLighting888.442.7333www.ardeelighting.com

Bartco714.230.3200www.bartcolighting.com

Belfer732.493.2666www.belfergroup.com

DaSal604.464.5644www.dasalindustries.com

Deltalight954.677.9800www.deltalight.us

Erco732.225.8856www.erco.com

GELumination216.606.6555www.led.com

PhilipsLightolier508.679.8131www.lightolier.com

LutronElectronics610.282.3800www.lutron.com

OsramSylvania978-777-1900www.sylvania.com

TechLighting8474104400www.techlighting.com

WilaLighting714-259-0990www.wila.net

Thefollowingrepresentasmallcrosssectionofmanufacturersoflightingequipment.

Lamps

GELightingwww.gelighting.com

OsramSylvaniawww.sylvania.com

PhilipsLightingwww.lighting.philips.com

Ushiowww.ushio.com

VentureLightingwww.venturelighting.com

Luminaires

Artemidewww.artemide.us

BegaUSwww.bega-us.com

BruckLightingSystemswww.brucklighting.com

ColorKineticswww.colorkinetics.com

ColumbiaLightingwww.columbia-ltg.com

CooperLightingwww.coooperlighting.com

Floswww.flos.com

JunoLightingwww.junolighting.com

Lightolierwww.lightolier.com

LouisPoulsenLightingwww.louispoulsen.com

Lithoniawww.lithonia.com