is human centric lighting really human centric in a...

IN DEGREE PROJECT ARCHITECTURE,SECOND CYCLE, 15 CREDITS

, STOCKHOLM SWEDEN 2017

Is Human Centric Lighting Really Human Centric in a Classroom?A holistic evaluation of a HCL-system in a classroom

Architectural Lighting Design

JONAS MALMBERG

KTH ROYAL INSTITUTE OF TECHNOLOGYSCHOOL OF ARCHITECTURE AND THE BUILT ENVIRONMENT

www.kth.se

ISHUMANCENTRICLIGHTINGREALLYHUMANCENTRICINACLASSROOM?

AholisticevaluationofaHCL-systeminaclassroom

JonasMalmberg

MasterThesis,ArchitecturalLightingDesignKTH,RoyalInstituteofTechnologyLightingLaboratory,2017

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ABSTRACTThepurposeofthisstudyistoevaluateHumanCentricLightinginaclassroom.Previousstudiestendtofocusprimarilyonthebiological,non-visual,effectsoftheHCL.Inthisstudy,amoreholisticapproachtoHCLisapplied,includingboththenon-visualaspectaswellasthevisualandemotionalaspects.Inordertofulfiltheaimofthestudy,thethreeaspects-visual,emotionalandbiological-willbeinvestigatedthroughfivedifferentmethodologies;observationandanalysisoflightingdistributionandbehaviouralanalysisoflightingsystemasavisualaspect,surveysaboutthemoodandemotionsasanemotionalaspectandvisualperformanceandvisualacuityasabiologicalaspect.TheevaluationtookplaceintheelementaryschoolSturebyskolaninStockholm,whereaclassroomwithaHCL-systemistobefound.Thesystemincludesthreelightingsettings;800lxand6000K(energylight/focuslight),500lxand4000K(standard/normallight)and300lxand3000K(calm/relaxedlight).Resultsshowpositiveeffectonvisualperformanceandbettervisualacuityinfocuslightingthaninrelaxedlighting.Focuslightingwasperceivedasacoldandhardlightingfortests,whiletherelaxedlightingwasperceivedasawarmandcalmlightingforacosyfeeling.Thelightingcharacteristicsaresuitedforatypicalclassroom.Theignoranceofthelightingsystemcanbeaproblemfortheexperienceandusageofthelightingintheclassroom.Insummary,todenominatealightingsystemasHCLandonlyconsiderthealteredcolourtemperatureandlightintensityisnotcomprehensiveenough.AHCL-systemneedstoconsiderthevisual,emotionalandbiologicalaspects,andthebiologicalaspectisexplicitlyconsideredinthislighting-system,whilsttheemotionalandvisualaspectsarehowevernotcarefullyconsidered.Asaproposaltoconsiderallthreeaspects,severallayersoflightcouldbeaddedinordertostrengthenthevisualaspectandcreateavividandinterestingatmosphere.Moreover,consciousarrangementofluminairesandluminaireswithflexiblecharacteristicscouldsimplifyandbroadentheopportunitiesintheclassroomandfacilitatetheuseoflightlayers.

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TABLEOFCONTENTSAbstract.............................................................................................................................2

Introduction.......................................................................................................................4

Aim....................................................................................................................................4

Hypothesisandresearchquestions....................................................................................4

Background........................................................................................................................5Visualperception............................................................................................................................5Non-imageformingeffectsoflight.................................................................................................6HumanCentricLighting..................................................................................................................7Lightinginschools..........................................................................................................................7

Methodology....................................................................................................................10Visualaspect.............................................................................................................................10

Lightingdistribution......................................................................................................................10Behaviouralanalysis.....................................................................................................................10

Emotionalaspect.......................................................................................................................10Perceptionofmood......................................................................................................................10

Biologicalaspect.......................................................................................................................11Visualperformance......................................................................................................................11Visualacuity..................................................................................................................................12

Limitations.......................................................................................................................13

Analysis............................................................................................................................14Lightingsystem.............................................................................................................................14Classroom.....................................................................................................................................15Controlgroupclassroom..............................................................................................................15Daylight.........................................................................................................................................15

Results.............................................................................................................................16VisualAspect.............................................................................................................................16

Lightingdistribution......................................................................................................................16Behaviouralanalysis,interviews...................................................................................................17

EmotionalAspect......................................................................................................................18Perceptionofmood......................................................................................................................18

Biologicalaspect.......................................................................................................................20Visualperformance......................................................................................................................20Visualacuity..................................................................................................................................21

Discussion........................................................................................................................22Proposal....................................................................................................................................27

Conclusions......................................................................................................................29

References.......................................................................................................................30Figuresandpictures..................................................................................................................33

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INTRODUCTIONSincethediscoveryofthethirdphotoreceptorintheeyeandtheevidenceofthebiologicalinfluencefromlight,thetermHumanCentricLighting(HCL)hasbecomemorepopularinthelightingindustry.Overall,HCLtendstofocustoomuch,oronly,onthenon-visualeffectsofthelightingwheretunablewhite-luminairesinsomecaseshasbeenequatedwithHCL.HCLisstillaquitenewconceptinthelightingindustryandstillmostlyusedinofficeandhealthcareenvironment.Alargeareaofapplicationcouldbeschoolsandeducationalenvironments.Duetomypreviousexperienceasateacher,Ifinditinterestingtoinvestigatetheeffectsoflightinginschoolenvironment.AtanelementaryschoolinStockholm,Sturebyskolan,thereisaclassroomwithHumanCentricLightingluminaireswhichareautomaticallycontrolledandvarylightintensityandcolourtemperatureaccordingtothetimeofday.AfewotherschoolsorclassroomshavetesteddifferentkindsofHCLsolutions,butthereisstillmoreresearchtobedoneinthisfield.Previousstudiestendtofocusonthebiological,non-visual,effectsoftheHCL.Inthisstudy,amoreholisticapproachtoHCLisapplied,includingboththenon-visualaspectsaswellasthevisualandemotionalaspects.ThepurposeofthisstudyistoemphasizethevisualaspectoflightingdesignandbroadentheviewofHCL.

AIMTheaimofthisstudyistoevaluateHumanCentricLightinginaclassroomfromavisual,emotionalandbiologicalaspect.AnotherobjectiveistoproposeasuitablelightingdesignwiththeuseofHumanCentricLightinginaclassroom.

HYPOTHESISANDRESEARCHQUESTIONSMyhypothesisisthatHCLneedsmoreconsiderationthanatunablewhiteluminairewithvaryinglightintensitiesandcolourtemperatures.Theresearchquestionsareasfollows:

- ArevaryingcolourtemperaturesandlightintensitiesenoughtocallalightingsystemHumanCentricLighting?

- HowcanaHumanCentricLightingdesignthatconsidersboththevisualandthenon-visualaspectslooklikeinaclassroom?

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BACKGROUNDVISUALPERCEPTIONInhisV/PLightingTheory,AndersLiljeforsmakesadistinctionbetweenvisualandphysicalentitiesandhebelievesthatthephysicalradiationisnotthestartingpointinalightingcontext,butthevisualexperienceofaspace.Liljeforsmeansthatevenifthemeasurementoftwolinesareequal,butweperceivethemvisuallyasdifferentlengths,thevisualperceptionisnotwrong,onlydifferentfromthemeasurement.“Thehorizontallineslookdifferentasaresultofthevision’sremarkableabilitytoperceivethevisualexperienceofspace.”(Liljefors,1999)Furthermore,Liljeforsmeansthat“Itisfullypossibletomethodicallydescribeareliableknowledgeofthevisualworld,basedoncommonvisualexperiences,intermswhichmakeitpossibletospecifybasicrelationsvisually-physically.”InV/PLightingtheorythevisualexperienceofaspaceisdescribedbyseventerms;

- leveloflightness,howlightordarkitisinaroom- spatialdistributionofbrightness,whereitisdarkerorlighterinaroom- shadows,wheretheyfallandtheircharacter- reflections,wheretheyoccurandtheircharacter- glare,whereitoccursandhownoticeableitis- colouroflight,thecolourexperienceofthelight- colours,iftheylooknaturalordistorted.(Liljefors,1999)

Seeingisanactiveinformation-seekingprocesswherevisualsensorydataarecoordinatedwithcontextualinformationfromothersenses,pastexperienceetc.AccordingtoLam,wehavethreeaspectsofperception;theattributive(matchingpatternsandclassification),theexpectant(associationswithsequencesandexpectationsduetopreviousexperience)andtheaffective(howstimuliaffectsouremotionalorevaluativeresponses),whichinrealityarehardtoseparatebecausetheyareintimatelyinterrelated.Inaddition,becauseourvisualattentionseeksthemostinterestingthinginthevisualfield,ourfocusselectordirectsourattentiontoabrightspotoranotherinterestingobjectwhichcanbeinformation(lightonasignorstage)oradistraction(whenilluminatedelementsareunrelatedtoourneeds).(Lam,1992)However,byfullyilluminatingspaceswithauniformlightthatmakeseverythingvisible,nothingisemphasised,whichmaycreatealackofvisualinterestwithnosupportfororientationandspatialunderstanding.(WänströmLindh,2013)Madsenhasdevelopedthetermlightzonestodescribespatialunitsmadeupoflightwithinthespaceasatoolforanalysis.Lightzonescanbegroupedintothreecategories:A)asingleorseparatelightzone,B)lightzonesincloseconnectionwitheachother,andC)lightzonesthatoverlapeachothertocreateacompound,illuminatedarea.Madsen’sobservationsbecamethestartingpointforviewingilluminatedfieldsinthescalemodelstudy.Madsenstudyonlyexaminednaturallight,butitispossibletoanalyseartificiallightsourceswiththesametool.(Madsen,2004).In1992,Ejheddidafullscalestudytoinvestigateifitwaspossibletocreateagrammarforlightingandenvironmentaldesign.Asamethodheused,amongother,semanticdifferentialscaleswherethetestsubjectswouldevaluatedifferentroomsbymakingnotesin31differentsemanticscales.Inordertomaketheabstractanswersmoretangible,thesemanticscalesweresupplementedbyquestionsaboutassociationsandcharacteristicsoftheroom.The

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evaluationresponseswereprocessedinamatrixprogramonacomputerwhichdeterminedthemeaningsofandrelationsbetweenthesemanticscales/pairsofwords.(Ejhed,1992)In1952RichardKellyestablishedaterminologyandprinciplesasatheoreticalfoundationinlighting.Hepresentedthreeelementsintheperceptionsofvisualdesign;focalglow,ambientluminescenceandplayofbrilliants.Thesethreeelementslaterbecameapointofreferenceinthefieldoflightingdesign.(Neumann,2010)NON-IMAGEFORMINGEFFECTSOFLIGHTBothhumansandanimalshaveacircadianrhythm,orinnerclock,whichforexamplecontrolsoursleepcycle.Foralongtime,itwasassumed,butnotproven,thatlighthadagreatimpactonthecircadianrhythm.Thediscoveryofthethird,non-imageforming,photoreceptor(NIF)in2002confirmedthatthereceptorsintheeyenotonlyhaveavisualfunction,butalsoabiologicalfunction(Bersonet.al.,2002)(Hattaret.al.,2002).Thethirdreceptors,intrinsicallyphotosensitiveretinalganglioncells(ipRGCs)worksimilartorodsandcones,exceptthatitdoesnottransmitinformationtothevisualcortex,butdirectlytothesuprachiasmaticnuclei(SCN)andfurtherontothepinealglandwherethehormonemelatoninissynthesizeddependingonthelightconditions.Thisdiscoveryexpandedtheknowledgeabouthowlightinfluencesourcircadianrhythmandourbiologythroughhormones.Hence,thelightcaninfluencealertness(SahinandFigueiro,2013)(Teixeiraet.al.,2013),sleep-cycles(Santhiet.al.,2008)andbehaviour(vanHoofet.al.,2009).Thesediscoverieswerethestartofthenon-visualapproachinthelightingindustryandledtoresearchandtestsontheimpactoftiming(Santhiet.al.,2008),colourtemperatures(SahinandFigueiro,2013)etc.Sincetheresponsesbythevisualandthecircadiansystemsaredifferenttoopticalradiation,acalculationproceduretomeasurecircadianlight(CLA) andcircadianstimulus(CS)weredevelopedandpresentedinareport(Reaet.al.,2010). InordertomeasurethecircadianstimulusmanyresearchersfromseveralcountriesandUniversitieshaveproposedanewmeasuringsystemforcircadianlight.“ThediscoveryofipRGCphotoreceptors,andourgrowingunderstandingoftheirroleinsettingphysiologicalandbehaviouralstate,hasrevealedthatcurrentmethodsoflightmeasurementareincomplete.Weproposemethodsoflightmeasurementthatquantifyeffectiveirradianceforeachofthephotoreceptiveinputstothissystemindependently”.(Lucaset.al.,2014) Furthermore,inareportonmetrictoquantifybiologicallightexposuredosesitisfoundthat“thecurrentlyusedlux(photopicirradiance)isnotthemostappropriateunittodescribehowmuchlightisneededtogeneratethebiological(NIF)effectsoflight.Luxischaracterizinglightonlywithrespecttovision,notwithrespecttoitsbiologicalNIFeffects.Incontrasttothis,α-opicirradiancesandthemelanopicdaylightequivalentilluminanceareusefulmetricstosupportlightdesignerstodecide,whichlightconditionscanbeusedtopromote,oravoid,certainbiological(NIF)responses.Thesemetricsareexpectedtobeparticularlyeffective,whendesigninglightconditionswithnarrowspectralbandsordifferentcolortemperatures.”(Giménez,2013)

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HUMANCENTRICLIGHTINGInthelightingindustry,thetermHumanCentricLighting(HCL)isfrequentlyusedinseveraldifferentcontexts.HCLhasnogeneraldefinitionanditisuptotheusertodefineit.Boyceexplains:“Whatthepeoplewhotalkabouthuman-centriclightingmeanislightingthatconsidersboththevisualandnon-visualeffectsofexposinghumanstolightandthatwidenstherangeofpossibleeffectsfromvisualperformanceandcomforttosleepquality,alertness,moodandbehaviourwithconsequencesforhumanhealth,learningandspending.”(Boyce,2016)Inseveralcases,thebiological,non-visual,parthasbecomethemostimportantone.Intermsofartificiallighting,HCLisoftentranslatedintoafixturewithtunablewhitewhereitispossibletochangecolourtemperatureanddimthelightintensityfromhightolow.HCLismostlyusedtoenhanceorimprovethecircadianrhythm,forexampleinoffices,retirementhomesandhealthcare.Forexample,“thenewuseoflightismadepossiblebecauseofthenewknowledgeonthebiologicaleffectsoflight,andbecauseofrecentinnovationsinlightingtechnology.WiththeintroductionofLEDs,orLightEmittingDiodes,tuneablewhitelightcanbeachievedinanenergy-efficientmanner,whichiseasytocontrolwithadvancedcontrolsystems.”(GlamoxLuxo,2017)and“…therightlightattherighttimeandintherightlocation.Also,biologicallyeffective,dynamicwhitelightwithabrightness-andlightcoloursequenceaccordingtothecourseofdaylight.Thissupportsthenaturalbiologicalrhythmtoincreaseourwell-beingandimproveourcapacitytoperform.”(Osram,2017)Inthisstudy,thedefinitionofHCListakenfromarecentlypublishedreportfromIALD,whereHCLisdefinedas“…theconceptdescribingtheconnectionbetweenlighting,healthandwellbeing.Lightingthatfocusesonpeopleshouldbalancevisual,emotional,andbiologicalbenefitsoflightingandpromotegoodvisionwhilesatisfyingtheemotionalandbiologicalneedsoftheusers.”(Ladopoulos&Shaw,2017)LIGHTINGINSCHOOLSInastudycarriedoutinSweden,in2015,26percentoftherespondentsthoughtthelightinginschoolswereuncomfortable.(Belysningsbranschen,2015)Throughhistory,theopinionshavevariedonwhatsignifiesgoodlighting,andthisisalsovisibleinschoolbuildingsbuiltindifferentdecades.Forexample,thesize,positionandorientationofthewindowsandtheamountofdaylighthavehaddifferentimportanceindifferentdecades.Intheearly20thcenturythewindowsinSwedishschoolsweresupposedtobebigandfacingsouthinordertoobtainasmuchlightaspossible.Later,thiswasreconsideredduetoenergysavingsandheating.(SwedishNationalHeritageBoard,2000)Between1900-1960,itwasrecommendedtohavehighceilingswithlargewindowsuptothetopofthewall,andthesizeofthewindowstobeequivalentto15-20%ofthesizeofthefloor.Inthe1960ththeceilingheightswerelowereddownandinthe1970thdaylightwasconsideredunnecessaryandtheclassroomsweremadetobedeepandwithsmallwindows(Holm&Alm,1990).OnethingthatregulatesthelightinginSwedishschoolstodayisthelawofworkingenvironmentwhereitisdeterminedthatthelightshouldhaveappropriatedistributionandaiming.Also,thecolourrenderingshouldbesuitedforthetask,thelightshouldbeflickerfreeandtherehavetobedaylightwithviewinclassroomsandstaffrooms(Arbetsmiljöverket,2009).Inaddition,thelightingintheschoolareasareregulatedbythelightingstandardsforworkplaces

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EN12464-1(inSwedenSS-EN12464-1:2011)withdifferentdemandsduetowhatkindofroomitis.Forexample,inaclassroomitisnecessarytohave300lx,19UGR,0,60Uo,80Ra.(SwedishStandardsInstitute,2011)SISAB,thepropertymaintenancecompanyforallmunicipalschoolsinStockholm,hastheirownguidelinesforlightinginshools;thelightsourceshouldbeLED,thelightingshouldbecontrolledwithpresenceanddaylightsensorsinordertosaveenergyandclassroomsshouldhavependantluminaireswithbothindirectuplightanddirectdownlight.Furtheron,arecommendationaboutthelightingqualityisstated:“Researchalsoshowsthatverticallight(onwalls)andambientlightareimportantfortheworkenvironmentandaffecttheperformance”(SISAB,2017,translationfromSwedishbytheauthor)Researchhasproventhatdaylightisimportantbothforresultsandwellbeinginaschoolenvironment.Inastudywithclassroomswithoutwindowsthecortisollevelswerehigherinthemorningswhichhadanegativeeffectontheconcentration,bodygrowthandsickleave.Intheconclusion,arecommendationnottohaveclassroomswithoutwindowswasproposed.(KüllerandLindsten,1992).Furthermore,anotherstudyfoundthatstudentswithmostdaylightintheirclassroomsprogressed20percentfasteronmathematicsand26percentfasteronreadingthanstudentshavinglessdaylightintheirclassrooms.(Loisos,1999)Differentlightsourceshavebeenpopularduringthehistoryandfull-spectrumfluorescentlightingwascommonbeforetoday’sLEDtechnology.Thefull-spectrumfluorescentlightingwasusedinordertomimicdaylightandgainthepositivehealtheffectsthatwecanattainfromdaylight.Butthereisnoevidencethatthefull-spectrumfluorescentlightingisbetterforyourhealthorcanmimicthedaylight,concludedinastudyfrom2001.(McColl&Veitch,2001)Today,almostallnewlightingisLED.InaSwedishstudy,LEDfixtureswerecomparedwithT5fluorescenttubesoverawholeacademicyearindifferentclassroomswith72studentsaged17-18.Thelightenvironment,electricityconsumption,andstudents’mood,lightperceptionandsalivacortisolconcentrationweremonitored.TheclassroomswithLEDfixtureswereslightlypreferred.(Gentileet.al.,2016)TheschoolenvironmentisalsoofinterestforHCL,butresearchabouttheeffectsofHCLarestilllimited.InastudyfundedbyPhilips,anevaluationoftheirHCL-systemSchoolVisionwasconducted.Twoclassrooms,eachintwoseparateschools,withvariablelighting(VL:lightingthatisvariableinilluminanceandcolourtemperature)werestudiedoveraperiodofninemonths.Theresultsshowedthatstudentsmadefewererrors,particularlyfewererrorsofomission,onastandardizedtestofattentionundertheVL“Concentrate”program.Readingspeed,asmeasuredusingstandardizedreadingtests,rosesignificantly.Incontrast,theachievementmotivationofthestudentsandtheclassroomatmospheredidnotchangeoverthenine-monthperiod.Overall,thestudentsandteachersratedVLpositivelyandfounditusefulduringlessons.(Barkmannet.al.,2012)Furthermore,eighty-fourthirdgraderswereexposedtoeitherfocus(6000K)ornormallighting.Focuslightingledtoahigherpercentageincreaseinoralreadingfluencyperformance(36%)asopposetocontrollighting(17%).(Mottet.al.,2012)

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Anotherpaperevaluatestheeffectoflightingconditions,carriedoutinthreeexperiments,(withverticalilluminancebetween350 luxand1000 luxandcorrelatedcolourtemperaturesbetween3000and12000 K)regardingtheconcentrationamongchildreninelementaryschool.Inthefirsttwoexperiments,aflexibleanddynamiclightingsystemwasusedinquasi-experimentalfieldstudiesusingdatafrom89pupilsfromtwoschools(Study1)and37pupilsfromtwoclassrooms(Study2).Thethirdexperimentevaluatedtwolightingsettingswithinaschool-simulating,windowlesslaboratorysetting.Theresultsindicateapositiveinfluenceofthelightingsystemonpupils’concentration.Thefindingsstresstheimportanceoflightingforlearning.(Sleegerset.al.,2011)Moreover,anon-publishedstudymadebyOsramin2011examinedtheeffectoflightinperformancecapabilityofpupils.Withthenewlightingdesignedtosimulatedaylight,participatingpupilsachievedbetterresultsinstandardizedtestsforconcentrationcapabilitythanthecomparisongroup.Performancespeedalsoincreasedsignificantly.(Helbig,2011)Inanotherstudy,thenearvisualacuity(400mmdistance)of27childrenaged10-11yearswasmeasuredundertwocommonfluorescentlampsofCCT3600Kand5500K.Acuitiesweremeasuredforthreelightingconditions.TheresultsshowedthatvisualacuitywassignificantlybetterunderthehigherCCTlampwith24of27childrenhavingbetteracuity.(Bermanet.al.,2006)

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METHODOLOGYInordertoanswertheresearchquestionsandtofulfiltheaimofthestudy,thethreeaspects-visual,emotionalandbiological-willbeinvestigatedthroughfivedifferentmethodologies;observationandanalysisoflightingdistributionandbehaviouralanalysisoflightingsystemasavisualaspect,surveysaboutthemoodandemotionsasanemotionalaspectandvisualperformanceandvisualacuityasabiologicalaspect.

VISUALASPECTLIGHTINGDISTRIBUTIONTheevaluationofthelightingdistributionwasrealisedbymeansofLiljeforsV/PLightingtheory.(Liljefors,1999)Theclassroomwasevaluatedandanalysedwiththeseventermsastool.Theevaluationofthelightingdistributionwasmadeintermsofsemanticlightingscalesfrom1-5.ThescalesarebasedontheV/PLightingTheory,withmodificationofFavero(seeappendix4),andareasfollows;

- Leveloflightness(leveloflight):1=verydark,5=verybright- Spatialdistributionofbrightness(lightdistribution):1=uniform,5=verydramatic- Shadows:1=veryvague,5=verymarked- Reflections:1=none,5=verymarked- Glare:1=none,5=intolerable- Colouroflight:1=cool/cold,5=warm- Colours(appearanceofsurfacecolour):1=natural,5=deteriorated

Theanalysiswascarriedoutonthe24thofApril2017andtheweatherconditionsatthetimefortheanalysiswereabrightdaywithovercastskyandwhite,lightclouds.Fourdifferentobservationsweremade;onewithonlydaylight,onewithrelaxedlightingandthecurtainsclosed,onewithnormallightingandthecurtainsclosedaswellasonewithfocuslightingandthecurtainsclosed.Theanalysiswasmadebytheauthorofthisstudyandcanbeperceivedassubjective.Hence,theanalysistoolismeanttobeusedbyprofessionals,notbycommonpeopleinasurvey.BEHAVIOURALANALYSISThetwomainteachersintheHCL-classroomwereinterviewedon24thofApril2017and8thofMay.TheywereaskedabouttheiruseoftheHCL-system,howtheyperceivethefunctionalityofthesystem,howtheyexperiencetheuser-friendlinessofthesystemetc.Inaddition,twootherteachersthatteachintheHCL-classroomwerebrieflyaskedabouthowtheyusethelightingsystem.ThelanguageintheinterviewswereSwedish,whichwaslatertranslatedintoEnglish.

EMOTIONALASPECTPERCEPTIONOFMOODAsurveywasdistributedtoallpupils’intheclasswithHCL,andwereansweredonthe15thofMayduringmentorstid(30minutesofinformationfromtheformteachers).Thepupilswerethesameasinthevisualperformancetest,whythissurveywascarriedoutafterthesecondvisualperformancetestinordertonotinfluencetheresultsorthoughtsaboutthelightingin

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thevisualperformancetest.Thesurveyisdividedintofourparts,thefirstpartincludesgeneralquestionsaboutpupils’moodandtheirperceptionoflighting.Parttwo,threeandfourallconsistofthesamequestions,regardingtheirmoodandtheirperceptionofthelighting.ThequestionsabouttheirperceptionofspaceareselectedandtakenfromEjhed’sstudyLjusochrum(Ejhed,1992),whichincludessemanticdifferentialscaleswithonewordineveryendofthescale.NotallsemanticscalesfromEjhedsstudyareincludedinthisstudy,theoneswhichhadmostrelevanceandweresuitableforthetargetgroup(14-year-oldpupilsinelementaryschool)werechosen.Inordertoanalyseanswersfromanentireclass,thescaleshaveninemarkerswhichcanbesummarizedaccordingtotheaveragenumbers.Therespondentsshouldwriteacrosssomewhereonthescalewhichshouldcorrespondtotheirspontaneousperceptionoftheroom.Thepupilswereinstructedtoplacethecrossinthemiddleofthescaleiftheydidnotunderstandthewordsorthescale.Duringparttwo,threeandfourofthesurvey,thelightingintheclassroomwaschanged,sothepupilsrespondedtoquestionsaboutthelightingthatwasactuallyintheroom.Hence,inpartoneandtwonormallighting(500lx,4000K)wasturnedon,inpartthree;relaxedlighting(300lx,3000K)andinthefourth;focuslighting(800lx,6000K).Thepupilswererequestedtostopaftereachpageinordertohavethecurrentandcorrectlightingforthewholeclassatthesametime.Atthetimeforthissurvey,thecurtainsintheclassroomwereclosedinordertodecreasetheinfluenceofdaylightandenhancetheeffectofthedifferentlightingsettings.Inaddition,selectedvolonteerpupilswereaskedsomefollow-upquestionsaboutthesurveyandthelighting.Thiswasmadeasacomplementtotheanswersinthesurveyinordertomaketheanswersmoretangible.Semanticdifferentialscalesarefrequentlyusedforresearchersinterestedinhumanresponsestothequalitativeaspectsoflightedenvironments.(TiflerandRea,1992)Inthisstudy,thesemanticdifferentialscalesareasuitabletoolforevaluatingtheperceptionandemotionsconnectedtothedifferentlightingsettingintheclassroom.

BIOLOGICALASPECTVISUALPERFORMANCEInordertotestthevisualperformanceandconcentrationindifferentlightingconditionsamatricesIQtestwasused.AmatricesIQtestisanon-verbal‘culturefair’multiplechoiceIQtest,whichmeasuresyourfluidintelligence,yourreasoningandproblemsolvingability.Ineachtestitem,thesubjectisaskedtoidentifythemissingelementthatcompletesapatternofshapes.Thepatternsarepresentedintheformofa3×3matrix.Inthefirsttest,pupilsreceived14matrixquestionswithfivemultiplechoicestosolveinfiveminutes.Inthesecondtest,pupilsweregivenanother14matrixquestions,withcorrespondingdifficultylevel,withfivemultiplechoicestosolveinfiveminutes.Thetestswerecarriedoutwithpaperandpencils.Thefirsttestoccasionwasonthe24thofApril2017,wherethelightingwascalmlightforrelaxedactivities(300lx,3000K).Thesecondoccasionwasonthe8thofMay2017andthelightingwasfocuslightfortestactivities(800lx,6000K).BothtestswerecarriedoutonaMondayat9.45inmentorstid.Thefurnishingwasdifferentduringthetwotests(seeanalysisfordetails).

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Acontrolgroupinanotherclassroomwithregularlighting(recessedfluorescenttubes)wasalsotestedwiththesamequestionsatthesamedates.BothtestswerecarriedoutonaMondayat14.00inanEnglishlesson.ThereasonforhavingamatricesIQtestwastocarryoutaculturefairtestwherepriorknowledgeandsubjectknowledgeshouldnotinfluencetheresultsconsiderably.Furthermore,thetestwaswellsuitedforafullclasswithapproximately30pupils,wasfasttocarryoutandeasytounderstand.Inaddition,thetesttestedconcentration,readingandvisualabilitywhichissimilartocommonschoolworkintheclassroom.Theprocedureofthetestwas:

- pupilswereinformedaboutthetestandusageoftheresults.Theywerehowevernotinformedaboutthepurposeofthetestortheobjectivesandsubjectofthestudy,inordernottoinfluencethem.

- pupilsexaminedtwoexamplesquestionsonthefrontpageofthetest- thefive-minuteteststartedwhenallpupilsweredonewiththeexamplesand

answeredaffirmativeonthequestioniftheywerereadytostart- pupilswereinformedaboutthetimeremainingeveryminuteandwhenthefive

minutesended(including15secondsbeforetheend)

PICTURE1EXAMPLEQUESTION,MATRICESIQTEST PICTURE2,QUESTIONINMATRICESIQTEST

VISUALACUITYVisualacuityreferstotheabilitytodiscerntheshapesanddetailsofthethingsyouseeorsharpnessofvision,intermsofthesizeofdetailwhichcanbedetectedbytheeyeatagivendistance.Avisualacuitytestisaneyeexamthatcheckshowwellyouseethedetailsofaletterorsymbolfromaspecificdistance.Differentalphabeticalandsymbolicalchartsareavailableasmethodsofmeasuringthevisualacuity.

Inthisstudy,theMonoyertestwasused,whichisachartoflettersindifferentsizesandarrangedinrowsandcolumns,viewedfrom5meters.Duringthetest,thepupils,onebyone,stoodata5meters’distancefromthechartandcoveredoneeye.Thetestleaderpointedataletterandthepupilsread,outloud,theletterstheycouldseewiththeiruncoveredeye.Theprocedurewasthenrepeatedwiththeothereye.Thetestwascarriedoutin2ndofJune2017wheretenvolunteerpupilswerechosentoproceedthetest,fiveduringrelaxedlighting(300

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lx,3000K)andfiveinfocuslighting(800lx,6000K).Duringthevisualacuitytest,thecurtainsintheclassroomwereclosedinordertodecreasetheinfluenceofdaylightinthistest.ThereasonforusingtheFrenchMonoyertestisbecauseitisastandardisedtestforvisualacuity,butnotcommonlyusedinSwedishclassroomswhichdecreasesthechanceofreiteration.

PICTURE3,MONOYERCHART,VISUALACUITYTEST

LIMITATIONSManydifferenttestsandevaluationsarepossibletocarryoutinordertoevaluatelighting.Duetothelimitedamountoftime,itwasnecessarytoleaveoutsometestsandfocusontheonesthatwaspossibletofulfilduringthetimeforthestudy,inspring2017.Inaddition,theamountofdatacollectedcanbesaidtocorrelatetothedisposabletime.Becauseofthis,thereisabiggerriskofcoincidentandlowervalidity.Tomeasuretheeffectsandtheperceptionintheclassroom,itwouldbepreferabletocarryouttestsregularlyduringawholeacademicyear.Inalongerperiodofdatacollection,itwouldalsobepossibletocomparedifferentseasons.Furthermore,thestudyandthetestswerecompletedinaseasonwithalotofdaylight,whichmadetheartificiallightingnotasinfluencingasitisinwintertimewithdarkmorningsandafternoons.Becauseofthis,theeffectofthelightingsystemisprobablylowerthanitwouldbeinwintertime.However,thedaylightchangesduringtheyearisnothingwecanregulateandinawayitisinterestingtoseetheresultsinthebrighttimeoftheyearaswell.

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ANALYSISLIGHTINGSYSTEMIntheelementaryschoolSturebyskolaninStockholm,thepropertymaintenancecompanySISAB,hasprovidedaclassroomwithaHCL-system.ThesystemwasinstalledinDecember2016andtheHCLclassroomisprimarilyusedbyaclassin8thgrade.TheluminairesinthesystemareprovidedbythemanufacturerGlamoxLuxo,andarependantluminaireswithdirectandindirectlightcalledReed,hangingattheheightof2,20meters.Elevenluminaires,inapatternofthreetimesthreeplustwowhiteboardluminaires,areconnectedtothesystem.Theluminairesonlyhaveonedriveranditisnotpossibletocontroltheindirectanddirectlightseparately.Allluminairesintheclassroomareconnectedtoacontrolsystemwithaclockthatchangesthecolourtemperatureandlightintensityaccordingtotime.Thedifferentsettingsinthissystemare:

- 800lx,6000K(energylight/focuslight),thisisusedinthefirsthourofschool,from8.00to8.51,asenergylight.Itcanalsobemanuallyswitchedonduringspecialactivities,liketestetc.asfocuslight.Whenitismanuallyswitchedon,itisautomaticallyswitchedoffmaximum30minutesafteractivation.

- 500lx,4000K(standard/normallight),thisisusedasstandardlightforcommonactivities,normallessonsetc.Exceptforthefirsthourofschool,thislightingisautomaticallyusedduringtheremainsoftheday.Itisnotpossibletomanuallyactivateduringthefirsthourofschool.

- 300lx,3000K(calmlight),canbemanuallyswitchedonforrelaxedactivitiesandisthenautomaticallyswitchedoffmaximum30minutesafteractivation.Itisnotpossibletomanuallyactivateduringthefirsthourofschool.

Thesystemismanuallydimmableandthesettingsaremanuallycontrolledthroughacontrolpanelintheclassroom.Inthetoppanel,youcanchoosethethreesettings;focus,normalandrelaxed.Thefourthbuttonswitchesofftheluminaires.Inthebottompanelitispossibletodimthelightmanuallyandcreateyourownsetting.Amanualismadebythemanufacturer,butsofar,themanualisstillatthepropertymaintenancecompanySISAB,andnotavailablefortheteachersatthisschool.Onthethemanufacturerswebpage,itispossibletoreadaboutHCLsolutionineducation;

Duringtheearlymorninghours,therightlightcanhelptowakeupwithlesssleepiness.Abetterlightenvironmentcanimprovealertnessandconcentrationduringlessons.Lightingsystemsthatgivehigherlightintensitiesandcolourtemperatureattherighttimecanhelptoimprovedurationofsleepandqualityofsleepandthusimprovelearningeffects.

Withbiologicallyoptimizedlightingsystemsineducationalenvironments,naturallightingconditionscanbeachievedmoreeffectively.Simplysaiditispossibletoimitatenaturallightinginsidetheclassroom.(GlamoxLuxo,2017)

PICTURE4,CONTROLPANELINCLASSROOM

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CLASSROOMTheclassroomissituatedonthebottomfloorinoneofthemainbuildingsoftheschool.Theroomisaformerlibrarywhichhasbeendividedintotwoclassrooms.Theshapeoftheroomisrectangularandthewindows,whicharecoveringalargepartofonewall,arefacingnortheast.Therearefourwindowswhichareeach1,30mwideand2mhigh,thesizeoftheroomis8,80mlong,6,50mwideand3,05mhigh.Therearealsowindowsontheoppositewallwhereyoucanseeintothemainhall/atrium,thesizeofthewindowsis4mwideand1,30mhigh.Thematerialofthefloorisadarkgreylinoleum,thewallsarepaintedinalightgreycolour,theceilingconsistsofwhite60x60panelsandthefurnitureismostlylightwoodmaterial.Onthe24thofApril2017,duringthefirstvisualperformancetest,thefurniturewassituatedingroupsof4-6deskswithatotalof28deskswithappurtenantchairs.Onthe8thofMay,duringthesecondvisualperformancetest,thefurniturewassituatedinlinesalongthewallsandagroupofdesksinthemiddleoftheclassroom.CONTROLGROUPCLASSROOMTheordinaryclassroom,whichwerethelocationforthecontrolgroupinthevisualperformancetest,islocatedatthesecondfloorinthemainbuildingoftheschool.TheshapeandsizeoftheclassroomissimilartotheHCL-classroombuttheceilingheightislowerandthewindowsarefacingtheoppositedirection,southwest.Thelightinginthisclassroomisceilingmountedfluorescenttubeswithacolourtemperatureof3000Kandnotpossibletodim.Thefurniturewassituatedinpairsofdesksandappurtenantchairs,atotalquantityof28desks.DAYLIGHTDuringthedaylightanalysisthecurtainswerecovering1/3ofthewindows(whichwastheordinarysetting)andtheartificiallightingwasswitchedoff.Timeforanalysiswasatnoononthe24thofApril.Thelargequantityofwindowsontheouterwallcontributedtolargeamountofdaylightintheroom.Thereweredifferencesinthelevelsoflight,werethedistancefromthewindowwalldeterminedtheillumination.Onthedesksfarfromthewindows,theilluminationwasapproximately100lux,onthedesksinthemiddleoftheclassroomtheilluminationwasapproximately170lux,onthedesksclosetothewindowstheilluminationwasbetween600-1200luxandonthewindow-ledgestheilluminationwasmorethan6000lux.Ananalysisofthelightingdistribution,showedthatthedaylightgaveaveryuniformlight,completelywithoutsharpshadowsandwasperceivedascoldandmediumbright.Noglarewasperceived,thereflectionsweremediummarkedandthecolourswereperceivedasnatural.

Level of light

1 2 3 4 5Very dark Very bright

Light distribution

1 2 3 4 5Uniform Very dramatic

Shadows

1 2 3 4 5Very vague Very marked

Reflections

1 2 3 4 5None Very marked

Glare

1 2 3 4 5None Intolerable

Colour of light

1 2 3 4 5Cold Warm

Colours

1 2 3 4 5Natural Detariroated

Only natural light

PICTURE5,CLASSROOMON8THOFMAY

FIGURE1,ANALYSISOFDAYLIGHT

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RESULTS

VISUALASPECTLIGHTINGDISTRIBUTIONThefindingsintheobservationsoftheartificiallightingincludenonereflectionsandglare,generallyuniformlightingaswellasoverallnaturalcolours.Thelevelsoflightandthecolouroflightdifferedaccordingtothedifferentsettingswithcoldandverybrightlightinfocuslight,mediumcold/warmandbrightinnormallightandwarmanddarkinrelaxedlighting.Theshadowswerevagueintherelaxedlightingandmediumvagueinthenormalandfocuslighting.Theobservationofthedaylightshowedsimilarfindingstotheartificiallightingconditions,withuniformlightwithoutshadowsandglare,naturalcoloursandcoldbutmediumbrightconditions.Thegreatestdifferencebetweentheartificiallightandthedaylightwasthereflections,whichwasclearlypresentedinthedaylightbutnotintheartificiallight.Inthisstudy,thelevelsoflightarenotviewedasascalefromtotaldarknesstoextremebrightness,andtheanalysisoflightlevelsisbasedon,andcomparedto,acommonclassroomwithordinarylighting,whichforexamplemeansthatresult1,outof5,isconsideredasadarkclassroom,notatotallydarkroom.Theresultvariesfromdarktoverybrightdependingonthelightingsettings;intherelaxedlightingtheleveloflightisconsideredlow,inthenormallightingitishigh,andinthefocuslightingitisconsideredasveryhigh.

Level of light


Light distribution


Shadows


Reflections


Glare


Colour of light

1 2 3 4 5Cold Warm

Colours


Artificial lighting, curtains closed, relaxed lighting setting

Level of light


Light distribution


Shadows


Reflections


Glare


Colour of light

1 2 3 4 5Cold Warm

Colours


Artificial lighting, curtains closed, normal lighting setting

Level of light


Light distribution


Shadows


Reflections


Glare


Colour of light

1 2 3 4 5Cold Warm

Colours


Artificial lighting, curtains closed, focus lighting setting

FIGURE2,ANALYSISOFFOCUSLIGHTING FIGURE3,ANALYSISOFNORMALLIGHTING FIGURE4,ANALYSISOFRELAXEDLIGHTING

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BEHAVIOURALANALYSIS,INTERVIEWSInthissection,twoteachers,AandB,havebeeninterviewed.Twootherteachers,CandD,werealsointerviewed,butnotasthoroughlyasAandB.TeacherAneverusesthedifferentsettingsinthecontrolsystem,onlyonandoffandneverusesthedimmer.TeacherAhasnoticedthedifferentsettings,especiallywhenthelightisdimmeddown,andprefersthebrightestlight(focuslight)andperceiveitasgoodworklightingaswellasthebestlightingtouseingeneral.Thepupilsoccasionallychangethelightingsettings,however,nottoooften.Thepupilspreferdarkersettingsandwantitmoredimmeddownandcosy,accordingtotheteacher.TeacherAdoesnotthinkthecontrolsystem/keypadiseasytouseandonlyusesthefunctiononandoff.Thekeypadisdividedintotwoswitchesandtheonewhereyoucandimdownandchosesettingsisbehindthewhiteboard,andthatisthestrongestreasonfornotusingthekeypad.TeacherAhasnotbeenintroducedoreducatedinthenewlightingsystemanddoesnotknowthepurposeofthelightingsystem.Ingeneral,theteacherisverysatisfiedwiththelightingsystemandthinksthatthelightingisbetterthaninordinaryclassrooms,bothforteachersandpupils.Ifitwouldbemoreuser-friendly,withallsettingsononekeypad,theteacherwouldwishforitineveryclassroom.SometimeswhenteacherAisaloneintheclassroomandworks/reads,thepresencedetectorsarenotactivatedandthelightingturnsoff,whichcanbeannoying,butthisissimplyaminoraspect.Comparedtootherclassrooms,thelightingisbetterandneveroutoforder.TeacherBrarelyusesthedifferentsettings,butdidsomoreinwintertimewhenitwasdarkoutside.Duringthewinter,teacherBchangedthesettingsapproximatelyoneortwotimesaweek,butnow,whenitisbrighteroutside,theteacheronlychangesthesettingsoccasionally.Ithappensthatpupilschangethesettings,mostlyfromfocuslightornormallighttorelaxedlight,butthiswasalsomorecommonduringwintertime.TeacherBexperiencesadifferencebetweenthedifferentlightsettingsandlikesthefocuslight,eventhoughitisabitharsh.TeacherBsaysthatthefocuslightisbetternowthaninwintertime,butisunsurewhetheritisbecausethecontrastisnotthatgreatnowwithmuchdaylightorbecauses/heissimplyusedtothepresentlight.Furthermore,teacherBthinksthecontrolsystemiseasytouse,buthasnotbeeneducatedorintroducedtothelightingsystemexceptforanexplanationofitspurposefromacolleague.TeacherBissatisfiedwiththelightingsystemandbelievesthatthelightinginthetestclassroomisbetterthaninotherclassroomsandthatthelightisbetterasworklightingthaninolderclassrooms.TeacherBsuggeststhatthesystemcouldbedifferentinwintertimewhenitisdarkoutsideandinsummertimewhenitisbrighteroutsideinordertodecreasethegreatcontrast.Inaddition,teacherBwouldliketohavetheHCL-systeminallclassrooms.TeacherCandDwerebrieflyaskedabouttheirusingofthelightingsystem,andtheywerebothunawareofthelightingsystemanddidnotknowhoworwhytochangelightingsettings.

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EMOTIONALASPECTPERCEPTIONOFMOODThesurveywasansweredby21pupils.Inthegeneralquestions,over95%ofthepupilssaidthattheywereawareofthelightingsystemandthatthelightingsettingsvaryduringtheday.Inanoralfollow-up,somepupilssaidthattheydidnotknowthatthelightingchangesautomaticallyduringtheday,onlythatitwaspossibletochangelightingsettingsmanually.Themostnotableperceiveddifferencewasthedifferentlightintensities,afewpupilsalsonoticeddifferentcolourtemperatures.Furthermore,over95%oftherespondentsansweredthattheywouldliketocontrolthelightattheirowndesk.Inthefollow-up,afewpupilsmentionedthatitwouldbeirritatingifeveryonecouldcontroltheirownlightatalltimesandthatitwouldprobablynotbethebestsolutionfortheoveralllightingintheclassroom.Theaveragemoodwas4,27ofmaximum5atthispoint.Inthequestionsaboutthenormallighting,13pupils,orapproximately60%,thoughtthattheirmoodwasaffectedbythelighting.Acommonanswertowhenthepupilswantthislightingwasattestsandmathlessons.Themoodatthistimewaslowerthanatthefirstquestion,4outof5.Mostoftheanswerswereinthemiddleofthescaleandhadanaverageof4-6of9.Thebrightnesswasperceivedasbright,inaverage3outof9,andhalfoftherespondentsperceivedtheconditionsasverybrightandanswered1.Thecolourtemperaturewasperceiveddifferentlywherealmosthalfoftherespondentsperceivedthecolourtemperatureas1or2,buttheaverageresultwas4,4becauseseveralanswerswereclosetowarmonthescale.Also,thequestionaboutactive-passivewasdiffering,almosthalfoftherespondentsanswered1or2.Inthefollow-up,severalpupilswereconfusedaboutthenormallightingandthefocuslightingandthoughttheywerethesame.Severalcommentsaboutthenormallightinthesurveywereactuallymeantforthefocuslighting.Infigure5,theaverageresultforeveryquestionispresented.

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

Soft

Pleasant

Varied

Negative

Restful

Unsafe

Bright

Cold

Lively

Active

Hard

Boring

Uniform

Positive

Tiresome

Safely

Dark

Warm

Calm

Passive

Normal lighting settingAverage result

6,9

6,0

6,7

5,6

5,7

6,4

3,0

4,4

5,5

4,1

FIGURE5,PERCEPTIONINNORMALLIGHTING

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Inthepartwithrelaxedlighting,16pupils,whichcorrespondsto76%oftheparticipants,thoughtthattheirmoodwasaffectedbytherelaxedlighting.Thepupilsprefertohavethislightingduringcalmlessonsandwhentheyread,andseveralanswersindicatedthatthepupilsalwayswantthislighting.Theaveragemoodinthislightingwasthehighestmeasured,4,5outof5.Withthislighting,itwasonlytwoofthequestionsthatgaveamediumresultwithanaveragebetween4-6;varied-uniformandactive-passive.Thislightingwasperceivedaspositive(7,2outof9),calm(8outof9),dark(7,5outof9)andsoft(2,8outof9).Furtheron,therelaxedlightingwasperceivedaspleasant(3,7outof9),restful(3,7outof9)andsafe(7,1outof9).Inthefollow-up,pupilstalkedaboutthiscosylightingassimilartootherlightingathome,andthattheysometimeschangethelightingtorelaxedduringlessons,especiallywhenitisdarkoutside.Infigure6,theaverageresultforeveryquestionispresented.Inthequestionsaboutfocuslighting,14pupils,or66%,answeredthattheirmoodwasaffectedbythelighting.Thepupilswantthefocuslightingonwhentheyhaveatestandneedtoconcentrateextra.Severalpupilsalsowantedthislightingintheafternoon,andothersspecificallyneverwantedthislightingtobeon.Theaveragemood,4,1outof5,waslowerthaninthefirstquestionandintherelaxedlightingbutequaltothenormallightingmood.Thepupilshadmixedopinionsaboutnegative-positive(4,3outof9),unsafe-safely(4,7outof9)andactive-passive(4,2outof9),whereforexample,11pupilsperceivedthelightingasveryactive(answered1or2)and9pupilsanswered1onthequestionaboutnegative-positive.Focuslightingwasclearlyperceivedashard(8,5outof9)andbright(2outof9).Inaddition,thelightingwasperceivedasboring(7,1outof9),uniform(7,5outof9),tiresome(6,5outof9),cold(3,2outof9)andquitelively(3,9outof9)inaverage.Inthefollow-up,pupilstalkedaboutthislightingasthe“dentistlighting”andthatitistoobrightandsometimesgivesyouaheadache.Severalpupilsalsomentionedthislightasatest-lightandthattheyknowitisseriouswhenthislightisswitchedon.Infigure6,theaverageresultforeveryquestionispresented.

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

Soft

Pleasant

Varied

Negative

Restful

Unsafe

Bright

Cold

Lively

Active

Hard

Boring

Uniform

Positive

Tiresome

Safely

Dark

Warm

Calm

Passive

2,8

3,7

4,3

7,2

3,7

7,1

7,5

7,9

8,0

6,4

Relaxed lighting settingAverage result

FIGURE6,PERCEPTIONINRELAXEDLIGHTING

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

Soft

Pleasant

Varied

Negative

Restful

Unsafe

Bright

Cold

Lively

Active

Hard

Boring

Uniform

Positive

Tiresome

Safely

Dark

Warm

Calm

Passive

8,5

7,1

7,7

4,3

6,5

4,7

2,0

3,2

3,9

4,2

Focus lighting settingAverage result

FIGURE7,PERCEPTIONINFOCUSLIGHTING

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BIOLOGICALASPECTVISUALPERFORMANCEAtthefirsttestoccasionin24thofApril,26pupilsparticipatedintheHCL-classroomand25pupilsinthecontrolgroupinanordinaryclassroom.Atthesecondtestoccasionin8thofMay,24pupilsparticipatedintheHCL-classroomand26pupilsintheordinaryclassroom.InthefirsttestintheHCL-classroom,364questionswereansweredand190ofthemwerecorrect,whichgivesaresultof52%correctanswers.Theaveragescorewas7,3outof14andthemedianresultwas7.Thehighestscoreatthisoccasionwas12outof14.Thefirsttestintheordinaryclassroomincluded350questionsand205ofthemwerecorrect,whichresultedin58,5%correctanswers.Theaveragescorewas8,2outof14andthemedianresultwas8.Thehighestscoreatthisoccasionwas12outof14.Thecontrolgroupscoredbetterinallcategoriesinthefirsttestoccasion;percentage,averageandmedian.InthesecondtestintheHCL-classroom,336questionswereaskedand184ofthemwerecorrect,whichmeans54,76%correctanswers.Theaveragescorewas7,66andthemedianscorewas8,bothslightlybetterthenthefirsttest.Thehighestscoreatthisoccasionwas11outof14,onelesscorrectanswerthaninthefirsttest.Thesecondtestintheordinaryclassroomincluded364questionsand205ofthemwerecorrect,whichmeans56,31%correctanswers.Theaveragescorewas7,88andthemedianscorewas8.Thehighestscoreatthistestoccasionwas12outof14.Thehighestscoreandmedianscorewerethesameasinthefirsttest,butboththepercentageandaveragescorewerelowerinthesecondtest.

6,46,66,87

7,27,47,67,88

8,2

RelaxedHCL,test1 FocusHCL,test2

HCL-classroom

Averageresult Medianresult

7,7

7,8

7,9

8

8,1

8,2

8,3

Ordinary,notHCL,test1 Ordinary,notHCL,test2

Ordinaryclassroom

Averageresult Medianresult

FIGURE8,VISUALPERFORMANCEINHCL-CLASSROOM

FIGURE9,VISUALPERFORMANCEINORDINARYCLASSROOM

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VISUALACUITYTenvolunteerpupilsparticipatedintheteston2ndofJune2017.Fivepupilscarriedoutthetestinfocuslighting,andtheotherfivecarriedoutthetestinrelaxedlighting.Duringthefocuslighting,onepupilusedlensesandduringtherelaxedlightingonepupilusedglasses,theotherpupilshadnoknownvisualdefects.TheMonoyerchartconsistsof77lettersdividedintotenlines.Duringtherelaxedlighting,thepupilshadintotal187incorrectanswers,89withthelefteyeand98withtherighteye,whichgeneratesanaverageof18,7incorrectanswersperpupil.Inthefocuslighting,atotalof135answerswereincorrect,71withthelefteyeand64withtherighteye,whichmeans13,5incorrectanswersperpupil.Twopupils,oneinrelaxedlightingandtheotherinfocuslighting,hadnoincorrectanswersatall.Furthermore,fourpupilshadfourorlessincorrectanswers,twoinrelaxedlightingandtwoinfocuslighting.Fourotherpupilshad50ormoreincorrectanswers,twoinrelaxedlightingandtwoinfocuslighting.Inordertomakeacomparisonbetweenthetwolightingconditionswiththeexactsameeyes,onepupilcarriedoutthetestinbothrelaxedlightingandfocuslighting.Theresultintherelaxedlightingshowed108incorrectanswers(Relaxed5*inthetable)and72incorrectanswersinthefocuslighting. Lefteye Righteye TotalRelaxed1 3 1 4Relaxed2 0 0 0Relaxed3 31 28 59Relaxed4 1 15 16Relaxed5* 54 54 108 Total 89 98 187Average 17,8 19,6 18,7 Focus1 27 42 69Focus2 4 6 10Focus3 2 0 2Focus4 0 0 0Focus5** 38 16 54 Total 71 64 135Average 14,2 12,8 13,5

*Glasses **Lenses FIGURE10,VISUALACUITY,NUMBERSOFINCORRECTANSWERS

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DISCUSSIONTheperceptionofmoodandemotionsconnectedtothedifferentlightingsettingswere,asexpected,mixed.Thepersonalexperiencecandifferalotfromsomeoneelse’sopinionandexperiencewhichmaketheindividualperception,andpartlyambiguousresults,understandable.Manypeoplehavecountlessexperienceandopinionsaboutdifferentkindsoflightandlighting.However,thefindingshavesomeclearresultswheremoreorlessallpupilshadthesameopinion.Theclearestresultsweretheperceptionoffocuslightingashardandbright,aswellastherelaxedlightingaswarmandcalm.Therelaxedlightingalsohadaclearaverageperceptionofpositivityatthesametimeasitwasperceivedasdark.Ifitisthecolourtemperatureorthelightintensitythatisperceivedaspositiveisnotclear,probablyacombination.Childrenandadolescentsdoesnotneedasmuchlightasadultstohavegoodvision,whichcanbeoneexplanationforthepositiveresultsintherelaxedlightingwithlowerlightintensity.Thefollow-upalsoconfirmedthatmanypupilsprefertohavelowerlightintensityandperceivethehigherlightintensitiesasdisturbing.Somepupilsexplainedthecalm,warmlightassimilartothelightingathome,whichprobablyisconnectedtoacosierfeelingthantheschoolenvironment.Almosteveryoneintheclasswantedtohavethepossibilitytohaveindividuallightingcontrolintheclassroom,inthefollow-upsomeofthemweremorescepticandalsoconsideredthenegativeaspectswithindividualcontrol.Itwouldprobablybeconfusingandlackofcoherencyintheroomwithtotallyindividualcontrol.Bycontrast,partsoftheclassroom/sectionsofluminairescouldbeseparatelycontrolledinordertocreatedifferentscenariosorlightingsettingsindifferentpartsofaroom.Itcouldalsobeinterestingtohavepre-setsupplementarylightingsettingsinordertobroadentheuseoftheclassroomandchooseadditionalscenarios.Ontheotherhand,thesystemcannotbetocomplexanditisgoodfortheendusersthatthesettingsarefewandclear.Furthermore,theresultsfromthesurveysshowthatmanypupilsassociatethecoldandhardfocuslighttotestandconcentration.Perhapstheperceptionandemotionsofhavingthefocuslightingaffectstheresultsandconcentrationlikeahabitualbehaviour.Someoftheanswersinthesurveytendtoshowthatthequestionsandthewordsinthesemanticdifferentialscaleswerehardtounderstand.Astheinstructionwastoputthecrossinthemiddleiftheywerehesitant,quitemanyscalestendtoshowaresultinthemiddleofthescale.Theintentionwastoonlyusescaleswithwordthat14-year-oldpupilscouldunderstand,butinretrospect,someofthescalescouldbereplacedorremoved.Tomanyscales/questionsalsohasanegativeeffectonpupils’involvementandcanleadtorandomandhastyanswers.Someofthequestionswereclarifiedduringthefollow-upanditwasthenobviousthatseveralquestionsgototheranswersorsubstantialadditions.Thefollow-upsfulfilledtheirpurposeandwereimportantfortheunderstandingsandanalysisofthesurveys,butitwouldprobablybeevenbetterwithinterviewswhereiteasiertocontrolifthequestionisunderstoodornot.Inaddition,whenitcomestopersonalexperiences,emotionsandperceptionofthelightingconditions,thereisalwaysariskthattheanswerscouldbeinfluencedbytemporarymoodanddistractions.Accordingtotheresultsofthebehaviouralanalysis,theignoranceofthelightingsystemcanbeaproblemfortheexperienceandusageofthelightingintheclassroom.Noneoftheconsultedteachersdidknowneitherthepurposenortheapplicationofthelightingsystem.Someoftheteachersusedthesystemobviouslywrongandnoneoftheteachersuseditconsistentlycorrectlylikeitshould.Whenthesystemisusedincorrect,allthreeaspects,

23

visual,emotionalandbiological,runtheriskoffailingtheirpurpose.Forexample,ifateacherfindsthefocuslightbestandusesitduringalllessons,thevisualaspectwillbeinfluenced(verybrightallthetime),theemotionalaspectwillbeinfluenced(pupilsexperienceitashardandnegativedentistlightingetc.),aswellasthebiologicalaspect(thesystemispre-setforchangesduringtheday,andifthefocuslightinginterrupteverylesson,thebiologicalimpactwillbelowerorevennegative).Accordingtotheanalysisoftheperception,thepupilsperceivethefocuslightingasatest-lighting,butifthetest-lightingisalwayson,thepupilswillmostlikelyadapttothelightingandconsideritasnormalandtheeffectofthedifferentlightingsettingswillbereduced.Itishardtoestimatehowmuchpoorerthelightingsystemiswithincorrectapplication,buthavingwronglightatwrongtimeinsteadofrightlightatrighttimeismostlikelynotgood.Asthesystemisautomatic,andonlychangesifyoumanuallypushthebuttononthecontrolpanel,theriskofruiningthesystemisquitelowthough.Passiveusers,thatonlyswitchonandoff,arenorealdangerforthesystembecausethesystemcanthenbetotallyautomatic.Activeeducateduserswouldbetheoptimum,usersthatknowwhenandwhytomanuallycontrolthesystem.Theworstusersaretheactive,noneducatedones,thatknowhowtocontrolthesystem,butdoesnotdoitcorrectanddonotknowthepurposeofthelightingchanges.Thekeytohavingcorrectusageofthesystemcouldbemoreinvolvedendusers(teachersandprincipals,aswellasthepropertymaintenancecompany)andbettercommunicationbetweenthedeveloper/manufacturer,propertymaintenancecompanyandenduser.Ashortintroductionandeducationaboutthepurposeofthelightingsystemandhowtouseitwouldprobablyimprovetheapplicationandtheresultofthesystemsubstantially.Rightknow,theinformationaboutthelightingsystemfromthemanufacturerisstillatthepropertymaintenancecompany,andnotprovidedtotheendusers,thestaffattheschool.Inaddition,inordertofacilitatetheuseofthesystemthecontrolpanelshouldbemoreuserfriendlyandclearfortheusershowtoapplyitandwheretofindit.Whenthecontrolpanelishiddenbehindawhiteboardandaccordingtotheinterviewswiththeteachers,itisnottotallyclearhowtouseit.Becauseofthis,theusageofthelightingsysteminthetestclassroomofSturebyskolan,tendsnottobeasindented.Theresultsofthevisualperformancetestverifytheresultsfrom(Barkmannet.al.,2012)(Mottet.al.,2012)(Sleegerset.al.,2011)(Helbig,2011)andshowsthatthefocuslightinghaspositiveeffectonpupil’sperformance.Thetestgrouphadbetterresultsinthesecondtestwithfocuslighting,bothpercentage-wise,median-wiseandaverage-wise.Incontrast,thecontrolgrouphadbetterresultsthanthetestgroupinboththefirstandthesecondtest.However,thecontrolgrouphadbetterresultsinthefirsttestthaninthesecond,whichcouldprovethatthefirsttestwasabitharderthanthesecondtest.Sincethetestsincludedifferentquestions,eventhoughitisthesamekindofquestionswiththesamedifficultylevel,itispossiblethattheyarenotperceivedasequallyhard.Ifthefactthatthesecondtestisperceivedasharder,theresultsofthevisualperformancetestinthisstudyconfirmsthepreviousresearchevenmorebecausethetestgrouphadbetterresultsinthesecond“harder”test.Incontrast,itissmalldifferencesintheresultsandeventhoughitisclearthatcorrectanswersincreasedinthefocuslighting,andatthesametimedecreasedinthecontrolgroup,thecausationisnotexplicit.Forexample,thenumberofpupilsinthefirstandthesecondtestwasnotthesame,neitherinthetestgroupnorthecontrolgroup,andwiththesmallmarginsintheresult,onepupilcanbecrucialfortheresult,bothinpositiveandnegativesense.Theresultsfromthetestgroupshowedthatthehighestscorehaddecreasedinthesecondtestfrom12to11,buttheoverallresultwasbetterinthesecondtestwith

24

higheraverage,increasedpercentageofcorrectanswersandmedianresultwasalsobetterinthesecondtest,whichimpliesthatthefocuslightinghelpedpupilswithlowresultinthefirsttesttoperformbetterinthesecondtest.Hence,thefocuslightingisparticularlygoodforweakpupilsandcanhelpthemtofocusandconcentrate.Moreover,thetestsinthetestgroupandthecontrolgroupwasnotcarriedoutatthesametime,ofpracticalreasons,whichalsocaninfluencetheresults.Thetestgroupperformedduringmorningtimeandthecontrolgroupperformedintheafternoon,whichcouldbeanexplanationofthehigherresultsinthecontrolgroup.Thedifferenttypesofclassrooms,windoworientationandamountofdaylightareotherfactorsthatcouldhaveinfluencedtheresults.Inthetestclassroom,thewindowstotheatriumcouldhavebeenadistractionwhichinthatcasecouldhaveinfluencedtheresultsnegatively.Inaddition,thefurnishinginthetestclassroomwasdifferentduringthefirstandthesecondtestwhichalsocouldbeaconsiderationfortheincreasedresults.Furthermore,accordingtotheanalysisoftheperceptionofmoodinthedifferentlightingsettings,thepupilsareinfluencedbythelightingemotionallyandthefactthattheyperceivethecoldandhardfocuslightingasatest-lightingorlightingwhereyoushouldconcentrateandbefocused,couldbethereasonfortheincreasedresultsduringthefocuslightinginthetestclassroom.Inaddition,lightingisonepossiblereasonfortheresults,butthereareplentyofotherreasonsthatcouldinfluencetheoutcomesofthetests.Assaidinthelimitations,thisstudyhasalimitedtimeframeandthuslimitedtestandtimeperiod.Todoamoreprofoundanalysiswhethertheresultsarecausedbylighting,andinthatcaseduetothebiologicalaspectorduetotheemotional/psychologicalaspect,thestudyneedsanalysisfrommoretestsduringalongertimeperiod,preferablyonewholeacademicyear.Moreteststoderivethebiologicaleffectisprobablyalsonecessarytoclarifythereasonfortheincreasedresultsinfocuslighting,suchasmeasurementsofmelatoninlevelsetc.Accordingtopreviousresearch,thephotometricmeasurements(lux,photopicirradiance)arenotwellsuitedforcircadianstimulus,andtoclarifywhethertheresultsareofbiologicaloremotionalreasonitcouldbenecessarytomeasurewithcircadianlux(α-opicirradiances).(Reaet.al.,2010)(Lucaset.al.,2014)(Giménez,2013)Theresultsoftheanalysisofthelightingdistributionshowedthatthelightingissuitedforatypicalclassroomwhereitisimportanttohavenoreflections,noglare,uniformdistributionandvagueshadows.Allthesecharacteristicsareindividuallypositiveandnecessarytofulfilthestandardsofclassroomlighting,butputtogether,thesecharacteristicscreatesaquitestaticandboringlighting.Itisofcourseimportanttohavegoodlightingconditionsintheclassroominordertoseeandcommunicate,bothforpupilsandteachers.Ontheotherhand,inaclassroomitisalsoimportanttohaveasafeandinspiringatmospheresothatpupilsandteachersfeelsmotivatedtolearnandteach.Thelightinghasabigimpactontheatmosphereofaroom,andtoomanystandardfulfillingcharacteristicscancontributetocreateaninsipidanduninspiringroom.AsLammentionedaboutthefocusselector(Lam,1992),wealwaysseekforthemostinterestingvisualexperience,andiftheclassroomisveryuniformilluminated,thefocuswillperhapsbeonthewrongthings.Inaddition,accordingtoWänströmLindh,auniformlightingwherenothingisemphasised,cancreatealackofvisualinterestwithnosupportfororientationandspatialunderstanding.(WänströmLindh,2013)

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Ofpracticalreasons,theanalysisofthelightingdistributionwasmadeduringcertaintimelimitation(whentheclassroomwasemptyduringdaytime),whichcontributedtochangesofthelightingsettingswhilebeingintheclassroom.Thefastchangesbetweenthelightingsettings(normal,relaxedandfocuslighting)werenoticeableandprobablyaffectedtheresultsoftheanalysis.Thecontrastbetweenthefocuslightingandtherelaxedlightingarelarge,andespeciallywhenyou,duringashorttime,arestayinginthesameroomandhaveshorttimetoadapt.Theresultsoftheanalysisofthelightingdistributionwouldprobablybeabitdifferentiftheanalysiswasmadeduringalongersessionwithpausesbetweenthedifferentsettings.Itwouldquitepossiblybelesscontrastsbetweenlevelsoflightandcolourtemperature.Theanalysiscouldalsohavebeenmadeseveraltimes,indifferenttimesofthedayandindifferentweatherconditionsandseasons,inordertomaketheanalysismorereliable.Thelimitationsofthisstudyincludesthebiginfluenceofdaylightinspring,whichprobablyreducesthebiologicaleffectoftheartificiallighting.Thisisamatterofconsiderationsincetheseasonsanddaylightwillnotchangeandduringspringandautumn,daylightwillinterferewiththeartificiallightingandinfluencethepeopleinsidetheclassroom.Inaccordancetopreviousresearchaboutdaylightinclassroom(KüllerandLindsten,1992)(Loisos,1999),daylightisalwaysbetterthanartificiallightingandduringlatespring/summer/earlyautumnweare,inSweden,exposedtodaylightalldaylong.Anartificiallightingsystemthattriestomimicdaylightandthevariationofitisnotbetterthanrealdaylight,butthedifferentsettingsisimpossibletoachievewithonlydaylight.Forexample,theeffectoftherelaxedlightingwillbeverydecreasedincombinationwithstrongdaylightlikeitisinlatespringandearlyautumn.Also,theeffectofthefocuslightingwillprobablydecreasebecausethedaylightisevenbrighterandcolderthanthefocuslighting,whichreducesthecontrastbetweendaylightandartificiallightandcreatesamorenaturalfeeling,andlesstestfeeling.Theresultsfromthevisualacuitytestshowedmorecorrectanswersinfocuslightingthaninrelaxedlighting.Thetestcannotgiveevidencetothefactthatthelightingisthereasonfortheresults,butitcouldbeacontributoryfactor.Inatestwithonlyfiveparticipantsperlightingsetting,thereisariskthatonepupilinfluencestheresultsstrongly.Forexample,iffourofthepupilswouldhaveallcorrectanswers,butthefifthpupilgetnonecorrectanswers,itwillbe154incorrectanswersintotalandanaverageof30,8incorrectanswers.Inthisstudytherearetwopupilsintherelaxedlightingandtwopupilsinthefocuslightingthatstandsoutwithahighrateofincorrectanswers.Theweakestresultwas108incorrectanswers,whichwascarriedoutinrelaxedlighting,andcontributedmuchtothetotalresult.Thepupilswerejustrandomlyplacedinorder,thefirstfivecarriedoutthetestinrelaxedlightingandthelastfiveinfocuslighting,anditcouldbeacoincidentthattheweakestpupilendedupintherelaxedlighting.Becauseoftheriskoflettingcoincidentdeterminetheresult,theweakestpupilalsogotthechancetodothetestinfocuslightingandgotabetterresult.Inordertoincreasethereliabilityofthetest,itwouldbeinterestingtotestallpupilsinbothrelaxedlightingandfocuslightingtoseeifthedifferenceisgeneraloronlypersonalfortheonlytestedpupil.Inaddition,itwouldalsobepreferablewithmoretestpupilsinordertohaveaconsiderableselectionofresults.Anyway,theresultstendtoshowthatpupilswithweakervisionarehelpedbyfocuslighting,butfocuslightingisnoguaranteeforgoodvision.Apresumablefactorfortheresultsisthedifferenceinlightintensitybetweentherelaxedlighting(300lx)andfocuslighting(800lx).Accordingtopreviousresearch,alsothecolour

26

temperaturecouldbeareasonforthedifferencebetweenthetwolightingsettings.(Bermanet.al.,2006)Insummary,todenominatealightingsystemasHCLandonlyconsiderthealteredcolourtemperatureandlightintensityisnotcomprehensiveenough.Accordingtothedefinitionusedinthisstudy(Ladopoulos&Shaw,2017),aHCL-systemneedstoconsiderthevisual,emotionalandbiologicalaspects.Thebiologicalaspectisexplicitlyconsideredinthislighting-system,whilsttheemotionalandvisualaspectsarehowevernotcarefullyconsidered.Thedifferentlightingsettingsthatcanprovokealteredemotionsandmoodscouldbeconsideredasanemotionalconsideration.Accordingtothefindingsinthisstudy,theemotionsconnectedtotheartificiallightingcouldbeanargumentforthelightingsystemasemotionallyconsidering.Ontheotherhand,thelightingsettingthataremostappreciatedbypupilsinthisstudy,relaxedlighting,istheleastusedinthelightingsystemandareneveractivatedintheautomaticsettings.Eveniftheintentionofthelightingsystemcouldbetoprovokedifferentfeelingsinthedifferentlightingsettings,itisnotexplicitandhencenotclearlyanemotionalaspect.ThetextabouttheHCL-systemonthemanufacturerswebpageindicatesthatthepurposeofthesystemissolelybiological.(GlamoxLuxo,2017)Furtheron,thevisualaspectispartlyconsideredwiththependantdirect/indirectluminairethatprovidestwodifferentlayersoflight.Inthemanufacturerswebpageitissaidthattheindirectlightcastlightbothonthewallsandtheceilingwhichincreasestheverticalilluminanceandimprovethevisualcommunication.(GlamoxLuxo,2017)Thevisualaspectinthislightingtendtofocusjustonthevisualcommunicationtoensuregoodworkingconditionsintheroom;rightamountofilluminance(onworkingplane,verticalandcylindrical),uniformbrightnessthatprovidesrightlightleveloneverydeskandavoidsharpshadowsandglare.However,thetotalvisualperceptionofthespaceisnotreallyconsideredandasdiscussedearlier,toomuchfocusonthevisualcommunicationrelatedtotheworkingconditionscannegativelyimplicatetheatmosphere.Whenitcomestothevisualaspecttheoverallperceptionandatmospherehavetobeconsideredaswellasthevisualcommunicationandworkingconditions,whichcanbeadifficultthingtobalance.Overall,thevisualperceptionoftheatmosphereinaroomhastobemoreimportantthanitisinthislightingsysteminordertoseeitascarefullyconsidered.

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PROPOSALFromtheresultsofthisstudyanevolvedlightingdesignthatconsidersallthreeaspects;visual,emotionalandbiological,areproposed.Theanalysisofthelightingdistributionshowedthatthelightingintheclassroomwasuniformwhichcouldleadtoastaticandboringatmosphere.Inordertocreateamorevividandinterestingatmosphereavarietyoflayersoflightwouldbepreferable.LikeKelly’sthreeelements(Neumann,2010)itcouldbelayerswithfocalglow,ambientluminescenceandplayofbrilliants.Inaclassroomthatcouldforexamplebe;highlightedobjectsorstage/frontofclassroomwhereteachersusuallystand,wallwashingeffectonwallswithoutwindowsandoneorseveralsmalldetailedbrilliantsoflightonthefrontwalloratthefrontdesk.Inthebudgetofaschool,thereisseldomspaceforextravaganceandinthelightingplanningofaschool,thereisusuallyalimitedtypeofluminairesinordertoreducethecostofmaintenanceandpurchase.Inordertocreatedifferentlayersoflightwiththesepreconditions,itisdesirabletouseluminaireswithseveralareasofapplication.Forexample,aluminairethatbothcouldworkforgenerallightingintheclassroom,andasawallwasherorspotlighttobringotherlayerstothelightingwouldbefunctionalinordertomaximisetheuseofeveryluminaire.Inthatcase,itisimportanttoarrangethepositionsoftheluminairesintheclassroominordertobeabletousethemwithdifferentcharacteristicsfordifferentoccasions.Forexample,placeluminairesclosetowallsthatneedwallwashingandluminairesthatcanworkasspotlightsinpositionswherehighlightingisneeded.Withflexibleluminairesandconsciousplanning,itwouldbepossibletocreatedifferentlayersoflightwithonlyoneortwodifferentkindsofluminaires.Thebacksideofcreatingluminaireswithmorefunctionsisthecostoftheluminaire,whichwillincrease.Forinstance,iftheluminaireshouldbeabletocontroltheindirectanddirectlightseparately,aseconddriverisneededandthecostoftheluminairewillincreasesubstantially.However,evenifthereisonlyastandardclassroomluminaire,itisstillpossibletocreatedifferentlayersoflightifthearrangementoftheluminairesisconsciousandsuitedforthedifferentneedsofthelightinginaclassroom.Furthermore,theuseofanadvancecontrolsystem,liketheoneinSturebyskolan,couldalsobeawaytobroadentheuseoftheclassroomwithseveraldifferentlightingscenarios.Thepossibilitytocontrolthelightingindifferentpartsoftheclassroomcouldbeagoodopportunitybothtoeasiercreateagoodatmospherewithdifferentlayersoflight,aswellastodividetheclassroomintodifferentareaswithdifferentpurposes.Forexample,ifitispossibletocontroleveryrowofluminairesseparately,twoorthreedifferentlightingscenarioscanbeapplied,oneforreadingandoneforgroupworkorcreativeworketc.Inaddition,thedifferentrowscanoperatewithdifferentcharacteristicsasawayofcreatinglayersoflight.Furthermore,asdiscussedearlier,thedaylighthasavastinfluenceduringpartsoftheyearwhichdecreasestheeffectoftheartificiallighting.Inordertoadaptthesystemtothedaylight,itwouldbepreferabletochangethesettingsduringtheyearsotheartificiallightingcorrespondstothedaylight.Thiswouldbepositivebothforthelightingpart,includingallthreeaspects,butalsofortheenergyconsumptionwhichcouldbereducedwithamoreadaptedsystem.Forexample,ifthesystemhassensorstomeasurethelightintensity,theilluminationfromtheluminairescanbereducedduringthebrightestpartoftheyear.Thiswillbothsaveenergyandenhancethedaylight,whichhavepositiveinfluenceonperformanceandhealth.(KüllerandLindsten,1992)(Loisos,1999)Asitisnow,theartificialfocuslighting

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illuminatestheclassroomwith800lxlikeitwouldbeadarkroom,eventhoughthedaylightadds100-1200lx(indifferentpartoftheroom).Tousethedaylightasanextralightsourcecouldalsobeanopportunitytoaddanotherlayeroflightintotheclassroom.Ifthedaylightisconsideredasagenerallightsource,theartificiallightingcouldbemoreadjustedtobringhighlights,washesandsharpdetailsintotheroom.Ontheotherhand,inthedarkpartoftheyear,thedaylightisverylimitedandcannotbeusedasagenerallightsourceduringallhoursofschool.However,iftheluminaireshavethecapacitytoincludeseveralpurposes/characteristics,thegenerallightcouldcomefromartificialluminairesduringthedarkperiodoftheyearandfromdaylightduringthebrightpartoftheyear.Inaddition,animportantpartofthelightingsystemistheapplicationofit.Asmentionedbefore,ifthesystemisnotusedasitissupposedto,noneofthethreelightingaspectswillbefulfilled.Topreventincorrectapplication,itisbygreatimportancethatthesystemisvisible,easytounderstandandsimpletouse.Toachievethis,itisrecommendedthatallusersarebeinginformedaboutthepurposeandeducatedinthelightingsystem,asasuggestionbythelightingdesignerormanufacturerthatisresponsibleforthelightingsystem.Inmunicipalschools,likeSturebyskolan,thepropertymaintenancecompanycouldbetheresponsiblepart,butaccordingtothecaseinSturebyskolan,itisbettertodecimatethenumbersofconcernedpartsinordertostreamlinethistask.Asuggestionisthatintroductionandeducationtothelightingsystemisapartoftheproduct.Theeducationisvaluablebothfortheend-users,sotheycanapplythelightingsystemcorrectlyandbebenefittedfromthat,butalsothemanufacturerwhichcanbeassuredthattheirproductisusedasitshouldbeandcanaccomplishtheeffectsthatthemanufacturerpledges.

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CONCLUSIONSTheaimofthisstudywastoevaluateaHCL-systeminaclassroombythemeansofthethreeaspects;visual,emotionalandbiological.Resultsshowsthatdifferentlightingsettingswereperceiveddifferently,wherethefocuslightingwasperceivedasacoldandhardlightingfortests,whiletherelaxedlightingwasperceivedasawarmandcalmlightingforacosyfeeling.Inaddition,theresultstendtoshowthatthelightingaffectstheperformanceasahabitualbehaviouralfactor,wheretheconcentrationincreasesconnectedtothefocuslighting.Furtheron,thelightingcharacteristicsaresuitedforatypicalclassroomwithuniformlighting,noglareandvagueshadows.Despitepositivelightingcharacteristicsindividually,puttogether,thelightingandtheatmospherecanbeperceivedasstaticandboring.Inaddition,duringpartsoftheyear,thedaylightinfluencesthelightintheclassroomwhichhaveagreatimpactontheartificiallightingwhichdecreasestheeffectofthelightingsystem.Moreover,thefunctionofthesystemdependsoncorrectapplicationoftheusers,andignoranceamongusersbecomesaproblem.Inordertohaveasystemthatworksproperly,itisimportantthatthesystemisuserfriendlyandthattheendusersareeducated.Resultsshowpositiveeffectonperformanceinfocuslighting,similartopreviousresearch.Focuslightingseemstobeparticularlygoodforweakerpupils,eventhoughitisnotcleariftheresultsarecausedbythelightingornot.Toassureiftheresultsdependsonthelightingornot,andwhetheritiscausedbytheemotionalorbiologicalaspect,moreresearchisrequired.Resultsalsoshowbettervisualacuityinfocuslightingthaninrelaxedlightingandpupilswithweakervisionseemstobehelpedbythefocuslighting.Insummary,theHCL-systemisconsideringthebiologicalaspectexplicitly,theemotionalandvisualaspectsarehowevernotenoughconsideredtodenominatethesystemashumancentric.Asaproposaltoconsiderallthreeaspects,severallayersoflightcouldbeaddedinordertostrengthenthevisualaspectandcreateavividandinterestingatmosphere.Moreover,consciousarrangementofluminairesandluminaireswithflexiblecharacteristicscouldsimplifyandbroadentheopportunitiesintheclassroomandfacilitatetheuseoflightlayers.Adevelopmentofthecontrolsystemcouldleadtoavarietyofscenariosandmoreopportunitiesintheclassroom,whichcouldstrengthentheemotionalaspect.Inaddition,educationcouldbeapartoftheproductinordertoassurethatthelightingsystemisusedcorrectly.Inthatcase,theenduserscanbebenefittedfromallfunctions,whilsttheproductisusedasitshouldbeandcanaccomplishtheeffectsthatthemanufacturerpledges.Inthisstudy,weakerpupilsseemedtobemorebenefittedfromthefocuslightingbothinvisualperformanceandvisualacuity.Accordingtothesefindings,moreresearchneedtobedoneabouthowHCLaffectsdifferentpupilswithdifferentknowledge/gradesetc.Iftheresearchwouldgoon,moreinvestigationisneededabouthowtocreatethepre-setlightingsettings,includingwhichcolourtemperatures,lightintensitiesandcharacteristicsoftheluminaires.Inaddition,researchabouthowHCL-systemsinschoolswithandwithouteducationfortheendusersworks,couldbeanimportantsupplementinfutureresearch.

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REFERENCESArbetsmiljöverket,2009.ArbetsplatsensutformningAFS2009:2Barkmann,C.,Wessolowski,N.,Schulte-Markwort,M.,2012.ApplicabilityandefficacyofvariablelightinschoolsPhysiology&Behaviorvol:105(3)pp:621-627Belysningsbranchen,2015.RättljusförmänniskaochmiljöBerman,SM.,Navvab,M.,Martin,J.,Sheedy,J.,Tithof,W.,2006.AcomparisonoftraditionalandhighcolourtemperaturelightingonthenearacuityofelementaryschoolchildrenLightingResearch&TechnologyVol38,Issue1,pp.41–49Berson,D.M.,Dunn,F.A.,Takao,M.,2002.Phototransductionbyretinalganglioncellsthatsetthecircadianclock(80)Science,295,pp.1070–1073Ejhed,J.,1992.LjusochRumKTHArkitekturBelysningslära,StockholmForsström,E.MatricesIQtest–fromMensa/DN,http://www.dn.se/nyheter/fragesport/iq-test-hur-intelligent-ar-du/downloaded2017-05-05Gentile,N.,Goven,T.,Laike,T.,2016.AfieldstudyoffluorescentandLEDclassroomlightingLightingResearch&TechnologyFirstpublisheddate:October-25-201610.1177/1477153516675911Giménez,M,2013.D3.7ReportonmetrictoquantifybiologicallightexposuredosesACCELERATESSLINNOVATIONFOREUROPÉ,LightingforPeopleGlamoxLuxo,2017.http://glamox.com/ie/solutions/test-small-class-roomDownloaded:2017-05-25GlamoxLuxo,2017.http://glamox.com/ie/hcl-in-educationDowloaded:2017-05-05GlamoxLuxo,2017.http://glamox.com/ie/human-centric-lightingDowloaded:2017-05-05Hattar,S.,Liao,H.W.,Takao,M.,Berson,D.M,Yau,K.W.,2002.Melanopsin-containingretinalganglioncells:architecture,projections,andintrinsicphotosensitivity(80)Science,295,pp.1065–1070Helbig,H,2011.Theeffectoflightinperformancecapabilityofpupilswww.osram.comDownloaded2017-04-28Holm,B.,Alm,L.,Ejhed,J.,1998.SkolansljusArkitektur(1998):6,p.40-47vanHoof,J.,Schoutens,A.M.C.,Aarts,M.P.J.,2009.HighcolourtemperaturelightingforinstitutionalisedolderpeoplewithdementiaBuild.Environ.,44,pp.1959–1969

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Küller,R.,Lindsten,C.,1992.HealthandbehaviorofchildreninclassroomswithandwithoutwindowsJournalofEnvironmentalPsychologyvol:12(4)pp:305-317Ladopoulos,I.,Shaw,K.,2017.LightingDesignforHealth,WellbeingandQualityofLight,AHolisticApproachonHumanCentricLightingAWhitePaperfromtheIALDEuropeanRegulatoryAffairsWorkingGroupLam,W.M.C.,1992.PerceptionandlightingasformgiversforarchitectureVanNostrandReinhold,NewYorkLiljefors,A,1999.Lighting–VisuallyandPhysically,V/PLightingTheoryLightingDepartment,SchoolofArchitecture,KTHStockholm(1999)Loisos,G.(1999).DaylightinginSchools-AninvestigationintotheRelationshipBetweenDaylightingandHumanPerformance.ThePacificGasandElectricCompany,CaliforniaBoardforenergyEffiencyThirdPartyProgram.CA:ThePacificGasandElectricCompany.Lucas,R.,Peirson,S.,Berson,D.M.,Brown,T.,Cooper,H.,Czeisler,C.,Figueiro,M.,Gamlin,P.,Lockley,S.,O’Hagan,J.B.,Price,L.,Provencio,I.,Skene,D.,Brainard,G.,2014.Measuringandusinglightinthemelanopsinage,TrendsinNeurosciences,Volume37,Issue1,January2014,Pages1-9,ISSN0166-2236,http://doi.org/10.1016/j.tins.2013.10.004.Madsen,M.,2004.Lysrum-sombegrebogredskab.(Light-zone(s):asconceptandtool.).PhD-thesis,DoctoralDissertation,KunstakademietsArkitekturskole,Copenhagen,Denmark.McColl,L.,Veitch,J.,2001.Full-spectrumfluorescentlighting:Areviewofitseffectsonphysiologyandhealth.PsychologicalMedicine,31(6),949-964.doi:10.1017/S0033291701004251Mott,M.,Robinson,D.,Walden,A.,Burnette,J.&Rutherford,A,2012.IlluminatingtheEffectsofDynamicLightingonStudentLearningSAGEOpen,Vol2,issue2Neumann,D.(editor),Addington,M.,Isenstadt,S.,Lambert,P.,MailePetty,M.andTanteri,M.,2010.Thestructureoflight:RichardKellyandtheilluminationofmodernarchitectureNewHaven:YaleUniversityPressinassociationwiththeYaleSchoolofArchitecture Palmberg-Eriksson,S.,2000.SkolhusetsomsamhällsspegelRiksantikvarieämbetet(SwedishNationalHeritageBoard)Osram,2017.https://www.osram.com/ls/verticals/office/human-centric-lighting/index.jspDowloaded:2017-05-05Rea,M.S.,Figueiro,M.G.,Bierman,A.,&Bullough,J.D.,2010.Circadianlight.JournalofCircadianRhythms,8,2.http://doi.org/10.1186/1740-3391-8-2

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Santhi,N.,Aeschbach,D.,Horowitz,T.S.,Czeisler,C.A.,2008.TheimpactofsleeptimingandbrightlightexposureonattentionalimpairmentduringnightworkJBiolRhythms,23(4),pp.341–352SkolfastigheteriStockholmAB(SISAB),2017.Ljusochbelysningilokalerochutewww.sisab.seDownloaded2017-05-05SwedishStandardsInstitute,2011.Lightandlighting-Lightingofworkplaces-Part1:IndoorworkplacesSS-EN12464-1:2011Tifler,D.,Rea,M.,1992.Semanticdifferentialscaling:ProspectsinlightingresearchLightingResearch&TechnologyVol24,Issue1,pp.43–51Wittmann,M.,Dinich,J.,Merrow,M.,Roenneberg,T.,2006.Socialjetlag:misalignmentofbiologicalandsocialtimeChronobiolInt,23,pp.497–509WänströmLindh,U.,2013.UnderstandingtheSpace:HowDistributionofLightInfluencesSpatialitySchoolofEngineering,Dept.ofCivilEngineeringandLightingScience,JönköpingUniversity,Jönköping,Sweden

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FIGURESANDPICTURESFigure1,Analysisofdaylight.......................................................................................................15Figure2,AnalysisofFocuslighting.............................................................................................16Figure3,AnalysisofNormallighting...........................................................................................16Figure4,AnalysisofRelaxedlighting..........................................................................................16Figure5,PerceptioninNormallighting......................................................................................18Figure6,PerceptioninRelaxedlighting......................................................................................19Figure7,PerceptioninFocuslighting.........................................................................................19Figure8,VisualperformanceinHCL-classroom.........................................................................20Figure9,Visualperformanceinordinaryclassroom..................................................................20Figure10,Visualacuity,numbersofincorrectanswers.............................................................21Picture1Examplequestion,matricesIQtest Picture2,questioninmatricesIQtest...........12Picture3,Monoyerchart,visualacuitytest...............................................................................13Picture4,controlpanelinclassroom..........................................................................................14Picture5,Classroomon8thofMay............................................................................................15

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Appendix1Surveyaboutperception,pupils

1 2 3 4 5

Hur är ditt humör just nu?

Ledsen Glad

Har du märkt någon skillnad på de olika belysningsinställningarna?

Ja NejKänner du till att belysningen i ditt klassrum ändras under dagen?

Ja Nej

Om ja, hur upplever du de olika inställningarna?

Skulle du vilja ha möjligheten att kontrollera ljuset på din egen bänk?

Ja Nej

Enkätfrågor om belysningen i klassrummet

Jag är intresserad av din spontana upplevel-ser och vill gärna att du svarar omedelbart på frågorna utan att tänka för mycket.

Vänta med att gå vidare med resten av frågorna, hela klassen behöver svara samtidigt.

35

1 2 3 4 5

Hur är ditt humör just nu?

Ledsen Glad

Ja NejPåverkas din sinnesstämning/humör av belysningen?

Finns det särskilda tider/stunder/lektioner då du vill ha den här belysningen?

Vilka tider/lektioner brukar ni ha den här belysningen?

Markera med ett kryss (X) på respektive skala det ord, som du tycker mest överensstämmer med din spontana upplevelse av rummet. OBS! Försök att bestämma dig fort, fundera inte, även om du tycker något ord är konstigt.

Negativt Positivt

Vilsamt Tröttsamt

Osäkert Tryggt

Ljus Mörkt

Kallt Varmt

Livligt Lugnt

Omväx-lande

Enformigt

Aktivt Passivt

Trevligt Tråkigt

Mjukt Hårt

36

Appendix2SurveyquestionsinEnglishEnglish

- Howisyourmoodrightnow?Sad1-2-3-4-5Happy- Areyouawareofthechanginglightingsysteminyourclassroom?- Haveyounoticedanydifferenceinthelightingsettings/properties?- Ifyes,howdoyouperceivethedifferentsettings?- Wouldyouliketocontrolthelightonyourowndesk?

Normallighting/RelaxedLighting/FocusLighting:

- Howisyourmoodrightnow?Sad1-2-3-4-5Happy- Isyourmoodaffectedbythelighting?- Aretherespecifictimes/lessonswhenyouwantthislighting?- Atwhattimes/lessonsdoyouusuallyhavethislighting?

Soft-1-2-3-4-5-6-7–8-HardRestful-1-2-3-4-5-6-7–8-TiresomeUnsafe-1-2-3-4-5-6-7–8-SafelyBright-1-2-3-4-5-6-7–8-DarkCold-1-2-3-4-5-6-7–8-WarmLively-1-2-3-4-5-6-7–8-CalmVaried-1-2-3-4-5-6-7–8-UniformBeautiful-1-2-3-4-5-6-7–8-UglySharp-1-2-3-4-5-6-7–8-DiffusePleasant-1-2-3-4-5-6-7–8–BoringActive-1-2-3-4-5-6-7–8–PassiveNegative-1-2-3-4-5-6-7–8–PositiveHarmonious-1-2-3-4-5-6-7–8–InharmonicNormal-1-2-3-4-5-6-7–8-Strange

37

Appendix3Interviewquestions,teachers(inSwedishandEnglish)Swedish

- Huroftaändrarduinställningarnapåbelysningeniklassrummet?- Ändrarnågonannanänduinställningarnaunderdinalektioner?- Uppleverdunågonskillnadmellandeolikainställningarna?Omja,vad?- Uppleverdukontrollpanelen/strömbrytarensomenkelattanvända?- Hardufåttnågonutbildning/introduktiontillbelysningssystemet?- Kännerdutillsyftetmedbelysningsanordningen?- Märkerdunågonskillnadpåelever/digsjälviHCL-klassrummetochandraklassrum?- Omduskullefåändra/förbättranågotmeddetnuvarandebelysningssystemet,vad

skulledetvara?- Skulleduviljahadettabelysningssystemiallaklassrum?Varför?

English

- Howoftendoyouchangethepropertiesofthelightingintheclassroom?- Isanyoneelsethanyouchangingthepropertiesduringyourlessons?- Doyouperceiveanydifferencebetweenthedifferentproperties?Ifyes,what?- Doyoufindthecontrolpaneleasytouse?- Didyougetanyeducation/introductiontothenewlightingsystem?- Doyouknowthepurposeofthenewlightingsystem?- Doyourecognizeanydifferenceinyour/yourpupils’behaviourintheHCL-classroom

andinotherclassrooms?- Ifyouhadthechancetochange/improvesomethinginthisHCL-system,whatwouldit

be?- WouldyouliketohaveHCL-systeminallclassrooms?Why?

38

Appendix47factorswithmodificationbyFavero.Fromlecture”Researchandwritingmethod”inC32016-11-07byFedericoFavero

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