Daylighting and Student Performancethedaylightsite.oxmond.com/wp-content/uploads/symposium...We tested 2 statistical models: Daylight code; or window + skylight Model 1: Daylight Code

We evolved to changing light conditions…We evolved to changing light conditions…

Daylighting and Student Performance

Velux Daylight Symposium Bilbao, Spain, May 7th, 2007

Daylighting and Student Performance

Velux Daylight Symposium Bilbao, Spain, May 7th, 2007

Lisa HeschongLisa HeschongHeschong Mahone Group, Inc.Heschong Mahone Group, Inc.

www.hwww.h--mm--g.comg.com

Copyright HMG 2007

A Brief History of School Windows(USA)

A Brief History of School Windows(USA)

�� 50 years ago all schools (and workplaces) were daylit50 years ago all schools (and workplaces) were daylit

�� 40 years ago California still required the State Architect to 40 years ago California still required the State Architect to review all new school plans for appropriate daylight designreview all new school plans for appropriate daylight design

�� In the late 60’s and 70’s windows began to be considered:In the late 60’s and 70’s windows began to be considered:�� a distraction for childrena distraction for children�� a energy liabilitya energy liability�� a maintenance liabilitya maintenance liability�� a security liabilitya security liability

�� The “Open Classroom” of the 70’s was often a windowless The “Open Classroom” of the 70’s was often a windowless classroom, in a big open plan (warehouseclassroom, in a big open plan (warehouse--style) buildingstyle) building

�� “Energy efficiency” retrofits have often removed daylight“Energy efficiency” retrofits have often removed daylight�� because automatic control of electric lights not part of the equbecause automatic control of electric lights not part of the equation…ation…

An Elementary School, circa 1960 Fresno, CaliforniaAn Elementary School, circa 1960 Fresno, California

A Fresno Elementary School, circa 1985A Fresno Elementary School, circa 1985

“Low maintenance” has replaced the garden of “kindergarten” with asphalt playgrounds (at 80-90 degrees C in summer)

“Energy Efficiency Retrofits,” circa 1995“Energy Efficiency Retrofits,” circa 1995

School Design, early 1990s(California)

School Design, early 1990s(California)

�� All schools must have 30% of classrooms “portable”All schools must have 30% of classrooms “portable”�� = 24’ x 48’ shoe box, which will never be moved= 24’ x 48’ shoe box, which will never be moved�� Whole schools sites nothing but portablesWhole schools sites nothing but portables

�� “Back to Basics” for education“Back to Basics” for education�� no music, no art, no libraries, no physical educationno music, no art, no libraries, no physical education�� internet connections = $5,000 / classroominternet connections = $5,000 / classroom

�� English is primaryEnglish is primary�� no bilingual educationno bilingual education�� second language not taught until 9second language not taught until 9thth grade.grade.

�� Classroom size reductionClassroom size reduction�� 35 >> 20 students per classroom35 >> 20 students per classroom�� Billions dollars per year = $10,000 / classroom Billions dollars per year = $10,000 / classroom

40% of all Classrooms in Fresnoare now Portables

40% of all Classrooms in Fresnoare now Portables

200,000 children in California attend 200,000 children in California attend school in portable classroomsschool in portable classrooms

School Window Design, early 1990s(California)

School Window Design, early 1990s(California)

�� prototype designs (for multiple reprototype designs (for multiple re--use) use) �� No ability to account for orientationNo ability to account for orientation

�� No window overhangsNo window overhangs�� too expensivetoo expensive

�� No skylightsNo skylights�� (they leaked in the 1950s)(they leaked in the 1950s)

�� No interior blindsNo interior blinds�� not part of state budget, the parents must raise money to pay fonot part of state budget, the parents must raise money to pay for….r….

�� Glass VLT = 14%Glass VLT = 14%�� “sunglasses for the windows”“sunglasses for the windows”

�� Single glazed windowsSingle glazed windows�� no money (or standards for) for good acoustics or thermal insulano money (or standards for) for good acoustics or thermal insulationtion

�� No review for compliance with state energy codes (!)No review for compliance with state energy codes (!)

Our proposal to PG&E, 1997Our proposal to PG&E, 1997

�� Daylit buildings had the potential to save a great deal Daylit buildings had the potential to save a great deal of energyof energy�� But there was strong market resistance from owners who did But there was strong market resistance from owners who did

not value daylight in their buildings….not value daylight in their buildings….�� (In USA, everything must be considered to be “cost effective”)(In USA, everything must be considered to be “cost effective”)

�� Could we show that daylight had an effect on better Could we show that daylight had an effect on better human performance?human performance?�� If so, would more building owners demand daylit buildings?If so, would more building owners demand daylit buildings?�� And PG&E could acquire more daylight energy savings…And PG&E could acquire more daylight energy savings…

Download from: Download from: www.hwww.h--mm--g.comg.com “Daylight and Classrooms”“Daylight and Classrooms”

PG&E 1999: First two “epidemiological” studiesPG&E 1999: First two “epidemiological” studies

�� Two types of “cookie cutter” study spaces:Two types of “cookie cutter” study spaces:�� Chain RetailChain Retail:: 3 years of sales data for 108 stores 3 years of sales data for 108 stores �� Elementary SchoolsElementary Schools:: 8000 students, test scores8000 students, test scores

�� Seattle, WASeattle, WA 62 elementary schools62 elementary schools�� Poudre, CO, Poudre, CO, 23 elementary schools23 elementary schools�� Capistrano, CACapistrano, CA 27 elementary schools 27 elementary schools

�� Huge data sets allow statistical analysis Huge data sets allow statistical analysis �� Linear multivariate regression equationsLinear multivariate regression equations�� Ability to control for multiple variables simultaneouslyAbility to control for multiple variables simultaneously�� Determine magnitude of effect, certainty, precisionDetermine magnitude of effect, certainty, precision

�� within real context of normal behavior and operationswithin real context of normal behavior and operations

“Evidence Based Design”“Evidence Based Design”

�� Term borrowed from medical fieldTerm borrowed from medical field�� Research on what worksResearch on what works�� Step away from charisma and “Step away from charisma and “stylistastylista” fads” fads

�� Build a Build a researchresearch basis of evidencebasis of evidence�� Use scientific disciplines to compare validity ofUse scientific disciplines to compare validity of

�� MethodologyMethodology�� Strength of findingsStrength of findings�� Test causalityTest causality

Lighting Research DisciplinesLighting Research Disciplines

�� BiologistsBiologists�� OphthalmologistsOphthalmologists�� NeuroscienceNeuroscience�� Organic ChemistryOrganic Chemistry�� Photo/ChronoPhoto/Chrono--biologybiology�� PsychologistsPsychologists�� Zoology/botanyZoology/botany�� EcologyEcology

�� Physical SciencesPhysical Sciences�� PhysicsPhysics�� ChemistryChemistry

�� Social ScientistsSocial Scientists�� SociologistsSociologists�� StatisticiansStatisticians�� EpidemiologistsEpidemiologists�� Economists Economists

�� EngineeringEngineering�� Electrical EngineersElectrical Engineers�� Lighting DesignersLighting Designers�� ArchitectsArchitects�� Urban PlannersUrban Planners�� Energy AnalystsEnergy Analysts

1313

The Three Legged Stool:The Three Legged Stool:

�� Laboratory Studies Laboratory Studies –– controlled experimentscontrolled experiments�� Probe for causal mechanismsProbe for causal mechanisms�� Difficult to gage effect in real worldDifficult to gage effect in real world�� Prove hypothesesProve hypotheses

�� Field Studies Field Studies –– “case study” of buildings“case study” of buildings�� Observational and/or intervention studiesObservational and/or intervention studies�� Real world complexityReal world complexity�� Difficult to control for outside influences, how applicable??Difficult to control for outside influences, how applicable??�� Form hypothesesForm hypotheses

�� Epidemiological Studies Epidemiological Studies –– big populationsbig populations�� Statistical control for other influencesStatistical control for other influences�� Magnitude and certaintyMagnitude and certainty ofof effects in real world conditionseffects in real world conditions�� Association only, no causal mechanismsAssociation only, no causal mechanisms�� Test hypothesesTest hypotheses

PG&E: The Three School DistrictsPG&E: The Three School Districts

�� Are Very Different!Are Very Different!�� Seattle; Ft. Collins Colorado; Capistrano, Seattle; Ft. Collins Colorado; Capistrano, CalifCalif�� 3 climate conditions 3 climate conditions �� 3 curriculums & administration styles3 curriculums & administration styles�� Wide range of building styles: Wide range of building styles:

�� finger plan, enclosed, 1finger plan, enclosed, 1--3 story3 story

�� 3 testing protocols3 testing protocols�� 10 skylight / toplight conditions10 skylight / toplight conditions

Would the results be consistent?Would the results be consistent?

Why Windows versus Skylights ?Why Windows versus Skylights ?

�� Districts were chosen to include toplit classroomsDistricts were chosen to include toplit classrooms�� Daylight from windows can also provideDaylight from windows can also provide

�� view, information on time of day, weatherview, information on time of day, weather�� ventilation, heating and cooling impactsventilation, heating and cooling impacts�� status, morale boost, stress reductionstatus, morale boost, stress reduction�� supervision / communicationsupervision / communication�� display surface (esp. in elementary schools)display surface (esp. in elementary schools)

�� Skylighting (or toplighting) is much simplerSkylighting (or toplighting) is much simpler�� allowing us to isolate a “daylight” effect ?allowing us to isolate a “daylight” effect ?

Capistrano Site ConditionsCapistrano Site Conditions

�� Typical California oneTypical California one--story schools: story schools: �� 50’s daylit “finger plan”schools50’s daylit “finger plan”schools�� 70’s open plans (w/ no windows)70’s open plans (w/ no windows)�� 5 types of skylights in 7 schools5 types of skylights in 7 schools�� package AC, retro AC, wall unitspackage AC, retro AC, wall units�� fixed and operable windows, clear or tintedfixed and operable windows, clear or tinted

�� Portable classrooms at all school sitesPortable classrooms at all school sites�� 40% of classrooms, essentially identical40% of classrooms, essentially identical�� A “placebo” control condition for each siteA “placebo” control condition for each site

Capistrano School DistrictCapistrano School District

�� Tightly managed district, with consistent teaching Tightly managed district, with consistent teaching methodsmethods�� Comparison of Spring to Fall ScoresComparison of Spring to Fall Scores�� Excellent demographic dataExcellent demographic data

�� A variety of daylighting conditionsA variety of daylighting conditions�� Typical California oneTypical California one--story schools: story schools:

�� 1950’s “finger plan” fully daylit schools1950’s “finger plan” fully daylit schools�� 1970’s open plans (w/ no windows)1970’s open plans (w/ no windows)�� fixed or operable windows, clear or tintedfixed or operable windows, clear or tinted

�� 5 types of 5 types of skylightsskylights in 7 schoolsin 7 schools�� Portables at all sites, 40% of classroomsPortables at all sites, 40% of classrooms

�� Mild coastal climate, desirable neighborhoodsMild coastal climate, desirable neighborhoods

50 Variables Examined in Model:50 Variables Examined in Model:

�� Physical ConditionsPhysical Conditions�� VintageVintage�� SF per schoolSF per school�� Classroom TypeClassroom Type�� Daylight availabilityDaylight availability�� Skylight typeSkylight type�� Window area and tint Window area and tint �� Operable WindowOperable Window�� Air Conditioning typeAir Conditioning type

�� School SiteSchool Site(accounts for:)(accounts for:)�� PTA or staff PTA or staff

morale at sitemorale at site�� neighborhood, or special neighborhood, or special

programs, or principal...programs, or principal...

�� Grade LevelGrade Level�� SocioeconomicSocioeconomic

�� Free & reduced lunch clsrm %Free & reduced lunch clsrm %�� Absences and tardiesAbsences and tardies�� Gifted and talentedGifted and talented�� English as a second languageEnglish as a second language�� EthnicityEthnicity�� GenderGender

�� School and Class SizeSchool and Class Size�� Students per classStudents per class�� Students per school Students per school �� Bilingual programBilingual program�� Year round scheduleYear round schedule

We tested 2 statistical models:Daylight code; or window + skylightWe tested 2 statistical models:Daylight code; or window + skylight

�� Model 1:Model 1:�� Daylight CodeDaylight Code 00--5: 5: by light reduction potentialby light reduction potential

�� uniformity and illumination leveluniformity and illumination level

�� Model 2:Model 2:�� Window CodeWindow Code 00--5: 5: area and tintarea and tint�� Skylight CodeSkylight Code: A,B,C or D: : A,B,C or D: by typeby type

CapistranoWindow Code 1

CapistranoOpen ClassroomWindow Code 2

Capistrano --

Open Classroom Window Code 0

Capistrano

Portable Classroom

Window Code 1

Daylight Code 2

Capistrano

Single LoadedFinger Plan School

Window Code 5

Daylight Code 5

Skylight A Skylight AADaylight Code 5

Skylight B

Daylight Code 4

Capistrano Delta RegressionCapistrano Delta Regression

�� Significant Significant (beta order)(beta order)

�� Grade LevelGrade Level�� GATE GATE �� Daylight CodesDaylight Codes�� School Site School Site �� Students per School Students per School �� Language ProgramLanguage Program�� Operable WindowsOperable Windows�� # of Absences# of Absences

�� Not SignificantNot Significant�� EthnicityEthnicity�� SocioSocio--Econ StatusEcon Status�� Age of SchoolAge of School�� GenderGender�� Number of TardiesNumber of Tardies�� Air ConditioningAir Conditioning�� Year Round Sched.Year Round Sched.�� Type of ClassroomType of Classroom

1 Year Progress on Test Scores1 Year Progress on Test Scores

ReadingReading MathMathThe Norm The Norm 8.88.8 12.512.5Max. DaylightMax. Daylight 11.111.1 ++26%26% 15.015.0 ++20%20%Operable WindowOperable Window 9.49.4 +7%+7% NSNS

ororMax. WindowMax. Window 10.810.8 ++23%23% 14.414.4 ++15%15%Skylight ASkylight A 10.510.5 ++19%19% 15.015.0 ++20%20%Skylight BSkylight B 7.07.0 --21%21% NSNSOperable WindowOperable Window 9.59.5 ++8%8% 13.313.3 ++7%7%

= One to two months faster learning= One to two months faster learningon the standard reading and math curriculumon the standard reading and math curriculum

Seattle School DistrictSeattle School District

�� Absolute value of spring standardized testsAbsolute value of spring standardized tests�� 60 Elementary Schools60 Elementary Schools

�� 1010--90 yrs old, including multistory90 yrs old, including multistory�� lots of aggressively daylit classroomslots of aggressively daylit classrooms

�� Cloudy, rainy northern climateCloudy, rainy northern climate�� short winter daysshort winter days�� indoor hallwaysindoor hallways�� indoor play areas, indoor eating areasindoor play areas, indoor eating areas�� fewer students per classroom, smaller schoolsfewer students per classroom, smaller schools

Seattle -- Dunlap

Window code 4

Daylight code 4

Seattle -- Dunlap addition

Window code 3

Skylight code 4

Daylight code 5

Poudre SD, Ft. Collins, COPoudre SD, Ft. Collins, CO

�� Data only available by grade, not by classroomData only available by grade, not by classroom�� NEEA Core TestsNEEA Core Tests�� 5700 records, same variables as Seattle5700 records, same variables as Seattle�� Hot and cold climate, many sunny daysHot and cold climate, many sunny days�� 11--story schools story schools

with interior hallwayswith interior hallways�� 5 5 -- 50 years old50 years old�� Seven identical Seven identical

schools with schools with southsouth--facing facing skylight monitorsskylight monitors�� w/ serious glarew/ serious glare

problemsproblems

Summary Findings:Summary Findings:

Capistranolearning rate

Seattlehigher scores

Ft Collinshigher scores

Windows 15% - 23% 13% - 15% 14% - 18%

Skylights 19% - 20% A 0% - 21% B

6% - 8% 0% - 3%

Daylight 20% - 26% 9% - 13% 7%

OperableWindows

7% - 8%

Follow-on Studies:Follow-on Studies:

�� Analyzed for “teacher bias” effectAnalyzed for “teacher bias” effect�� Only 2% of clsrm assignment explained by daylightOnly 2% of clsrm assignment explained by daylight�� No change in significance of daylight effectNo change in significance of daylight effect

�� Considered Grade LevelsConsidered Grade Levels�� No grade level effectsNo grade level effects

�� Looked at AbsenteeismLooked at Absenteeism�� No daylight effect on absenteeismNo daylight effect on absenteeism

�� Follow on CEC validation study at FresnoFollow on CEC validation study at Fresno�� Much greater detail on site conditionsMuch greater detail on site conditions

Fresno Schools, CEC PIER 2003Fresno Schools, CEC PIER 2003

�� Same testing protocol as CapistranoSame testing protocol as Capistrano�� 36 school sites, 8500 children, grades 336 school sites, 8500 children, grades 3--66

�� 454 classrooms, 55% portables454 classrooms, 55% portables�� less variety of daylight conditionsless variety of daylight conditions�� no skylightsno skylights, no photocontrols, no photocontrols�� less than 20% rooms with appreciable daylightless than 20% rooms with appreciable daylight

�� Urban districtUrban district�� 55% non55% non--English speakersEnglish speakers�� 80% low income80% low income�� Over crowded. Two and three lunch periodsOver crowded. Two and three lunch periods

Download from: Download from: www.hwww.h--mm--g.comg.com “Windows and Classrooms”“Windows and Classrooms”



40% of all FUSD Classrooms are Portables

40% of all FUSD Classrooms are Portables

Fresno Schools, PIER 2003Fresno Schools, PIER 2003

�� 36 school sites, 8500 children, grades 336 school sites, 8500 children, grades 3--66�� 454 classrooms, 55% portables454 classrooms, 55% portables�� less variety of daylight conditionsless variety of daylight conditions�� no skylightsno skylights, no photocontrols, no photocontrols�� less than 20% rooms with appreciable daylightless than 20% rooms with appreciable daylight

�� Hot, inland, urban school districtHot, inland, urban school district�� 55% non55% non--English speakers, 80% low incomeEnglish speakers, 80% low income�� over crowded over crowded (2 or 3 lunch periods)(2 or 3 lunch periods)

�� dirty air: dirty air: second highest asthma rate in CAsecond highest asthma rate in CA

Download from: Download from: www.energy.ca.gov/pierwww.energy.ca.gov/pier or www.hor www.h--mm--g.comg.com

Fresno Data CollectionFresno Data Collection

�� 19 demographic variables19 demographic variables�� student demographicsstudent demographics�� teacher education, tenure, salary indexteacher education, tenure, salary index

�� 72 physical variables 72 physical variables -- site visit to all roomssite visit to all rooms�� neighborhood and site conditionsneighborhood and site conditions

�� maintenance, playground, age, economic statusmaintenance, playground, age, economic status

�� classroom conditionsclassroom conditions�� daylight code and window characteristicsdaylight code and window characteristics�� view, glare, ventilation, HVAC, IAQview, glare, ventilation, HVAC, IAQ�� carpet, sinks, pets, computers, security, etc.carpet, sinks, pets, computers, security, etc.

Capistrano versus Fresno findingsCapistrano versus Fresno findings

�� Explanatory powerExplanatory power�� Overall Model ROverall Model R22 = FUSD much lower= FUSD much lower

�� Vastly more variability in students and curriculumVastly more variability in students and curriculum

�� Partial RPartial R2 2 for physical variables = FUSD higherfor physical variables = FUSD higher�� More precision in definition of physical variablesMore precision in definition of physical variables

Fresno Findings: bad news and good news…Fresno Findings: bad news and good news…

�� Holistic “Daylight code” by itself Holistic “Daylight code” by itself �� was not significant….was not significant….�� sample size too small ? sample size too small ? (only 20% of sample) (only 20% of sample) �� confounded with other factors?confounded with other factors? (poor acoustics and air quality)(poor acoustics and air quality)

�� All window characteristics were All window characteristics were HIGHLYHIGHLY significant:significant:�� positivepositive:: view size, view contentview size, view content

�� +6% to +10% (if vegetation or activity in view)+6% to +10% (if vegetation or activity in view)�� +14% (per 100 +14% (per 100 sfsf view window area for reading, up to +30%)view window area for reading, up to +30%)

�� negativenegative:: glare, sun penetration, no blinds, security grillsglare, sun penetration, no blinds, security grills�� Other significant classroom variables:Other significant classroom variables:

�� positivepositive: # computers, marker boards, connecting classrooms: # computers, marker boards, connecting classrooms�� negativenegative: ballast hum, noisy ventilation system, musty smell: ballast hum, noisy ventilation system, musty smell

Examples of resulting window effects for reading

Examples of resulting window effects for reading

Finger planFinger plan

Activity view Activity view = + 6%= + 6%

160 160 sfsf view view = +14%= +14%

DC 5 DC 5 = = -- 14%14%

2 ext doors 2 ext doors = + 10%= + 10%

Total windowsTotal windows = + 16%= + 16%

PinwheelPinwheel

Activity view Activity view = + 6%= + 6%

15 15 sfsf view view = = -- 7%7%

DC 1 DC 1 = + 6%= + 6%

South windowSouth window == -- 9%9%

Total windowsTotal windows = = -- 10%10%

Portable Portable

East window East window = = -- 8%8%

No binds No binds = = -- 5%5%

DC 2 DC 2 = + 0%= + 0%

64 64 sfsf viewview = + 0%= + 0%


Examples of resulting window effects for math

Examples of resulting window effects for math

Finger planFinger plan

Vegetation view Vegetation view = + 10%= + 10%

150 150 sfsf high win high win = + 8%= + 8%

DC 5 DC 5 = = -- 13%13%

Total windowsTotal windows = + 5%= + 5%

PinwheelPinwheel

0 0 sfsf high win high win = = -- 2%2%

DC 1 DC 1 = + 4%= + 4%

South windowSouth window = = -- 9%9%


Portable Portable

East window East window = = -- 12%12%

No binds No binds = = -- 5%5%

DC 2 DC 2 = + 0%= + 0%

0 0 sfsf high winhigh win = = -- 2%2%


SMUD Call Center Study, PIER 2003SMUD Call Center Study, PIER 2003

�� 100 workers100 workers�� Two months of studyTwo months of study�� 15 minute automated 15 minute automated

performance dataperformance data�� Range of Range of

�� Daylight exposureDaylight exposure�� ViewView�� VentilationVentilation�� TemperatureTemperature

�� IdenticalIdentical�� AcousticAcoustic�� ErgonomicErgonomic


Desktop Study, PIER 2003Desktop Study, PIER 2003

�� Evaluate performance Evaluate performance of 200 office workersof 200 office workers�� In their working In their working

environmentenvironment�� Administered 5 Administered 5

“mini“mini--tests’ tests’ cognitive testscognitive tests

�� at workers computerat workers computer�� 1x week, 5 weeks1x week, 5 weeks�� auto data collectionauto data collection

��

��

��

��


Call Center & Desktop Results –Daylight levels significant in 1 of 6 outcomesCall Center & Desktop Results –Daylight levels significant in 1 of 6 outcomes

�� More daylight More daylight (horizontal photopic illumination)(horizontal photopic illumination): : positive positive

�� +0.4% better performance +0.4% better performance with each 10% increase in daylight illuminationwith each 10% increase in daylight illumination�� Logarithmic scaleLogarithmic scale

�� More electric light More electric light (horizontal illumination):(horizontal illumination):

�� No detectable effectNo detectable effect

Backwards Numbers score in relation to Daylight Illumination

3

4

5

6

7

- 10 20 30 40 50 60 70 80 90 100

Daylight (footcandles)

Bac

kwar

ds N

umbe

rs S

core

One point change in average score from 1 fc to 67 fc

0.7 point change in average score from 1 fc to 20 fc

= 13% improvement= 13% improvement = 19% improvement= 19% improvementNormal adultNormal adult

15 yr old15 yr old

7 yr old7 yr old

High functionHigh function

99th percentile99th percentile

“Digit Span Backwards” cognitive performance test“Digit Span Backwards” cognitive performance test

Does View Matter? Does View Matter?

View was the big winner !View was the big winner !

�� Call Center Call Center �� Faster performance, all 3 modelsFaster performance, all 3 models

�� +7% to +12%+7% to +12%

�� Desktop studyDesktop study�� 3 mental acuity tests3 mental acuity tests

�� +10% to +25%+10% to +25%

�� Less fatigueLess fatigue�� Schools studySchools study

�� Faster learningFaster learning�� +7% to +30%+7% to +30%

(And…window glare is negative)(And…window glare is negative)

�� Schools: Schools: �� More glare, sun penetrationMore glare, sun penetration

no window controlsno window controls�� --5% to 5% to --9% for student growth9% for student growth

�� Offices:Offices:�� Desktop Study: Desktop Study:

More glare from windowsMore glare from windows�� --15% to 15% to --21% for 3 cognitive tests21% for 3 cognitive tests�� --7% to 7% to --21% for 3 visual tests21% for 3 visual tests

�� Not studied for Call CenterNot studied for Call Center

Desktop Health Questions:Number of times in the past week: Desktop Health Questions:Number of times in the past week:

�� HeadacheHeadache�� MigraineMigraine�� Neck or shoulder acheNeck or shoulder ache�� Back or joint achesBack or joint aches�� FatigueFatigue�� Difficulty Difficulty

concentratingconcentrating�� Flu symptomsFlu symptoms

�� Common coldCommon cold�� AllergiesAllergies�� AsthmaAsthma�� Eye strain, dry eyesEye strain, dry eyes�� Stomach upsetStomach upset�� High stress levelHigh stress level�� Other________Other________�� Elevator usageElevator usage�� Stair usageStair usage

Those who reported the least fatigue:(and least headaches, difficulty concentrating, eye strain…)

Those who reported the least fatigue:(and least headaches, difficulty concentrating, eye strain…)

�� My view is relaxingMy view is relaxing --.31.31�� My view is interestingMy view is interesting --.27.27�� I have a view of plantsI have a view of plants --.26.26�� The lighting is just rightThe lighting is just right --.25.25�� Air quality is just rightAir quality is just right --.25.25�� I have a view of people outsideI have a view of people outside --.24.24�� I have a view of cars outsideI have a view of cars outside --.23.23�� I have no temperature problemsI have no temperature problems --.22.22

�� Surveyor rating of view sizeSurveyor rating of view size --.15.15

Pearson’s correlationPearson’s correlation

What is the magic of view?What is the magic of view?

�� Is it mental stimulation?Is it mental stimulation?�� A richer visual environment…A richer visual environment…

�� Is it stress reduction?Is it stress reduction?�� “Attention Restoration Theory”“Attention Restoration Theory”

�� Is it exposure to daylight illumination?Is it exposure to daylight illumination?�� Is Is vertical circadian vertical circadian illumination illumination

at the at the eyeeye a better measurement than a better measurement than horizontal photopichorizontal photopic illumination at the illumination at the tasktask??

�� Allowing us to feed our “appetite” for light?Allowing us to feed our “appetite” for light?

BrainardBrainard et al. et al. Journal of Neuroscience, 2001, 21(16):6405Journal of Neuroscience, 2001, 21(16):6405--64126412

Luminous Efficiency Functions

00.10.20.30.40.50.60.70.80.9

1

400 500 600 700Wavelength (nm)

Rel

ativ

e va

lue

phototopicscotopiccircadian

Spectral Power DistributionSpectral Power Distribution

�� Varies by light sourceVaries by light source�� “Sunlight” (from the sun)“Sunlight” (from the sun)

�� has the greatest range of has the greatest range of wavelengths (colors)wavelengths (colors)

�� “Daylight” (from the sky) varies“Daylight” (from the sky) varies�� Sunrise, noon, sunset, cloudySunrise, noon, sunset, cloudy

�� Fluorescent sourcesFluorescent sources�� Vary with the mix of phosphorsVary with the mix of phosphors

�� Incandescent Incandescent �� Is “full spectrum,” but…Is “full spectrum,” but…

Circadian EffectivenessCircadian Effectiveness

�� Is a function of the overlap Is a function of the overlap between:between:�� the spectral power the spectral power

distribution of the light distribution of the light source, andsource, and

�� the sensitivity of the the sensitivity of the circadian systemcircadian system

�� i.e. its “action spectrum”i.e. its “action spectrum”

Circadian Imbalance:Circadian Imbalance:

1.1. Poor AttentionPoor Attention

2.2. Sleep disturbancesSleep disturbances

3.3. Carbohydrate CravingsCarbohydrate Cravings

4.4. Confusion / Poor CoordinationConfusion / Poor Coordination

5.5. Malaise / BluesMalaise / Blues

6.6. Susceptibility to Infectious DiseaseSusceptibility to Infectious Disease

Hormones and Peptides(health and growth)

Hormones and Peptides(health and growth)

�� Turned on by DARKTurned on by DARK�� VIP VIP VasoactiveVasoactive Intestinal PeptideIntestinal Peptide Blood pressureBlood pressure�� GH GH Growth HormoneGrowth Hormone Growth, in children Growth, in children

adults: decrease body fat, increase lean musclesadults: decrease body fat, increase lean muscles

�� Turned on by LIGHTTurned on by LIGHT�� CRF CRF CorticotropinCorticotropin Releasing HormoneReleasing Hormone StressStress�� GRP GRP GastrinGastrin Releasing PeptideReleasing Peptide HungerHunger�� NPY NPY NeuropeptideNeuropeptide YY HungerHunger�� FSH FSH Follicle Stimulating HormoneFollicle Stimulating Hormone Reproduction Reproduction

Neurotransmitters(Cognitive performance & mood)Neurotransmitters(Cognitive performance & mood)

�� Turned on by DARKTurned on by DARK�� Melatonin Melatonin –– sleep, mood, puberty sleep, mood, puberty �� NoreprinephrineNoreprinephrine –– mood, intelligence, insulin resistancemood, intelligence, insulin resistance�� Acetylcholine Acetylcholine –– learning, memorylearning, memory

�� Turned on by LIGHTTurned on by LIGHT�� Seratonin Seratonin –– impulse control, carbohydrate cravingsimpulse control, carbohydrate cravings�� Dopamine Dopamine –– motivation, muscle coordinationmotivation, muscle coordination�� GABA GABA (Gamma(Gamma--AminobutyricAminobutyric Acid)Acid) –– calm, focus, inhibitioncalm, focus, inhibition

�� “Light is a Drug”“Light is a Drug”

Circadian ResponsesCircadian Responses

�� a cascade of hormonal changes in the a cascade of hormonal changes in the following glands:following glands:�� Pituitary Pituitary -- sleep wake cycles and growthsleep wake cycles and growth�� Pineal Pineal -- reproductivereproductive�� Adrenal Adrenal -- stressstress�� Thyroid Thyroid -- metabolismmetabolism

�� The sensitivity of the response is itself, The sensitivity of the response is itself, circadian!circadian!

�� And changes with age…..And changes with age…..

Age related circadian issuesAge related circadian issues

�� Newborns are not yet “entrained”Newborns are not yet “entrained”�� Need UV to turn on liver blood filtrationNeed UV to turn on liver blood filtration�� Excessive UV and blue light can harm eye developmentExcessive UV and blue light can harm eye development

�� Children have very high melatonin levelsChildren have very high melatonin levels�� Fall asleep at the drop of a hatFall asleep at the drop of a hat�� But ADDH children have sleep disturbances, poor attention controBut ADDH children have sleep disturbances, poor attention controll

�� Teenagers are naturally “owls”Teenagers are naturally “owls”�� More sleep = better learningMore sleep = better learning�� Not mentally awake until about 10 amNot mentally awake until about 10 am

�� Older adults have decreasing melatonin levelsOlder adults have decreasing melatonin levels�� Waking ever earlierWaking ever earlier�� Difficulty sleeping through the nightDifficulty sleeping through the night�� Extreme case = Alzheimer's sleep disruptionsExtreme case = Alzheimer's sleep disruptions

Children’s Visual DevelopmentChildren’s Visual Development

�� Myopia is associated with industrializationMyopia is associated with industrialization�� NonNon--urbanized people have less myopiaurbanized people have less myopia

�� Urban immigrant populations increase in myopiaUrban immigrant populations increase in myopia�� Same gene pool (Eskimos, Chinese, Indians)Same gene pool (Eskimos, Chinese, Indians)

�� Myopia develops in young children, 5yrs Myopia develops in young children, 5yrs –– 15 yrs15 yrs�� Myopia caused by low interior lighting levels?Myopia caused by low interior lighting levels?

�� Myopia caused by exposure to light while sleeping?Myopia caused by exposure to light while sleeping?

�� Myopia caused by lack of proper spectral stimulus? Myopia caused by lack of proper spectral stimulus?

�� Myopia caused by restricted focus?Myopia caused by restricted focus?�� i.e. lack of distance view opportunities?i.e. lack of distance view opportunities?

Given these findings….Given these findings….

�� how do we know how to optimize daylight how do we know how to optimize daylight conditions in classrooms?conditions in classrooms?�� is it room brightness?is it room brightness?

�� If so, when? how long? how much?If so, when? how long? how much?

�� is it brightness of view?is it brightness of view?�� perhaps circadian stimulus available for “snacking”perhaps circadian stimulus available for “snacking”

�� is it the quality of the view? is it the quality of the view? �� sky? vegetation? “interest”?sky? vegetation? “interest”?

Next Steps:Next Steps:

�� Ability to set daylight (& view) standardsAbility to set daylight (& view) standards�� can we define minimum thresholds ?can we define minimum thresholds ?

�� versus optimized conditionsversus optimized conditions

�� testable, verifiable, predictable….testable, verifiable, predictable….�� adaptable to climate conditionsadaptable to climate conditions�� adaptable to new technologiesadaptable to new technologies�� from design concept to asfrom design concept to as--operated conditions…operated conditions…

�� = “Dynamic Daylight Metrics”= “Dynamic Daylight Metrics”�� based on annual (6760 hr) climate simulation tools based on annual (6760 hr) climate simulation tools �� IESNA subcommittee, 3 yr processIESNA subcommittee, 3 yr process�� 3 funded studies to compare field studies to simulation data3 funded studies to compare field studies to simulation data

Thank you for Thank you for your interest!your interest!

www.hwww.h--mm--g.comg.comCopyright HMG 2007

Daylighting and Student Performancethedaylightsite.oxmond.com/wp-content/uploads/symposium...We tested 2 statistical models: Daylight code; or window + skylight Model 1: Daylight Code

Documents