successful daylighting techniques and technologies

1

Successful Daylighting Successful Daylighting Techniques and Techniques and TechnologiesTechnologies

Russ Leslie, AIA FIES LCRuss Leslie, AIA FIES LC

Professor and Associate DirectorProfessor and Associate DirectorBetter Buildings Better Buildings

By DesignBy Design

2008 Conference2008 Conference

© 2008 Rensselaer Polytechnic Institute. All rights reserved.


22

Portland, ORPortland, OR Architects, Engineers, DesignersArchitects, Engineers, Designers

New York, NYNew York, NY Architects, Engineers, DesignersArchitects, Engineers, Designers

Charlotte, NCCharlotte, NC Owners, Developers, ManagersOwners, Developers, Managers

Des Moines, IADes Moines, IA Owners, Developers, ManagersOwners, Developers, Managers

Orange County, CAOrange County, CADesigners, Owners, Developers, Designers, Owners, Developers, ManagersManagers

Daylight DividendsDaylight DividendsFocus GroupsFocus Groups

2


33

Daylight DividendsDaylight DividendsFocus Group ResultsFocus Group Results

�� Top three perceived benefitsTop three perceived benefits

›› Occupants’ feeling of wellOccupants’ feeling of well--beingbeing•• ComfortComfort

•• Feel good about selfFeel good about self

•• Like being outdoorsLike being outdoors

•• ProductivityProductivity

›› Energy savingsEnergy savings

›› Improved aestheticsImproved aesthetics


44

Daylight DividendsDaylight DividendsFocus Group ResultsFocus Group Results

�� Primary barriersPrimary barriers

›› First cost and cost effectivenessFirst cost and cost effectiveness

›› Problems with technologiesProblems with technologies

›› Building’s site locationBuilding’s site location

›› Added design/financial riskAdded design/financial risk

›› Inconsistency in daylight availability across the Inconsistency in daylight availability across the building and during the course of the daybuilding and during the course of the day

3


55

Building FormBuilding Form–– Letting the Light InLetting the Light In


66

�� Bring light in highBring light in high

�� Use light color surfacesUse light color surfaces

�� Diffuse the sunDiffuse the sun

�� Bring people to the lightBring people to the light

�� Switch off the electric lightsSwitch off the electric lights

4


77


88

Side LightingSide Lighting

�� Rule of thumb:Rule of thumb:›› Effective daylight penetration (D) = 1.5x window height (H)Effective daylight penetration (D) = 1.5x window height (H)

Daylight penetration Daylight penetration increases with increases with window heightwindow height

5


99


�� DELTA Portfolio: DeGraff St. Industrial DELTA Portfolio: DeGraff St. Industrial Center, Office and Small Manufacturing Center, Office and Small Manufacturing www.lrc.rpi.edu/programs/delta/publications/publicationsDetails.asp?id=141&cat=14www.lrc.rpi.edu/programs/delta/publications/publicationsDetails.asp?id=141&cat=14


1010

�� DELTA Portfolio: SONY Disc Manufacturing, DELTA Portfolio: SONY Disc Manufacturing, Administration and Support Spaces Administration and Support Spaces www.lrc.rpi.edu/programs/delta/publications/publicationsDetails.asp?id=173&cat=12www.lrc.rpi.edu/programs/delta/publications/publicationsDetails.asp?id=173&cat=12

Clerestory LightingClerestory Lighting

6


1111


�� DELTA Portfolio: Sacramento Municipal Utility District, Office BuildingDELTA Portfolio: Sacramento Municipal Utility District, Office Buildingwww.lrc.rpi.edu/programs/delta/publications/publicationsDetails.asp?id=139&cat=12www.lrc.rpi.edu/programs/delta/publications/publicationsDetails.asp?id=139&cat=12

›› High occupant satisfactionHigh occupant satisfaction

›› 8% savings by daylight8% savings by daylight

›› $56K yearly energy $56K yearly energy savingssavings

South WallSouth Wall

North WallNorth Wall


1212

Top LightingTop Lighting

�� DELTA Portfolio: Sacramento Municipal DELTA Portfolio: Sacramento Municipal Utility District, Office BuildingUtility District, Office Buildingwww.lrc.rpi.edu/programs/delta/publications/www.lrc.rpi.edu/programs/delta/publications/publicationsDetails.asp?id=139&cat=12publicationsDetails.asp?id=139&cat=12

Splayed SkylightsSplayed Skylights

7


1313

Top LightingTop Lighting

�� Rule of thumb: Rule of thumb: ›› Skylight spacing (S) = 1 to 1.5 x ceiling height (H)Skylight spacing (S) = 1 to 1.5 x ceiling height (H)


1414

Electric Lighting ControlElectric Lighting Control

Harvesting the Energy Savings: Harvesting the Energy Savings: Switch or Dim the Electric LightsSwitch or Dim the Electric Lights

8


1515

Daylighting and Energy SavingsDaylighting and Energy Savings

�� Market penetration Market penetration is poor is poor

�� Less than 1% of new Less than 1% of new construction uses construction uses photosensors photosensors


1616

TomoTherapy, Inc.

Madison, Wisconsin

�� TT--5 HO lamps in direct/indirect 5 HO lamps in direct/indirect lighting fixtures with dimming lighting fixtures with dimming electronic ballastselectronic ballasts

�� LPD = 1.0 watts/ft²LPD = 1.0 watts/ft²

�� Long payback of dimming Long payback of dimming ballast and daylighting ballast and daylighting controlscontrols

www.lrc.rpi.edu/programs/daylighting/pdf/TomoTherapyCaseStudy.pdfwww.lrc.rpi.edu/programs/daylighting/pdf/TomoTherapyCaseStudy.pdf

9


1717

Fluorescent Lamps Weren’t Designed for Fluorescent Lamps Weren’t Designed for Dimming Dimming

�� Compatibility issues Compatibility issues exist to dim without exist to dim without degradation to lamp degradation to lamp life?life?

2.42.6

2.83

3.23.43.6

3.84

4.2

4.44.6

4.85

5.2

5.45.6

5.86

100%

52%

100%

68%

33%

100%

79%

57%

45%

100%

86%

61%

47%

100%

74%

50%

41%

100%

82%

53%

45%

100%

78%

54%

45%

100%

95%

63%

50%

100%

73%

51%

42%

100%

82%

60%

48%

A1 A2 A3 B1 B2 C1 D3 D4 E1 F1

Ballast Designs and Dimming Conditions

Filament Heating Voltage (V)

Dummyload VF VF lamp A VF lamp B VF lamp C VF lamp Cxl


1818

Dimming T8 Fluorescent Dimming T8 Fluorescent System ProblemsSystem Problems

�� Lamps (broken electrodes)Lamps (broken electrodes)

�� Luminaires (improper wiring, Luminaires (improper wiring, disconnected wires)disconnected wires)

�� Ballasts (failing, low input Ballasts (failing, low input voltage, lack of power)voltage, lack of power)

�� Installation (lamps not rotated Installation (lamps not rotated into place, discontinuity in into place, discontinuity in electrode heating circuit)electrode heating circuit)

�� Troubleshooting procedureTroubleshooting procedure

Sponsors

CEC. Iowa Energy

Center, NYSERDA,

US EPA

www.lrc.rpi.edu/nlpip/publicationDetails.asp?id=905&type=4www.lrc.rpi.edu/nlpip/publicationDetails.asp?id=905&type=4

10


1919

Simplifying Daylight TechnologiesSimplifying Daylight Technologies

�� Automatic on/offAutomatic on/off�� Designed to retrofitDesigned to retrofit�� Low costLow cost

The DaySwitchThe DaySwitch


2020

DaySwitch Energy Savings PotentialDaySwitch Energy Savings Potential

Energy savings comparision of systems in open office plans for different cities

15%12%

14%

17%

13%

24%

19%22%

28%

20%

37%35%

37%39%

34%

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

Albany NY Sacramento CA Portland OR Charlotte NC Phoenix AZ

Energy savings over base case

Dayswitch DaySwitch and AutoBlinds Perfect dimming

11


2121

0

10

20

30

40

50

60

Feb-02 Mar-02 Apr-02 May-02 Jun-02 Jul-02 Aug-02 Sep-02Time

Cumulative energy use (kWh)

Without photosensor

With photosensor

0

10

20

30

40

50

60

Feb-02 Mar-02 Apr-02 May-02 Jun-02 Jul-02 Aug-02 Sep-02Time

Cumulative energy use (kWh)

Without photosensor

With photosensor

Test office

Daylight DimmingDaylight Dimming

� Wireless, remote sensor

� Self-commissioning

� Occupant preference adjustment Sponsor: Connecticut Light and PowerSponsor: Connecticut Light and Power

21© 2005 Rensselaer Polytechnic Institute. All rights reserved.

Commissioning time < 3 Commissioning time < 3 minutes in most casesminutes in most cases


2222

Daylighting Controls: Making Them WorkDaylighting Controls: Making Them Work

›› Proper selection of the Proper selection of the correct controller for the correct controller for the design situationdesign situation

›› Proper location of the Proper location of the controlscontrols

›› Proper adjustment to Proper adjustment to ensure correct operationensure correct operation

12


2323

�� Specifier Reports: PhotosensorsSpecifier Reports: Photosensors›› October 2007 October 2007 www.lrc.rpi.edu/nlpip/publicationDetails.asp?id=916&type=1www.lrc.rpi.edu/nlpip/publicationDetails.asp?id=916&type=1

�� TrendsTrends›› Photosensors part of lighting control or whole building Photosensors part of lighting control or whole building control systemcontrol system

›› Interface with load shedding or Interface with load shedding or occupancy sensingoccupancy sensing

›› Added features (such as remote Added features (such as remote controls or remote interfaces) for controls or remote interfaces) for simpler adjustments and simpler adjustments and commissioning procedurescommissioning procedures

Spatial response graphicSpatial response graphic


2424

�� No one product satisfied all requirements or was fully No one product satisfied all requirements or was fully adaptable to different installationsadaptable to different installations

�� Complex products perform no Complex products perform no better than simple productsbetter than simple products

�� Products tested perform no Products tested perform no better than those tested ten better than those tested ten years ago at meeting the years ago at meeting the design criteria: constant design criteria: constant workplane illuminanceworkplane illuminance

Spectral response graphSpectral response graph

13


2525

Control Characteristics and Features Control Characteristics and Features MatrixMatrix

Key:

MH = Must Have HD = Highly Desirable O = OptionalThe matrix below indicates when a characteristic is

important to consider with a particular product type. .

CharacteristicsCharacteristicsOpen Loop Open Loop Switching Switching SystemsSystems

Open Loop Open Loop Dimming Dimming SystemsSystems

Closed Loop Closed Loop Switching Switching SystemsSystems

Closed Loop Closed Loop Dimming Dimming SystemsSystems

Range of responseRange of response MHMH MHMH MHMH MHMH

Spectral responseSpectral response HDHD HDHD HDHD HDHD

Spatial responseSpatial response MHMH MHMH MHMH MHMH

DeadbandDeadband MHMH —— MHMH ——

Compatibility with applicable temperature and Compatibility with applicable temperature and humidity conditionshumidity conditions

MHMH MHMH MHMH MHMH

Ballast and component compatibility Ballast and component compatibility –– manufacturer manufacturer should list compatible ballasts and the components should list compatible ballasts and the components necessary to make a complete operating systemnecessary to make a complete operating system

MHMH MHMH MHMH MHMH

Power requirements Power requirements -- operating voltage, input and operating voltage, input and output current must be clearly indicatedoutput current must be clearly indicated

MHMH MHMH MHMH MHMH

Number of ballasts the device is able to controlNumber of ballasts the device is able to control MHMH MHMH MHMH MHMH


2626

Sun ControlSun Control

14


2727


2828

15


2929


3030

Visual DiscomfortVisual Discomfort

�� People will take action to People will take action to reduce or eliminate daylight if reduce or eliminate daylight if it causes discomfort or it causes discomfort or increases task difficultyincreases task difficulty

--Maniccia et al., 1999Maniccia et al., 1999

16


3131

Auto Blind ConceptsAuto Blind Concepts

�� Manual anytimeManual anytime

�� Auto open once per dayAuto open once per day›› East facade: East facade: afternoonafternoon

›› West and south West and south facades: eveningfacades: evening

�� PV or mechanical PV or mechanical device: no wiring device: no wiring requiredrequired


3232

Auto Blind Energy Savings PotentialAuto Blind Energy Savings Potential

Leslie et al., Lighting Research and Leslie et al., Lighting Research and Technology 37,1 (2005) pp. 21Technology 37,1 (2005) pp. 21--40.40.

17


3333

Integrated Skylight Luminaire (ISL)Integrated Skylight Luminaire (ISL)

�� High bay applicationsHigh bay applications

›› “Big box” retail“Big box” retail

›› WarehousesWarehouses

›› Light industrialLight industrial

�� Demo in Norwich, CTDemo in Norwich, CT

Sponsored by:Sponsored by:

New York State Energy Research and Development AuthorityNew York State Energy Research and Development AuthorityConnecticut Light & PowerConnecticut Light & Power


3434

ISL Design CriteriaISL Design Criteria

�� Meet manufacturers’ and owners’ concernsMeet manufacturers’ and owners’ concerns

�� Automatically capture energy savingsAutomatically capture energy savings

�� Glare control; no harsh shadowsGlare control; no harsh shadows

�� Know it is daylightKnow it is daylight

�� Work under clear and overcast skiesWork under clear and overcast skies

�� Easy to install, commission, and maintainEasy to install, commission, and maintain

�� Use simple, low cost technologyUse simple, low cost technology

�� Applicable to many buildingsApplicable to many buildings

18


3535

Integrated Integrated Skylight Skylight LuminaireLuminaire


3636

Step Step Switching:Switching:

Rings of lamps are turned off; balance lamp life of Rings of lamps are turned off; balance lamp life of each ringeach ring

All lamps are dimmed at same time until they turn offAll lamps are dimmed at same time until they turn off

Continuous Continuous Dimming:Dimming:

Lighting Controls OptionsLighting Controls Options

19


3737

Commissioning ProcedureCommissioning Procedure


3838

Integrated Skylight LuminaireIntegrated Skylight Luminaire

Before installing ISLsBefore installing ISLs After installing ISLs (daytime)After installing ISLs (daytime)

After installing After installing ISLs (nighttime)ISLs (nighttime)

20


3939

Energy Savings from Three*

Integrated Skylight Luminaires

Spring, Summer, Fall 2002

0

1000

2000

3000

4000

5000

kWh (8 months)

Previous metal

halide

ISL without

dimming control

ISL with

dimming control

(actual)

4 0 %

Saving s2 8 %

Saving s

*Note: Data were available for three of the four units, including

both step dimming and continuous dimming operation.

Energy SavingsEnergy Savings


4040

Benefits Beyond EnergyBenefits Beyond Energy

21


4141

Daylighting Benefits Beyond EnergyDaylighting Benefits Beyond Energy

�� Report reviewed by blue ribbon panelReport reviewed by blue ribbon panel

›› Enhancing Enhancing ProductivityProductivity

›› Daylight & HealthDaylight & Health

›› Daylight & FinanceDaylight & Finance

›› MisunderstandingsMisunderstandings

Boyce, P. et al. 2003. The Benefits of Daylight Boyce, P. et al. 2003. The Benefits of Daylight through Windowsthrough Windows


4242

The Biophilia HypothesisThe Biophilia Hypothesis

�� Innate need to be in Innate need to be in contact with nature?contact with nature?

�� The one reason why The one reason why windows are inherently windows are inherently superior to electric superior to electric lightinglighting

22


4343

Preference for WindowsPreference for Windows

“90% of people say it is important or very important to have windows in their office.”Puleo and Leslie, “Some Effects of the Sequential Experience of Windows on Human Response.” JIES, Winter 1991.


4444

Preference for WindowsPreference for Windows

�� As long as people are As long as people are thermally comfortable thermally comfortable and do not lose privacyand do not lose privacy

23


4545


4646

FinanceFinance

�� A wall containing windows costs more to A wall containing windows costs more to construct and maintain than one withoutconstruct and maintain than one without

�� Windows have a positive effect on the Windows have a positive effect on the rental value of a spacerental value of a space

›› Office space with windows = $15Office space with windows = $15--$20/ft²$20/ft²

›› Office space without windows = $12Office space without windows = $12--$17/ft²$17/ft²

Boyce, P. et al. 2003.Boyce, P. et al. 2003. The Benefits of Daylight through WindowsThe Benefits of Daylight through Windows

24


4747

Is View a Factor in Price Structure?Is View a Factor in Price Structure?

% “yes”% “yes”

Hotels Hotels (n=21)(n=21) 48%48%

$15$15--70/night for those that 70/night for those that price by viewprice by view

Apartments/CondosApartments/Condos(n=15)(n=15) 87%87%

One condo reported $15,000One condo reported $15,000--25,000 increase with view25,000 increase with view

OfficesOffices(n=22)(n=22) 73%73%

From Daylight Dividends Seed Research Report: From Daylight Dividends Seed Research Report: Are Windows and Views Really Better? A Are Windows and Views Really Better? A Quantitative Analysis of the Economic and Psychological Value of ViewsQuantitative Analysis of the Economic and Psychological Value of Views, Dr. Jong, Dr. Jong--Jin Kim, Jin Kim, University of Michigan, 2005.University of Michigan, 2005.


4848

Task Performance/ProductivityTask Performance/Productivity

�� More light gives better task More light gives better task performanceperformance

�� Better vision for Better vision for seniors/people with low seniors/people with low visionvision

�� Good color characteristicsGood color characteristics

25


4949

The Circadian ConnectionThe Circadian Connection

�� Physiologically, daylight Physiologically, daylight is an effective stimulant is an effective stimulant to the circadian systemto the circadian system

�� The impact of daylight The impact of daylight on task performance on task performance and health operating and health operating through the human through the human circadian system?circadian system?


5050

Building Design/Building Design/Case StudiesCase Studies

26


5151


5252

Building section: roof monitor, Building section: roof monitor, skylights, flower diffusersskylights, flower diffusers

27


5353

35 Skylights 35 Skylights 2 Roof Monitors2 Roof Monitors


5454

28


5555

Higher light levels to draw people into these areas: produce, back of store

Diffuse solution: no direct sunlight below monitor

Baffles for visual interest as daylight pattern progresses across them


5656

1212--month Progression…month Progression…

29


5757

December 21December 21 June 21June 21 March/September 21March/September 21

09:00

09:00

12:00

12:00

15:00

15:00


5858

January March June

January 1 vs August 112:00 Noon

30


5959

InspirationInspiration


6060

Design EvolutionDesign Evolution

31


6161

Leaf from customer’s logo/identity Leaf from customer’s logo/identity used as a branding toolused as a branding tool


6262

North ElevationNorth Elevation

Loading dockLoading dock

Proposed window height: 18’Proposed window height: 18’--10”10”

32


6363

West ElevationWest Elevation




6464

Natural light brightens the hallway Natural light brightens the hallway while small light shelves eliminate direct sun glare.while small light shelves eliminate direct sun glare.

West Corridor Daylight StudyWest Corridor Daylight Study

33


6565

CaféCafé

Rest roomsRest rooms

East ElevationEast ElevationProposed window height: 11’Proposed window height: 11’--10”10”



6666

8am September morning8am September morning 8am December morning8am December morning

CaféCafé

East ElevationEast Elevation


34


6767

Daylight Daylight transmits transmits through to through to men’s roommen’s room

Rest roomsRest rooms

East ElevationEast ElevationProposed window height: 11’Proposed window height: 11’--10”10”


6868

Base Case 1Base Case 1

�� No skylightsNo skylights

�� Developer’s sidelightingDeveloper’s sidelighting

�� Energy cost: $527,366/yrEnergy cost: $527,366/yr

›› Base Case 1 meets ASHRAE Base Case 1 meets ASHRAE 90.190.1--2004 requirements2004 requirements

›› WholeWhole--building method used for building method used for lightinglighting

›› For retail store, 1.5 watts/ft² for For retail store, 1.5 watts/ft² for general overhead lightinggeneral overhead lighting

›› Additional 1.6 watts/ft² for task Additional 1.6 watts/ft² for task lighting in retail arealighting in retail area


Developer’s windows, no skylightsDeveloper’s windows, no skylights

Partly cloudy, Sept. 22, 11 a.m.Partly cloudy, Sept. 22, 11 a.m.

35


6969


�� 35 skylights35 skylights

�� Efficient electric lightingEfficient electric lighting

›› Base 1 Energy Cost: Base 1 Energy Cost: $527,366$527,366

›› Base 2 Energy Cost: Base 2 Energy Cost: 444,215444,215

›› Savings:Savings: $ 83,151$ 83,151


Developer’s windows, developer’s skylightsDeveloper’s windows, developer’s skylights



7070

LRC Alternate 1LRC Alternate 1


›› Base 1 Energy Cost:Base 1 Energy Cost: $527,366$527,366

›› LRC Alt 1 Energy Cost:LRC Alt 1 Energy Cost: 442,497442,497

›› Savings:Savings: $ 84,869$ 84,869


Developer’s windows, LRC’s skylightsDeveloper’s windows, LRC’s skylights


36


7171



�� 2 roof monitors2 roof monitors



›› Savings:Savings: $85,186$85,186


Developer’s windows, LRC’s skylights/monitorsDeveloper’s windows, LRC’s skylights/monitors



7272


�� Improved sidelightingImproved sidelighting



›› Savings:Savings: $ 84,231$ 84,231


Developer’s skylights, LRC’s windowsDeveloper’s skylights, LRC’s windows


37


7373



�� 2 roof monitors2 roof monitors

�� Improved sidelightingImproved sidelighting›› Base 1 Energy Cost:Base 1 Energy Cost: $527,366$527,366


›› Savings:Savings: $ 86,233$ 86,233


LRC’s windows, LRC’s skylights/monitorsLRC’s windows, LRC’s skylights/monitors



7474

More light, less energy!More light, less energy!



















38


7575





















Cloudy, Dec. 21, 11 a.m.Cloudy, Dec. 21, 11 a.m.



Sunny, clear, Jun. 21, 11 a.m.Sunny, clear, Jun. 21, 11 a.m.


7676

Smith Middle SchoolSmith Middle School

Chapel Hill, North CarolinaChapel Hill, North Carolina

www.lrc.rpi.edu/programs/daylighting/pdf/SmithCaseStudyFinal.pdfwww.lrc.rpi.edu/programs/daylighting/pdf/SmithCaseStudyFinal.pdf

39


7777


�� Built in 2001Built in 2001›› 637 students637 students›› 135,764 ft² 135,764 ft² ›› 54% daylit54% daylit


7878

Daylighting StrategyDaylighting Strategy

�� Integrate daylighting into Integrate daylighting into the building’s designthe building’s design

›› SouthSouth--facing wall windowsfacing wall windowsemploy light shelvesemploy light shelves

›› Minimize eastMinimize east-- and and westwest--facing windowsfacing windows

40


7979


�� Integrate the daylighting strategy into the Integrate the daylighting strategy into the building’s designbuilding’s design

›› Utilize southUtilize south--facing roof facing roof monitorsmonitors

›› Use unevenly spaced clothUse unevenly spaced clothbaffles to eliminate glarebaffles to eliminate glare

41


8181


�� WallWall--mounted luminaires mounted luminaires are used where the roof are used where the roof monitor meets the monitor meets the ceilingceiling

�� DropDrop--in, threein, three--lamp, lamp, parabolic troffers are parabolic troffers are used in the drop ceilingused in the drop ceiling


8282

Main hallwayMain hallway

Gymnasium uses Gymnasium uses

daylighting daylighting

Daylighting awareness Daylighting awareness

programprogram

42


8383

Lighting ControlsLighting Controls

�� All fixtures use dimming ballasts; each class All fixtures use dimming ballasts; each class room uses closedroom uses closed--loop photosensors and loop photosensors and control panelscontrol panels

�� Motion sensing is through Motion sensing is through a dual technology a dual technology (ultrasonic and infrared) (ultrasonic and infrared) controllercontroller


8484

Control SchemeControl Scheme

43


8585

Lighting Controls InstallationLighting Controls Installation

MonitorMonitorlightinglighting

Wall switchWall switch

Motion sensorMotion sensor

Light level Light level

sensorsensor

Dimming Dimming

ballastsballasts

Lighting controllerLighting controller

PhotosensorPhotosensor

WindowWindowparabolicsparabolics

InteriorInteriorparabolicsparabolics

Zone1

Zone2

Zone3


8686

Commissioning the SystemCommissioning the System

�� Too many parts and controlsToo many parts and controls

�� Quote from the maintenance supervisor: Quote from the maintenance supervisor: “Commissioning was a pain in the @$%&!”“Commissioning was a pain in the @$%&!”

�� Expensive to replace dimming ballastsExpensive to replace dimming ballasts

›› $90 vs. $20 for standard ballast $90 vs. $20 for standard ballast

44


8787

Building CostsBuilding Costs

�� Total incremental daylighting cost: $158,098Total incremental daylighting cost: $158,098

›› $1.23/ft² over entire building (about half is $1.23/ft² over entire building (about half is daylit)daylit)

›› Includes roof monitors, light shelves, lighting Includes roof monitors, light shelves, lighting controls, cloth baffles, etc.controls, cloth baffles, etc.

�� Reductions in peak cooling load (78 tons) Reductions in peak cooling load (78 tons) and lighting needs reduce the daylighting and lighting needs reduce the daylighting incremental costincremental cost


8888


�� Reduction in annual lighting energy of Reduction in annual lighting energy of daylit spaces: 70% daylit spaces: 70%

�� Reduction in annual cooling energy: 19%Reduction in annual cooling energy: 19%

�� Increase in annual heating energy due Increase in annual heating energy due to reduced internal heat from lighting: 20% to reduced internal heat from lighting: 20%

45


8989

Paying for DaylightingPaying for Daylighting

�� Incremental cost: $1.23/ft²Incremental cost: $1.23/ft²

�� Annual lighting & cooling savings: $0.33/ft²Annual lighting & cooling savings: $0.33/ft²

�� Annual heating cost increase: $0.04/ft²Annual heating cost increase: $0.04/ft²

�� Total annual energy savings: $0.29/ft²Total annual energy savings: $0.29/ft²

�� Simple payback: 4.2 yearsSimple payback: 4.2 years


9090

Building Occupant SatisfactionBuilding Occupant Satisfaction

�� “They like it.”“They like it.”

�� Teachers love the amount and Teachers love the amount and quality of lightquality of light

�� There is a feeling of spaciousnessThere is a feeling of spaciousness

�� Principal uses the daylighting Principal uses the daylighting design as a selling point to attract design as a selling point to attract teachers to work at the schoolteachers to work at the school

�� Students and teachers find the Students and teachers find the lighting better here than at other schoolslighting better here than at other schools

�� One teacher said, “I thought I died and went to heaven One teacher said, “I thought I died and went to heaven when I came to work here.”when I came to work here.”

46


9191

Lessons LearnedLessons Learned

�� Daylighting must be integrated into total building Daylighting must be integrated into total building design from the beginningdesign from the beginning

�� Teachers believe there are less behavioral Teachers believe there are less behavioral problems and there is more motivation to learn problems and there is more motivation to learn due to daylightingdue to daylighting

�� The cost of replacement dimming ballasts must be The cost of replacement dimming ballasts must be factored into any economic analysis of daylightingfactored into any economic analysis of daylighting

�� Awareness and management support is critical to Awareness and management support is critical to energy savingsenergy savings

Harmony Library

Fort Collins, Colorado

Plan view

www.lrc.rpi.edu/programs/www.lrc.rpi.edu/programs/daylighting/pdf/daylighting/pdf/HarmonyLibraryCaseStudy.pdfHarmonyLibraryCaseStudy.pdf

47


9393

Design StrategyDesign Strategy


9494


�� Clerestory glazingClerestory glazing

›› Overhanging roof eavesOverhanging roof eaves

›› NeutrallyNeutrally--tinted glasstinted glass•• 22% visible transmittance22% visible transmittance

48


9595


�� General lightingGeneral lighting

›› Low ambient luminanceLow ambient luminance

›› Augment with task lighting as necessaryAugment with task lighting as necessary


9696


�� Initial control schemeInitial control scheme

›› Did not meet design intentDid not meet design intent

›› Complex for usersComplex for users

›› Upgraded after one yearUpgraded after one year

�� New control systemNew control system

›› Two main componentsTwo main components•• RelayRelay--based automatic switching system based automatic switching system

•• Lighting scene moduleLighting scene module

49


9797

Lighting ScenesLighting Scenes

�� PrePre--programmed scenesprogrammed scenes

›› OpeningOpening

›› PublicPublic

›› PrePre--shutdownshutdown

›› NightNight

�� Scenes automatically switched according to Scenes automatically switched according to programmed scheduleprogrammed schedule


9898

OpenOpen--loop Switchingloop Switching

�� RoofRoof--mounted photosensormounted photosensor

�� Operates nonOperates non--dimming ballastsdimming ballasts

›› Minimizes hardware costsMinimizes hardware costs

50


9999

Photosensor OperationPhotosensor Operation

�� Photosensor Photosensor kept lights off kept lights off most days, April most days, April 20042004›› Intermittent Intermittent on/off cycling on/off cycling on overcast days on overcast days (5 of 31 days)(5 of 31 days)

›› Few complaints Few complaints about cyclingabout cycling


100100


�� Roof photosensor controls nearly 50% of Roof photosensor controls nearly 50% of lighting watts in main areaslighting watts in main areas

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Occupant SatisfactionOccupant Satisfaction


102102

Occupant SatisfactionOccupant Satisfaction

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�� WellWell--designed buildings reduce reliance on designed buildings reduce reliance on blinds for sun shadingblinds for sun shading

�� Task lighting helps low ambient lighting Task lighting helps low ambient lighting design conditiondesign condition

�� Dark tinting on windows is not objectionable Dark tinting on windows is not objectionable on sunny dayson sunny days


104104


�� Switching is noticeable, but not offensiveSwitching is noticeable, but not offensive

›› Sometimes confusing (Is it closing time?)Sometimes confusing (Is it closing time?)

�� Switching can save energy costs and avoid Switching can save energy costs and avoid initial expense of dimming ballastsinitial expense of dimming ballasts

�� Public facilities need simple lighting scenes Public facilities need simple lighting scenes that can also be automatically switched off that can also be automatically switched off on scheduleon schedule

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Online ResourcesOnline Resources

�� Available at Available at www.daylightdividends.org www.daylightdividends.org and and www.lrc.rpi.edu/programs/NLPIP/index.aspwww.lrc.rpi.edu/programs/NLPIP/index.asp

�� Available at Available at www.daylightdividends.org www.daylightdividends.org and and www.lrc.rpi.edu/programs/NLPIP/index.aspwww.lrc.rpi.edu/programs/NLPIP/index.asp


Guide for Guide for Daylighting SchoolsDaylighting Schools

TomoTherapy, Inc.TomoTherapy, Inc.

Harmony LibraryHarmony Library Lighting Lighting Diagnostics: Diagnostics: Dimming T8sDimming T8s Specifier Reports: Specifier Reports:

PhotosensorsPhotosensors


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Thank you.Thank you.

successful daylighting techniques and technologies

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