Part I SSL Technology Update - Lighting Research Center · Solid-State Light Sources Light Emitting...

© 2008 Rensselaer Polytechnic Institute. All rights reserved.

Part IPart ISSL Technology UpdateSSL Technology Update

Nadarajah Narendran, Ph.D.Lighting Research Center

Rensselaer Polytechnic InstituteTroy, NY 12180

Solid State Lighting WorkshopAlbany, NYMay 1, 2008


http://upload.wikimedia.org/wikipedia/commons/b/b4/Gluehlampe_01_KMJ.png

1809: Humphry Davyinvented the first electric light.

1879-1880: Thomas Edisondeveloped the first practical incandescent, electric light source. http://inventors.about.com/library/inventors/bledison.htm

Thomas Edison (1847-1931)

Electric lightingElectric lighting


LightingLighting

Over the past 100 years,incandescent and gas dischargetechnologies have provided many light fixtures for a variety of lighting applications.

www.sportsvenue-technology.com/contractors/flood/abacus/abacus2.htmlimages.google.com/images?q=hotel%20lighting&hl=en&lr=&ie=UTF-8&sa=N&tab=wi

10x lm

100x lm

10000x lm

1000x lm


Solid-State Light Sources

Light Emitting Polymer (LEP) orOrganic Light Emitting Diode (OLED)

Light-Emitting Diode (LED)

UniversalUniversal--displaydisplay

Evolving new light sourcesEvolving new light sources

Cree XLamp® LED


Industrial14%

Outdoor Stationary

8%

Commercial51%

Residential27%

Lighting22%

Other78%

.

Motivation for solidMotivation for solid--state lightingstate lighting

About 22% of the total energy use in the U.S.Demand for energy keeps increasing

Source: U.S. DOE Website


White LED promiseWhite LED promise

15 lm/W

90 lm/W

120 lm/W

150 lm/WEnergy savings

1000 hrs

20,000 hrs30,000 hrs

100,000 hrsLower maintenance cost

By 2012


Banning of the light bulbBanning of the light bulb

United StatesDecember 2007 – Clean Energy Act of 2007 was

signed into law.

This legislation effectively banned (by January 2014) incandescent bulbs that produce 310 - 2600 lumens of light. Bulbs outside this range (roughly, light bulbs currently less than 40 Watts or more than 150 Watts) are exempt from the ban. Also exempt are several classes of specialty lights, including appliance lamps, "rough service" bulbs, 3-way, colored lamps, and plant lights.


Lighting market forecastLighting market forecastForecast from Optoelectronics Industry Development Association (OIDA)

Incandescent will be the worst affectedOpportunity for SSL systems

http://images.google.com/imgres?imgurl=http://wrtassoc.com/__oneclick_uploads/2007/11/ssl-forecast.jpg&imgrefurl=http://wrtassoc.com/&h=346&w=575&sz=31&hl=en&start=7&um=1&tbnid=ziWTcKTuWLmgAM:&tbnh=81&tbnw=134&

prev=/images%3Fq%3Devolution%2Bof%2Bhigh%2Bpower%2Blight%2Bemitting%2Bdiodes%26um%3D1%26hl%3Den%26sa%3DX


Life after lightingLife after lightingLight bulb aquarium

http://www.itsnicethat.com/images/507.jpg

http://blog.makezine.com/archive/retro/2.html


Junction(depletion region)

Light

P N-+

- --++

+

+ ---

-Electrons

--

LightLight--emitting diodeemitting diode

P material: Has a slight “deficiency” of electrons for molecular bonding when forming a crystal. N material: Has excess electrons left over from the crystal bonding process, which can move and carry current.Photons (light) are generated when the positive and negative charges recombine.


+ + + + + + + + + + + + + + + ++ + + + + + + + + + + + + + + + + + + +

pn Junction at bias VF

- - - - - - - - - - - - - -- - - - - - - - - - - - - - - - -

VFTrap

LightEg

ElectronElectron--hole recombinationhole recombination

Not all recombinations result in lightCharges trapped in defects result in heatBandgap energy depends on the semiconductor materialColor of the light output depends on the bandgap energy


LED: StateLED: State--ofof--thethe--artart

LumiLeds Lighting


Mixing different colored LEDs (red, green, and blue) in the right proportions produces white light.

Combining blue (or UV) LEDs with phosphors produces white light.

White light with LEDsWhite light with LEDs

White LED

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

380 430 480 530 580 630 680 730

Wavelength, nm

Rel

ativ

e ou

tput

RGB High

0.0

0.5

1.0

400 500 600 700 800Wavelength (nm )

Rel

ativ

e O

utpu

t


White LEDWhite LED

To achieve higher luminous efficacy with white LEDs, improvements are needed at several stages:

internal quantum efficiency extraction efficiency from the die phosphor-conversion efficiency extraction efficiency from the package

DieEpoxy

& phosphor

Reflector


Light extraction from the chipLight extraction from the chip

In traditional LEDs, more than 70% of the light generated by an LED is trapped within the device.

Total Internal Reflections (TIR) Fresnel reflection limits light extraction

θc = sin-1 (n2/n1)For θ > θc TIR

n1 = 2.4 to 3.7

n2 = 1.5

Fresnel reflection

r = {(n1 - n2) / (n1 + n2)}2

n2 = 1.5

n1 = 2.4 to 3.7

TIR


Methods for improving chip light extractionMethods for improving chip light extraction

RCLED

Alter surface finishto improve extraction efficiency

OSRAM Opto’s thin film device

LumiLeds’ (TIP) LED

http://web.mit.edu/cmse/www/IRG-I.nug02.htmlPhotonics Bandgap


EncapsulantsEncapsulants

Encapsulants can affectlight extraction (refractive index mismatch)life of the LED (yellowing, photodegradation)

The industry is still looking for new phosphors and down-conversion materials, like quantum dots, for LEDs.

Air = 1.0008Encapsulant = 1.4 ~ 1.6 Phosphor = 1.85 Die = 2.4 ~ 3.7


HighHigh--flux LEDsflux LEDs

For state-of-the-art LEDs, the extraction efficiency is in the range 40 to 50%.

Lumileds

http://seoulsemicon.co.kr/_homepage/home_eng/product/product.asp?topCODE=1&midCODE=25

Cree

Lamina

Seoul


UV pcUV pc--LEDLED

405-nm LED + RGB phosphors Potential for better color stability1-W and 4-W versions (~162 lm)

http://www.lumination.com/literature/VioDataSheetWEB8_7_07.pdf

70 & 85 CRI3000 K to 4100 K

Manufacturer’s data:


AC LEDAC LED

AC operation No need for drivers

Flux2W: 65 to 80 lm4W: 150 to 195 lm

http://seoulsemicon.co.kr/_homepage

Manufacturer’s data:


Commercial White LEDs Commercial White LEDs –– (March 2008)(March 2008)

Warm White

Vio Vio

OstarOstar

Z-Power P4

Acriche

XRE(P3)

Luxeon Rebel

Luxeon ILuxeon K2

Rigel

Platinum DRAGON

Golden DRAGON

Titan

Moonstone

Luxeon K2

0

10

20

30

40

50

60

70

80

90

100

0 200 400 600 800 1000Luminous flux (lm)

Lum

inou

s ef

ficac

y (lm

/W)

Cool White

Moonstone

Diamond DRAGON

Z-Power P4

Acriche

XRE (Q5)

Luxeon Rebel

Luxeon ILuxeon K2

Luxeon III

Rigel

Platinum DRAGON

Golden Dragon

Ostar

Titan

0

10

20

30

40

50

60

70

80

90

100

0 200 400 600 800 1000Luminous flux (lm)

Lum

inou

s ef

ficac

y (lm

/W)


White LED Color IssuesWhite LED Color Issues


White LightWhite Light

General illumination:CCT: 2800 K to 5500 K

CIE x,y values close to the blackbody locus

Good color-rendering properties


CCT & CRICCT & CRI

New phosphors have enabled white LEDs with a variety of CCT and CRI values.

Now most commercial vendors are offering at least two CCTs (warm and cool white)Some of the new white LEDs have CRI values greater than 92

The industry is still looking for new phosphors and down-conversion materials, like quantum dots, for LEDs.

Nichia White LEDs


LEDLED--toto--LED color variationLED color variation

1931 CIE Chromaticity DiagramMacAdam EllipsesRepresent the loci of just-noticeable color difference

ANSI SpecificationCalls for a 4-step MacAdam ellipse for certain types of lamps

Wyszecki and Stiles, “Color Science,” 1982

Large color variations between similar light sources is an undesirable feature.


LED color binsLED color bins

Most LED companies bin their LEDs Products are tested and sorted into performance bins, and color is one of them.


Life of LEDLife of LED

I = Io exp – α(t)

70%

80%

90%

100%

0 10000 20000 30000 40000Hours

Ligh

t Out

put

Thermocouple

R2 = 0.96

010000

2000030000

4000050000

35 40 45 50 55 60T-point Temperature (deg C)

Life

(hrs

)


LED lifeLED life

All LEDs are not created the sameLife varies significantly

High power white LED

70%

75%

80%

85%

90%

95%

100%

100 1000 10000 100000Time (hours)

Rel

ativ

e lig

ht o

utpu

t

F

C

A D

E B

1W white LEDs operated at 35 deg C, 350 mA


Present industry trendPresent industry trendGrowing number of LEDs and LED fixtures



Ballast (Driver)

Heat Sink

Optics (Lens)

LED Array

Optics (Diffuser)

Electrical Grid

Fixture Housing

Controls

Circuit Board

LED lighting systemLED lighting system


Examples of commercial systemsExamples of commercial systems

http://www.colorkinetics.com/ls/rgb/colorburst6/

Lamina

6 Golden DRAGON™ LEDs connected in series

enLux LED R30

OptiLED's DESIGNER models


LED systemLED systemOptimized system

LEDElectricalOpticalMechanical (heat sink / housing)

Luxeon


http://www.display-optics.com/pdf/tech_papers_oct2002.pdf

OpticsOptics

Options for LEDs:Conventional refractiveConventional reflectiveDiffractiveMicrostructured refractive

Small source size of LEDs allows for more efficient optics


LED lighting systemLED lighting system

LED

Optical

Thermal

Electrical

System efficiency ~ 58%

Lighting Research Center

System efficacy ~ 55% of LED efficacy


Lighting systems performance Lighting systems performance

0

50

100

150

200

250

2000 2004 2008 2012Year

Perf

orm

ance

(Lm

/W)

White LEDR&D Results

Liner Fluorescent Systems

CFL SystemsLED Systems Incand. Systems

(2007)

To the end user, system performance matters…not source performance


System reliabilitySystem reliability

Reduced replacement cost is one of the promises of LEDs

It is the final system performance that matters to the end user

http://members.shaw.ca/sagelighting


Market spoilersMarket spoilers

Over-promised, under-delivered products

Not good for the LED lighting industry

Taipei


Energy output of electric light sources

65 %34 %18 %Heat(Conduction- Convection)

15 %13 %Ballast

Low29 %72 %IR

20 %23 %10 %Light

LED(estimate)

Fluorescent*(T-8 F32 rare earth)

Incandescent*(100 W)

* IESNA Handbook – 9th Edition

Why is thermal management important?Why is thermal management important?


Impact of heat on LEDsImpact of heat on LEDs

Heat affects LED performanceLight outputColorLife

1 Watt White LEDs

60%70%80%

90%100%110%

40 60 80 100 120Tj

Rel

ativ

e lig

ht o

utpu

t

LED A

LED B

LED C

R2 = 0.96

010000

2000030000

4000050000

35 40 45 50 55 60T-point Temperature (deg C)

Life

(hrs

)


Time

Ligh

t O

utpu

t

100%

0%

Heat at the p-n junction increases the degradation rate

Individual LED vs. SystemIndividual LED vs. System


Ceiling tiles (Poor thermal conductor)

Halogen / Incandescent Fixture

LED Fixture

Conducted heat

Radiant heat

Insulation material above the ceiling area

Application issuesApplication issues

Even a properly designed LED fixture can perform badly if installed incorrectly


ApplicationsApplications

To date, the most popular application for LED technology is colored lighting.Compared to traditional light sources, LEDs offer greater benefits for colored light applications.

Less energyLonger lifeMore control optionsShallow-profile fixtures

www.tirsys.com/resource-center/showcase/structures-bridges.htm


ApplicationsApplications

White light applications are just starting Not as popular as colored lightingEnergy savings only in certain niche applications

Two most-touted applications for white LEDs:

Downlights – interior applicationsStreet and parking lot lights – outdoor applications

Are LEDs ready for these applications?

stylmark.com


DownlightingDownlighting

IncandescentHalogen CFL LED

One of the most-touted applications for white LEDs is downlighting

Now, many technologies can cater to the same application.


Commercial LED downlightCommercial LED downlight

System efficacy = 15 lm/W


Commercial CFL downlightCommercial CFL downlight



Commercial LED downlightCommercial LED downlight



Initial costInitial cost

At the present time, most LED lighting fixtures have a higher initial purchase cost than incandescent or fluorescent fixtures (approximately 3 to 6 times higher).

Downlights: Incandescent 75W ~$50CFL ~$90 to $140LEDs (PC) ~$300 to $500

(*LLF LED fixture under $100)


Life cycle costLife cycle cost

In hospitality applications, the cost of using LED systems is approaching the cost of using traditional lighting systems.

The following cost estimates are based on the assumption that LED systems would last 50,000 hrs or longer.

Residential Application

$0$500

$1,000$1,500$2,000$2,500$3,000$3,500

Inc 1

Inc 2

Inc 3

CFL 1

CFL 2

LED 1

LED 2

LED 3

Tota

l Cos

t for

10y

rs

Hospitality Application

$0$1,000$2,000$3,000$4,000$5,000$6,000$7,000

Inc 1

Inc 2

Inc 3

CFL 1

CFL 2

LED 1

LED 2

LED 3

Tota

l Cos

t for

20y

rs

(LLF was not considered in this calculation)

$670$1400


SummarySummary

Rapid development of LED technologyAchieving 150 lm/W by 2012 appears feasibleImprovements needed

Internal quantum efficiency Extraction efficiency from the die Phosphor-conversion efficiency Extraction efficiency from the package

Achieving 100 lm/W system efficacy is challengingImprovements needed

OpticsThermal management componentDrivers and other control devices

Growing applications for white LEDs


Part IIPart IITesting and Evaluating SSL SystemsTesting and Evaluating SSL Systems

Nadarajah Narendran, Ph.D.Lighting Research Center

Rensselaer Polytechnic InstituteTroy, NY 12180

Solid State Lighting WorkshopAlbany, NYMay 1, 2008


Need for MetricsNeed for Metrics

Rapid development of LED technologyApplications community interested in using LEDsMany commercial products for general illumination

Some products have exaggerated claims Insufficient performance data availableLack of measurement standards is one reasonMeasurements made at standard conditions may not represent performance in applications

Failed applications can hurt the entire industryMany agencies are actively working on standards

Insufficient understanding of technology can lead to bad standards


ASSISTASSIST recommendsrecommends

LRC conducts research on LED systems to develop and disseminate information that is useful to users and standards-setting bodies

The project goal is to develop a series of publications

ASSIST recommendsRecommendations for testing and evaluating LED systems Application guides

• Recommendations for using LED light fixtures in applications


Introduction: Introduction: ASSISTASSIST


History & backgroundHistory & background

ASSISTASSIST: Alliance for Solid-State Illumination Systems and Technologies Established: 2002Goal: To support the development and widespread application of LEDs for general illumination

Identify and reduce the major technical hurdles currently facing solid-state lighting

Activities: Industry collaboration, research, demonstration, and education



What is What is ASSIST recommendsASSIST recommends??

When standard definitions and metrics for LED technology are not available, ASSIST develops and publishes recommendations.

The recommendations are developed through research conducted on behalf of ASSIST by the LRC.

ASSIST recommends helps manufacturers present information to end users in a consistent manner.

ASSIST also publishes application guidelines to help end users select and apply LED technology successfully.


Industry activitiesIndustry activities

Standards-setting organizations such as NEMA, CIE, ANSI, …….and others have been working on certain standards.

ASSIST is conducting research to develop information that can be useful for metrics and setting standards.

ASSIST recommends


Jan 2004 June 2004 Jan 2005 June 2005 Jan 2006

ASSISTASSIST

Extracted from March 30, 2004 ASSIST roundtable meeting— Las Vegas

Roadmap to standardsRoadmap to standards

IES NEMA ANSI

Industry Adopts


ASSIST recommendsASSISTASSIST recommendsrecommends

LED Life for General Lighting (Released in 2004)

Life definition: 70% lumen maintenance (50% for indicators or decoration)

Life reported by both LEDand fixture manufacturers


Current statusCurrent status

Some of the LED manufacturers who already have collected data are in the process of compiling information per ASSIST recommends.

Several organizations have referenced ASSIST recommends: LED Life

NEMA DOEIES

Several additional ASSIST recommends published


LED applicationsLED applications

LED performances have been steadily improving.Two potential illumination applications in the near term are:

Under-cabinet lightingDirectional lighting


DocumentsDocuments

Three partsGeneral guide to applicationsGuide to selecting LED fixturesTesting and evaluation recommendations

AudienceGuides – Homeowners, general contractorsTesting and evaluation – Manufacturers, standards-setting bodies, state and federal agencies, public benefit program administrators, independent test labs


Under-cabinet Lighting


UnderUnder--cabinet Lightingcabinet Lighting

Application efficacy = Total lumens on the taskTotal fixture power

18-inch

12-inch

Under-cabinet luminaire

Application efficacy in realistic conditions

φi = Ei . Ai

φv = ∑ Ev . Av ; φh = ∑ Eh . Ah

4” x 4”


Test Data per Test Data per ASSISTASSIST recommendsrecommends

05

10152025303540

Hal. T5 A T5 B T8 C T2 D LED A LED B LED C LED D LED E LED F

App

licat

ion

Effic

acy

(lm/W

)

Hal. T5 A T5 B T8 C T2 D LED A LED B LED C LED D LED E LED FFixture length (in) 12 12 12 20 18 24 24 12 12 21 12

Horizontal flux (lm) 53 91 72 180 199 95 77 87 111 172 173Horizontal average (lux) 96 163 129 277 307 128 104 155 199 252 311

Horizontal uniformity (max:average) 4:1 2:1 2:1 2:1 2:1 2:1 4:1 2:1 2:1 2:1 2:1Verticalflux (lm) 23 107 97 256 286 64 21 65 69 199 109

Vertical average (lux) 49 230 210 473 528 103 34 140 149 350 235Vertical uniformity (max:average) 4:1 3:1 4:1 4:1 3:1 3:1 3:1 4:1 2.5:1 2:1 3:1

(Fixture+Driver) Input power (W) 18.1 8.2 6.9 13.8 14.7 13.5 8.0 8.8 7.7 10.78 7.6(Fixture+Driver) Voltage (V) 119.0 119.5 119.0 118.8 119.2 118.3 118.9 24.0 119.8 119.8 120.0(Fixture+Driver) Current (A) 0.16 0.11 0.11 0.20 0.22 0.12 0.13 0.37 0.07 0.199 0.06

Ambient temperature (C) 23 23 22.9 23 23 23 23 23 23 24.6 23Fixture operating temperature (C) 38.2 33.6 40.1 44.8 41.9 37.7 28.2 41.4 30.6 35.2 35.5

Application flux (lm/ft) 76 198 169 262 324 80 49 152 180 212 283Application Efficacy (lm/W) 4 23 23 30 33 11 12 17 23 34 37

Fixture light output (lm) 88 281 420 623 616 194 151 222 417 420Fixture Efficacy (lm/W) 5 33 57 42 42 14 18 29 38 56

CCT 2591 3044 3965 2813 3223 2943 2868 5887 3500 7542CRI 100 87 86 82 78 73 65 76 73 71

Driver input power (W) 18.4 8.6 7.4 14.7 14.6 13.9 8.2 7.8 10.9 7.6

Grid measure

Sphere measure

ASSIST Reccomends MethodASSIST Recommends Method


UnderUnder--cabinet Lightingcabinet Lighting

67%

81%74%

54%

85%0

102030405060

Halogen F8T5 - 1 F8T5 - 3 LED 1 LED 2

Effic

acy

(lm/W

)

Fixture Efficacy Application Efficacy


SummarySummary

Application efficacy is a more meaningful metric than light source efficacy

Near-field photometry is useful to determine the task lumensSome manufacturers already provide illuminance data on the task

Application efficacy = Total lumens on the taskTotal fixture power


ASSISTASSIST recommendsrecommends

Recommendations for Testing and Evaluating Recommendations for Testing and Evaluating Luminaires Used in Directional LightingLuminaires Used in Directional Lighting


Directional lighting test methodDirectional lighting test method

ASSIST Recommends proposed three environmental conditions to test fixtures:

Open air: Here the light source and the driver have plenty of ventilation around them.

Semi-ventilated: Here the light source and the driver have limited ventilation around them.

Enclosed: Here the light source and the driver have almost no ventilation around them.


Sphere photometrySphere photometry

Temperature, Ts, is measured while operating the fixture in the three environments.

Fixture is placed inside a heated enclosure which is place inside the integrating sphere.

Data gathered once the temperature, Ts, reaches application temperature.

Heater

Lamp

Driver

Heated enclosure

Feedbackcontrol

Ts


Luminaire testing Luminaire testing

Several commercial LED fixtures are being tested in three environments (per ASSIST recommends)

Open airNon-ICIC

Short-term testingFlux and color

Long-term testingLumen depreciation and life (L70)Color shift


Flux (lumens)Flux (lumens)

Well-designed luminaires maintain light output even in hotter environments.Poorly designed luminaires have more than 30% lower light output in IC-condition.

236

649583

263212

678

446

223

643

396

183

0100200300400500600700800

Fixture A26W

Fixture B26W

Fixture C12W

Fixture D30W

Flux

(lum

ens)

Open air Non-IC IC


Efficacy (lm/W)Efficacy (lm/W)

Generally, system efficacy values are 30% to 50% lower than LED efficacy values. However, well-designed luminaires have achieved over 50 lm/W.

10

22

54

8917

7715

5457

0

10

20

30

40

50

60

70

Fixture A26W

Fixture B26W

Fixture C12W

Fixture D30W

Effic

acy

(lm/W

)

Open air Non-IC IC


Board temperature ( Board temperature ( °°C)C)

With increasing Tj the life shortens Generally half the life for every 10°C increase

83 °C 87 °C

42 °C

80 °C95 °C

107 °C

50 °C

90 °C

115 °C 119 °C

60 °C

-0

20

40

60

80

100

120

140

Fixture A26W

Fixture B26W

Fixture C12W

Fixture D30W

Boa

rd T

empe

ratu

re (d

eg C

)

Open air Non-IC IC


Lumen depreciation & color shiftLumen depreciation & color shift

In the IC condition:Life (L70) is less than 3000 hrsThe color shift is greater than a 36-step MacAdam ellipse (reached within 3000 hrs)

Fixture A - 26W LED Downlight

50%

60%

70%

80%

90%

100%

110%

100 1,000 10,000Time (hours)

Rel

ativ

e Li

ght O

utpu

t

Enclosed Semi-ventilated Open air

83 °C95 °C115 °C

Open airNon-ICIC

Fixture A - 26W LED Downlight

0

10

20

30

40

50

100 1,000 10,000Time (hours)

Mac

Ada

m E

llips

es



Fixture B - 26W LED Downlight

50%

60%

70%

80%

90%

100%

110%

100 1,000 10,000Time (hours)

Rel

ativ

e Li

ght O

utpu

t



In the IC condition,Life (L70) is less than 3000 hrsThe color shift is greater than a 19-step MacAdam ellipse (reached within 4000 hrs)

87 °C107 °C119 °COpen airNon-ICIC

Fixture B - 26W LED Downlight

0

10

20

30

40

50

100 1,000 10,000Time (hours)

Mac

Ada

m E

llips

es



Fixture C - 12W LED Downlight

50%

60%

70%

80%

90%

100%

110%

100 1,000 10,000Time (hours)

Rel

ativ

e Li

ght O

utpu

t



Even in the IC condition:Life (L70) seems very longThe color shift is within a 4-stepMacAdam ellipse (in the 3000 hrs)

42 °C50 °C60 °C

Open airNon-ICIC

Fixture C - 12W LED Downlight

0

2

4

6

8

10

100 1,000 10,000Time (hours)

Mac

Ada

m E

llips

es



Fixture D - 30W LED Downlight

50%

60%

70%

80%

90%

100%

110%

100 1,000 10,000Time (hours)

Rel

ativ

e Li

ght O

utpu

t


80 °C90 °C

Open airNon-IC

Even in the IC condition:Life (L70) seems very longThe color shift is within a 3-stepMacAdam ellipse (in the 3000 hours)


Fixture D - 30W LED Downlight

0

2

4

6

8

10

100 1,000 10,000Time (hours)

Mac

Ada

m E

llips

es

Semi-ventilated Open air


SummarySummaryOut of the 4 fixtures presented here, only one showed results acceptable for general lighting, considering:

Light outputEfficacyLumen depreciationColor shift over time

“ASSIST recommends” test methods were designed to:Provide more useful information for selecting and using LED directional lighting luminairesHelp differentiate between good and poor performing LED luminaires in terms of light output and life

Additional “ASSIST recommends” in preparation:LED light engineFreezer case luminairesOutdoor (parking lot) luminaire


Standards for LEDsStandards for LEDs


Product Performance and Measurement StandardsProduct Performance and Measurement Standards

ANSI - American National Standards Institute(www.ansi.org)

C78.377: Specifications for the Chromaticity of Solid State Lighting Products

In preparation:C82.SSL1: Power Supply C82.77-2002: Harmonic Emission Limits – Related Power Quality Requirements for Lighting



UL – Underwriters Laboratories(www.ul.com)

"UL 8750: Outline of Investigation for Light Emitting Diode Light Sources for Use in Lighting Products" is now published and will now be used in product investigations involving LEDs for use in Lighting applications.

UL 1993 - Self-Ballasted Lamps and Lamp Adapters



IESNA - Illuminating Engineering Society of North America(www.IESNA.org)

LM79: IESNA Approved Method for the Electrical and Photometric Measurements of Solid-State Lighting Products TM-16-05: IESNA Technical Memorandum on Light Emitting Diode (LED) Sources and Systems

In preparation:RP-16:Nomenclature and Definitions for Illuminating Engineering Addendum (revision)LM-80: IESNA Approved Method for Measuring Lumen Depreciation of LED Light Sources


U.S. DOE SSL ProgramU.S. DOE SSL Program

Information onENERGY STARCALiPERStandards DevelopmentTechnical Information NetworkTechnology DemonstrationsDesign Competition

http://www.netl.doe.gov/ssl


AcknowledgmentsAcknowledgments

Linc, NYSERDA and CEG

Sponsors of ASSIST Program

LRC faculty, staff, and students


Thank you

www.lrc.rpi.edu/programs/solidstate

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