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Designing with Solid State Designing with Solid State Technology and Light Technology and Light Emitting Diodes (Emitting Diodes (LEDsLEDs))

AIA BEST PRACTICES

Insight Lighting sponsors this course provided by Hanley Wood, a Registered Provider with the American Institute of Architects Continuing Education Systems. Credit earned on completion of this learning unit will be reported to CES Records for AIA members. Certificates of Complete are available for non-AIA members.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services should be directed to the course sponsor, Insight Lighting, upon completion of this online learning unit.

LEARNING OBJECTIVES

► Recount the history and development of LEDs► Describe the architecture of an LED

► Describe the difference between white LEDs and RGB LEDs

► Describe performance benefits of LEDs over traditional light sources

► Discuss test and accreditation standards for LEDs

Light Emitting Diodes (LEDs)– What is an LED

LED light sources have considerable advantages over traditional lighting sources:

– Long lifetimes (20,000 to 100,000+ hours)– Lower overall total cost of ownership– Control and display of light output

INTRODUCTION

Recount the History and Development of LED Technology

Because of their small size, LEDs have improved design flexibility.

– Digital control with 100% dimming capability– Low DC voltage operation– Vivid saturated colors without filters– Dynamic color control – white point tunable– Robust design for thermal and vibration shocks– Pinpoint Beam Control

INTRODUCTION


Because of their ‘anatomy’, LEDs are environmentally friendly

– No hazardous materials are required– Highly energy efficient– No IR or UV light in beam output– Directed light output for increased system efficiency

INTRODUCTION


HISTORY & DEVELOPMENT

Relative improvement in luminous efficiency over time

1962First visible-spectrum LED developed by Nick HolonyakJr.

1972First yellow LED and 10x brighter red and red-orange LEDsinvented by M. George Craford

1907First report of a solid-state light emitting diode, H.J. Round of Marconi Labs

1997Development of first blue LED lead to development of first white LED

2006Millennium Technology Prize awarded to ShujiNakamura for invention of YAG phosphor coating

1961Patent issued for infrared LED to Bob Biard and Gary Pittman

1955Infrared emission from gallium arsenide (GaAs) and other semi-conductor alloys reported by Rubin Braunstein

1920sOleg VladimirovichLosev created the first LED

HISTORY & DEVELOPMENT

LED development began with infrared and red devices made with gallium arsenide. Advances in materials science have made possible the production of devices with shorter-wavelengths, producing light in a variety of colors.

The first red LEDs were used as indicator lights because they were not bright enough to illuminate an area.

(Panel Boards & Digital Clocks)

As technology and materials became more advanced, light output increased and LEDs were able to be used for illumination.


HISTORY &DEVELOPMENT

LEDs as indicators (LEFT) and as illuminators (RIGHT)

Typical construction for a High Flux LED

- Typical Flux > 3 lm

- Number of LEDs to equal the output of a 60W incandescent light bulb <20

- Typical Flux = 3 lm

- Number of LEDs to equal the output of a 60W incandescent light bulb = 200

Typical Construction for a 5mm LED


HISTORY &DEVELOPMENT

Construction difference between a 5mm LED and a High Flux LED

LEARNING OBJECTIVES





There are two ways to produce white-light LEDs– RGB (Red, Blue, Green) method, mixing the primary

colors to achieve white.– Phosphor deposition (Coating with a phosphor

material to create white light).

CREATING WHITELEDs

Describe the difference between RGB LEDs and white LEDs

The mixing process requires sophisticated electro-optical design used to control the blending and diffusion of RED, BLUE and GREEN LED’s

– this approach has rarely been used to mass produce white LEDs in the industry.

Nevertheless this method is particularly interesting to many researchers and scientists because of the flexibility of mixing different colors.

CREATING WHITELEDs


There are several types of multi-colored white LEDs: di-, tri-, and tetra-chromatic white LEDs.

Product of white light by mixing the primary colors is affected by color stability, color rendering capability, and luminous efficacy.

– Dichromatic LEDs have the best luminous efficiency (120lm/W), but the lowest color rendering capability

– Tetra-chromatic white LEDs have excellent color rendering capability but often have poor luminous efficiency.

– Tri-chromatic white LEDs are between, having both good luminous efficiency (>70 lm/W) and fair color rendering capability.

CREATING WHITELEDs


• Phosphor Coating can provide white light form the warm to the cool white spectrum.

Phosphor Deposition Examples

CREATING WHITELEDs


CREATING WHITELEDs


RGB Blue + Phosphor

Advantages

•Color can be changed dynamically

•As a luminance source, millions of colors can be produced

•Highest theoretical luminous efficiency of all three methods

•No UV output

• High theoretical luminous efficiency

• Can provide color temperatures between 3200 K (warm white) and 10,000 K (cool white)

• No UV output

Disadvantages

• Color can shift due to aging and temperature

• Requires more sophisticated electronics

• Poor color rendition• Fixture efficiency

drop caused by color mixing

• Potential to create variations in tint

• Must be controlled using optics and binning

LEARNING OBJECTIVES





PERFORMANCE

Describe the performance of LEDs over traditional light sources.

Traditional reflected light fixtures are typically very inefficient.

LuminaireType

MeasuredLumen

(per Watt)

UseableLumens

(on target)

Coefficient ofUtilization(efficiency)

150 W Type IIStreet Light 13,908 6,921 50%

400 W MetalHalide HIDwith glasshousing

29,013 15,771 54%

400 W MetalHalide with

Metalhousing

29,013 17,597 61%

Fluorescent 11,400 10,260 85%

PERFORMANCE


Comparing traditional sources to LEDs, you can see that LED efficiency continues to improve over these older light sources.

LED’S are improving in efficiency every year. This chart compares types of LEDs against each other, showing improvement within the LED category.

Effic

ienc

y (lu

men

s pe

r Wat

t)

PERFORMANCE


LEDs …– Are very energy efficient

85 LPW (near-term roadmap to > 200 LPW)

– Are directionalNo wasted light – more useable lumens

– Have a very long lifetime>50,000 hours to 70% lumen maintenance

– Are inherently ruggedNo filament to break

– Start instantlyNanoseconds vs. >10minutes re-strike HID bulbs

– Are environmentally soundNo mercury, lead or heavy metals

– Love cold temperaturesNo cold starting issues

PERFORMANCE


LEDs are a sustainable alternative to traditional lighting –but there are several myths and misunderstandings about LEDs.

– Useable life– Heat– Moisture– ESD– Color – Binning– Environment– Manufacture

PERFORMANCE


PERFORMANCE


Traditionally, lifetime was the time it took for 50% of the population of incandescent bulbs to fail.

Many light sources don’t fail catastrophically – Define EOL by reduction in light output from initial values for example 70% or 50% of initial value

Under what conditions do we measure lifetime?

LIFE

PERFORMANCE


LEDs do produce heat. They do not radiate the heat into the room, like other sources.

HEAT

PERFORMANCE


Thermal Management Issues

Calculating Safe Junction Temperatures- What is Junction Temp- Increase in Junction Temp Decrease in Life/OutputHEAT

PERFORMANCE


Thermal management is the most important design element facing LED fixture manufacturers. Improper thermal management can reduce life expectancy.

Which heat sink is most appropriate?HEAT

40o C/W OR 0.4o C/W

PERFORMANCE


Application Environments

Generally, light sources or fixtures operate in thermal environments such as:

– Fully ventilated (e.g., track lighting, open air)– Semi-ventilated (e.g., recessed downlight, non-IC)– Enclosed (e.g., recessed downlight with ceiling

insulation, IC)

HEAT

HEAT

PERFORMANCE


It is important that LED light fixture manufacturers understand the operating temperature parameters of the LED chip that they are utilizing.

- verify the intended operating temperature of the PCB and make sure that the LED is compatible with that requirement.

- make sure that the design meets your intended use for an interior or exterior environment.

Heat at the junction affects the performance of LEDs– Light output– Color– life

HEAT

PERFORMANCE


LED’s have to be protected from moisture intrusion.

Excessive humidity will reduce the effectiveness of LED’s.

MOISTURE

PERFORMANCE


Electrostatic Discharge – the sudden and momentary electric current that flows between two objects at different electrical potentials.

ESD is often caused by static electricity or by electrostatic induction.

ESD

PERFORMANCE


PERFORMANCE


ESD can be caused by static electricity, or otherturbo-charging scenarios.

- walking on a rug- rubbing plastic combs against dry hair- removing types of plastic packaging

ESD can also result from electrostatic induction- redistribution of excessive charges on one object to another.

ESD

PERFORMANCE


Not all ESD events produce a visible or audible ‘spark.’

– These types of ESD events can cause device failure and malfunction

– ESD degradation of a component may affect long term performance, but it may not be noticeable immediately

ESD

PERFORMANCE


White LEDs are replacing other ‘white light’ luminaires. The color temperature of an LED diode does effect its efficiency.

COLOR

A warm white LED is generally 20 % less efficient than a cool white LED.

The color temperature of a blackbody is associated with a color on the CIE diagram.

Plot of the color of light emitted by a blackbody with respect to its temperature.

STATIC WHITE

PERFORMANCE


PERFORMANCE


The color temperature of the LED chip being used by the manufacturer must be reliable and consistent.

BINNING

Color temperature is an important consideration for lighting a space. A range of colors are available from warm to cool.

BINNING

PERFORMANCE


Light fixture manufacturers select color bins based on what will work best with their fixtures. They do not get to select the ‘best’ bin lots directly from diode manufacturers.

PERFORMANCE


Manufacturers can be separated into those that propagate their own technology and those who offer an LED product.

Understand terminology used by manufacturers and suppliers. Know the difference between watts and lumens and how this will affect performance.

- wattage measurements emphasize output ratherthan efficiency or quality of light.

MANUFACTURERS

LEARNING OBJECTIVES





For LED products to be listed as safe by the Underwriters Laboratory (UL), they must comply with NEC Article 411.

Even with this compliance, this does not guarantee that the entire system fixture has been tested and deemed safe by UL.

– A lighting manufacturer that provides fixtures with power supplies from other manufacturers, or providing a fixture with a remote UL recognized power supply under UL 60950-I are not in compliance with NEC 411.

2008 NEC/ULDEFINITIONS

STANDARDS

Describe accreditation and performance standards for LEDs

IES LM 79STANDARDS


► IES approved method for photometric testing of solid state luminaires.

► Absolute photometry- actual delivered lumens measured from the complete fixture at certified testing laboratory.

► Measures luminous flux, luminous intensity, efficacy, actual power consumption, and chromaticity and CRI.

IES LM 79

IES LM 80STANDARDS


► IES approved method for measuring lumen depreciation of SSL (LED) sources from diode manufacturers.

► LM80 establishes a performance baseline of the performance of actual LED at certain temperatures over a length of time.

► Minimum test of 6000 hours

► Measures lumen maintenance data, chromaticity shift, electrical conditions but can make no estimation of life beyond the test time.

IES LM 80

Energy StarSTANDARDS


► Under DOE/ EPA supervision

► Commercial and residential luminaire requirements regarding life expectancy, luminaire efficacy, CCT, etc.

► Example:► Commercial cove lighting

►min lumen output 200 lumens per foot. ► 45 lumens per watt ( delivered lumens) ► 35% of total lumens within 120-150 degrees. ► 2700K, 3000K, 3500K allowable CCT

Energy Star

When specifying LEDs as part of your lighting plan, look for a manufacturer that has products compliant with both NEC and UL standards.

LEDs must be tested and marked for use as a complete system.

Ask for data on LM79 and LM 80.

See if they have complied with Energy Star requirements.

ASK the hard questions


STANDARDS


STANDARDS


White LED trends– Higher luminous efficiency (lumens/watt)– Higher lumens per package– Lower thermal resistance– Lower cost per lumen– Lower cost per LED– Tighter color bins– Specific color and flux bin availability– Higher CRI values

LUMINIOUSEFFECIENCY TRENDS


STANDARDS


Make sure that the information you receive from a LED light fixture manufacturer is reliable and consistent. It’s about the system!

LEDs are well suited for certain applications.– Selecting the correct LED product for its best

application must depend on verifiable information that is based on a system approach.

Photometric, electrical and LED data; including thermal performance, product longevity, power consumption, lumen performance and Kelvin temperature data should be based on proven design technology that has been tested as an integrated system.

STANDARDS


APPLICATIONSAPPLICATIONS

APPLICATIONS

• The time for LEDs has come– Technology is ready– Economics work for now for many installations

• Buying motivation go well beyond pure economics– Consumers, municipalities, and businesses are

ready for GREEN lighting solution– Regulatory impact – CA Title 24, Australia,

European Union, U.S. DOE

• LEDs are a paradigm change from bulbs– Must think in terms of LUMINAIRES, not re-lamp– Luminaire design for LEDs will be different and

require new expertise

SUMMARY

Review of the topics covered

THANK YOU

Insight Lighting believes in the integrity of product and lighting design. Our mission is to develop innovative new products to assist our customers in meeting their lighting challenges. By creating functional, aesthetic and energy conscious products, we strive to enhance the appearance and performance of a working environment.

This concludes the AIA portion of this learning unit.

If you have questions about how LED technology can improve the performance of your design, please contact us.

LEGACY LIGHTING612 WINFLOAUSTIN,TEXAS512-481-9971SHAWNA SIECK-512-779-8254RANDY DAVIS-512-825-8208

6288: Insight Lighting online CEU quiz

1) What are the two most common ways used to produce white light

LEDs?

a) Secondary color mixing

b) Primary color mixing

c) Phosphor deposition

d) Through filters and reflectors

2) TRUE or FALSE: LED technology has significantly improved over the

last decade, while traditional technologies have remained stable.

3) _______________ is the most important design consideration for LED

fixtures

a) Thermal management

b) Efficiency

c) Lumen output

d) Color

4) TRUE or FALSE: LEDs can be used for exterior applications because

they are not easily damaged by water infiltration or humidity.

5) What is the “silent killer” of LEDs?

a) Improper ventilation

b) Water or humidity damage

c) Compact fluorescent bulbs

d) Electrostatic discharge

QUIZ

QUIZ (cont.) 6) Which white LED is typically more efficient?

a) Cool white

b) Indicators

c) Illuminators

d) Warm white

7) TRUE or FALSE: Selective binning separates color temperatures of white

light.

8) LEDs are energy efficient because: (choose two)

a) No hazardous gases are required to function

b) They do not emit heat

c) They do not emit IR or UV light

d) A smaller bulb provides more light than traditional sources

9) TRUE or FALSE: LEDs have to meet NEC/UL codes as a complete system,

rather than a single bulb.

10) When considering LEDs, which is most important?

a) Wattage output

b) Lumen output

c) System Integration

d) Light direction

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