Introduction to LED Lighting - Westar Energy > Home · PDF fileLO1: What is an LED? Lighting Emitting Diode. An LED is a type of solid-state diode that emits light when voltage is

Introduction to LED Lighting

Presented by:Darrell Huffman

Mercer-Zimmerman

Learning Objectives

LO1: What is an LED?

LO2: LED Terminology

LO3: Why LED?

LO4: LED Equivalency

LO5: LED Control


Lighting Emitting DiodeAn LED is a type of solid-state diode that emits light when voltage is applied. The light output of an LED is a function of its physical construction material used, and amount of current passing through the device. LED can also radiate infrared (heat) energy or UV energy.

LED luminaires use light emitting diodes to produce light very efficiently. The movement of electrons through a semiconductor material illuminates the tiny light sources we call LEDs. A small amount of heat is released backwards, into a heat sink, in a well-designed product; LEDs are basically cool to the touch.

Generated Light from Direct Electronic

Transitions in a Semiconductor Device

No Filament Failures

Ongoing Technological Advancement

AC/DC Conversion

Thermal Management

Optical Efficiency

White Light:There are two primary ways of producing white light-emitting diodes (WLEDs), LEDs that generate high-intensity white light. • One is to use individual LEDs that emit three primary colors— red, green, and blue —and then mix all

the colors to form white light.• The other is to use a phosphor material to convert monochromatic light from a blue or UV LED to broad-

spectrum white light, much in the same way a fluorescent light bulb works.• Phosphor: A coating of phosphorescent material which photons from a royal blue LED pass through

causing those photons to exit with a different color property.• Remote Phosphor: A phosphor conversion technique in which photons from a royal blue LED pass

through a phosphor material that is not attached to the LED chip.

BlueLED

phosphor

white light

greenred

blueRGB SYSTEM

y

cmw


PHOSPHOR SYSTEM


LED Die (Chip)• Light emitting semiconductor.

LED Package• LED Chip integrated with electrical, thermal,

optical, and mechanical interfaces.

LED Array • An assembly of LED packages on a printed

circuit board that are intended to connect an LED driver.

LED Module• A component part of an LED light source that includes one or more

LED arrays connected to the LED driver. Electrical, thermal, optical, and mechanical components may also be part of an LED module.

LED Driver • A power source with integral LED control circuitry designed to meet

the specific requirements of a LED array.

LED Luminaire • A complete LED lighting unit consisting of a light source and driver

together with parts to distribute light, to position and protect the light source, and to connect the light source to a branch circuit.

Heat Sink• A part of the thermal system that conducts or convects heat away

from sensitive components, such as LEDs and electronics.



Dimmer or

Control System

Power Supply &

DriverLED

PackageHeat Sink

Secondary Optics Diffuser

Power Input

Light Output

Component Selection, Luminaire Design, Final Assembly, Testing

Thermal Management

Power Management

Optical Management

Luminaire Assembly Integrity

Lumen Output• The total lumens emitted of a light source, system or solution.


Color Rendering Index (CRI)• A measure of the degree of color shift objects undergo when illuminated by

the light source as compared with the same objects when illuminated by a reference source of comparable color temperature. The reference source has a CRI of 100.

Correlated Color Temperature (CCT)• The absolute temperature of a blackbody whose chromacticity most nearly

resembles that of the light source. Usually specified in Kelvin (K). The lower the Kelvin temperature, the warmer the light feels, or appears.

Efficacy• The light output of a light source divided by the total electrical power input to

that source, expressed in lumens per watt (lm/W).

LM-79 Test• LM-79: Measures an LED luminaire or integral lamp as a whole

systemTotal Luminous Flux (Lumens)Luminous Intensity Distribution (Photometrics)Luminous Efficacy (LPW – Lumens Per Watt)Color Characteristics (CRI, CCT, etc.)

• LM-79 requires that solid state lighting products be tested to “Absolute Photometry.” Conventional HID/Fluorescent uses “Relative Photometry.”

• Absolute Photometry - lumen output of LED based luminaires that is dependent on the chip, thermal management, drive current and optical system.


LM-80 Lumen Maintenance Information• LM-80: Measures lumen maintenance of light source to the array or

module but not as a complete system. 3 Temperatures to be tested at: 55C, 85C and 3rd is selected by LED

Manufacturer. 6K hours min testing period. 10K preferred. Testing on a component level approved method for measuring lumen depreciation of solid-state

(LED) light sources, arrays & modules

• LM-80 does not cover measurement of luminaires.• LM-80 does not define or provide methods for estimation of life.


TM-21


• TM-21: provides a method for determining an LED luminaire or integral replacement lamp’s expected operating life, based on initial performance data collected per LM-80 testing.

• For 6,000 hrs of data (LM-80 min) and up to 10,000 hrs, use data from the last 5,000 hrs.

• For greater than 10,000 hrs of testing, use the last ½ of the collected data.

• TM-21 can extrapolate up to 6 times the data.

• IES has determined end-of-life of LED products to be when the lumen output is 70% of its initial output (30% depreciation). This is known as L70. • Conventional lamp life is rated when 50% of the lamps in an installation

burn out. This is known as B50. LED Luminaires and lamps do not “fail” like conventional sources. LED

luminaires and lamps gradually decrease in output over time.

50,000 Hours is…….?137 Years 1 Hour/Day68.5 Years 2 Hours/Day34.2 Years 4 Hours/Day22.8 Years 6 Hours/Day17.1 Years 8 Hours/Day11.4 Years 12 Hours/Day5.7 Years 24 Hours/Day



Lamp TypeEfficacy (LPW)

CCT (°K) CRI Lifetime (Hours)

LED 100+ 2700 – 6500 70 – 95 30,000–100,000+Incandescent 8 – 15 2500 – 2800 97+ 750 – 1500Tungsten Halogen 10 – 15 2800 – 3200 97+ 3000 -- 5000Compact Fluorescent 50 – 80 2700 – 5000 80 – 85 10,000 – 16,000Linear Fluorescent 70 – 110 2700 – 8000 50 – 90 24,000 – 55,000+Induction 48 – 75 2700 – 5000 80 – 85 100,000Metal Halide 70 – 125 2700 –

10,00060 – 95 10,000 – 20,000

High Pressure Sodium

70 – 145 1800 – 2550 20 – 25 16,000 – 55,000

Lighting Facts• Lighting Facts® is a program of the U.S. Department

of Energy that showcases LED products for general illumination from manufacturers who commit to testing products and reporting performance results according to industry standards.


Energy Star • ENERGY STAR is a joint program of the U.S.

Environmental Protection Agency and the U.S. Department of Energy whose goal is to help consumers save money and protect the environment through energy efficient products and practices.

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ReducedMaintenance

Controls Integration

Visual Comfort(safety)

Instant on/off

(safety)

Mercury / Lead Free

Reduced Carbon

Footprint

Energy Savings

Long Life, No Lamp

Replacement

Financial

Emotional

LO3: Why LED? – Financial & Emotional

Most LED Fixtures Comply With RoHS,(Restriction of Hazardous Substances)

LO3: Why LED? – Environmentally Friendly

• No mercury or lead• 4 mg of mercury (most commercial lamps have <5 mg) is

enough to contaminate up to 7,000 gallons of freshwater.• The mercury from one fluorescent bulb can pollute 6,000

gallons of water beyond safe drinking levels.• Each year and estimated 600 million fluorescent lamps

are disposed of in U.S. landfills amounting to 30k lbs of mercury waste.

Sources: EPA.gov, NaturalNews.com, lamprecycle.org, energywiseepa.org/why/mercury

Solid State Construction

LO3: Why LED? – Rugged Construction

• LED chips are completely embedded in an epoxy resin enclosure which is much more sturdy than traditional glass bulbs and fluorescent tubes.

• With no loose or moving parts LEDs are virtually indestructible.

Thermal Management• Every 10C° ↑ = ½ life of LED

• Every 10C° ↑ = 5% loss in output

• Every 10C° ↓ = 2x life of LED

• Every 10C° ↓ = 5% gain in output

LO3: Why LED? – Thermal Management

Lighting Efficacy 40 LPW

HID:

100 lm/W

40% Utilization Efficiency

Lighting Efficacy 80 LPW

80% Utilization Efficiency

LED:100 lm/W

LO3: Why LED? - Controllability

Energy Savings, Higher min., Better uniformity

• Best way to compare Traditional Lamp Sources vs LED is by doing calculations via lighting calculation software.

• Fixture selection is dependent on the following:• If replacing existing:– What type of fixture are you replacing (troffer, parabolic, etc)?– How many lamps are in the existing fixtures?– Are you needing the same amount of light, more light, less light?

Look at IES recommendations and run calcs.– Are you trying to do a one-for-one replacement?– What LED product are you trying to use?• If new space:– What type of space are you trying to light? Look at IES

recommendations and run calcs.– What LED product are you trying to use?


• In addition, as you have been learning, it is hard to do a direct comparison of LED lumens to traditional source lumens. With LED’s, the lumen output given is typically the DELIVERED lumens. With traditional sources, you are typically looking at the raw lumens of the lamps and then have to take into account the efficiency of the fixture.

• However, you can do some quick comparisons to give you an idea.– Interior: 3 Lamp T8 Fluorescent Recessed Troffer

• Bare Lamp Lumens = 2950 lumens x 3 = 8850 lumens• Fixture Efficiency (look at fixture cutsheet) = let’s assume 78%• 8850 lumens x 0.78 = 6903 lumens (need an LED fixture that has approximately

6903 DELIVERED lumens)

– Exterior: Look at street side Downward Delivered Lumens.


TYPE III 250W MHPS TYPE III 107W LED


HID vs. LED

283W PSMH 22,000 lms 107W LED [Absolute] 10,680 lms

71% Luminaire Efficiency [15,620 Fixture lms] 100% Luminaire Efficiency [10,680 fixture lms]55 LPW [Luminaire Efficacy] 99.8 LPW - Luminaire Efficacy

Street Side = 45% 9,908 lms Street Side = 82.8% 8,845 lms[63.4% of Fixture Lumens]

0.72 LLF [Light Loss Factor] 7,134 lms 0.912 LLF [Light Loss Factor] 8,067 lms

Comparible Task Lumens While Saving 30-75% Energy.

62% Energy Reduction


HID (Metal Halide) vs. LED

DIRT (LDD) 0.90 DIRT (LDD) 0.95

Lumen Depr’n (LLD) 0.65-0.80 Lumen Depr’n (LLD) 0.96

LLF = 0.9 * 0.80 = 0.72 LLF = 0.95 * 0.96 = 0.912

LLD = Mean Lumens [40% Rated Life] ÷ Initial Lumens

LLD = Lumen depreciation per TM-21 50,000 Hrs @ 25°C Ambient

LLF = BF * LDD * LLD

Ballast Factor 1.0 Ballast Factor 1.0


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LO4: LED Lighting Case Study

Project Description: (61) Existing 1000W MH fixtures Replaced with (53) Cooper Ventus LED (303W)

Aflac Support Center Headquarters – Columbus, GABefore After

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LO4: LED Lighting Case Study

Benefits: Reduced load by 76% (49 kW) Average $17,500 in annual savings (166,000 kWh) 3.4 Year Payback Maintenance-free for over 10 years Reduction equivalent to 120 metric tons of CO2 emissions annually

Aflac Support Center Headquarters – Columbus, GABefore After

Verify control system, LED Driver & method are compatible Fixture LED Driver Control Unit

Switching control• Local wall station• Schedule-based• Occupant-based• Lumen-based• Panel-based

Bi-Level Switching• Option 1: Turn off

50% of the LEDs.• Option 2: Dim LED

module to 50%.

Dimming Methods• Forward Phase (Leading

Edge, Triac, SCR, Incandescent)

• Reverse Phase (Electronic Low Voltage, Trailing Edge)

• Three-wire (Lutron Hi-Lume)

• 0 – 10V• DMX 512• DALI

LO5: LED Control

Start by asking a few questions:• Will loads be switched or dimmed?• If dimmed, is the LED driver dimmable?• Which dimming method(s) does the LED driver support?

(i.e. forward phase, 0-10V, etc.)?• Which dimming controls have been tested for

compatibility with the LED driver?• Can the LED driver/control provide the desired minimum

dim level?• Are there special requirements from the driver or

controls manufacturer (ie inrush power)?• Is color changing control required?• Does the fixture need to work with existing controls? If

so, what are the existing controls?

LO5: LED Control

QUESTIONS?

Documents

Introduction to LED Lighting - Westar Energy > Home · PDF fileLO1: What is an LED? Lighting Emitting Diode. An LED is a type of solid-state diode that emits light when voltage is