introduction to led lighting - westar energy · introduction to led lighting presented by: darrell...

Introduction to LED Lighting

Presented by:

Darrell Huffman

Mercer-Zimmerman

Learning Objectives

LO1: LED Terminology

LO2: Why LED?

LO3: Thermal Management

LO4: LED Equivalency

LO5: LED Control

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.


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).

LO2: Why LED?

Pros & Cons of LED

• Exceptionally long life

• Very slow rate of lumen depreciation

• Require far less energy to operate

• Dramatically reduced maintenance costs

• Increased safety/reduced liability

• Fully dimmable and highly adaptive

• Available in a wide range of CCTs

• Environmentally friendly (RoHS compliant)

• Higher up front cost/investment

• Only a few standards currently in place

• Lots of games being played

• Lots of misinformation being published

• Requires new terminology & paradigms

• Limited base of installed products to view and experience first hand

LO2: Why LED?

Exceptionally Long Life

• The useful life of Metal Halide lamps is measured by it’s failure rate.• Metal Halide lamp, by approximately 15,000 hrs, only ½ of

the lamps will still be burning (50% failure rate in under 4 years).

• In addition, Metal Halide lamps lose 20-30% of it’s initial output by 6,000 hrs of operation

• Because LEDs last so much longer and their light diminishes so slowly, we measure their useful life in terms of L70

• L70: The point in time at which a diode’s lumen (light) output has diminished to 70% of its initial output (ie. L93 @ 60,000 hrs)

50,000 Hours is…….?

137 Years 1 Hour/Day

68.5 Years 2 Hours/Day






LO2: Why LED?

LO2: Why LED?

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 – 1500

Tungsten Halogen 10 – 15 2800 – 3200 97+ 3000 -- 5000

Compact Fluorescent 50 – 80 2700 – 5000 80 – 85 10,000 – 16,000

Linear Fluorescent 70 – 110 2700 – 8000 50 – 90 24,000 – 55,000+

Induction 48 – 75 2700 – 5000 80 – 85 100,000

Metal Halide 70 – 125 2700 – 10,000 60 – 95 10,000 – 20,000

High Pressure Sodium 70 – 145 1800 – 2550 20 – 25 16,000 – 55,000


• The most critical aspect of LED luminaire design is Thermal Management; removing heat from the fixture in order to maintain the lowest operating temperature possible.

• Thermal management involves a heat sink that utilizes both conduction and convection

• The Operating temperature plays a primary role in determining these aspects of the LED:• Rate of lumen depreciation to L70• Lumens per watt produced (efficacy)• Color stability over time

• Even with the higher efficacy LEDs, only about 20% of the energy from each watt gets converted to visible light. That leaves 80% remaining as heat. LEDs do not shed heat thru infrared or ultraviolet radiation, so heat sink is critical


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


• 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 (Illuminating Engineering Society) 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?


Types of LED Retrofits

• LED T8 Replacement Lamps

• LED Lamps/trim retrofit kit

• LED Retrofit Kits

Troffer kit

Shoebox/Cobrahead Kit

Strip fixture kit

Floodlight/Highbay Kit

• LED “Corncob” Lamp (HID Replacement)

• New Fixture


Retrofit Kit vs. New LED fixture• Retrofit kits are a cheaper alternative to purchasing a new LED fixture

• However, because the original fixture was not designed with an LED heat sink, that tradeoff significantly impacts your performance and payback .

• Expect a shorter useful life (faster lumen depreciation).

• Expect reduced efficacy and therefore reduced energy savings

• Possibility of color shifting, from warmer color temperatures to cooler, more bluish color

• Make sure retrofit kit will be UL or ETL listed once installed into existing fixture

• Is the manufacturer a new company? Have they been around longer than their claimed warranty?

• What is the product warranty? What triggers the warranty?

• Is the retrofit kit/lamp rated to be used in an enclosed fixture? What is the ambient rating of the fixture?

LO4: LED EquivalencyLED T8 Replacement Lamps: 3 Different Kinds

LED Tube – Runs off existing fluorescent ballast

• Pros:

• Easiest to install

• No modification to existing fixture

• Low cost

• Cons:

• Point of failure w/ existing ballast

• Typically shorter lamp life

• May have compatibility issues w/ existing ballast

LED Tube w/ Integrated Driver – Line Voltage

• Pros:

• Low Cost

• More efficient than lamps that run off existing ballast

• Cons:

• Modification to existing fixture (bring line voltage to lamp socket)

• Potential liability - installers exposed to line voltage with no buffer

• Limited dimming control and compatibility issues w/ EM operation

• Pros: • Longest life• Highest Efficacy• Best compatibility w/ dimming

& EM operation

• Cons• Higher cost• More labor intensive

LED Tube w/ Remote Driver


Converting or Comparing HID to LED

• When comparing exterior applications between metal halide and LED the most important aspect is street side Downward Delivered Lumens

• With LED, watts are irrelevant in terms of comparing light levels; their relevance is in the area of energy-savings only.

• Take into consideration: lamp orientation, lens material and optics

• Don’t assume that you need equivalent lumens. Your current lighting may be too bright or dark and is probably less uniform that what you can achieve with LED


0°

90°

100% Aimable Light

LED Chip

Lens

vs. Controlled Optics

107W 11,059 lms

0°0°

285W 22,000 lms

Point-By-Point (20’ MH, 80’ Spacing)

Avg Max Min Max/Min__

1.46 4.55 0.49 9.29

Point-By-Point (20’ MH, 80’ Spacing)

Avg Max Min Max/Min___

1.16 1.85 0.65 2.85

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 100% Luminaire Efficiency [10,680 fixture lms]

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


LO4: LED Lighting Controls

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?

QUESTIONS?

introduction to led lighting - westar energy · introduction to led lighting presented by: darrell...

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