LED Lighting Facts Card

LED Facts Card - Learning Objectives

What is a lighting Facts card?
How to read a lighting Facts card?
LED problems?
What is CRI?
What is TM-30?
How many lumens are produced by a 100 watt incandescent light bulb?

Why did the DOE (Department of Energy) create and mandate that the 'Lighting Facts' data to be printed on packaging for light bulbs?

Since LED light sources do not mimic daylight, there is a need to have some metrics for comparison to familiar light sources of sunlight, incandescent and halogen. Lighting Facts is a good start, for more details consider the Kelvin, CRI, and TM-30 metrics.

LED = Light Emitting Diodes - now the standard for new construction in the state of California, mandated by Title 24 energy code power limits, the most restrictive power allowances in the world, preceding adoption of similar codes worldwide. LED bulbs (or lamps as the lighting industry calls them, or Light Engines as the lighting designers call them) are inherently color biased. Since the Blue White chip was developed for the commercial market, manufactures have been struggling with achieving balanced white light. A combination of coatings, voltage, age, and manufacturing processes all affect an LED's spectral and lumen output, industry terms for color and brightness.
Good lighting design should always include analysis of color rendering, light intensity, beam spread, flicker, and glare.
GLARE = Visual Disability Due to the extremely small light source of LEDs, glare can cause visual disability - squinting and averting the eyes.
EYE ADAPTATION = Increases with age and brightness. LEDs can be too bright. "There's well over a million-fold change in intensity between a starlit night and a bright sunny day at the beach. This is a challenge for the nervous system because neurons have a very limited response range: -80mV to +50 mV of graded potential in the non-spiking cells of the retina, or 0 to about 200 spikes per second for ganglion cells. The retina solves this problem by adapting to the ambient level of illumination. If the light level changes by a relatively small amount, then the visual system compensates for the change almost immediately. However; if the light level changes by a lot, then the eye takes a long time to re-adjust." [1]
Light Source Choices = The bewildering array of light bulb choices is confusing. Industry professionals refer to light bulbs and light sources as 'lamps'. Examples of how colors appear under different light sources are discussed on this page. As LED lamps continue to evolve, there are many decisions to be made about color rendering (ability of light source to show color of objects and surfaces) and light output (intensity of light emitted measured in lumens).

R9 Color Rendering Test Colors

Color Rendering Index (CRI) indicates the ability of a light source to render color accurately. The problem is that the original 8 muddy colors, and the addition of 4 additional colors are not enough to judge a light source's ability to accurately render all colors.
Sunlight and Halogen Incandescent lighting score 100 serving as the basis for color comparisons for values of CRI.
Regulations in California (Title 24) require 90 CRI or higher in Residential applications. Commercial projects often use light sources with 80 CRI or as low as 70.
As LED light source technology advances, the CRI is improving; however, it is important to learn about the color rendering and limitations of a particular light source before specifying or purchasing, since most light sources cannot be returned, because the wholesaler or retailer cannot tell how many hours the lamp (light source) has been used.

TM-30 Color Type Key:
A-Nature B-Skin C-Textiles D-Paints E-Plastics F-Printed Materials G-Color Systems

TM-30 Color Rendering Test Colors

TM-30 uses state-of-the art scientific advances in color science. As a result, it is more accurate than the CRI, especially for narrow-band spectra where the CRI can fail.
TM-30 provides more accurate information such as a fidelity index Rf which replaces the CRI index and indicates whether colors look natural.
TM-30 also provides more insight into the gamut index Rg which indicates a color's saturation and an accuracy graphic which gives advanced information about the rendering of specific colors.
https://www.ies.org/store/technical-memoranda/ies-method-for-evaluating-light-source-color-rendition/

Lighting Facts - Comparing the numbers

Lumens Per Watt = Efficacy of light source
Watts = Power Consumption
CRI = Color Rendering Index
R9 = Red light component
CCT - Correlated Color Temperature -K = Degrees Kelvin, or color temperature of the light
Flicker = dimability and stability
TM-30 = New Color Rendition Metric by IES

DOE - Department of Energy
Lighting Facts

Standard Label with Optional Metrics Anatomy of the LED Lighting Facts® Label Light Output/Lumens

Measures light output. The higher the number, the more light is emitted.
Reported as “Total Integrated Flux (Lumens)” on LM-79 test report.

Watts

Measures energy required to light the product. The lower the wattage, the less energy used.
Reported as “Input Power (Watts)” on LM-79 test report.

Lumens per Watt/Efficacy

Measures efficiency. The higher the number, the more efficient the product.
Reported as “Efficacy” on LM-79 test report.
A typical pear shaped incandescent light bulb, 100 watt A-19, produces 1,600 Lumens.

IESNA LM-79-2008

Industry standardized test procedure that measures performance qualities of LED luminaires and integral lamps.
Allows for a true comparison of luminaires regardless of the light source.

LED Lumen Maintenance

Listed as a percentage, this metric estimates the amount of light the LED light source is projected to emit at 25,000 hours at a given ambient test temperature, compared to its initial light output. This percentage is based on LM-80, in-situ performance, and TM-21 projections.

Model Number

Unique manufacturer’s model number for the product.

Type

Specific type of solid-state lighting fixture.

Brand

The brand under which each product is available.

Color Rendering Index (CRI)

Sunlight is the basis for color compairsons of light sources, measured as Color Rendering Index (CRI) sunlight having a CRI of 100.
CRI measures color rendering accuracy.
Color rendition is the effect of the lamp’s light spectrum on the color appearance of objects.

R9 measures the way red is shown up in items under the light source.
Since LED light sources are inherently blue, rendering red correctly is challenging enough that some jurisdictions include an R9 value over 50 as the minimum standard, for example in Title 24 in California residential construction.

Correlated Color Temperature (CCT)

Measures light color.
“Cool” colors have higher Kelvin temperatures (3600–5500 K).
“Warm” colors have lower color temperatures (2700–3500 K).
2200K is considered candlelight, 10000K is considered daylight at high-noon.

Product Warranty

If a label indicates that the product has a warranty, a URL with more information has been verified by the program and is available from the product summary. [2]

Light Source Color Rendering Chart
R9 Chart %
Consult Individual LED Manufacturer for Test Results

Flicker

"Flicker is a rapid variation in light source intensity, usually most noticeable in peripheral vision. Individuals vary widely in flicker sensitivity. Almost all lighting systems produce some flicker, but most people are ale to tolerate minor fluctuations in light output over time. More -severe flicker can contribute to headaches, photosensitivity, epileptic seizures, and other health issues. Even if the flicker cannot be consciously detected by an individual, it may still affect the person neurologically." [3]

Footnotes

Professor David Heeger - Light/Dark Adaptation
www.lightingfacts.com
IES RP-28-16 Seniors and Low Vision http://www.ies.org/

Photo Credits

Lighting Facts Card - DOE - Department of Energy
Test Colors for CRI & Light Source Color Rendering Chart - EYE Lighting
TM-30 Test Colors - IES TM-30-15 Errata