In the last two months, Lightology has partnered with top LED manufacturers, Edge Lighting, Pure Lighting and Philips Lightolier to teach Chicago’s architects and designers all about LEDs. Through these presentations, we’ve collected 5 helpful tips on LEDs that anyone can use to make sure they purchase the right LED for any project!
1) Look for the Lighting Facts Label
Sponsored by the Department of Energy, the Lighting Facts Label is the ‘nutrition facts label’ for LEDs, providing a quick summary of product performance data.
By introducing transparency to the lighting supply chain, the label guards against exaggerated claims and helps ensure a satisfactory experience for lighting buyers.
Luminaire manufacturers who take the pledge agree to use the label to disclose performance results in five areas—lumens, efficacy, watts, correlated color temperature (CCT), and color rendering index (CRI)—as measured by the industry standard for testing photometric performance, IES LM-79-2008.
2) Color (Correlated Color Temperature)
Students Visit the Color Temperature Wall, which shows all the different colors of light, at the Lightology Showroom
Color Temperature measures light color.
- “Cool” colors have higher Kelvin temperatures (3600–5500 K).
- “Warm” colors have lower color temperatures (2700–3500 K).
These colors are charted on the Kelvin scale for you to use when choosing a light source. Many LEDs are developed with a color temperature of 2700K, which is the same as a standard incandescent, or 3000K, which matches the color of Halogen light.
It is important to match the color temperature in all light sources when designing a space, otherwise the differences might be quite noticeable.
3) Quality (Color Rendering Index)
This picture shows that the colors on the tissue box look better under LEDs with a higher CRI. All three tissue boxes are lit under the same Color Temperature, only the CRI is different.
CRI measures color accuracy, or more specifically, it is the effect of the lamp’s light spectrum on the color appearance of objects.
Based on a scale from 1-100 (100 being the best), a low CRI LED will make colors in fabrics, paint and people look duller, less vibrant. It’s a great idea to place color samples from your project underneath LEDs with differing CRIs, this can help you decide which LED source makes the color in your sample look the best.
Typically, a CRI in the mid-70s and up is acceptable for commercial applications. For residential applications, A CRI of 80 or above are preferable.
4) Lumens, Watts and Lumens per Watt
This chart shows the comparison in efficacy between an incandescent, fluorescent and LED.
Lumens measures light output. The higher the number, the more light is emitted.
Watts are ONLY a measurement of the energy required to light the product. The lower the wattage, the less energy used.
Lumens per Watt is a way to measure efficiency, similar to the Miles Per Gallon you get in your car. The higher this number is, the more efficient your product is.
5) Thermal Management
The Scope LED Head uses aluminum as a heatsink to pull heat away from the LED, making sure it maintains the 50,000 hour lifespan.
Heat plays a major factor in the lifespan of an LED. LEDs are a condensed point source that gets very hot, so an aluminum heatsink is necessary to dissipate the heat over a larger surface and keep the junction (where the LED meets the circuit board) temperature below 80°C.
Running an LED just a few degrees too warm can shorten the lifespan of an LED up to 50%! A good rule of thumb is in an open air environment, the LED needs 2.5 square inches of heatsink for every 1 watt.
Use Edge Lighting’s Scope LED as an example. At 9 watts, the scope needs 22 sq. inches of heatsink. The cylindrical fixture is 2.24”W x 4”H. You use the formula below to determine the square inches of the aluminum fixture (the heatsink).
Width x π x Height
2.24 x 3.14 x 4 = 28 square inches
The Scope LED fixture exceeds the required amount of heatsink to guarantee LED lifespan. Keep in mind that enclosed fixtures, like recessed LEDs can require around 15 square inches per 1 watt, so the heatsinks on these fixtures will be much larger, but still hidden from view.
Download a PDF of our Lamp Comparison Chart to see some of the basic differences between lighting options available to you.
