Page 44 - Lighting Magazine April 2020

No-BluE lighting
Circadian ZircLight’s 2x2 troffer
“Any light at night is disruptive to sleep. Light – including the circadian- sensitive curve – is more disruptive, and cyan- containing light is the most disruptive.”
system.” As further evidence of the growing trend, Circadian ZircLight light engines and controllers will also be used in some Acuity Brands products.
Another leading company in this market is healthē by Lighting Science. Rather than “no- blue,” healthē focuses on enriching and depleting the blue wavelengths that create the greatest circadian stimulus/disruption. Jay Goodman, VP/ Strategy states, “We don’t claim ‘no blue,’ rather ‘cyan-depleted’ (for night) and ‘cyan-enriched’ (for daytime). 480nm is peak sensitivity for the circadian sensitivity curve. Other blues are pres- ent in our cyan-depleted products. In the future, we will extend to wavelengths beyond the visible spectrum” (a reference to ultraviolet and infrared wavelengths).
When asked if he sees any risk that the no-blue trend oversimplifies circadian lighting, Goodman comments, “I agree completely that intensity, du- ration, time of day, user age, and spectrum matter, but we should get the spectrum right first, as it is the most technically challenging to solve, and then the other variables are less complex to address. Regarding intensity, a cloudy day can be 1,000 footcandles, while most offices are around 30 to 50 footcandles.” That’s ~0.5 percent or less of the intensity of a cloudy day. Goodman adds, “Any light at night is disruptive to sleep. Light – including the circadian-sensitive curve – is more disruptive, and cyan-containing light is the most disruptive.”
Another example of no-blue products is Soraa’s ZeroBlue line of lamps. Similar to Circadian ZircLight, they’re another product line using phos- phor-converted, violet-pumped LEDs to deplete blue from the spectrum. Additional information on all of these companies’ products can be found on their respective websites.
42 enLIGHTenment Magazine | april 2020
www.enlightenmentmag.com
Circadian ZircLight’s blue-enriched and blue-depleted light engine