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PROJECT
| lighting & electrical For circadian lighting, WELL establishes four types of environments and requires a minimum level of light capable of producing circadian stimulation. Measured at the eye level, this light is measured as equivalent melanopic lux, an alternative metric to footcandles/lux that is weighted to non-visual photoreceptors. A key enabler for HCL strategies is lighting controls, a segment of the lighting industry undergoing its own digital revolution. These are the sensors, controllers, apps and programs, and communication technologies that enable manual and automatic control of light and color output. Because LED lamps and luminaires are already electronically controlled, they are inherently compatible with intelligent systems capable of sophisticated control and data collection from sensors. Using this data, operators can optimize energy cost savings while gaining valuable insights into user lighting preferences and satisfaction. REALIZING HCL
What does this mean for designers? Rather than a fixed utility used to produce the commodity of light, lighting has become an asset offering far greater value. There is According to the “SSL-erate” European Union project, exposure to light similar to natural daylight at the right time can help improve the mood of residents in retirement and care homes as well as patients in hospitals, helping prevent depression and reducing anxiety in patients in the early stages of dementia.
no single lighting solution that is ideal for every client and application. What leading commercial architects and designers are doing is looking beyond traditional design thinking and changing the conversation they’re having
on time of day, such as cool during business luncheons to warm during evening dining. In HCL, the greatest value of dimming and color con-
Daylight is ideal, though it is not always available, and the electric-lighting system can work with daylight for an optimal solution.
with their clients. This requires education that, in turn, will fuel a different conversation about lighting—not one limited to light
trol may be found in circadian lighting design. Scientific
Finally, this brings us to standards. Best practices for
levels and watts, but one that incorporates all of lighting’s
research has shown that specialized photoreceptor cells in
circadian lighting are still emerging, such as International
current possibilities and best practices. From color tuning
the eye are connected to circadian functions, and has
Standard DIS 026/E:2018, which is being considered by
and dimming, to more effective ways to light spaces, to
identified spectra, quantity of light, duration, and timing
the International Commission on Illumination, Vienna,
data collection, today’s lighting technology, application,
capable of producing circadian stimuli. From this under-
Austria. This standard would define spectral sensitivity,
and thinking has taken the category far beyond its static
standing came actionable approaches to design, with
quantities, and metrics to describe light radiation for its
traditions, with more value on the table than simple
good circadian design typically focused on:
ability to stimulate each of the five types of photoreceptor
vision. CA
• Spectral distribution, or saturation of specific wavelengths in the visible-light spectrum that we typically as-
cells in the eye that produce non-visual effects in humans. One standard that is oriented toward application and
Alberto Pierotti is head of R&D and Smart, USC at LED-
sociate with the light being warm or cool in appearance.
actionable today is WELL, a rating system focused on
VANCE, Beverly, MA, makers of Sylvania general light-
Circadian regulation is most responsive to short-wave-
evaluating how effectively a building supports human
ing products in the U. S. and Canada. He is leveraging the
length light (460 nm), which is in the blue range of the
health and wellness. Launched in 2013 by the Internation-
company’s century of expertise in light to chart the path
visible spectrum).
al WELL Building Institute, New York, this rating system
into the intelligent, distributed-lighting systems of the fu-
• Spatial distribution, which defines where the light emitted by a luminaire falls in the observer’s field of view
awards points for various building features and practices.
ture. For more than 20 yr., Pierotti has been involved in
This includes lighting, notably circadian lighting, visual
every step of the product-development process in fields
(FoV). For circadian response we want a sufficient quanti-
comfort, glare control, color quality, automatic dimming
spanning medical devices to capital equipment, and from
ty of light on the upper quadrant of the environment for
and shading, and daylighting.
wearable consumer electronics to architectural lighting.
sufficient periods of time during the day. Equate this to the outdoors, where the sky occupies the top section of our FoV. This requires vertical illumination (uplighting walls and ceilings, or workstation luminaires), in addition to the standard work-surface-targeted lighting devices.
• Temporal distribution, which simply means the right light (in terms of CCT and intensity) at the right time of
Want more information from LEDVANCE, Beverly, MA (ledvance.com)? Circle 7 on the Reader Service Card. Sources listed below are linked at commercialarchitecturmagazine.com/1904ledvance.
day. A circadian lighting solution ideally exposes users to
• LightingEurope, lightingeurope.org
• International Commission on Illumination, cie.co.at
high-intensity, short-wavelength-heavy light in the morn-
• International Association of Lighting Designers, iald.org
• International WELL Building Institute, wellcertified.co
ing, which can taper to lower light levels of long-wave-
• A.T. Kearney, atkearney.com
length light in the afternoon. 24
APRIL 2019
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