I recently had the opportunity to interview Rahul Shira, Senior Product Marketing Manager, Signify US, for an article about tunable-white lighting I developed for tED Magazine. This is the transcript.

DiLouie: How would you characterize demand for tunable-white lighting?

Shira: There is a lot of interest around tunable-white lighting. This interest is fueled by increased adoption of the Well Building standard and with more research demonstrating the positive impact tunable-white lighting can have on our moods and productivity.

It’s still a developing market though. More awareness and education needs to be done around the end-user benefits and how to quantify those benefits.

DiLouie: How would you characterize demand for circadian-friendly lighting designs? Has the COVID pandemic spurred more interest in wellness and lighting’s role in it?

Shira: The COVID pandemic has certainly spurred interest around designing for health and wellness. Keeping employees healthy is a major workplace concern. There is significant interest in UVC lighting, as it is well-proven as an effective disinfectant. Companies can also use connected lighting infrastructure to make informed decisions about space management and guiding employees through a facility in line with physical distancing measures. Designers are exploring technologies like tunable-white lighting to comply with Well Building standards.

DiLouie: What role does color spectrum specifically play in circadian regulation?

Shira: Lighting has a profound effect on how we feel and how we function. It affects how productive we are, how comfortable we feel and how well we sleep.

These non-visual effects of light are strongly driven by ipRGC photoreceptors in the retina. Due to the sensitivity curve of the ipRGC, the spectrum of light plays an important role in circadian regulation and our natural rhythms. Scientific publications suggest that light with more energy in the short-wavelength range (approximately 450-530 nm) is more effective for orchestrating our natural rhythms.

DiLouie: What is the full functionality that tunable-white luminaires offer to support circadian lighting designs?

Shira: Signify offers tunable-white luminaires in our Daybrite, Ledalite and Lightolier brands. These luminaires are capable of CCT variations between 2700K to 6500K, and are packaged with compatible Dynalite controls, so they can be configured to various modes that support circadian lighting designs. These include:

  • Dynamic mode – Allows you to automatically mimic daylight patterns by adjusting the color temperature and brightness with respect to the time of day.
  • Scene-setting mode – Offers four different pre-sets – Standard, Presentation, Focus and Calm – to instantly set the scene for room ambiance or support scheduled tasks or spontaneous activity. These light scenes have been proven to help people stay focused and alert; they can also be altered and customized to suit your unique needs.
  • Person-control mode – Allows you to easily change LED intensities and CCT from warm white (2700K) all the way to cool daylight (6500K).

DiLouie: Otherwise, what role can tunable-white lighting play in promoting occupant mood, satisfaction, and well-being?

Shira: We recommend reading this customer story here. Innogy in the Czech Republic used tunable-white lighting to mimic natural daylight at the beginning of the day, providing a useful energy boost. It then decreased light levels until after lunch and gave this same boost with brighter light to help staff combat the mid-afternoon slump.

DiLouie: A challenge of plugging tunable-white lighting into a circadian design is that circadian stimulation may be more closely related to spectral profile than CCT. Do you agree this is an issue, and if so, how is your company and the industry in general addressing it to adapt the technology to circadian lighting?

Shira: The intent of circadian lighting is to support users’ natural rhythm or body clocks. To meet the intent of circadian lighting the industry can leverage different technologies – CCT, spectral tuning, intensity, light distribution, timing and duration or with a combination of multiple technologies. What’s important to remember is that delivering visual and non-visual illumination is application environment dependent. It is unlikely for a single technology to have the highest impact across applications. Signify works closely with its customers to balance its technology choices and to ensure its effectiveness for that customer segment, based on the customer’s energy-savings goals, cost considerations, and end-user satisfaction and comfort.

DiLouie: Currently, there are two specifications for circadian lighting, one promoted by UL/LRC and the other by the WELL Building Standard. What are the metrics these use, and how do they primarily differ? What do they offer the industry?

Shira: Both institutions use metrics that try to quantify the impact of lighting on melatonin suppression based on lighting in the vertical illumination plane (in other words, the amount of light entering the eye). Both of these metrics use spectral distribution as their foundation to determine the overall impact, but there are technical differences between the two metrics, which is best explained in this IES article.

LRC’s model provides the design community with an intuitive tool for effective lighting design. The WELL Building Standard, on the other hand, provides a certification to buildings by recognizing and rewarding those who invest in occupant wellbeing similar to what LEED certification does for those who invest in sustainability.

At Signify, for circadian lighting, we follow the quantification guidelines set out by the CIE and embraced by the scientific world.

DiLouie: How does circadian lighting in general and tunable-white lighting installations in particular differ from typical lighting designs, and what can distributors do to support the process to ensure good outcomes?

Shira: Typical lighting designs focus on visual comfort and energy-savings levels in line with building codes and user expectations.

Tunable-white lighting design principles tend to consume more energy, as they target on delivering higher vertical illumination levels to trigger the right stimulation. These fixtures also need to be specified with compatible controls platforms to ensure that CCT and intensity variations can be managed effectively.

Distributors can help guide end-user customers on their lighting decisions, and advise them on how to shift their focus from energy savings-based ROI and take advantage of a combination of energy and occupant wellness-based justifications. Moreover, distributors can add value by promoting qualified tunable-white lighting packages between fixtures providers and controls providers, with the understanding that manufacturers that offer both elements have robust and consistent performance and are capable of dealing with the complexity of CCT, intensity and spectral tuning.

DiLouie: What can distributors do to position their firms to promote and sell tunable-white lighting? What should they do to sell or prepare to sell circadian lighting solutions?

Shira: Tunable white is a technology that is controls dependent. Customers who are investing in wellness programs will not limit their scope to just one technology feature, and will most likely consider solutions that offer much more such as connectivity and being IoT-ready. These decisions are expected to deliver long-term results, and end users are looking for trusted partners who can assist and team up with them in their transition journey.

Therefore, distributors should consider acquiring new talent or skillsets  around modern controls and systems to proactively get ahead of and be able to manage future trends as well as have constructive dialogues with their clients, positioning themselves as trusted partners.

DiLouie: If you could tell the entire electrical industry just one thing about tunable-white lighting’s role in circadian lighting, what would it be?

Shira: Circadian lighting benefits can be realized with multiple strategies (CCT variations, intensity & timing, spectral tuning, etc.). There is no universal rule that fits all. Choosing the right strategy will depend on the application space and target group. Moreover, implementing these strategies typically result in more energy consumption, so financial ROI justifications for tunable white lighting should not be completely based on LED & controls savings but rather incorporate benefits like employee wellbeing, satisfaction and engagement, and talent retention and attraction.