I recently had the opportunity to interview David Venhaus, Manager of Training and Curriculum Development in the Lighting Solutions Center at Hubbell Lighting, for an article about tunable-white lighting that will be published in the November 2020 issue of tED Magazine. Here’s the transcript.
DiLouie: How would you characterize demand for tunable-white lighting?
Venhaus: Curiosity is high but adoption is moderate as more lighting designers gain an understanding of the application and value of tunable white.
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?
Venhaus: Designers are applying tunable white in education, healthcare and higher-end commercial suites, where the circadian effects or the aesthetic has value. COVID is driving more interest in disinfection options like UV-C or 405nm visible blue disinfection lights.
DiLouie: What role does color spectrum specifically play in circadian regulation?
Venhaus: More and more information is pointing to proper spectral power distribution (SPD) being a key factor in circadian and humancentric designs.
DiLouie: What is the full functionality that tunable-white luminaires offer to support circadian lighting designs?
Venhaus: Typically, the luminaires themselves will be configured to deliver a range of CCTs using a second 0-10V control signal. In the case of warm dim, this range is usually 3000K to 1800K with the dim signal permanently linked to the main dim signal, so the warm dim effect happens with no additional controls other than the single 0-10V dim input.
Tunable white will separate the two inputs, with one to dim the luminaire and another to control the color temperature. In most cases the color temperature range is 2700K-5000K or 2700-6500K, however that varies by manufacturer.
Keep in mind these two inputs can be tied to other lighting controls allowing preset scenes and scheduled control of the color temperature and light levels in a space.
DiLouie: Otherwise, what role can tunable-white lighting play in promoting occupant mood, satisfaction, and well-being?
Venhaus: Research shows tunable white has the potential to be a valuable tool for lighting designers to affect the user experience within a space. This applies whether meeting the WELL Building Standard, LRC guidelines, or self-imposed targets.
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?
Venhaus: There is evidence that points to Spectral Power Distribution (SPD) playing a vital role in circadian stimulation, with an emphasis on bringing a “flatter” SPD curve that more closely simulates daylight at cooler color temperatures. Many of the emitter manufacturers have offered products that deliver this. It’s now up to the luminaire manufacturers to incorporate these into their products.
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?
Venhaus: Both offer similar end goals – delivering the correct amount as well as quality of light at various times of the day.
DiLouie: What is the impact tunable-white lighting can have on adherence to these requirements?
Venhaus: Tunable white helps enhance the “quality” portion of the equation. In addition, by tuning the CCT less total light is potentially needed to meet a specific requirement.
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?
Venhaus: Tunable white solutions typically require a more sophisticated control system to deliver the best user experience. Continuing education and training is critical for all parties involved.
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?
Venhaus: Begin by investing time and resources into education for the sales staff so they can better understand the design methods used by the specifier. Specifically, why they chose the solution deployed and how to best ensure the proper installation, commissioning and use.
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?
Venhaus: Invest the time, energy and resources to establish a solid baseline understanding of the latest developments in tunable white technology. Get familiar with the technology in the luminaires and the control systems used. And make sure you understand how the final end user interface works because this is the key to a successful user experience.