Ease of Flexibility
The opportunity to change the look of a space with lighting has never been easier. With the push of a button, a voice command, an automatic schedule or simply by walking into a space, the lighting can transition in color and intensity. In the future, it may even be common for the distribution of the light exiting a fixture to change. This flexibility allows spaces to adapt to changing needs, such as providing more or less light depending on the age of the occupants.
The initial commissioning of the BHU control system did not result in the desired change specified by the architect. Because of a variety of reasons, the intensity was too high, the change in CCT was not as specified, and the transition between CCT and intensity throughout the day was too abrupt. To address these issues, a control system allowed for adjustments to easily be made to the CCT and intensity throughout the day to further improve the space for the staff and patients without causing disruption to the BHU.
In the K-12 classrooms, the incumbent fluorescent system included the ability to switch off the lights closest to the projector screen. With advances in technology, the projector screens in the classrooms were replaced with interactive boards; however, in one of the classrooms documented, the interactive board was placed on a different wall so the lights could no longer be switched off just in the area near the interactive board. With a tunable lighting system, this problem can be solved without any rewiring of fixtures. The change in screen location doesn’t necessarily warrant a change in the color of the light, but if there were a considerable change in the color of the furniture and walls in a space, then a change in the color of the light might be a considered appropriate in this and other applications.
Design and Manufacturing
The DOE SSL program also recently supported the development of an advanced patient room lighting system that changed the color and intensity of the light throughout the patient room; however, for this project the changes in color went beyond white hues to saturated oranges, pinks and blues. The ability to tune lighting fixtures to different colors opens up new opportunities and challenges to those that design spaces and also new areas of research. Learning what colors and changes over time occupants find acceptable and how this translates to different applications, regions and cultures will be an important part of the transition to tunable lighting. It may also provide an opportunity for designers to select the color of the light after the interior of a space is complete, instead of during the design when the color of finishes and furniture can change. Manufacturers also may be able to reduce the number of product variations they manufacture as the technology matures for tuning color, intensity and other attributes, such as distribution.
Energy Savings
The energy implications of tunable lighting are dependent on the product and application. A given tunable fixture may be less efficacious than a similar non-tunable model, yet tunable lighting may allow the occupant to dim or turn off lighting when not needed. The BHU nurses observed that the majority of the lighting fixtures in the main gathering area could be turned off during the nighttime hours, so this change was implemented as part of the automatic programming of the control system. The nurses also often chose to decrease the light levels further in the evening hours, increasing energy savings.
There are many other possible uses for tunable lighting, and as with many other pieces of technology, we may soon find that lighting fixtures with the addition of sensors, networking capability and other devices will serve many more purposes than simply delivering light. Additionally, the increasing availability of tunable lighting will hopefully expand what is known about the benefits it may provide to human biology. In turn, tunable lighting can then be modified to account for the latest research and best practices, increasing the benefit to occupants of the built environment.
For more information on tunable lighting, visit the Department of Energy’s SSL website.
Attend this Presentation at Lightfair
Andrea Wilkerson will be co-presenting “How to Do Tunable WELL: Points, Pitfalls, and Potential,” at Lightfair International 2018, an annual architectural and commercial lighting trade show and conference. This session will review the lighting requirements of the WELL Building Standard and describe how a tunable white lighting system can meet these requirements. Lightfair is being held May 8-10 at McCormick Place in Chicago. Learn more and register here.
Photos: Pacific Northwest National Laboratory