LED lighting: just another innovation riding on the shoulders of those that came before, right? Is LED merely a new tool lighting designers can use to illuminate buildings and our environment, like those arc lamps, incandescents, halogens, and fluorescents we are all familiar with?

While it is true that the LED light source is continuing the tradition of advancing quality, efficiency, and performance, the really exciting part of this story is that this particular technology is also ushering in a major and fundamental shift in what lighting systems can do and how they are used. Lighting has made that leap into the digital realm, and it can now participate in our lives in even more wondrous and perhaps unexpected ways. With technology trends like Human-Centric Lighting (HCL), PoE Lighting, and Visual Light Communications (VLC, a.k.a. “Li-Fi”) coming into mainstream awareness, what can architects and owners expect for the future of lighting design?

The possibilities for how electric lighting can now be used has moved far beyond a simple utility serving the purpose of helping us to see our surroundings and our work. The digital luminaire can be tuned, programmed, reprogrammed, scaled, and controlled in more ways than we can probably even conceive at this time. Here’s a brief tour of some exciting new lighting technologies entering the market today and some not so new technologies being implemented in innovative and different applications.

Tunable White and Human-centric Lighting
The light of day, bright and cool, followed by the warm, soft glow of firelight in the evening have been serving to define patterns of wakefulness and sleep in mankind for millennia, operating in profound and unconscious ways. We now know that the light energy that enters our eyes has an alternate, perhaps even more ancient, pathway beyond the one that allows us to create images and patterns and sense color information for our brains to process. It turns out that light acts as a metronome for the human body in a very direct way, keeping time for our circadian rhythms so that our bodies and minds can continue to work effectively. Daylight suppresses production of the “sleepy” hormone in our bodies, keeping us awake and alert. Firelight promotes the production of this hormone, making calm and preparing us for sleep. A mix of these lighting conditions on a regular schedule can promote health and well-being. So now that we can efficiently and effectively recreate these stimuli with our lighting fixtures, how can we use this technical know-how to design environments that help us be and do our best?

Tunable white LED luminaires, by virtue of their controllability, can support and influence our circadian rhythms, allowing buildings to better relate to their inhabitants and users. A building that can respond to the physiological needs of a person is a building that is a friend to humanity, rather than being an additional source of stress, discomfort, or sickness. Schools, hospitals, and office buildings have a lot to gain from this human-centric approach of understanding that the health and mood of an employee, student, or patient can be a major factor in that person’s productivity, progress, and growth.

Happier, More Productive Employees
This method of using tunable white lighting has begun to see applications in these types of spaces especially. In K-12 classrooms, for example, the atmosphere can help to manage the pace and energy of the students: high levels of cool white “daylight” in the morning hours to promote focus and utilize those productive hours might be followed by a period of dim warm white light immediately after recess or lunch to relax the students’ energy and recharge a bit before getting back into tasks that require more focus. In hospitals, lighting that mimics the natural daily rhythms of color and intensity can help to provide some normalcy and comfort in an environment that can be otherwise noisy, hectic, and disorienting. In any kind of space where there is not access to natural light, tunable white lighting can help maintain that connection that may otherwise be cut off. The granularity for controls that can be achieved with digital lighting means that it could be possible in some cases for an individual to be able to tune their personal workspace to optimize their own schedule. This in turn can make for a happier, more productive employee. The LED seems to be the ideal medium for improving this technique of developing lighting systems that affect and respond to human psychology and physiology. I believe that as we use these systems and learn more, we will find more and better applications, helping our buildings to bring out the best in people.

At The Sextant Group, our Technical Lighting discipline focuses primarily on lighting and control systems that complement and enhance the other AV media in the space, and we consistently utilize tunable white lighting in a different way. Where we have found it to be very effective is in spaces where cameras are present and we want to have the ability to match the color quality of the other ambient light. At the Point Park University’s Center for Media Innovation in Pittsburgh, for example, there is a small television broadcast studio with two full walls of storefront type windows, allowing ample daylight into the space. We included tunable white luminaires for both the architectural lighting and the studio lighting to provide versatility to the space for shooting in any lighting conditions. We were sure to include tunable white for the makeup stations as well, so that the talent would be able to do their makeup in the same lighting conditions that they would be seeing in the studio. This is one example of a different application for tunable white. Stay tuned for more to come!

Power Over Ethernet Lighting
The high efficiencies that LEDs can achieve are allowing for luminaires that can output a lot of light while consuming very little energy. As a result, we are seeing some lighting systems where all the power needed to operate the luminaires can be carried along a single Ethernet cable. These cables have traditionally been used for passing data, but have also been used for a long time to provide power for certain pieces of equipment that have very low current draw, such as telephones and security cameras. What is happening now is that the power requirements for the lighting fixtures are reducing, while the standards for Power over Ethernet (PoE) are changing to allow for greater power transmission. This is a big deal because it means that lighting systems can employ a single cable to deliver both power and control data.

Additionally, this single point of connection is a low voltage cable that does not require conduit, nor a licensed electrician to install. This can reduce infrastructure costs, while allowing for future changes or adjustments to be made quickly and easily, without bringing an electrician onsite. This can be a real game-changer in terms of how lighting systems are designed, installed, and maintained.

All the luminaires in a PoE lighting system (or networked lighting system, where the difference is that power is fed to each luminaire separately from the control input rather than via the control input cable itself) are essentially smart electronic devices that can take-in as well as feed back information. All of this information flow can be centrally and remotely managed, allowing for myriad possibilities for utilizing the system. For example, data can be taken in from the luminaires and other control devices to aid in management and analysis of energy usage, occupancy, etc. Also, luminaires can be zoned, re-zoned, and have their characteristics changed dynamically without needing to physically touch or re-wire them. This provides a versatility for the lighting system that has never before been possible, and an architecture of interconnections that are in fact simplified.

Oh, the Possibilities!
There are so many possible applications for PoE lighting, with the most common one perhaps being an open office type of space, where the furniture and equipment layout may change every once in a while and the lighting would need to adjust to conform to the changes. However, we have identified another prime candidate for this type of system, which is a space designed for video teleconferencing and telepresence. A space like this may have changing needs over time in terms of where luminaires should be located and aimed, as well as their output characteristics. The ability to move and remove PoE luminaires without an electrician’s license makes this kind of arrangement much more fluid and malleable.

Furthermore, the possibilities for control are extremely robust, increasing the potential for more intricate control schemes. This would allow for things like AV control systems to interact with lighting systems more dynamically. Take the example of a VTC system that can increase the intensity of light on the person who is talking, based on their mic being active. Another possibility would be that the cameras themselves (via control and processing equipment) could have a digital dialogue with the lighting to make adjustments to optimize the captured image in real time as a reaction to the varying conditions in the room.

Visual Light Communication (VLC, aka Li-Fi)
A logical but maybe not so obvious extension of the digital nature of LEDs, and what PoE or networked lighting brings to the table is that the lighting fixtures themselves can now be capable of transmitting and receiving digital information. Where your Wi-Fi router sends and receives this information over radio waves, LED luminaires can send and receive data using the visual light spectrum (hence the name Li-Fi).

This offers up many benefits. It can provide a secure means of wireless communication because the light cannot travel through any opaque materials, confining the signals to within the walls of the space. A whole new range of available frequencies could be utilized in communications, freeing up some traffic in those other heavily used areas. The regular distribution and ubiquity of lighting fixtures could be used to facilitate way-finding, providing a kind of indoor GPS that could pick up where the satellites are unable to follow. It could merge two systems that would need to be installed in a space, potentially reducing overall infrastructure. Although it would most likely not replace Wi-Fi entirely, Li-Fi could certainly supplement it to great effect. By the way, if you are wondering if the lights need to be on for the communication aspect to function, they do not. They can send signals at intensities and frequencies of modulation that are imperceptible to the human eye.

Obstacles to Overcome
The benefits and enormous positive potential for these cutting-edge lighting systems are very exciting. However, they leave me with a number of questions that I believe will take some trial and error to figure out. For PoE and Li-Fi applications, who installs and maintains a lighting system that is almost entirely low voltage or is also now part of the IT distribution network? How should design documentation be handled? Should the lighting network be incorporated into the structured cabling infrastructure and treated like IT equipment, or should it remain separate? Who manages it? Is it a facilities electrician or an IT person? What about emergency egress lighting, can these types of systems conform to the necessary code requirements? For human-centric lighting, when the lighting system is being used to affect human psychology and physiology, who defines the details about lighting changes, timing, etc.? Who programs the lighting controls, not just during system commissioning and setup, but throughout the life of the system when changes need to be made? It may be that some new ways of working will need to be defined, and perhaps even some new job positions created. However it pans out, there’s no going back now, so we had better keep working it out.

These questions represent the growing pains to be expected when major shifts in our means and methods of doing things occur. For owners and architects, these technologies are worth understanding and embracing for the future. Ultimately, they have the potential to make the built environment more interactive, responsive, and versatile.

Where to next?
We are in the midst of the LED revolution, with the first wave of change having brought dramatic energy savings and the next wave changing our very relationships with electric light and lighting systems. The low power, low voltage, inherently direct current nature of the LED can work very well with alternate designs for energy transmission and management like buildings that are all low voltage DC power distribution, or off the electrical grid completely. They create less heat per lumen of light output, allowing HVAC systems to have less to overcome, and helping the horticultural industry by allowing light sources to be positioned closer to the growing plants to maximize both energy use and yield. They are small and scalable, allowing for many new and innovative form factors and applications. The range of colors that they can produce covers virtually the entire gamut of our perceptions, even extending to the infrared and ultraviolet. All of these qualities give designers and engineers a powerful toolkit to work with.

These tools can be used to solve many problems in ways that are just starting to get realized. We should expect to see continued improvement in workflow and efficiency. Technical problems involving communications, data management/analysis, and information gathering/dissemination will continue to be resolved and improved upon. Lighting systems that are being programmed to have a kind of artificial emotional intelligence will continue to evolve and promote improvements in our health and well-being. A broad avenue for creativity has been opened up to allow us to find new ways to express ourselves, to feel new sensations, experience new ideas, and to inspire new kinds of wonder.

The most exciting part now is figuring out new and beneficial ways to put these tools to work for design, and watching as others do the same. Arthur C. Clark’s adage “Any sufficiently advanced technology is indistinguishable from magic” comes to mind as I wait to see what magical possibilities all this new lighting technology will bring!

Image @2016 Ed Massery