ONLINE EXCLUSIVE: Full-spectrum controls unlock the potential of dynamic lighting

Jan. 5, 2021
Lutron’s CRAIG CASEY outlines a lighting-specification primer for educating clients on critical concepts that merge dynamic solid-state lighting with controls to optimize wellbeing and enhance the light experience in the built environment.

New light sources and control technologies have now ushered in the era of dynamic light — light that is digitally controlled, flexible and responsive, and able to reflect the natural progression of daylight over the course of the day with changes in both color temperature and intensity. Dynamic light goes beyond basic dimming to provide advanced capabilities including warm dimming, tunable white, and full spectrum control, inviting an even more symbiotic relationship between light and the people in a space.

Today, advanced LED solutions enable flexible design palettes that include all hues of white, fully saturated colors, tunable white capabilities, warm dimming that mimics the familiar comfort of the stalwart incandescent lamp, and tremendous energy efficiencies. The more we understand the link between dynamic light and wellbeing, comfort, productivity, and human performance, the more compelling and powerful it is.

To make the most of these opportunities, lighting designers can work with the client to develop deeper, detailed portraits of how the building or space will be used. Later, we will focus on the client interview, but the high-level goal is to define fine details of the project in order to write the appropriate performance specification. Today’s dynamic LED solutions are often capable of far more than many clients are aware of, maybe more than they’ve even imagined. A two-way conversation will ensure clients can fully convey their expectations, and lighting designers have the opportunity to present their most creative and compelling design vision.

This article will delve into the different aspects of dynamic light and highlight the elements you’ll want to consider as part of a powerful lighting design.

Understand the needs of the space

Lighting design should reflect the needs of the space and the people in it. Light is the medium; the dynamic control solution is the paintbrush that allows designers to create lighting magic. Sometimes you want a light show. Sometimes simple control of light is appropriate, but dynamic lighting is a tool to complement and expand fundamental design strategies. Especially in commercial architecture, dynamic LED lighting can enable virtually infinite variation in color, color temperature, and color rendering.

By digging into key questions about the building application, designers can determine where dynamic lighting technology and the dynamic lighting design process best supports the occupant’s visual needs. Where do they need light that adjusts to different tasks or activities? Where do they need light to be most flexible and responsive?

Dynamic light can help provide more human centric, comfortable, and flexible spaces, and this is not a one-size-fits-all proposal. Determine the type of dynamic light that best suits your project: ask a few key questions about each space, define all use cases ahead of time, and get the lighting design right at the start of the project.

The first three questions start with: Will there ever be …

… A desire to mimic daylight to enhance connection to the outdoors?

Consider open office environments where natural light is a highly desired amenity. Building owners may see natural lighting and the ability to offer a connection to the outdoors as a competitive advantage in their property, an opportunity to increase comfort for occupants and make the space more versatile for long-term tenants.

Dynamic light has the ability to mimic the outdoor lighting quality — bringing the outdoors in, so to speak — and offering an environment that unobtrusively changes to reflect the natural progression of daylight over the course of a day.

… A desire to use color – full-spectrum or tunable white – to support the mood of people or the impression of the environment?

In restaurants, lounges, and bars, for example, lighting often changes over the course of the day — bright and energetic earlier, while late-night lighting encourages people to relax and spend a little more time. With today’s advanced lighting solutions, new LED sources and system apps combine to offer an almost infinite palette of colors, hues, and vibrancies that can pull colors out of art, make food more appetizing, and appeal to a refined sense of vibrancy and color.

In these spaces, for example, design considerations include vividness (the light source should be capable of adjusting the chroma of various colors while maintaining the CCT), and user experience (use controls and apps that make it easy for the end user to make changes to scene setup and timing).

 … A concern about interior design changes that will alter your choice of light spectrum?

Spaces such as hotel lobbies, interactive classrooms, ballrooms, and auditoriums benefit from lighting that can quickly accommodate a new event or help improve “curb appeal.” What your client needs today is likely to be different in five years, and dynamic lighting sets the stage for spaces that can be easily updated without expensive rewiring or major renovations.

The classroom is an excellent example of a space that has changed dramatically in just the past year. A dynamic lighting design can help ensure a space that accommodates in-person instruction and can also quickly be adjusted to suit the needs of virtual students. As we have learned in the last few months, lighting has to be nimble enough to accommodate the unexpected.

Finally, does light spectrum have the opportunity to dramatically affect the impact of products, artwork, or other rotating visual elements, and do those elements change frequently?

Museums, hotel lobbies, restaurants, retail areas, and community spaces use color to create interest, encourage an emotional reaction to the space, and emphasize their brand. Lighting can put an exclamation point on these design elements, can help guide visitors or customers through a space, highlight a piece of art or merchandise, or invoke a desired mood, setting, or feeling.

Dynamic lighting is more than a commercial consideration; it can be very personal. In retail stores and salons — spaces dedicated to making us feel better about ourselves — lighting can help people look and feel their best. Color quality, user experience, vividness, and color consistency will be critical to these clients.

Application specifics: What type of dynamic lighting do you want?

Once you’ve answered these questions, you have deeper insight into where dynamic lighting will deliver essential flexibility and design freedom for any space. The next step is to determine what type of dynamic light is best for a given space or building — warm dimming, tunable white, or full spectrum.

Warm dimming

If all anticipated uses of the space fall into either full, bright light (cooler, more energetic light for setting up or cleaning a space, for example) or dimmed light (light that promotes a more calming, relaxing environment) warm dimming may be sufficient. Warm dimming is ideal for incandescent-like lighting, night lighting, and home-like environments. Restaurants, hospitality spaces, and retail locations typically require warm dimming.

Warm dimming offers a broad dimming range. With the right control solution, the range can go from 100% to as low as 0.1% light. At its brightest setting, warm dimming provides color temperatures to mimic an incandescent or halogen lamp (e.g., 2700 or 3000K). Consider the multiple, and different, use cases in a single space like a café, a mother’s room, or an office common area.

Full spectrum/color changing

Take a project to the next level with the ability to alter color without limits, recall pre-programmed lighting sequences, seamlessly replicate the look of natural light, and infinitely adjust lighting over the course of an event, a day, or a season.

Color-changing lighting is obvious for applications where you want to make an impressive statement, but color-change capabilities should also be considered for spaces like lobbies or other common areas that occasionally need to host a special event, a VIP, a black-tie party — full-spectrum lighting ensures flexibility when and where you need it. Additional examples are high-end hospitality, retail showrooms, and fitness centers, as well as executive suites, conference centers, board rooms, and sports facilities.

To maximize the impact of full-spectrum control technology, it’s critical to know the source you choose is capable of producing the desired color effect and produces them consistently across all fixtures and lamps.

Tunable white

Tunable white is usually the answer to dynamic lighting needs that don’t neatly fall into warm dimming or color-changing categories. Tunable white is ideal in spaces where connection to the outdoors is important, or where light can enhance the mood of a space like offices, classrooms, collaboration spaces, healthcare facilities, and conference centers. Tunable white enables independent control of CCT and intensity, ensuring that you can achieve the right light at the right time.

With a tunable white solution, color quality — preference, vividness, and fidelity — is an important consideration in your specification. For more detailed information, reference Annex E of ANSI/IES TM-30-18. Tunable-white solutions that automatically mimic daylight progression throughout the day are available, and the most preferable ensure seamless transitions with 10-minute fades between settings.

Depending on the control system you choose, you can easily mix and match control protocols within the same system, using the right type of control, in the right space, without compromise.

The end-user interview: Defining the sequence of operations

The right lighting is very much about understanding the client’s expectations and desires. Conducting a careful client interview is key. Consider the fixtures that will be used on your project and match the fixture type to the desired performance of the light. Ask about sequence of operations (SOO); understand the many ways the space will be used, and the variety of people who will be in the space.

The interview takes time and patience but is also the key to in-depth understanding of how people will interact within the space, and how the lighting can enhance performance.

Mentally walk through each space and consider how the lighting should perform. Look for scenarios where lighting needs may conflict and determine the hierarchy for which operation should take precedence under various circumstances. Finally, include the narrative for each scenario in project documents to ensure system commissioning matches design intent, controls are properly engraved, and all use-case scenarios have been accounted for. This ensures that you are designing lighting to meet all the needs of a given space. A sample scenario plan for a healthcare application is given at the end of this article.

Controls essential to preferred lighting strategy

How advanced are the control requirements? Specify the control solution that best supports your preferred lighting system strategy. A tunable white system that allows individual control of both lighting intensity and CCT will give you the freedom to deliver quality light, and a digital solution provides the greatest flexibility to set up the lighting for current needs, and then easily adjust zones, scenes, and fixture assignments when the space use changes.

Currently, for example, 0‒10V control solutions can meet some aspects of a design spec but do not offer robust tunable white, and there is no way to easily rezone lighting or control updated driver technologies — digital, software-upgradable solutions can enable both.

0‒10V is an ambiguous, analog protocol. To use 0‒10V effectively, you need to know exactly what 5.7V is going to give you on a device-by-device basis. Digital protocols, such as DALI Type 8, are designed in such a way that commands for the final light output are not device-dependent. If the digital command to the source is “go to 3500K,” there is only one way to interpret that command. The digital nature of the protocol allows the designer to add features without changing the physical device.

New commands can be added to the base language, but the scope of expansion for analog protocols is limited. Besides open protocols, such as DALI Type 8, there are a variety of proprietary protocols that are developed by manufacturers to offer advanced connectivity and features.

Finally, carefully consider the controls. Once scenarios have been visualized and the SOO defined, separate fixtures into appropriate control zones, consider labeling conventions, and document the controls narrative with specifics: Reference actual zones and lighting levels, and do so for each keypad. Work with your controls provider to ensure the performance specification of the lighting design can be met by the selected control system.

Careful planning is the key to dynamic lighting that meets both today’s and tomorrow’s needs. It is a detailed, time-intensive process, but in the long run, you will deliver a space that is flexible, built to enhance the human experience of the space, and capable of easily pivoting as newer technologies are introduced and situations inevitably change.

Dynamic lighting application scenario: Hospital patient room

As an example of the client interview process, we’ll examine a hospital patient room. The goal of the interview is to define, write down, and mentally walk through each scenario to help identify potential conflict and understand the appropriate sequence of operations (SOO) within each scenario.

Consider the default lighting schedule, whether the space will need to mimic daylight with color temperature and intensity changes throughout the day, and how manual overrides will be used over the course of the day.

If you are recommending tunable white, ask about the desired color temperature range (2700–5000K is typical indoor CCT, but dimmed incandescent can go as low as 1400K, and blue sky can be in excess of 10,000K). Visualize the lighting transitions and discuss these with the client — in this case, the facility manager and medical professionals who will use the space. Also, ask about including keypad engraving to make scene selection intuitive.

Regardless of the type of space, this important, up-front planning will reveal the extent to which the lighting will have to accommodate the client’s needs and will equip you with the information you need to deliver a complete lighting design proposal.

Sample proposal

Scenario — Daily Care

  • From 6am to 10pm patient downlights set to medium. CCT follows daily cycle
  • From 10pm to 6am patient downlights set to low. CCT follows daily cycle
  • Patient care staff needs 24/7 access to lighting override to adequately check on patient. Access at different times of day require different light levels, but CCT can follow daily cycle. Patient care provider override will feature higher levels during the day, and lower levels at night, lasting for 15 minutes

Scenario — Patient Exam

  • During Exam override, patient room lights set to a medium light level. Lights over the bed are set to bright level. CCT follows daily cycle
  • During Exam, patient care staff needs higher light level regardless of time of day. Patient controls will be disabled. Override lasts one hour

Scenario – Patient Emergency

  • During Emergency override, patient room lights and lights over the bed are set to bright level, and CCT is a constant 5000K
  • During Emergency exam, patient care staff needs higher light level, regardless of time of day. All other keypads (patient and any wall controls) will be disabled. Override lasts until a staff member presses the assigned emergency keypad to avoid any accidental light change

Scenario – Patient Control of Lights

  • Lights are not scheduled to predetermined changes based on time of day
  • Patient keypad turns all lights on or off, and adjusts and lowers headboard light, and can change the CCT of the color-changing luminaire
  • There may be Exam override or Emergency override controls for the patient care staff
  • Additional scenarios may include a patient’s family visiting, multi-patient situations, or a patient who needs something in the middle of the night like a restroom, drink, etc.

The patient room is a good example because there are typical scenarios that can be figured into every patient space, and the SOO is critical to good patient care. But the same interview and documentation process should be used in any situation to understand and plan for the varied use-case scenarios in the space. Office, classrooms, lecture halls, a commercial shift work operation, a hotel reception desk — in-depth understanding of the different ways lighting will serve the space leads to better lighting design for your client.

Get to know our expert

CRAIG CASEY is building science leader for Lutron Electronics Co. Inc., where he conducts applied research on energy and on the human benefits of lighting and daylighting controls. He is active in the Illuminating Engineering Society (IES), has presented multiple times at IES Annual Conferences, and has presented at LightFair the past three consecutive years. Casey sits on the Daylight Metrics Committee of the IES, and received the IES Presidential Award for chairing the 2015 Conference Steering Committee. Casey is a former graduate assistant, lecturer, and researcher at Penn State University. He holds bachelor’s and master’s of architectural engineering degrees from Penn State, and is currently pursuing his PhD.

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