Lighting controls: Know the updates, changes

There has been a move away from traditional lighting controls approaches, which have only incrementally improved over decades, and toward an entirely new way of thinking about, designing, and implementing lighting controls—wirelessly, with internet connectivity, and in an individually addressable capacity all at once.
By Katy C. Boat, Electrical Engineer & Lighting Designer, SmithGroupJJR April 23, 2018

This article has been peer-reviewed.

Learning Objectives:

  • Know the meaning of, and key differences between, DALI- and IoT-based lighting controls.

  • Understand primary benefits of the IoT as it relates to end users and owners in buildings.

  • Consider important design considerations and common pitfalls of an IoT-based lighting control design.


The task of the lighting designer or engineer is a moving target in the year 2018. This was not always the case, but now seems to be at least a semipermanent state of affairs. Why has a once reliable, even predictable, field become so difficult to nail down? Let’s count the reasons:

  • Over the past decade, we’ve seen the rise of the light-emitting diode (LED) source to outright prominence—even ubiquity—accompanied by the demise of incandescent, halogen, metal-halide, and fluorescent sources. The degree of ubiquity may depend on the geographic location, industry, project type, or budget. Every designer has been impacted by this evolution (and the associated learning curve).

  • Every third year, energy codes tighten the reigns on power densities in pursuit of lower energy-use intensity (EUI), necessitating an evolving toolkit and approach for designers.

  • The same codes are invoking heighted control requirements including daylight response and additional control steps (dimming, step-dimming, or the like) and pushing toward vacancy sensing over occupancy sensing.

  • Somewhere in the lobbying loop—be it on the front end in pushing for more stringent requirements or on the back side as a response to code changes—controls manufacturers are stepping up their game. While the same time-honored control devices are still available in the marketplace, manufacturers aren’t focused on their relay panels and hard-wired occupancy sensors any longer. They have ventured into unchartered waters and tapped their Silicon Valley friends to bring something new to bear.

The last bullet will be the focus of this article, which will explore the nature of lighting controls in 2018 and beyond—specifically, the who, what, when, where, why, and how of wireless, addressable lighting controls and their applications today, plus where they might be going.

Alphabet soup: DALI and the IoT

Before we determine where lighting controls are headed, let’s look at one approach that has been around for close to 20 years: the digital addressable lighting interface, known as DALI (trademarked by the Digital Illumination Interface Alliance). While this acronym is familiar to many in the architecture, engineering, construction (AEC) industry, DALI is still somewhat of a specialized system, and one that continues to advance. There are some basics to understand:

  • DALI is an open, standardized, international protocol that allows devices from multiple manufacturers to work together as long as they adhere to the standard.

  • DALI technology is built on 0 to 10 V dimming by replacing one-way communication with two-way, establishing a back-and-forth between the controller and the controlled devices. This created a back-check on success or failure of a command.

  • The 2002 release of DALI standard International Electrotechnical Commission (IEC) 62386 standardized the DALI protocol. IEC 62386 was most recently updated in 2017 to incorporate additional devices including occupancy and light-level sensors. Additions to the standard that are currently in progress, but have not yet been incorporated, include requirements for wireless DALI systems, load shedding, and light-output compensation over the lifetime of a fixture, to name a few.

  • DALI assigns an individual address to every driver or ballast in each (up to) 64-device network. A controller sends messages to those devices, either individually or in groups, to control their behavior. Multiple networks of 64 devices can be combined with the addition of gateways.

  • Two wires connect all DALI devices to one another in a daisy-chained arrangement. The polarity of the wiring connections does not matter, which simplifies installation.

Figure 1: This tiny sensor integrates seamlessly into a metal endcap of a suspended linear direct fixture. The small antenna could be mistaken for a hair, but it is critical for temperature sensing. Courtesy: SmithGroupJJRThe advent of DALI in the early 2000s gave designers and owners a tool to build a system that could adapt to a changing space layout or be used without any electrical work, which saved time and money for clients with variable needs. Still, DALI’s name was beleaguered in the industry by a reputation for being costly and overly complicated for many projects. While it is true that DALI drivers or ballasts often come at a premium, the simpler wiring and afforded flexibility balance the lifecycle cost for some projects. One could argue that DALI has become more applicable today due to the ease with which its individually addressable approach allows for compliance with stricter energy codes.

That same approach has been adopted by a newer wave of controls that fall under a different umbrella: Internet of Things (IoT). While DALI creates a network of lighting control devices, IoT creates a network of everything imaginable—almost.

At its most fundamental, the IoT is a generic term for a network of objects injected with electronics, communication capabilities, and software that enables them to connect to the internet and communicate with one another. These elements do not need to be typical network devices—rather, the IoT is built of objects we wouldn’t expect, like lighting control sensors, that are able to harvest and report data, react to environmental conditions and one another, and be controlled remotely.

Because the current focus is on building applications, let’s rephrase the prior sweeping statement: IoT has the potential to create a network of every electronic “thing” in a building by connecting each thing to the internet wirelessly and allowing all the things to communicate with one another. This is probably not news for anyone reading this, but it’s still big and relevant and rapidly changing. Right now, there is greater potential than has been realized, but the concept could allow for all of the building systems we currently program and control separately (like lighting controls, fire alarm, and HVAC systems), and then try desperately to synthesize on a building management system, to actually work together.

This implies a lot—many standards would need to be developed across disparate industries, and codes would have to be developed or revised, but the dangling carrot (smart buildings that run efficiently and tell us about themselves and about ourselves) is worth the effort.

Smarter buildings

Figure 2: The same sensor that was shown integrated into a fixture in Figure 1 can be mounted flush in a drywall ceiling via a custom detail. A remote-sensor approach is necessary when fixtures cannot accommodate an integral device. Courtesy: SmithGroupJJRWhat could buildings be telling us about themselves and ourselves, exactly? And how would this be helpful to us? Is this something that makes sense for everyone, or just for certain (rare) projects and clients?

When contemplating these questions, one is inevitably reminded of the “smart home” concept that has caught on so fiercely over the past few years. Spurred on by streaming services and millennials establishing their first residences, the notion of a home that synergizes many different systems and can be controlled remotely is de rigueur. Collectively, Americans are growing accustomed to the idea that security systems, thermostats, lightbulbs, music players, TVs, door locks, garage door openers, refrigerators, and washing machines should all be able to communicate with us when we’re not home so we can know what they’re up to and tell them if we don’t like it.

And, if this is done at home, it also becomes an expectation in the world at large—or, at the very least, this level of connectivity and control becomes something we’re comfortable seeing and interacting with outside our own homes. Plus, this concept makes even more sense on a larger scale, where energy is spent in droves. If users can control the devices using this energy more effectively, we stand to benefit substantially.

An increased comfort with technology’s infiltration of the built environment only slightly lagged behind the recovery from the recession that began in 2008. One of the most profound impacts on the building industry during those years was a long, hard look at the use of space. Private offices were abandoned by many industries in favor of open workspaces with bench-style stations that might have once been called “bull pens” (law firms notwithstanding). Working from home was considered by many employers as a method to cut rented square footage. Retail stores bet on consumer data that they harvested to boost sales. Anyone renting significant real estate was looking for ways to make that space work harder, and that mindset has not diminished even as the economy has righted itself.

In answer to that pursuit, the IoT, masquerading as a lighting control system, has emerged as a means to optimize square footage in two key ways:

  • As with DALI, by allowing spaces to be reprogrammed or reconfigured via an intuitive user interface on any internet-connected device.

  • By allowing owners, renters, and lessors to study the use of their spaces to better understand traffic patterns, space use, and room scheduling.

These benefits are the tip of the proverbial iceberg when it comes to IoT, but they are valuable enough to warrant a flurry of research and development in recent years, which has manifested as a host of new “lighting controls” manufacturers in the marketplace that we’ve never heard of. Because IoT lighting controls aim to improve efficiency in terms of square feet per person (which really means dollars), the demand is strong and the time is ripe for information technology (IT)-savvy companies to break into this game.

Figure 3: Open-ceiling applications pose a greater challenge when it comes to locating sensors. Here, a surface-mounted cylinder fixture is used, leaving no opportunity to integrate a sensor. Courtesy: SmithGroupJJREfficiency in this context means using a space in a way that best serves a population with the least amount of error and waste. It means designing spaces that function optimally with respect to their overall square footage, amenities, layout, and design—in other words, designing buildings and spaces that are right-sized for the groups that occupy them, have the correct programs, and meet the needs of their occupants without wasting square footage on areas people don’t like to use. If all of these are done well, an owner or tenant will get the most bang for their buck out of their real estate.  

Still more money stands to be saved by an IoT-enabled system that monitors energy usage and informs owners of their energy waste in an easy-to-understand format, and then allows them to modify their controls settings in an easy-to-manipulate interface. The addition of tagging technology using Bluetooth signals allows expensive equipment, key personnel, or even substances to be tracked in real time on a digital floor plan, saving hours in hunting things down the old-fashioned way.

One can easily imagine these benefits slotting into many project types: commercial offices in high-rise buildings, entire corporate campuses, hospitals, classrooms, retail, hotels, or hospitality. There is no market sector that doesn’t want to know how its space is being used, or does not have an opportunity to direct, market to, or otherwise engage its constituents.

Design considerations

When designing an IoT lighting control system, it is important to realize that the system is all about the sensors—the more, the better. The point of an IoT system is first and foremost to harvest data, and the data pool will be better if it’s bigger (assuming things are working properly).

Maximizing the number of sensors has been addressed by some manufacturers by taking a one-to-one sensor-to-fixture approach—that is, integrating a sensor into each fixture. This is more easily said than done, as fixture types like recessed downlights, decorative pendants, or wall sconces don’t typically allow for seamless sensor integration, ruling that option out due to aesthetics. This illustrates one disadvantage newcomers to the lighting industry may have—they aren’t as familiar with the intricacies of lighting design in an architectural sense, sometimes resulting in hiccups like this one. Still, this is a small problem, only requiring that a stand-alone sensor be installed in lieu of an integrated one for these types of fixtures (though that may still not be the aesthetic ideal).

When sensors are integrated, it is best to complete the integration at the factory prior to shipping fixtures to a job site. This isn’t unique to IoT-type integrated sensors, but they may make the task more complicated, as many IoT controls manufacturers are only starting to establish original equipment manufacturer (OEM) partnerships with fixture manufacturers.

Adding the complexity of shipping sensors and any additional integrated controls components could result in any number of headaches for fixture manufacturers—UL violations when devices don’t fit properly in a listed luminaire assembly, increased lead times, and extra fees. When deploying new technology, it is advisable to keep things simple by working within established partnerships whenever possible, which may unwittingly inform the lighting design itself.

When using any type of wireless control device, particularly if it’s internet-connected, there are certain familiar foibles that could cause complications. Internet outages, bugs, and software upgrades all pose potential threats to smooth operation, while battery failures and maintenance must be expected over time (though most systems should be able to warn you in advance when batteries need to be swapped, and batteries should last 10 years or more). The advantages of wireless technology, however, are not to be overlooked; less wiring and flexible sensor and switch locations simplify and reduce the cost of installation and enable users to modify their spaces in the future without the help of an electrician.

While sensor-integration and wireless-connectivity issues are possible, network security is of even greater concern to end users of IoT lighting control systems. Organizations handle their security protocols differently, which can create challenges when trying to implement IoT systems that offer only one or two options for network integration. Sending vast amounts of data out of a corporate network structure to perform analytics in a cloud requires advance involvement on the part of the end user to ensure that any perceived security weaknesses are identified and addressed prior to implementation. In fact, assessing the IT requirements should be one of the earliest steps in selecting the right IoT system for a user.

Future development

It’s pretty clear that wireless technology and IoT are the darlings of the lighting controls world right now, but there’s still much to resolve and improve upon before they earn the trust of conservative specifiers and end users. Great potential remains to be realized, creating an exciting opportunity for a wide variety of perspectives to be heard and incorporated into the solutions and advancements to come.

The IoT is opening the lighting controls world up to the technology sector. While this is unlocking a data-rich world inside the buildings we design and inhabit every day, it may also be putting us—the designers of these buildings and specifiers of the lighting controls within them—at risk of being left out of the conversation.

Input from the AEC industry must remain critical to the development of IoT controls, lighting, and otherwise, because we bring experience and knowledge that complements that of traditional controls manufacturers and IT-industry manufacturers alike. We are most definitely responsible for helping direct this development so that we end up with the best possible toolkit for the optimization of the buildings we’re charged with designing.


Katy C. Boat is an electrical engineer and lighting designer with SmithGroupJJR, concentrating on higher education, workplace, and health care projects with a sustainable focus.

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