Lighting Controls

By Craig G. Malesic, PE, LC, PMP

In our recent blog post about Lighting Trends, Thomas Schubert and I shared that lighting control systems are becoming very complex, the “why” is too often being ignored, end-users don’t understand the controls, and the lighting is often not properly commissioned. However, since ever-changing building and energy codes are driving the increased application of advanced lighting controls, I wanted to follow-up the trends blog with an overview of the various types of lighting controls.

Groups like the Illumination Engineering Society of North America (IESNA), the American Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE), and the International Code Council (ICC) create the various energy codes that have been driving adoption of advanced lighting controls.  Specifically, the International Energy Conservation Code (IECC) and AHRAE/IESNA 90.1 are the enforced codes that determine the requirements for an energy-efficient design. These codes and guidelines dictate which types of controls must be used and how they must be configured. The primary purpose for the lighting design codes is to minimize energy used by selecting energy-efficient sources and to eliminate wasted energy by either turning off lights that have no reason to be on or dimming the lighting when appropriate. As the design and construction industry continues its march toward the goal of net-zero energy use in buildings, codes are doing their part by mandating increasingly stringent rules. With each subsequent code update, we see ever-decreasing allowed connected lighting wattage requirements. The good news is that sources such as LEDs use less total wattage per light output, existing design practices often result in over-lit spaces, and occupants easily adjust to lower levels of lighting.

Even with these increased requirements, not all spaces and applications are treated equal. Within codes there are exceptions included for specific cases. Because of safety concerns there are some applications where lighting controls could potentially lead to injury. The code is sensitive to this and provides a exception for potentially hazardous control schemes in these areas.  For instance, a worker in a mechanical and electrical room doesn’t want the lights to automatically shut off while they are working on an energized electrical panel. A well-designed system does not provide this typical energy saving feature, but an inadvertent failure or poor design not taking these realities into account could be catastrophic. Another example would be a manufacturing or machining operation that has many moving parts, and therefore a risk associated with the space suddenly becoming dark.  The code also allows exceptions for controls where security is an issue but is understandably vague.  Because a reasonable argument can be made that application of a code in a particular area could pose a danger, it is generally accepted by code reviewers to forgo controls in these areas.  In each of these situations, a designer needs to be careful where an exception is made and be prepared to present a reasonable case if questioned by the Authority Having Jurisdiction (AHJ).

Because of the many types of lighting controls available today, we’ll cover the options in a series of posts. This is not intended to be a design guide (that’s why you hire a professional lighting designer!), but rather an overview of the types of lighting controls, how they work, and basic applications. We will go beyond the often-used concept of “just” putting in an occupancy sensor. They certainly have a place, but I would like you to be able to navigate a well-thought-out lighting control scheme that may make more sense. To do this, you need to understand the options.  I am a big believer that complex things can be simplified for all to understand and will attempt to remove the mysteries of the various ‘magical’ devices that we use every day.  It may get slightly technical, but only at a general level.  While you may never be called upon by a manufacturer to utilize the newest release of their lighting control product, it is still good to have a base understand of how it works.

The types of lighting controls that will be covered include:

  • Occupancy Sensors
  • Vacancy Sensors
  • Dimmers
  • Daylighting
  • Integrated Controls (within light fixtures)
  • Room Controllers
  • Scene Controllers
  • Whole Building Systems / Campus Wide Systems

There are codes related to each of these options, which we’ll cover as well.

Before we get started, your “homework” is to check out these other blogs, which will provide some foundational knowledge for our new series:

Lighting Trends: Everything is Changing, But Not Everyone is Keeping Up

Understanding Correlated Color Temperature

What is the Ideal Color Temperature for Your Lighting?

Illuminance and Perceived Brightness

Understanding Selectable Color Temperature

Ready to get started? In our next post, we’ll focus on the first three types of lighting controls:

  • Occupancy Sensors
  • Vacancy Sensors
  • Dimmers

Have questions about lighting? Looking for a professional lighting design team for your next project? Check out JDB Illumination and reach out to me at [email protected] or 717-434-1559.

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