Specifying Lighting: What You Need to Know

Images courtesy Hubbell Lighting
Images courtesy Hubbell Lighting

by Terry Arbouw
The introduction of light-emitting diode (LED) fixtures has changed the established view of light sources. Best known for their ability to provide quality lighting with lowered energy costs, LEDs, in reality, represent a paradigm shift in the capabilities of a light fixture.

Prior to the introduction of LEDs, lighting fixtures for the most part were relatively simple devices providing a method of mounting a light source, generally a lamp, and a means of directing the light towards a task.

While they may appear similar to classic light fixtures, LED luminaires are, in fact, very different.

The LED fixture is a complex electronic circuit whose primary purpose, at first glance, is to simply illuminate indoor or outdoor spaces. These same circuits, however, can be easily expanded to exchange data, incorporate sensing technologies, or employ other technical assets. The LED lighting fixture—unlike many devices in today’s buildings—exists in some form to provide light to every usable square foot of a facility. They are everywhere. Therefore, LED lighting has the potential to become the primary location for the deployment of assets to monitor building environmental conditions and collect occupant information. There are a variety of applications already being considered and explored, including:

  • indoor positioning;
  • energy monitoring;
  • asset tracking and management;
  • occupant comfort and control; and
  • space usage.

Additionally, LEDs have opened the door to innovative control capabilities, such as:

  • low-cost dimming control (i.e. the ability to adjust intensity without the cost or complexity of dimming incandescent, fluorescent, or high-intensity discharge [HID] lighting);
  • color temperature tuning (i.e. the ability to statically or dynamically adjust a lighting fixture’s color temperature to suit the needs of the occupant);
  • circadian lighting whereby the color temperature of the lighting fixture is adjusted throughout the day to mimic the color changes produced by the sun; and
  • full red, green, and blue (RGB) color changes, allowing for the selection of essentially any color in the rainbow.

The lighting industry is on the cusp of change as additional assets are beginning to appear on the fixture but are not yet mainstream.

Consider the typical office. Prior to LED lighting, the space would be outfitted with an occupancy sensor, and perhaps a switch to allow the tenant to manually turn on or off the lights. Today, it is becoming common practice to provide an occupant with not only on and off controls, but also the ability to reduce the lighting to a desired level without any of the complications involved in dimming fluorescent, HID, or even incandescent lamps. Fluorescent lighting, unlike LED, require special dimming ballasts costing on average $30 more than their non-dimming counterparts. Additionally, fluorescent lamps must be “burned in,” meaning they must run at 100 percent for 100 hours prior to being dimmed. Fluorescent ballasts and lamps have different dimming ranges—most go from 100 to 10 percent—while specialized ballast may dim as low as one percent. Fluorescent fixtures must be carefully designed to insure proper dimming, which is why they use a special dimming, non-shunted “tombstones” lamp connector located at the ends of each fixture the lamp plugs into. As fluorescent lamps age, its dimming performance is affected. Fluorescent lamps are also sensitive to temperature changes; cold air passing over the lamps from an air-conditioning system can affect dimming performance.

LED fixtures are fundamentally changing how an occupant interacts with the lighting in their space. Now occupants can adapt their visual environment to suit the task at hand. The byproduct of this functionality for building owners and operators is increased occupant satisfaction and productivity.

Drill deeper into a typical conference room or classroom setting, and one can see even more significant changes. In the past, lighting control capabilities such as user-controllable, preset lighting scenes and manual control were reserved for spaces that could justify the cost of a specialized architectural dimming system. Today, this functionality is mainstream and provided at a much lower cost with even more solutions. New capabilities such as color temperature controls are finding their way into classrooms, and healthcare and assisted living facilities.

Example of color temperature tuning.

Perhaps the most attractive aspect of today’s LED fixtures is they are becoming more “connected.” A lighting fixture is essentially required to be anywhere people are within an enclosed space because one needs light to see. This establishes the luminaire as an attractive integration point for Internet of Things (IoT) as well as other assets.

Consider how a smartphone has not always been “smart.” At one point it was just a phone. As a personal communications device, it was always with us, making it the perfect gadget to attach additional assets like cameras, voice recorders, electronic day timers, alarm clocks, and music players. The phone had everything required for supporting and deploying additional assets. It had a battery and a way of recharging so it could supply power to other things. It was connected and it had a means of connecting to other things via cables, wireless, and even the Internet.

Similarly, LED luminaires have the required infrastructure to deploy additional assets. Luminaires are generally located above occupants with a clear view of where they are and what they are doing. They have a power supply (line mains or DC). They are becoming connected. In short, luminaires may well be the perfect location for tracking assets within a building (e.g. location of medical equipment, portable computers, testing equipment, or even people), location services, and wireless communications, as well as monitoring conditions such as air quality and gas-leak detection.

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