By Craig DiLouie
1. LEDs. LEDs are the hottest lighting technology to watch right now. They are extremely compact, efficient, easy to dim, long lasting, and available in a variety of colors. While technical barriers remain to LEDs becoming truly competitive as a general light source, they offer significant advantages for colored lighting applications as well as niche white light applications such as cove lighting.
Regarding colored lighting, LEDs can make lighting fun and even more creative. As white LED technology advances, the industry will need to step up its efforts at standardization - until then, some LED products, such as white LED products, can be difficult to specify, and manufacturer performance claims should be taken with a grain of salt. In addition, the light fixture manufacturers will need to begin exploring the full potential of the light source with a new generation of light fixtures.
Assessment: Use LEDs when they bring something necessary and unique to the project.
2. Cutoff optics. Light pollution laws and LEED are making outdoor lighting that minimizes impact on the sky and neighboring properties more and more common. One solution is to use semi-cutoff, cutoff, or full-cutoff optics that limit the amount of light being emitted upward to varying degrees. Full-cutoff optics is not a panacea; the other solutions may work even better, depending on the lighting needs of the project. House-side shields can be added to restrict the light pattern and reduce light trespass. Ask manufacturers for examples of the effects of each, and consider all methods that address light pollution (including glare), before choosing the solution that is right for the project.
Assessment: Addressing light pollution is good practice in lighting, within which cutoff optics can be a good choice for many projects.
3. Energy-efficient components. Energy codes are tougher on lighting power density. LEED-NC is now based on exceeding ASHRAE/IES Standard 90.1-2004, and efficiency is good lighting practice. A new generation of lighting components, which form the actual light-generating system within the light fixture, is enabling significant reductions in the total ownership cost of the lighting system for the owner. Examples include the new high-efficiency type of electronic ballast, high-lumen T8 lamps, energy-saving types of T8 lamps, and others.
Assessment: Visual needs should always come before energy. Always go with the solution that first meets the owner's lighting needs, then try to meet those needs with the most efficient lighting.
4. Daylighting. Thanks to the sustainable design movement, daylighting has re-entered the mainstream of construction. Daylighting is considered both an architectural and a lighting discipline, and also both an art and a science. Studies indicate that people respond very positively to daylight in offices, and also to a view of the outdoors. Energy savings are possible through daylight harvesting, which uses controls to reduce lighting use during times of high daylight contribution.
Assessment: Use daylighting whenever possible, but be careful to avoid direct sunlight penetration. Good daylighting, and daylight harvesting, projects require strong upfront collaboration across the design team.
5. Lighting controls. Scheduling and/or occupancy sensors are now a mandatory component of lighting design due to prevailing energy codes, and fluorescent dimming is expanding outside its traditional domain of the conference room. Scheduling and occupancy sensing are simple, tried-and-true strategies, while dimming, while offering more capabilities, can be more expensive and requires greater commissioning.
As an example of how far fluorescent dimming has come, providing occupants with individual dimming control is now achievable and has been demonstrated in studies to increase worker satisfaction and generate energy savings.
One interesting technology now emerging is a demand reduction system designed to dim the lights to a specific amount during peak demand hours, which can result in dramatic utility cost savings for the owner. Another is wireless controls for commercial applications, based on either the Zigbee or Z-Wave protocols. These controls offer significant promise and are just emerging as a technology. Meanwhile, digital control, such as DALI, currently allows the ultimate in fluorescent dimming capabilities for projects both large and small.
Assessment: Specify automatic shutoff wherever applicable and whenever required by code, and consider dimming for various applications outside the usual suspects such as conference rooms.