It’s not fair.
Energy-efficient line voltage lighting, especially fluorescent, receives all the attention, it seems. But unheralded low voltage lighting saves energy, too, and offers benefits not available with line voltage lighting.
Low voltage lighting, by definition, operates at 30 volts or less. A transformer, either integral (part of the fixture) or remote (located in a service area), steps down line voltage to either 12 or 24 volts.
When powered properly, low voltage lighting produces two-and-a-half times as much light as line voltage incandescent lamps. Stated in other terms, a 50-watt low voltage lamp generates as much light as a 125-watt line voltage lamp.
The per-lamp savings for each 1,000 hours of operation can reach up to $7.50, based on a kilowatt-hour rate of 10 cents. This caliber of energy efficiency produces a compelling case to consider low voltage lighting for task, accent, and even general lighting applications.
Other reasons to consider low voltage lighting include: light quality, design flexibility, safety, and lack of waste.
It’s the Light
Even if it weren’t energy efficient, low voltage lighting would still be specified for commercial space; no other type of lighting can quite duplicate its light quality. More than other lighting technologies, low voltage systems can establish a desired ambience, or mood, for the occupied environment. It’s suitable for cove and recessed lighting, and for downlighting and uplighting.
Mood also can be established with the design flexibility of low voltage lighting that allows a variety of dimming and beam control options. Lighting systems using remote transformers enable full-range dimming from 0- to 100-percent of light output. And, the comprehensive range of lamps and fixtures available makes it easier than it is with line voltage lighting to control the light spread for wall washing and grazing, focusing on tasks, or accenting.
Let There Be Less
Aesthetics include the lighting system’s appearance. In this case, less is better. Fixture trim holes for low voltage lighting can be as small as two or three inches in diameter, providing that remote transformers are specified rather than integral transformers, which dictate a larger fixture housing and opening. Considering the fact that many installations call for 200 or more fixtures, the ability to make lighting unobtrusive, and even transparent, rates as an important design criterion for building owners and managers.
Optimizing Safety, Minimizing Waste
Low voltage lighting is safer than line voltage lighting because wiring and lamps have about one-tenth the voltage flowing through them once the transformer has stepped down the voltage, which reduces shock hazard.
Also of concern is waste disposal. New low voltage lamp designs and materials have increased lamp life up to 10,000 hours. If the lamps are dimmed to 50 percent, for example, life expectancy can double to 20,000 hours, further cutting disposal and maintenance costs.
Another way to reduce waste is proper transformer selection. Remote transformers are warranted for 25 years, which practically eliminates them as a waste issue.
The package of benefits that low voltage lighting offers for enhancing commercial environments deserves consideration for a range of applications. And that’s fair.
David S. Pitts is president of Manchester, NH-based Semper Fi Power pply Inc. (www.semperfipowersupply.com). He can be reached at (603) 656-9729 or at (firstname.lastname@example.org).