Compared to the older options, LED-based illumination provides the following benefits:
- Dramatic reductions in energy consumption and related costs.
- Significant reductions in maintenance costs.
- Thinner lightboxes, to save space in sign designs.
- More even illumination.
- Meeting regulatory requirements for greater sustainability.
Arguably the most obvious lightboxes relying on LED-based illumination today are the exit signs installed in places of business, government buildings and other facilities. Since these signs must operate non-stop, 24-7, energy efficiency has been a higher-priority consideration in their engineering than for many other types of signs. They must be clearly visible and readable at all times.
Incandescent bulbs were the first standard lights for exit signs and are still somewhat prominent in commercial buildings because of their low upfront cost, but they are the least energy-efficient option and entail the most maintenance, since they have the shortest lamp life.
Fluorescent lights have advanced technologically, with compact fluorescent lamps (CFLs) becoming a common sight. The lamps are very bright, but uneven. They are more energy-efficient and longer-lasting than incandescent bulbs, but carry a higher replacement cost. And compared to LEDs, their lamp life is only moderate.
Being small semiconductor chips that convert electricity into light without much heat emission, LEDs can provide excellent illumination over a long bulb life, using ultra-low amounts of energy. They are more expensive upfront, but carry minimal operational and maintenance costs.
The most prominent types of bulbs for exit signs, by way of example, use 40, 11 or 2 W. The traditional 40-W incandescent bulb will last six months. According to Energy Star, an international standard adopted by Natural Resources Canada’s Office of Energy Efficiency (OEE), over the course of one year, this option will entail $26 in bulb and labour costs and $39 in energy costs, for a total of $65.
The Fashion Outlets of Chicago feature 11 full-colour LED-based displays along their exterior façade.
An 11-W fluorescent bulb will last the full year. Energy Star estimates its costs over that time include $27 for the bulb and labour and $11 in energy, for a total of $38.
Finally, Energy Star claims a 2-W LED will last 10 years. With the upfront purchase and installation, the first-year costs are highest, including $20 for the bulb itself and $25 in labour, but only $2 in energy. Then, over the course of those 10 years, there are no further annual bulb and labour costs, saving hundreds of dollars in an ongoing context.
So, as operating costs for conventionally illuminated exit signs can accumulate greatly over time, it has made sense for facility managers to change out all of their old bulbs and replace them with LEDs.
Digital signage
Many ongoing evaluations of the future of LEDs have considered their potential to displace traditional lights in architectural applications, but there is a need to overcome misconceptions about their true value proposition. While many applications of LEDs are indeed intended to replace existing fixtures, others are using LEDs as a new model for ‘digital light,’ exploiting dynamic ways to control light to provide information. Hence, they have become highly useful in the digital signage sector.
The Fashion Outlets of Chicago opened in August 2013 along Interstate 294 (I-294) in Rosemont, Ill., not far from Chicago O’Hare International Airport. In the hope of attracting both visitors’ and locals’ attention as the closest outlet mall to Chicago, the two-level, 49,239-m2 (530,000-sf) building features approximately 1,720 m2 (18,500 sf) of outdoor digital video screen space.
This space comprises a series of 11 full-colour LED-based displays along the mall’s exterior façade. They were built by Daktronics, which is reportedly now the world’s largest supplier of computer-programmable displays, large-format video screens, digital billboards, electronic scoreboards and the corresponding control systems.
