LED The Field Museum for Natural History made a successful experimental switch to LED lighting in recent years. Located in Chicago, IL, the Field Museum is one of the oldest and biggest natural history museums in the United States. The Pacific Northwest National Laboratory (PNNL) conducted this experiment in late 2009 with the support of the U.S. Department of Energy GATEWAY Solid-State Lighting Technology Demonstration Program. Officials changed the lighting in the enclosed Brooker Gallery from 32 halogen track luminaries to 26 light-emitting diode (LED) track fixtures. Both halogen and LED lights were manufactured by Lighting Services, Inc.
Officials at the Field Museum had several motives for undergoing this experiment and making the change to LED lighting. First, the museum wanted to go green. LED light bulbs are very environmentally-friendly lighting options since they use a fraction of the wattage that most lamps need and are highly energy-efficient. Museum officials also wanted to reduce the negative effects of lighting on their display items. LED bulbs emit minimal UV and IR rays, both of which are especially detrimental to artifacts. Therefore LED lights were a safer option than halogen lights, which emit so much harmful radiation that museum officials have to buy special UV filters to protect artifacts. Another reason for using LED lighting was to cut down on air-conditioning. Warm temperatures can damage museum pieces, so officials use the air conditioning system constantly and at high-levels. Luckily enough, LED bulbs give off almost no heat, making them a great alternative to halogen lights. Museum staff also wanted long-lasting bulbs since replacing accent lighting is a hassle. Accent lights are usually focused to a specific spot in the museum and moving them can cause problems. In addition, replacing an accent lighting fixture requires bring a lift or ladder into the museum area, which presents more hazards. Luckily for museum officials, LED bulbs are especially durable and can last for years. Finally, LED bulbs are directional, making them ideal for use as accent lights.
By the end of the experiment, this exhibit had saved 63 percent more energy with LED lighting while producing the same or better illumination than the halogen lights. These remarkable energy savings resulted from three things; first, LED bulbs were more energy-efficient than the halogen bulbs they replaced; second, LEDs had a greater centerbeam intensity for similar beam angles; and third, fewer LED fixtures needed to be installed because LED fixtures had better lighting distribution than the halogen lights. Calculated energy savings also included the reduced air-conditioning use.
The payback for this specific experiment was about 3 years, although in a typical one-to-one replacement basis the payback could take anywhere from 4.5 to 11 years. The drastically shorter payback that the Field Museum experienced occurred because officials were able to reduce the amount of fixtures used. In addition, they did not need to buy UV filters that they had been using for the halogen lights, since LED lights do not give off any UV radiation.
The only drawbacks of the LED lights that observers found related to the dimming feature and the beam angle size. In general, LED light bulbs are not always compatible with the driving designs of dimming systems. Industry officials are still trying to work on this feature of LED lights to make them dim past fifty percent without any problems and while still maintaining high energy efficiency. The beam angle size of the LED was a concern because in order to create a smaller beam, the actual lamp size needs to be bigger. It is not difficult to get away with a large lamp in a high-ceilinged museum, but LED lights with beam angles that are smaller than 20 degrees often appear overly-large in a different setting such as retail or office spaces.
Overall, the feedback on the new LED lights from both museum staff and lighting professionals were positive. LED lights had amazing energy-saving benefits and were less damaging to the artifacts than other lighting systems. They were better for the environment and had illuminated the area just as well or better than the halogen lights had. As extremely durable lights, LED bulbs saved museum staff the headache of constantly having to replace them. All things considered, it is little wonder that the Field Museum had such a successful experience with these environmentally-friendly light bulbs. As LED lights continue to improve, it is likely that they will keep growing in popularity across the U.S. and around the world.