By Craig DiLouie
A field of stars in a public space, a dramatic restaurant, a color-changing forest - when used correctly, LEDs can deliver stunning visual environments.
While LEDs are touted for their efficiency, long service life, color changing, compact size, no UV output, and other benefits, architects should be careful about using LEDs for illumination as the technology is still relatively young.
Paul Gregory, principal designer for New York City-based lighting design firm Focus Lighting Inc., sees LEDs as an important new tool in design, focusing on applications where they deliver strong visual effects and unique benefits. He points to three projects where LEDs solved unique problems and extended the possibilities of lighting: the Pier at Caesars, Morton's Trevi, and Alingsas.
"The same visual effects in these projects would not have been realized had we used a different lighting technology other than LEDs," he says.
A Sea of Stars at the Pier
The Pier at Caesars in Atlantic City is a 1,500-foot-long, three-story shopping arcade that extends into the Atlantic Ocean and connects to Caesars hotel via a glass sky-bridge. Gregory and J.R. Krauza of Focus Lighting teamed up with architectural firm Rockwell Group to create a serene experience that would offer visitors a world apart from the chaotic bustle of the city.
The design team strung 2,000 color-changing LED nodes by Color Kinetics on aircraft cable in a rolling pattern on the ceiling in the hallway, creating a sparkling star field that also obscures ductwork and piping at the open ceiling.
"The original concept was to simulate a twinkling field of stars," says Gregory. "We started with white LEDs for their long lamp life. The design shifted to the strings with the advance of the technology and what was capable. The LEDs gave us the full color-changing capability and expanded the possibilities of the ceiling."
On the third story, the restaurant promenade features a wave ceiling with views of the ocean. The design team integrated 90 wave projectors into the side columns to fill the blue preformed canopies with moving water images. The concept of this feature was to create a slowly moving projection of water patterns as if they were reflected from the ocean onto the ceiling.
"One challenge in bringing this project to fruition was maintaining the same level of brightness on the wave ceiling during the day as at night," says Krauza. "The floor-to-ceiling windows allow a lot of daylight to pour into the space, but we were successful in finding the best angle for the projectors and integrating them with the architecture to ensure the daylight in a way that would not affect the brightness of the ceiling."
Gregory concludes: "Together, these unifying elements create an exciting space on the shore of the Atlantic Ocean."
Energy Code Compliance at Trevi
Trevi, a festive Italian restaurant at The Forum Shops at Caesars Palace in Las Vegas, presented a challenge to the designers of Focus Lighting: The design called for a large number of surfaces to be addressed in the lighting treatment, but Las Vegas' commercial energy code mandated a maximum lighting power density of 2.8 watts per square foot.
"As the design progressed, it became apparent that more surfaces would need to be accented than were possible within the code using traditional sources," says Gregory. "As many of these surfaces required edge lighting or grazing light, we turned to LEDs as the solution."
A key advantage of LEDs, he adds, is that they are directional light sources, enabling them to be more efficient; they produce a relatively high level of brightness for the power required. At 7 watts per foot, the LEDs would require far less power than traditional alternatives such as low-voltage strips.
"Their light distribution characteristics, including a tight beam, enable LEDs to light a surface or be emitted through a surface much better than low-voltage strips or fluorescent sources," Gregory points out.
Another advantage of LEDs compared to fluorescent sources is that LEDs are small enough to enable arrays to bend where fluorescents could not, he adds.
The entry canopies are each made of four sections of deeply etched glass; each section, in turn, is edge-lighted with LEDs from IO Lighting concealed in the framing structure. The entire structure was fabricated offsite to simplify installation. The power supplies are located in the frame as well and accessible from the top side, which cannot be viewed by occupants. Focus coordinated with Savoy, a glass fabricator, to determine how deep the etching needed to be to produce the best effect.
"The biggest challenge was getting the structure correct to allow for the proper placement of the LED strips," recalls Krauza.
The bar dies are lighted with LED strips from IO Lighting. The curves use 18-inch sections of LEDs to navigate the curve. The fixtures are difficult to access, so LEDs were given top consideration due to their long life in addition to their low power draw.
"The face of the bar was mocked up to determine the best overall lighting effect," Krauza adds. "It was decided that a textured surface caught the light the best. The blue color ties in the bar face with the metal-clad walls within the restaurant."
Adds Gregory, "The LEDs were very efficient in the method we were using them and were the right source for the bar face and the canopies. Both the bar dies and canopies demanded very direct sources. LEDs are small, bright, and directional."
The stairs presented another difficult-to-access location requiring directional edge-lighting. In addition to IO LED strips, Focus added warm amber gel to the fixtures to increase the saturation of the glass risers. Due to the small size of the glass - only 7 inches tall - the LEDs fill the glass with light and appear fairly even.
"The repeating pattern of lighted steps adds visual interest to the entry and draws the diner in for a closer look," says Krauza. "The only challenge here was working with the stair fabricator to ensure the LEDs would fit into the shoe provided and the glass would be supported in such a way that would not create shadows. This was achieved in the show-drawing phase, and very few adjustments were required in the field."
He points out a disadvantage of LEDs that they contended with in this project was difficulty in dimming, as dimming had to be achieved through a 0-10VDC dimmable ballast. This required a gateway device to convert DMX into 0-10VDC. The system worked perfectly, however, once the design team worked it out, he adds.
ROBERT PEARSON
Color Changing in a Swedish Forest
Paul Gregory accepted an invitation from the European Lighting Designers Association (ELDA) to mentor design students participating in an ELDA Plus event workshop in Alingsas, Sweden. The students were presented with a canvas - a pathway closely lined on both sides by rows of trees - and tasked to design and build their own creations based on a general concept: "cathedral of nature, cathedral of light."
"The area is only open to pedestrians," says Gregory. "The thicket of trees, being so dense and close, creates a sort of roof of leaves. The idea was to literally ‘paint' this enclosed space with light."
Students used Color Kinetics RGB LED projectors to light the space with precise bands of bright color. The projectors are controlled by a sequence-programmed system to enable color changing.
"One of the major challenges of this project was to sensitively accent the 16 trees in a way that was respectful to nature and would also create eight beautiful first looks, balancing the beautiful surroundings," Gregory points out.
The color-changing LED system was used to accent different sections of the leaves, creating depth and volume within the trees. In addition, the tree trunks were streaked with white light produced by 50-watt MR16 lamps. All equipment was loaned by Color Kinetics for the purpose of this educational project.
Craig DiLouie ([email protected]), principal at ZING Communications Inc. (www.zinginc.com), is a consultant, analyst, and reporter specializing in the lighting and electrical industries.
