Light emitting diodes (LEDs) offer great promise for general lighting applications. Their small size and color tunability open up possibilities for lighting to be the defining element for architectural spaces. Their promised high efficiency also makes LEDs an attractive choice for green building design. At Intertech’s LEDs 2004 conference, held last month in San Diego, manufacturers, system designers and system integrators all expressed optimism that the promise of LEDs will soon be realized.
An example of the basis for optimism is the announcement from CREE, Inc., Durham, N.C., that they had reached a luminous efficacy of 57 lumens per watt in a high-power, white-light diode package. Perhaps equally important is the trend towards standardization among the major LED manufacturers, with several competing manufacturers now offering surface-mount packages using the same size footprint. The surface-mount packaging allows customers to use automated assembly techniques, while the standardization reflects the growing maturity of the industry. Regardless of these indications of industry maturity, applications of LED illumination still seem to be limited to unique niches.
Sheila Kennedy is out to change that. Kennedy is Director of Design & Applied Research at KVA, an architecture firm that integrates innovative new technologies in architecture. Kennedy recently collaborated on a prototype building infrastructure project incorporating LED illumination and smart building systems. The prototype system, a Herman Miller Creative Office project, was installed at Harvard University’s Design School. One of the project’s key innovations is an LED net structure that is lightweight, flexible and shippable. Like an open weave fabric, the net can spread easily to cover ceiling panels. The lighting is configurable, allowing variable color illumination, and the smart building infrastructure enables the LED panels and other lighting elements to be coupled and linked to different switches to create different lighting scenarios to support a variety of research and teaching uses in the classroom. The design is UL rated and building code compliant.
Although building codes place restrictions on the design of ceiling elements-for example, a ceiling can not block a building’s sprinkler system-Kennedy believes that if LEDs are to realize their potential as an architectural illumination system, designers and the LED industry must share the responsibility to establish creative approaches for the design of integrated LED lighting systems that meet current building requirements.
