Using LEDs to Their Best Advantage

How do building owners, facility managers, and lighting specifiers choose lighting products? Purchase price and operating costs (energy and maintenance) are usually the top concerns but a host of other aspects may come into play, depending on the application. Here are some unique LED characteristics:

• Directional light emission – directing light where it is needed.
• Size advantage – can be very compact and low-profile.
• Breakage resistance – no breakable glass or filaments.
• Cold temperature operation – performance improves in the cold.
• Instant on – require no “warm up” time.
• Rapid cycling capability – lifetime not affected by frequent switching.
• Controllability – compatible with electronic controls to change light levels and color characteristics.
• No IR or UV emissions - LEDs intended for lighting do not emit infrared or ultraviolet radiation.

What makes LEDs different from other light sources?
LEDs are semiconductor devices, while incandescent, fluorescent, and high-intensity discharge (HID) lamps are all based on glass enclosures containing a filament or electrodes, with fill gases and coatings of various types.

LED lighting starts with a tiny chip (most commonly about 1 mm²) comprising layers of semi-conducting material. LED packages may contain just one chip or multiple chips, mounted on heat-conducting material and usually enclosed in a lens or encapsulant. The resulting device, typically around 7 to 9 mm on a side, can produce 30 to 150 lumens each, and can be used separately or in arrays. LED devices are mounted on a circuit board and attached to a lighting fixture, architectural structure, or even a “light bulb” package.

General illumination applications that may most benefit from the LED attributes described in this section including the following:

• Undercabinet lighting
• In-cabinet accent lighting
• Adjustable task lighting
• Refrigerated case lighting
• Outdoor area lighting
• Elevator lighting
• Recessed downlights
• Accent lights
• Step and path lighting
• Cove lighting
• Spaces with occupancy sensors
• Food preparation areas
• Retail display cases
• Art display lighting