Since the invention of the incandescent light bulb in the 19th century, electric lighting has become the norm in developed countries. In 2008, the European Union endorsed measures to reduce the level of greenhouse gas emissions, including phasing out all filament bulbs by 2012. Manufacturers, under pressure to develop affordable, low-energy alternatives, introduced halogen lamps, compact fluorescent lamps and, more recently, lamps that use light-emitting diodes, all of which offer the consumer some advantage. Dimmable LED lights are now available for recessed ceiling fittings in homes and offices.
Other People Are Reading
LEDs are common in many types of electronic equipment, often operating as indicators that emit low intensity light. LEDs produce light highly efficiently compared to incandescent and fluorescent sources, both of which generate more heat than light. High output LED lamps with a life of at least 25,000 hours are now commercially viable. The light output from an LED is unidirectional, and LED lights provide light exactly where it is required, making them particularly suitable for downlighting in domestic and commercial buildings. LED lights require drivers, or controls, that are matched to the design of the LED array.
Recessed ceiling lights
As of 2011, recessed ceiling lights, or downlights, are the fitment of choice in most new residential properties for rooms that require general ambient lighting. Unobtrusive, they offer designers options that cannot be matched by traditional surface-mounted or suspended fittings. Conventional recessed downlights typically rely on an internal reflector that focuses the light beam to cover a defined area, whereas LED lamps generate a focused beam by design. LED lamps with inbuilt drivers can be retrofitted to conventional downlights, while purpose-designed LED downlights generally have external drivers.
Early versions of dimmable LED lights often performed poorly as conventional dimmers were unsuitable for many LED drivers. A correctly matched LED light dimmer provides smooth dimming without flicker across the entire dimming range. Step changes in light intensity are highly undesirable, and many LED dimmers allow the lowest light intensity to be adjusted after installation. Some dimmers require a minimum electrical load in order to operate and the low power consumption of LED lights may require several fittings to reach this threshold.
Although LED lights generate relatively low levels of heat during operation, this is generally directed to the rear of the fitting. Given the enclosed nature of a recessed ceiling light, particularly in an insulated ceiling void, the fitting requires a correctly specified heat sink to prevent the luminaire from overheating. Failure to dissipate heat effectively from a recessed LED ceiling light can lead to reduced operating life, variation in light colour or other less obvious problems.
- 20 of the funniest online reviews ever
- 14 Biggest lies people tell in online dating sites
- Hilarious things Google thinks you're trying to search for
- Department of Energy & Climate Change; Carbon Emissions Reduction Target; June 2009
- ENERGY STAR: ENERGY STAR Qualified LED Lighting
- ENERGY STAR: Learn About LEDs
- U.S. Department of Energy; Residential Recessed Downlights; January 2008
- "LD+A" magazine; The Quest for Dimmable LEDs; A. Beebe; January 2011