Incandescent and Other Old Lamps, and LEDs
In the past, most lighting schemes would probably have used a variety of lamp types whereas today LEDs (light emitting diodes) offer a new approach.
Before electricity, most artificial lighting depended upon flames. Light, from the familiar but now largely defunct incandescent lamp, was produced by heating a material until it glowed or became ‘incandescent’.
The story of lighting over the last 200 years has been one of continuous development with new lamps being devised and old ones either being improved or discontinued. In most technologies the old is quickly replaced by the new. With lighting however, (until recent EU Directives EC244/2009 and EC245/2009 progressively banned less efficient light sources), the old was being retained even though it was known that the new was more energy efficient. This was the case with incandescent lamps for many years. They were familiar, cheap, uncomplicated to operate or control and easy to replace.
LEDs first appeared on the scene as indicator lights such as those found in early hand-held calculators. About 10 years ago they started to be available as replacements for a number of other lamp types such as incandescent, fluorescent, mercury and sodium. However, initially they were very expensive in comparison to old incandescent lamps and the integral control gear, or driver, often made them heavy so they were unpopular.
A great deal of product development has happened in the intervening years and the size, weight, wattages, colour operating temperature ranges and physical shapes have multiplied and the per unit costs have dropped considerably. A reasonably priced LED lamp is now available for most internal light types and uses, including heritage fitments and chandeliers. There is also a wide range of LED choices for external lighting schemes.
Remote drivers (or control gear) can save on the lamp weight, and the long operating life of LEDs can considerably reduce maintenance complexities.
New lighting installations are now nearly all LEDs, with the exception of linear fluorescent and fibre optic lamps, and you will rarely find any of the other former lamp types being used (for example compact fluorescent, halogen, cold cathode, fibre optic with a mercury halide, or son lamps).
