In the dark about light bulbs?

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Light bulb technology is evolving at a dizzying pace, with the old incandescent bulbs being replaced by CFLs and LEDs. So what’s what, and which works where?

Incandescent bulbs
These are the original ‘old fashioned’ bulbs with a tungsten filament that lights up inside the glass globe. Incandescent bulbs cast a warm, ‘omnidirectional’ light, so can illuminate large areas. They do, however, generate a great deal of heat as well as light and are extremely inefficient compared to new alternatives. The most inefficient of these are being phased out in the US beginning in January 2012.

Halogen bulbs
These replace incandescent and although each bulb is more expensive, they consume far less power. Their shelf life is however quite short.

Compact fluorescent lights are the original low-energy, long-lasting alternative to incandescent lights. Although early versions were slow to light up, flickered and buzzed, and produced a cold, harsh light, the colour of the light and the ability to dim these bulbs is improving.

Light Emitting Diodes contains silicon chips that throw light in one direction only. Although expensive to purchase, they are far more energy efficient than the alternatives and should last for 20 years or more. LEDs work well in recessed lights or accent lights but the ‘unidirectional’ light makes them unsuitable for use in lampshades or ambient lighting. Manufacturers are working to produce multidirectional LEDs, however.

Rather than describing bulbs in terms of watts, which is a measure of power, in future light bulbs the power of a light will be measured in lumens, a measure of the light the bulbs cast. To ease the transition, a ‘watt equivalent’ measure will be included.