The incandescent light bulb invented by Thomas Edison was the only type available before the late 20th century, when compact fluorescent bulbs — CFLs — were introduced. Homeowners today have the extra choice of light emitting diode — LED — bulbs. They provide advantages over the other types, but have a few disadvantages also. When choosing light bulbs, then consider variables that are relevant to light quality and intensity, health and economics.
An LED is not a light bulb — it’s an electronic circuit component called a diode whose goal is to convert alternating current into direct current. All diodes emit some type of mild, but the semiconducting material in an LED emits visible light. The initial LEDs emitted red light, however, engineers found ways to manufacture versions that emit yellow, green as well as blue light. White-light-emitting LEDs are infrequent, and many LED bulbs, which consist of clusters of individual LEDs, have phosphor coatings which glow with white light when excited by light from the LED clusters. LED bulbs occasionally include complex pre-assembled circuitry.
CFLs produce light via the excitation of gas within the curved tube which creates the bulb, which can be more efficient than producing light by heating a filament — the process which happens inside an incandescent bulbs. By comparison, the production of light by an LED is much more effective. To create 800 lumens of light, an incandescent bulbs absorbs 60 meters, a CFl 13 to 15 watts, and an LED just 6 to 8 watts. Additionally, LEDs produce virtually no heat and last six times more than CFLs and more than 30 times longer than incandescent bulbs. The initial price of an LED could be 5 times, or longer, greater than that of a CFL, nevertheless.
Among the downsides of LED clusters is they are directional. This makes them perfect for spotlights, but much less well suited to ambient lighting. Their directionality is not as noticeable within a phosphor-coated casing, because the entire casing glows, however, the bulk of the light emerges from the surface of the bulb. The quality of light an LED emits depends upon the circuitry of the bulb, and there’s a large difference between bulbs. The best bulbs, including high profile circuitry, create full-spectrum white light like that generated by halogen bulbs — high-temperature incandescents. Lower-quality LEDs could be relatively dim.
The Occupational Safety and Health Administration has recognized flickering from fluorescent bulbs as a health hazard, but because LEDs convert alternating to direct current, they never flicker. Additionally, LEDs contain no mercury — a component of CFL bulbs — and can be safely discarded. Another benefit of LEDs over CFLs is the former emit no ultraviolet light, and you can place one on a desk beside you with no the fear of absorbing radiation. Compared to incandescent bulbs, LEDs generate virtually no heat, and an unattended LED presents very little risk of starting a fire.