What compact fluorescent light bulb do I buy to replace a 60-,75-,100-or 150-watt regular bulb? How are the watts calculated?
While a regular (incandescent) light bulb uses heat to produce light, a fluorescent bulb creates light using an entirely different method that is far more energy-efficient — in fact, 4-6 times more efficient. This means that you can buy a 15-watt compact fluorescent bulb that produces the SAME AMOUNT OF LIGHT as a 60-watt regular incandescent bulb. Don't worry about the math,though — we make it easy for you to figure out which compact fluorescent bulb to buy by displaying the equivalent regular watts you're used to prominently on the package.
What makes compact fluorescent and fluorescent bulbs more energy-efficient than regular bulbs?
Fluorescent light bulbs (including compact fluorescents)are more energy-efficient than regular bulbs because of the different methods they use to produce light. Regular bulbs (also known as incandescent bulbs) create light by heating a filament inside the bulb; the heat makes the filament white-hot, producing the light that you see. A lot of the energy used to create the heat that lights an incandescent bulb is wasted - in fact about 90% of the energy they emit is in the form of heat (Also called Infrared radiation).
A fluorescent bulb, on the other hand, contains a gas that, when excited by electricity, hits a coating inside the fluorescent bulb and emits light. Because fluorescent bulbs don't use heat to create light, they are far more energy-efficient than regular incandescent bulbs. The fluorescent bulbs used in your home emit only about 30% of their energy in heat, making them far cooler as well !
Do light bulbs (such as compact fluorescent bulbs)give off hazardous amounts of ultraviolet(UV)light?
Regular fluorescent light bulbs used in your home and office do not produce a hazardous amount of ultraviolet light (UV).The UV produced by fluorescent light bulbs is far less than the amount produced by natural daylight.
Also, here's a great video introducing CFL Bulbs put together by CommonCraft: