Regular light bulbs, 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. Halogen light bulbs create light through the same method. Because incandescent and halogen bulbs create light through heat, about 90% of the energy they emit is in the form of heat (also called infrared radiation). To reduce the heat emitted by regular incandescent and halogen light bulbs, use a lower watt bulb (like 60 watts instead of 100).
Fluorescent light bulbs use an entirely different method to create light. Both compact fluorescent bulbs and fluorescent tubes contain a gas that, when excited by electricity, hits a coating inside the fluorescent bulb and emits light. (This makes them far more energy-efficient than regular incandescent bulbs.) The fluorescent bulbs used in your home emit only around 30% of their energy in heat, making them far cooler than regular bulbs and an ideal choice whenever reducing heat from bulbs is important. The white powder that you see inside a fluorescent lamp is called phosphor, which is a substance that emits white, visible light whenever it absorbs light waves. Both compact fluorescent bulbs and fluorescent tubes contain a gas that gives off invisible light when excited by electricity. This invisible light travels to the phosphor coating on the bulb, where it is transformed into light visible to the human eye. [Non-text portions of this message have been removed]
