How much heat is emitted by incandescent, halogen, and compact fluorescent lamps?
Incandescent lamps create light by heating a filament inside the bulb; the heat makes the filament white-hot, producing the light that you see. Halogen lamps create light through the same method. Because incandescent and halogen bulbs create light through heat, about 90% of the energy used is wasted to generate heat. To reduce the heat emitted by regular incandescent and halogen lamps, use a lower watt lamp (like 60 watts instead of 100).
