Incandescent lamps consist of a wire filament inside a glass bulb that is usually filled with inert gas, and they produce light when an electric current heats the filament to a high temperature. Incandescent lamps have a low efficacy (10-17 lumens per watt) compared with other lighting options—because most of the energy released is in the form of heat rather than light—and a short average operating life (750–2,500 hours).
The three most common types of incandescent lamps are:
- Standard incandescent (A-type) lamps
- Energy-saving incandescent (halogen) lamps
- Reflector lamps.
Visit Energy Saver to learn more about the types of incandescent lamps that may be found in homes, as well as efficiency standards that affect the types of lighting sold in stores.
