Electricity runs through a tungsten filament that glows and produces a soft, warm light. Because so much of the energy used is lost as heat, these are highly inefficient sources of light. Halogen lamps are a special, more energy efficient type of incandescent lamp containing halogen gas to produce a brighter, whiter light than incandescents. Having originated in and being produced, growing, living, or occurring naturally in a particular region or environment. The unchecked movement of outdoor air into a building through cracks around windows and doors or in walls, roofs, and floors.
Infiltration generally refers to cold air during the winter and hot air during the summer.
Infrared radiation is experienced as heat. A heat engine in which the combustion that generates the heat takes place inside the engine proper, as in a car's gasoline engine, instead of in an external furnace, such as a steam engine. The solar power incident on a surface. The plot of the current versus voltage characteristics of a device such as a solar cell, battery, or resistor. For a solar cell, three important points on the I-V curve are the open circuit voltace, short circuit current, and peak power operating point.