Noble gas as in other metallurgical processes and in the production of silicon for the semiconductor industry. Noble gases are commonly used in lighting because of their lack of chemical reactivity. Argon, mixed with nitrogen, is used as a filler gas for incandescent light bulbs. Krypton is used in high-performance light bulbs, which have higher color temperatures and greater efficiency, because it reduces the rate of evaporation of the filament more than argon; halogen lamps, in particular, use krypton mixed with small amounts of compounds of iodine or bromine. The noble gases glow in distinctive colors when used inside gas-discharge lamps, such
Phase-out of incandescent light bulbs lives than incandescent bulbs. When bulbs are used infrequently, such as in little-used closets and attics, it may take a long time to compensate for the higher initial cost of the bulb. The overall energy savings from changing to more efficient lighting depends on the climate. In warm climates, efficient lighting has the additional energy-saving effect of reducing the amount of cooling required. In cold climates increased heating energy demand may offset some of the lighting energy saved with efficient lighting. A report published in January 2008 found that in Los Angeles, where incandescent lighting results in increased air conditioning,