Posted on April 5, 2012 by Alex Wilson
Over the last two weeks I've covered the major strategies for improving the energy performance of windows: adding extra layers of glass, increasing the thickness of the air space between the layers of glass, and adding low-emissivityAmount of heat radiation emitted from a particular body or material. Emissivity is expressed in a fraction or ratio, with the lowest values indicating low emissivity and the highest indicating the high emissivity of flat black surfaces. coatings. Another important strategy is to use a low-conductivity gas instead of air in the space between the layers of glass. Most commonly argonInert (chemically stable) gas, which, because of its low thermal conductivity, is often used as gas fill between the panes of energy-efficient windows.
is used, though kryptonA colorless, odorless inert gas, often used with argon in fluorescent lighting and sometimes used as gas fill in high-performance glazing. is available for the highest-performance windows, and xenon is occasionally used.