Smart Electric Windows: Innovation Time

Found this interesting article at the Txchnologist site today. Windows that can change color at the touch of a switch, could be a great energy conservation resource in coming years.

Smart window technology, thermally insulating fenestration that changes color at the flip of a switch, is the next wave in windows. Smart glass’ most visible application right now is in the auto-dimming rearview mirrors in high-end cars. But the technology is poised to move out of the Mercedes and into homes and businesses, where it could potentially save one-eighth of all the energy used by buildings in the U.S. if it replaced all the conventional windows in the country, according to researchers at the National Renewable Energy Laboratory (NREL) in Golden, Colo. That’s about 5 percent of the nation’s entire energy budget.

Such huge savings are possible because standard, clear windows leak heat on chilly days and allow sunlight to warm rooms excessively on hot ones, forcing buildings’ heating and air conditioning systems to work overtime. Smart windows can let in the sun to help heat rooms when it’s cold outside or block the visible and near-infrared light that can overheat houses in the summer. They can also reduce the need for electric lighting during daytime and partially eliminate the need for shades and blinds.
Smart, Green, but Costly

Smart, or dynamic, window technology can turn glass from transparent to translucent (usually blue or blue-gray in color) and back again when it is briefly exposed to low voltage that is fed to it via a simple circuit to the building current, thus controlling the transmission of visible and near-infrared light. The technology is not new; color-changing glass has been available for more than two decades. But it has always been a premium product that, at $50 to $100 per square foot, has been too costly for most commercial and residential construction projects.

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