A Denver-based technology company has developed a "smart" window that can transform itself to maximize energy efficiency.
RavenBrick LLC's Raven Window Filter responds to sunlight and temperature to change the tint of the window and allow more or less light into a building.
RavenBrick CEO Alex Burney said the filter can reduce a building's energy consumption by 30 to 40 percent.
"Windows aren't much different today than they were when they came out in the 1200s," Burney said. They are "ripe for innovation," he said.
Some of the first filters will be installed at the National Renewable Energy Laboratory in Golden, Colo., this summer.
Aerospace engineer and author Wil McCarthy created the filter, which is placed between the two sides of a double-pane window. In the summer, the filter tints itself to keep sunlight out. In the winter, the sun can still warm the house.
The technology adds about 30 percent to the cost of an installed window but can pay for itself in two to six years through lower utility bills, RavenBrick said.
The innovation originated from a science fiction story McCarthy wrote about "programmable matter," an idea that the molecules of a material can be changed so it interacts differently with light.
McCarthy said RavenBrick is also applying the technology to create a wall with the same energy-conserving properties.
RavenBrick is working with Denver-based manufacturer Accent Windows to make filters available for sale this summer.
The company is also working on a "smart" laminate, which would achieve similar results when applied to the window. Burney says he hopes it will be available in retail stores by the end of 2010.