Like blood circulating through the human body, a new system out of Harvard harnesses channels of running water to cool windows that receive a lot of sun. The water carries away heat, leading to less work for air conditioners and a lower electricity bill.
The channels are ultra-thin and encased in a sheet of clear silicone rubber that is stretched over a window. They crisscross to create a mesh-like pattern. While the channels are visible when empty, they become transparent when they contain water.
The project grew out of the Wyss Institute at Harvard, where researchers were using water channels to cool small medical and research devices. A team led by Wyss Institute founding director Don Ingber figured out a way to scale up the channels, making the material ideal for windows.
In the lab, the team tested the system by heating a small window panel to 100 degrees. The circulating water cooled it without a problem. A mathematical model shows that six ounces of water is enough to cool a window pane by 14 degrees.
The water channels could also be added to rooftop solar panels, which need to be cooled to more efficiently create electricity.
“The idea of using nature’s lesson to create kind of a living skin on a building is a very important and promising direction for how buildings should and will be constructed in the future,” Wyss Institute visiting scholar Chuck Hoberman said in a release.