While double-glazed windows do help save energy, Singaporean scientists have tweaked the concept to make it even more effective. Instead of leaving an air gap between the two panes of glass, the researchers have inserted a heat-absorbing, light-blocking liquid.
Developed at Nanyang Technological University, the experimental new “smart window” consists of two panes of ordinary glass, the space between which is filled with a solution consisting of a proprietary hydrogel, water, and a stabilizing compound.
During the day, as sunlight passes through the window, the liquid absorbs and stores that light’s thermal energy. This keeps the room from heating up, reducing the need to run the air conditioning.
Additionally, as the liquid warms up, the hydrogel within it changes from a transparent to an opaque state. Although this ruins the view out of the window, it also reduces the amount of visible light that passes through from outside, further helping to keep the room cool.