Everyone knows what it feels like in the summer, whether at the office or at home, when windows intensify the sun’s heat. So much so that there’s no other option but to lower the blind, close the shutters or pull the curtains. But what if the solution to the problem was the windows themselves? Researchers have turned glass façades into systems that regulate energy flow, capable of heating homes and offices in the winter and keeping them cool in the summer.
The panes developed by the Fluidglass European research programme look like a double-decker sandwich, separated by a gas providing thermal insulation. On the outside, two sheets of glass hold a liquid that stores the sun’s heat, and on the inside two other sheets contain a variable-transparency liquid. The first pair feed a heat exchanger, while the second regulates the transmission of light inside a building, allowing a minimum amount to pass through for cooling and a maximum amount for heating. This generates savings of 50 to 70% in energy consumption, specifically in heating and air conditioning.