Can you make your home more comfortable and pleasant without installing heating and cooling? British scientists have developed a new smart window coating that precisely adjusts how much solar radiation is reflected and it could cut energy costs for building heating and cooling by a third.

The key to the smart glass coating developed by the University of Oxford in the United Kingdom is the "chalcogenide" phase change material. When it is very cold outside, the material will absorb the infrared rays in the sunlight and then dissipate it indoors as heat but when the sun is shining, it reflecting collected infrared rays back out and try to keep the indoors cool.

The team also embedded small and transparent heating units into the coating which can be used to more precisely adjust the coating ratio, such that 30% of the material is used for heat dissipation and the remaining 70% is used to absorb and dissipate heat.

According to the team, no matter what state the material is in, it will not affect incoming light nor will it affect indoor lighting. The team estimates that compared with traditional double-glazed glass, smart windows can save 20%~ 34% in energy usage in homes every year.

The team believes the new design should be relatively simple and cheap but it will be some time before it sees the market. Professor of applied nanomaterials at the University of Oxford, Harish Bhaskran, stated that, while a lot of research was needed before commercialization, the results showed promise and further efficiencies can be made. 

In the past, many teams have developed similar technologies such as the use of electrochromic materials, liquid-filled films, or the use of tilting mirrors to reflect sunlight. Scientists hope to use these technologies to make rooms warm in winter and cool in summer without turning on the air conditioner. Not yet commercialized but all working to reduce building energy costs

（Image：Flickr/Scott S CC BY 2.0）