United States: Researchers at the University of Chicago designed a building material that changes the color of infrared light and the amount of heat it absorbs or releases based on the outside temperature.
On hot days, it can emit up to 92% of the infrared heat contained in the material, helping to cool the interior of the building. However, on cold days, the material emits only 7% of the infrared radiation, thus keeping the building warm.
“We basically figured out a low-energy way to treat buildings like people. ), said Associate Professor Po-Chun Hsu, who led the study. “This kind of smart material allows us to maintain the temperature inside the building without using a lot of energy.”
The research team designed a noncombustible electrochromic building material containing two conformational layers: solid copper, which retains most of the infrared heat, or an aqueous solution, which emits infrared radiation. At any chosen trigger temperature, the device can use a small amount of electricity to induce a chemical shift between states by either depositing copper into a thin film or stripping it away.
In a new paper published in natural sustainability, The researchers have detailed how the device switches between metallic and liquid states rapidly and reversibly. They showed that the ability to switch between the two conformations is efficient even after 1,800 cycles.
The team then created models of how the material could reduce energy costs in typical buildings in 15 different US cities. In an average commercial building, the power used to induce the electrochromic change in materials is less than 0.2% of the building’s total power usage, yet could save 8.4% of the building’s annual HVAC energy consumption. they reported.
“Once you switch states, you don’t need to add any more energy to stay in either state,” Hsu said. “Thus, buildings that don’t need to switch between these states very often are actually using a negligible amount of electricity.”
So far, Hsu’s group has produced materials only about 6 cm in diameter. But they imagine many such patches of material could be assembled into a larger sheet. says. The water phase is transparent and almost any color can be placed behind it without affecting its ability to absorb infrared radiation.
Researchers are currently investigating different methods of manufacturing the material. We also plan to investigate how intermediate states of materials can help.