2019-05-24 13:46:40 UTC
This engineered wood radiates heat into space, potentially slashing cooling costs | Science | AAAS
"Households in the U.S. Southwest spend about $400 per year to cool their homes, about twice the national average. Now, a new type of wood that radiates heat into space could offer some relief. If used on a building’s exterior, such as in siding and roofs, the material could drop a building’s temperature as much as 10°C and reduce cooling costs as much as 60%.
“This is just brilliant work,” says John Simonsen, a chemist who specializes in wood science at Oregon State University in Corvallis. However, he says, the new wood could be expensive, and potential energy savings may not offset the price.
"When most materials heat up, they emit that heat as photons of near infrared (IR) light. The light is readily absorbed by molecules in the surrounding air, trapping the heat—and keeping houses, for example, hot. But in the past 2 years, researchers have devised plastic films and paints that absorb heat and re-emit that energy at longer mid-IR wavelengths, which air doesn’t absorb. If emitted toward the sky, these photons pass unimpeded and dump their energy into deep space. But to use these materials in buildings, engineers need to laminate rooftop or siding materials with the plastics or apply the heat-emitting paints."