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This engineered wood radiates heat into space, potentially slashing cooling costs | Science | AAAS
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s***@gmail.com
2019-05-24 13:46:40 UTC
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This engineered wood radiates heat into space, potentially slashing cooling costs | Science | AAAS
https://www.sciencemag.org/news/2019/05/engineered-wood-radiates-heat-space-potentially-slashing-cooling-costs

"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."
Sergeio
2019-05-24 15:01:11 UTC
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Post by s***@gmail.com
This engineered wood radiates heat into space, potentially slashing cooling costs | Science | AAAS
https://www.sciencemag.org/news/2019/05/engineered-wood-radiates-heat-space-potentially-slashing-cooling-costs
"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."
"The researchers hit upon a simple chemical procedure. They soaked
basswood in a solution of hydrogen peroxide, which chops normally long
lignin molecules into small fragments. The fragments diffuse out of the
solution and can be washed away. The team then used a hot press, an
industrial vise for making wood composites, to compress the remaining
cellulose and hemicellulose components together. The result was an
engineered wood with eight times the strength of natural wood."

SO, you have to soak the wood for months to oxidize it, then try to
diffuse out the broken wood particals, then compress it.

then you have to show it lasts 20 years in the sun and rain. (bet not)

should have 8 times the cost too. (add more for installation)

easier to add an insulating sheet of plastic inside the attic, or under
the shingles.

OR just paint your roof bright white. (but then the mold will show a
year later...)
j***@specsol.spam.sux.com
2019-05-24 15:34:20 UTC
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Post by s***@gmail.com
This engineered wood radiates heat into space, potentially slashing cooling costs | Science | AAAS
There have been solar reflective paints for decades, ass hat.
--
Jim Pennino
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