Scientists have designed a novel type of wood that radiates heat away, paving the way for building materials that could keep homes cool and help save on electricity bills.
Researchers at the University of Maryland and the University of Colorado in the US have harnessed nature’s nanotechnology to help solve the problem of finding a passive way for buildings to dump heat that is sustainable and strong.
Wood is already used as a building material, and is renewable and sustainable, they said.
Using tiny structures found in wood — cellulose nanofibres and the natural chambers that grow to pass water and nutrients up and down inside a living tree — the specially processed wood has optical properties that radiate heat away, according to the study published in the journal Science.
By removing the lignin, the part of the wood that makes it brown and strong, the researchers created a very pale wood made of cellulose nanofibres.
They then compressed the wood to restore its strength.
To make it water repellent, they added a super hydrophobic compound that helps protect the wood.
The result is a bright white building material that could be used for roofs to push away heat from inside the building.
Researchers tested the cooling wood and found that it stayed, on average, five or six degrees cooler than the ambient air temperature — even at the hottest part of the day, the cooling wood was chillier than air.
It stayed on average 12 degrees cooler than natural wood, which warms up more in the presence of sunlight.
The mechanical strength per weight of this wood is also stronger than steel, which makes it a great choice for building materials, researchers said.
It also damages less easily and can bear more weight than natural wood. (PTI)
