“Cool wood” could take the heat out of buildings
USA: University research groups claim to have developed a new wood-based building material which is able to passively take heat out of homes or offices.
Researchers at the University of Maryland and University of Colorado Boulder have created the new material by removing lignin, the key organic polymer that gives wood its strength and colour. The resulting pale wood made of cellulose nanofibers was then compressed to restore its strength and a super hydrophobic compound added for protection and to make it water repellent.
The result is said to be a bright white building material that could be used for roofs to push away heat from inside a building.
The researchers tested their cooling wood on a farm in Arizona in warm, sunny, and low wind conditions. There, they tested the cooling wood and found that it stayed, on average, 5-6F (2.8-3.3C) cooler than the ambient air temperature – even at the hottest part of the day. It stayed on average 12º cooler (6.7C) than natural wood, which warms up more in the presence of sunlight.
It is said to be ten times stronger than natural wood and stronger than steel by weight. It is also less susceptible to damage and can bear more weight than natural wood, the researchers say.