Passively cool your house with wood
Researchers at the University of Maryland and the University of Colorado in de US harnessed nature’s nanotechnology to create a type of engineered wood that can help to cool buildings passively.
To make the material, the researchers removed lignin, the part of the wood that makes the material brown and strong. Without it, the wood is very pale, consisting of cellulose nanofibers. To give the material back its strength, it is then compressed and a super hydrophobic compound is added. The result is a bright white building material that could be used for roofs to direct heat away from inside the building.
The material was tested on a farm in Arizona, where the weather is always warm and sunny. On average, the white wood was 2.8 to 3.3 degrees Celsius (5-6 degrees Fahrenheit) cooler than the ambient air temperature, even at the hottest part of the day. It stayed 6.7 degrees Celsius (12 degrees Fahrenheit) cooler than natural wood.
According to the researchers’ calculations, at least for US buildings built after 2004, the use of the new material could save on average 20 per cent of cooling costs.
In addition, the mechanical strength per weight of the white wood is stronger than both natural wood and steel. It is also more scratch-proof and can bear more weight than natural wood, making it an ideal building material.
Photo: University of Maryland