It would have been awesome if instead of using expensive devices, the building material of the house performed the cooling and reduced the electricity expenses. Scientists from the University of Maryland and Colorado have used the technology found in nature for solving the heat problems which is also sustainable. The results of this study have been published in the Science journal.
Researchers have found the solution in wood which is sustainable and is already used for building homes. By using the structures found in wood, the cellulose nanofibres and the chambers which allow the passage of water and nutrients, the optical properties of the wood expel the heat.
Professor Jian Li of Northeast Forestry University remarked that due to this research, wood can be used in fighting the current energy crisis. University of Maryland professor, Liangbing Hu along with the co-authors of the paper Tian Li and Shuaiming He has been working on the advanced applications of wood for several years now. The team has invented many wide-ranging technologies based on wood such as transparent wood, affordable batteries based on wood and also a water purifier.
The cooling wood is only composed of wood and it does not contain any other component like polymer. When it will be used for building purposes, this material can cool down the building without the help of external sources such as water, electricity.
Lignin is removed from the wood, which is the component responsible for the strength and brown colour of the wood. By removing it, researchers manufactured a pale wood comprising of cellulose nanofibres. For making it water repellent, a hydrophobic component was added for protecting the wood. This led to a white building material suitable for making the roof of buildings to repel heat.
For testing purposes, the wood was taken to the farms in Arizona which has sunny weather. The cooling wood was tested and they found that on average it remained five to six degrees Fahrenheit cooler than the normal temperature. Even in the hottest time of the day, the wood remained cooler than air. When compared to the normal wood in sunlight, it remains 12 degrees cooler.
On the strength aspect, the per weight mechanical strength of the wood is more than steel which is why it is very suitable for construction purposes. As compared to natural wood it is 10 times stronger and also passes the scratch test.
Researchers found that in hotter cities like Phoenix, Honolulu this cooling wood would save the maximum energy and in the buildings made after 2004, it would save 20% of the cooling costs.