According to the latest statistics from the United Nations Meteorological Organization, it is very likely that 2015 to 2019 will become the hottest five years since humans have meteorological records. How hot is it in 2019, we all have deep experience, especially in the south of our country, if summer There is no air conditioning, even if it is indoors, it will be sweating. In the north, many households have used air conditioners.
However, the use of air conditioners emits a large amount of greenhouse gases, which has laid a foundation for the future heat. Isn’t this a vicious circle? Is there no better way to fight the heat?
Scientists have not given up on the hope of being more environmentally friendly. They have been studying building materials that can automatically cool down and use them to build houses that will automatically cool down, eliminating the need for air conditioning.
As early as 2017, scientists in the United States developed a refrigerating building material, a glass polymer film that is only 50 microns thick and slightly thicker than the commonly used aluminum foil. It can dissipate the heat of the sun in the form of infrared radiation for cooling. In the test, 10 to 20 square meters of this material is laid on the roof to cool the house, and more importantly, it does not consume any energy and water when cooling. However, its quality is relatively light, and how to lay it on the roof without being scraped away is a problem to be considered.
Recently, another team of scientists in the United States created a cooling material called “cooling wood” that could really be used to build a house.
The lignin in the wood is the main component of the absorption of solar heat. If the lignin is removed, the remaining cellulose and hemicellulose in the wood are compressed together to obtain an engineered wood having an intensity eight times that of the original wood. This wood is more white than the original wood, and light wood reflects more sunlight.
In the experiment, the wooden house built with this kind of wood was 8.8 ° C lower than the ambient temperature at night and 7.2 ° C lower during the day. Accordingly, the researchers estimate that if this material is applied to a building, it will reduce the cost of air conditioning by 35%, which will significantly reduce carbon emissions and energy consumption.
However, this material is most suitable for tropical regions with long summers and short winters, and the cooling film mentioned above can be used in the summer in the north.
It may take more time for the above two materials to be commercialized, but a cooling coating called “the coldest white” in Switzerland has already been put on the market. “Coldest White” is a very white, extremely UV resistant and extremely durable coating. It is a fluorine-containing polymer coating that is more durable than traditional polyester-based coatings. It can last for 40 years and can be used on metal or glass walls such as aluminum and steel. And because of its extremely white color, it has the strongest ability to reflect sunlight compared to other paints, so its cooling effect is also a lever.
Global warming and the urban heat island effect have indeed become more and more fierce, and we only have one planet. We can’t escape from the hotter and hot mothers. We can only do our best to keep the earth from going on. Let it cool down. Seeking environmentally friendly cooling methods and reducing the use of air conditioners is what we should do.