Chinese scientists have invented a paint that cools walls by 25°C without the need for electricity or water

Chinese scientists have developed a paint that reduced the temperature of the painted surface by 25°C during summer tests. The coating combines two methods of reducing wall heating – reflective cooling in the infrared range and radiative cooling. The combination of these two methods creates a composition whose combination of properties significantly exceeds all previous developments of this type.

The water tank on the left is covered in experimental paint. Image source: Science and Technology Daily

The final composition of the paint was developed by scientists from Harbin Institute of Technology (HIT) in Heilongjiang province and experts from the state-owned China Construction Company in Suzhou. This summer, the coating is operating at a capacity of 3000 meters³ Liquefied gas from a petrochemical plant in Hainan. On a 30-degree day, the temperature of the container wall is 25°C lower than the temperature of the adjacent container wall with a conventional coating. In addition, the contents of the container were also reduced by 7°C.

Cooling blankets require no power and operate passively. In order to achieve a cooling effect similar to traditional paint, 35 tons of water need to be sprayed from nozzles to the container every day. A lot of resources and energy can be saved. The same coatings can be used to cover building walls, reducing building heat and improving spatial reflection of heat from heated walls in the 8-13 micron range, the wavelength for which the Earth’s atmosphere is transparent. Experiments show that the room temperature in urban areas can drop by another 4°C, and in tropical areas it can drop by another 1°C.

It should be emphasized that this experiment was beyond the scope of laboratory testing. Developers have developed technical processes to produce 600,000 tons of this dye per year. Incidentally, this paint is based on the suggestion of human skin wrinkles, which help cool the body. The composition of the paint has been chosen so that its application thickness can be reduced from 500 microns to 100 microns, which means a reduction in paint weight and its consumption.