White paint coating developed by Purdue University.
Researchers at Purdue University (USA) have invented a very white white paint coating that can have a cooling effect on buildings. The results were published April 15 in the journal Applied Materials & Interfaces of the American Chemical Society (ACS).
The white paint currently on the market reflects about 80% to 90% of the sunlight, but can absorb ultraviolet light, so it does not give the surface coated with these paints effective cooling. The study says the new paint can reflect 98.1 percent of sunlight and can play a role in cooling buildings.
The study said that the paint uses barium sulfate (BaSO4) as the pigment, which does not absorb UV light at all, while the common titanium dioxide pigment will absorb UV light. Furthermore, the paint uses pigment particles with a concentration of up to 60%. Finally, since different sizes of particles reflect different wavelengths of light, the pigment particles used in this paint contain a variety of sizes that correspond to and reflect a wide range of light within the solar spectrum. The combination of these factors makes this ultra-white paint reflect sunlight far better than the ordinary white paint available today.
The study claims that field tests conducted show that the barium sulfate coating can maintain a temperature 4.5 degrees Celsius lower than the ambient environment, with an average cooling power of 117 watts per square meter. For example, if the ambient temperature is 30 degrees Celsius, the coating can cool down to 25.5 degrees Celsius.
Study leader Xiulin Ruan, a professor of mechanical engineering at Purdue University, said that if the roof of a 1,000-square-foot home was painted with the paint, it would have the equivalent of 10 kilowatts of cooling power, which is more powerful than the central air conditioning used in most homes today.
Because barium sulfate is cheaper than titanium dioxide, this new paint should cost about the same as today’s paint, about $30 to $40 per gallon, the researchers said.
Purdue University’s research team is applying for a patent for this technology, and has found a large company to work with, and expects to put this paint on the market within the next year or two.
Recent Comments