What is China's 'rooftop rain', which drops temp by 5-8°C, amid heat wave?

As China faces record-breaking heatwaves, with temperatures climbing as high as 44°C, the country has adopted a 'rooftop rain' system. This mist-spraying cooling system is installed at a high-rise apartment complex in China's central Shanxi Province, where it drops surface temperatures by 5-8°C within minutes. The system has been installed in 12 residential buildings and cost nearly $2.43 million.