Heat Reduction with Rooftop Misting in China

In several parts of China, rooftop misting systems are being installed on tall buildings to combat rising temperatures. These systems release ultra-fine water droplets into the air, forming dense cooling clouds that help lower surrounding temperatures, even extending their effect to nearby streets. As heatwaves intensify worldwide, this innovative approach is attracting attention from cities across the globe. Similar misting setups are now commonly seen in parks, intersections, pedestrian pathways, and bus stops across many Chinese cities.

This cooling method, known as evaporative cooling, uses high-pressure nozzles to spray fine mist that evaporates quickly, absorbing heat from the surrounding air—much like how the human body cools itself through sweating. When outdoor temperatures reach around 38°C, the system can reduce air and surface temperatures by 5–8°C. The droplets evaporate rapidly, preventing roads or pedestrians from getting wet. Compared to traditional air conditioning, it consumes less electricity and requires only water, pumps, and nozzles. However, while some experts raise concerns about water usage in drought-prone regions, others argue that the system uses minimal water. Scientists attribute China’s frequent heatwaves to climate change and the urban heat island effect caused by dense infrastructure.