A study from the University of Manchester has used AI technologies to collect rainwater from city rooftops and spray it onto buildings during hot weather.
The research says that spraying buildings with rainwater could decrease air-con use and lower the overall urban temperature.
In the Tokyo case study, cooler roofs transferred less heat into buildings, while lower air con use meant less waste heat was released into the city.
Lead author, Dr Zhonghua Zheng, said: “Cities around the world are facing growing challenges from extreme heat. Air conditioning can help keep people safe and comfortable, but it also consumes large amounts of energy and releases additional heat into the urban environment”
“What is particularly encouraging is that the benefits become even greater during hotter years, suggesting this approach could become increasingly important as the climate continues to warm.”
Urban watering technologies could become an important method for reducing extreme heat in cities, but their use is often limited by the availability of water.
The study found that applying extra water did not always lead to more cooling, as some remained on the roof instead of evaporating.
Researchers say the approach could help local authorities and urban planners evaluate how rainwater-based cooling systems might work in their own regions.
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