Recycling rainwater from city rooftops to cool buildings could help to lessen the intensity of extreme heat events, a study has found.
University of Manchester researchers have showed that collecting rainwater from rooftops and using it to spray buildings during hot weather cuts air conditioning use and reduces the impact of heatwaves.
While urban watering technologies are used to help cool cities, they are only effective if there is water available, which is often severely restricted during a heatwave. The alternative is air conditioning systems but the disadvantage of these is that their operation increases energy demand, while the waste heat released further contributes to urban heating.
In their study, the researchers developed a system that collects rainwater from rooftops and then automatically sprays it onto buildings during hot weather.
Using Tokyo as a case study, they tested their system using process-based numerical simulations and AI. The results showed that the cooler roofs...