Using a combination of cooling strategies and techniques has the potential to reduce both temperature and energy demand in Riyadh, Saudi Arabia. A recent study by UNSW Sydney shows that significant temperature reductions can be achieved while reducing energy costs in major cities located in hot desert climates.

Recently published findings Nature Cities, details a multifaceted strategy to cool the Saudi capital by 4.5°C by combining highly reflective “supercooled” building materials developed by the High Performance Architecture Laboratory with juicy greenery and energy. modernization measures. The study, carried out in collaboration with the Riyadh Royal Commission, is the first to examine the large-scale energy benefits of modern heat reduction technologies in urban applications.

“The project demonstrates the huge impact of advanced heat reduction technologies and techniques to reduce urban overheating, reduce cooling needs and improve lives,” says UNSW Scientia Professor Matteos (Mat) Santamouris, the Anita Lawrence Chair in High Performance Architecture and senior author of the study.

Professor Santamouris specializes in the development of heat reduction technologies and strategies to reduce urban temperatures in cities. Extreme urban temperatures affect more than 450 cities worldwide, increasing energy demands and negatively impacting health, including heat-related illnesses and death.

Riyadh, the capital of Saudi Arabia, is one of these cities. Located in the middle of the desert, it is one of the hottest cities in the world, with summer temperatures exceeding 50°C. Additionally, climate change and rapid urbanization increase the extent of overheating.

“Limited greenery and large artificial surfaces made of common building materials such as asphalt and concrete trap heat, meaning the city continues to warm,” says Professor Santamouris. “Vehicular pollution and additional heat from industrial activities also increase temperatures in the city.”

Simulation of city-scale heat reduction scenarios

For the study, a team led by UNSW researchers conducted large-scale climate and cooling energy simulations in Riyadh’s Al-Masiaf district, including the energy performance of 3,323 urban buildings under eight different heat reduction scenarios to assess the optimal value. temperature reduction strategies. cities and reducing the need for cooling.

Simulations examining different combinations of supercooling materials, vegetation types, and energy regeneration levels showed that it was possible to reduce the city’s outdoor temperature by approximately 4.5°C (8.1°F) in summer. The strategy will also increase the city’s cooling energy savings by 16 percent.

The proposed heat reduction (or cooling) scenario for Riyadh includes the use of supercooling materials on building roofs and more than doubling the number of irrigated trees to improve transpiration cooling.

On the contrary, blind application of urban cooling methods that are not based on detailed and advanced scientific optimization, such as the use of green areas without irrigation, can lead to serious increases in urban temperatures.

“By applying the right combination of advanced technologies and heat reduction techniques, it is possible to reduce ambient temperature at a field scale,” says Professor Santamouris. “Significantly reducing cooling needs for a hot city the size of Riyadh is also extremely important for sustainable development.”