Sydney Water and the University of New South Wales (UNSW) have partnered together to try to find ways to turn down the heat in Western Sydney.
The Cooling Western Sydney study investigates how water and related infrastructure, greening, and building materials keep temperatures down, with the area suffering from extreme summer temperatures due to its dearth of ocean breezes and southerly winds.
“Temperatures are six to 10 degrees higher in Western Sydney during the summer period than they are in the east and there can be up to three times as many deaths in Western Sydney during heat waves than there are in Eastern Sydney,” according to Sydney Water Research Direction and Value Manager Dr Michael Storey.
“Energy consumption for cooling purposes in Western Sydney is up to 100 per cent higher than in the eastern zones of the city. Peak electricity demand increases by almost 100 per cent when temperature increases from 20 degrees to 40 degrees.”
UNSW Professor Mat Santamouris said the study has challenged conventional thinking around mitigating urban heat, including the approach to the built environment, energy demand, public health and ‘greening’ cities.
“The solution is not just about planting trees, which seems to be the commonly held view,” he said.
“Trees create a cooling effect through a process called evapotranspiration, where water stored in the tree evaporates through the leaves during hot temperatures. However, when trees are subjected to extreme heat stress, they go into survival mode to conserve water to keep themselves cool.”
“While greenery does have a cooling effect, the study shows the most effective urban heat mitigation technologies use a combination of water-based technologies including fountains in conjunction with cool material technologies such as cool roofs and pavements.”
Storey said with the changing climate expected to deliver more prolonged summer heatwaves, it will be critical for temperature peaks to be reduced to improve the comfort for people living in Western Sydney.
“The careful selection of water-based technologies and building materials can achieve a decrease of up to 4.5 degrees, which will take the ‘tops’ off the peak temperatures in extreme heatwave conditions in Sydney’s west,” he added.