SYDNEY, June 15 (Xinhua) -- A team of researchers from the University of New South Wales (UNSW) have shown how city-wide cool roofs would reduce energy bills, lower indoor temperatures, decrease urban heating and improve the health of vulnerable populations.
The research, the findings of which were published on Wednesday, analyzed the cost-benefit of adopting cool roof technology across major Australian cities, revealing that it could cool residential cities by up to 40 percent.
"We used simulated climatic modeling to understand conditions with and without cool roofs. The results showed urban areas, including Western Sydney, Perth, Melbourne, Adelaide, Darwin and Brisbane, had the most to gain from cool roofs," said Scientia Professor Mattheos Santamouris, Anita Lawrence Chair in High Performance Architecture at UNSW School of Built Environment.
He added that the need for a multi-pronged approach to cooling would become more and more necessary as the effects of climate change worsen.
"If not, the cost of climatic change in the next 10 to 15 years will be tremendous," added Santamouris.
The analyses used highly accessible and affordable methods to retrofit cooling onto roofs using highly reflective paint, metal surfaces and reflective tiles. They estimated that the cost of cool roofing material would be about 13 Australian dollars (about 9 U.S. dollars) per square metre.
Once implemented, homes with reflective roofs were on average 4 degrees Celsius cooler during the summer, and during summer indoor temperatures remained under 26 degrees for an extra 100 hours.
Further to the benefit to individual homes and their energy bills, reflective roofing was also shown to reduce outdoor temperatures by an average of 1.5 degrees, countering the "urban heat island effect" caused by buildings, roads and other infrastructure absorbing and re-emitting the sun's heat.
"Cool roofs can reduce heat-related mortality by up to 25-30 percent. They will also help address energy poverty - an issue severely impacting the quality of life of low-income households." ■