Keeping a building cool is the focus of a new study launched by the University of Melbourne and the City of Melbourne which shows that painting the roof of a building white can go a long way to reducing the interior and exterior temperatures.
The research results—which will be available to building owners across Melbourne—assessed the benefits of white roofs and looked at helping residential, commercial, and industrial building owners determine whether a white roof would be suitable and beneficial for their buildings.
By monitoring the temperatures of five test buildings located at the University of Melbourne’s Burnley Campus, the researchers found that white roofs experienced significantly cooler temperatures, both on the outside and within.
Lord Mayor Robert Doyle said Council had already put the research into practice by trialing a white roof on its ArtPlay building.
“There has been a lot of talk about the energy consumption benefits of white roofs and we commissioned the University of Melbourne to undertake this research so we could get a local perspective on how white roofs can work in our city,” the Lord Mayor said.
Councillor Cathy Oke, Chair of the Future Melbourne (Eco-City) Committee said commercial buildings in the City of Melbourne would benefit most from this tool.
“White roofs can cool commercial buildings by three per cent on hot days, which helps reduce the urban heat island effect and improve the health of city users,” Cr Oke said.
Dr Dominique Hes, a senior lecturer at the University of Melbourne in sustainable architecture and lead author of the research explained that, when painted white, roofs are able to reflect heat away from the building rather than absorbing it.
“Reflective white paint on commercial building roofs reduces the energy used to cool the building. Melbourne’s CBD has over 3,500,000m2 of lettable commercial space. If the roofs of these buildings were painted white, the city could in theory reduce its CO2 emissions by 4.5 million MJ per year, 1.5 million kilos of CO2 or 3 million black balloons,” Dr Hes said.
“White roofs are a low cost solution in making buildings more sustainable, particularly for our older buildings. And if our air conditioners are not working as hard, there are financial benefits for buildings owners as well.”
While former US President Bill Clinton, Energy Secretary Steven Chu, and many others have encouraged adoption of white roofs, there jury is still out on whether or not they are good for the climate. In some locales, though, it is clear they are good for reducing electricity usage and bills.
Source: University of Melbourne