The term cool roof refers to roofs built using products with high solar reflectance and high thermal emittance properties. High solar reflectance helps keep roofs cooler by reflecting more of the sun’s energy, while high thermal emittance helps maximise the roof’s ability to release any absorbed heat (via radiation to the sky).
Cool roofs have the potential to make a positive contribution in four key areas:
- Improving occupant comfort.
- Reducing energy demand, which can mean reduced energy usage and costs, as well as reduced greenhouse gas emissions from power generation.
- Reducing maintenance and replacement costs for equipment (such as air conditioning units), roof system components and solar panels. A cooler roof space can have a significant impact on the performance of air conditioning – how much energy is used for cooling, the maintenance requirements and lifespan of the system. They can also have a positive impact on the performance of solar panels.
- When large areas have cool roofs installed, they can help mitigate the effects of urban heat islands by reducing temperatures across communities and suburbs.
Cool roofs offer benefits at scale
Supported by the Department of Industry, Science, Energy and Resources (DISER), a comprehensive study was undertaken by the High Performance Architecture research group at the University of NSW to understand the applicability and cost benefits of using cool roof technology on buildings in Australia.
Simulations were performed for 17 types of buildings – at both building scale and city scale – across capital cities.
The study found that significant cool energy savings were to be gained when applied across a region – even for high-rise and heavily insulated buildings – due to the heat mitigation effect. Importantly, it found that the cooling energy savings of installing cool roofs substantially outweighed the heating energy penalty in all cities with the exception of Hobart.
Darwin, Brisbane and Sydney cooling energy consumption decreases could be up to 40-50 per cent; Adelaide, Melbourne and Perth energy consumption decreases could be up to 20-35 per cent.
COLORBOND® steel cool roofing colours
Inspired by nature and developed for diverse and extreme environments, COLORBOND steel has always celebrated the colours, textures and light of Australia’s unique landscapes. COLORBOND steel cool roofing colours, a targeted selection from the product and colour range, all feature low solar absorptance (SA) values of less than or equal to 0.45, which enables ‘deemed-to-satisfy’ compliance for the roof cladding material within the National Construction Code (NCC) Section J energy efficiency provisions.
COLORBOND® COOLMAX® steel optimum thermal performance
Innovative COLORBOND Coolmax steel is a tailored roofing product designed to provide and maintain high solar reflectance. The technology behind COLORBOND Coolmax steel includes an optimised combination of durable ingredients to create the company’s highest solar reflective product. Tested under Australian conditions, COLORBOND Coolmax steel is BlueScope’s ultimate product for cool roofing performance in commercial and industrial roofing applications in Australia.
View the full range of additional COLORBOND® steel cool roofing colours at colorbondstudio.com
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