African Design Magazine April 2015 | Page 69

i without changing their appearance. This provides greater thermal comfort all year round whilst using less energy for air-conditioning and hence mitigating the UHI effect” he says. “In addition our product’s outstanding dirt resistance property ensures the roof looks newer for longer. This also assists in cooling.” In a comparison between a Clean COLORBONDTM and a conventional steel roof, both uninsulated, the positive effect of dirt resistance technology is illustrated. Tests show that after two years’ exposure, assuming an irradiance of 1000W/m², exterior temperature of 36°C and a high thermal emittance value of 0.86, typical of prepainted steels, the Clean COLORBONDTM steel roof’s temperature is almost 10° cooler than the conventional steel roof and it radiates more than 40W/m² less heat down into the building. This is a considerable easing of the HVAC load for any building, regardless of size. AD Feature: Roofing TM Clean COLORBOND steel’s dirt resistance also assists in cooling ABOVE: Tests show that after two years’ exposure, assuming an irradiance of 1000W/m², exterior temperature of 36°C and a high thermal emittance value of 0.85, typical of pre-painted steels, the Clean COLORBONDTM steel roof’s temperature is almost 10° cooler than the conventional prepainted steel roof and it radiates more than 40W/m² less heat down into the building. africandesignmagazine.com 69