Take the heat off cooling costs

The reality is energy costs are going up, not down. That's a concern for most commercial and industrial building owners and tenants. So it's reassuring to know that a roof made from COLORBOND® Coolmax® steel in Whitehaven® could help reduce the annual cooling energy costs of your building by up to 7.5%1 compared to COLORBOND® steel in Surfmist®.

Best of all, COLORBOND® Coolmax® steel delivers all the quality, durability and warranty* support that comes only with genuine COLORBOND® steel.

For a cooler building it pays to start at the top

Cooler, more energy efficient buildings make financial as well as environmental sense, so your choice of roofing material is critical. You can be confident that COLORBOND® Coolmax® steel will assist to maximise the thermal performance of your building.

Payback the investment premium within 5 years²

By helping to reduce the ongoing cooling energy costs of your building, a roof made from COLORBOND® Coolmax® steel can pay back the initial investment premium within 5 years2, compared to COLORBOND® steel in Surfmist® and ZINCALUME® steel.

Reduce upfront air-conditioning equipment costs³

Reducing cooling energy operating costs is a major benefit. But the use of COLORBOND® Coolmax® steel in roofing could also reduce the up-front, capital cost of air-conditioning equipment.

By specifying a roof made from COLORBOND® Coolmax® steel you may help reduce the peak cooling load on your building, which may enable you to downsize the capacity of the air-conditioning equipment3.

One very cool colour

COLORBOND® Coolmax® steel Whitehaven®COLORBOND® Coolmax® steel is available only in the colour Whitehaven® – to deliver maximum thermal performance, and greater financial and environmental benefits. Nominal Solar Reflectance4 = 0.77.

For swatch samples call Bluescope Steel Direct on 1800 022 999.

Maintains solar reflectance

COLORBOND® Coolmax® steel in Whitehaven® is designed to maintain all the qualities of COLORBOND® steel. One such quality is the excellent resistance to dirt retention and maintenance of solar reflectance. As an example samples of COLORBOND® steel in Surfmist®, exposed over a decade at the BlueScope Steel testing facility in Rockhampton QLD, retained 95% of their initial solar reflectance. Reference: Adams JC & Stark GK, The benefits of light coloured steel roofing, BlueScope Steel Research, BSR/S/2005013, August 2005.

Help mitigate the impact of Urban Heat Islands

Specifying COLORBOND® Coolmax® steel over lower solar reflectance roofing materials may help mitigate the impact of Urban Heat Islands (UHI). Elevated temperatures from UHI, particularly during summer, can affect a community's environment and quality of life. According to the USA EPA, impacts include increased energy consumption, elevated emissions of air pollutants and greenhouse gases, and impaired water quality. For more information on UHI visit http://www.epa.gov/heatisland/about/index.htm

Peace of mind

Beauty, strength and a warranty* backed by Australia's BlueScope Steel. COLORBOND® Coolmax® steel delivers all the advantages you've come to know and trust, plus even greater thermal efficiency.

Cool Roofs in Winter

One perceived negative impact of cool roofs is that they can have a winter heating penalty. However, cool roofs are still appropriate for most climates as the summer cooling benefit usually more than offsets any winter heating penalty, especially in climates that have both cool winters and hot summers. This is particularly true for buildings that are predominantly cooled during the daytime, such as commercial buildings. The winter penalty is often of much less significance for cool temperate climates in Australia as the winter sun is lower in the sky so sunlight on the roof is less intense, days are shorter and there is often more cloud cover. This means there is less opportunity for heat generation by a roof in winter compared to summer therefore the positive benefits of a cool roof in summer often outweigh any winter penalty.

Cool Roofs and Glare

An often assumed negative impact of a cool roof is glare. The assumption is that there is a direct relationship between a highly reflective roof and glare. High solar reflectance and glare are not the same phenomenon, and in the case of cool roofs, high solar reflectance does not necessarily translate to increased potential for glare.

While solar reflectance is important for thermal comfort, it is not always a good indicator of the visual attributes of the surface. The high solar reflectance required to create a cool roof is usually achieved by increasing reflectivity in the infrared part of the light spectrum, which is not visible to the human eye, as well as using lighter colours (which may be perceived as brighter).

Glare is a phenomenon of the visible part of the light spectrum. Problem glare (specular glare) is known to be associated with mirrored sunlight from new surfaces. Specular glare has little to do with colour and is more strongly related to gloss. An important point to note is that many new roofing materials have a glossier surface when first installed but over time the surface dulls, reducing the resulting glare.

Installing cool roofs on commercial and industrial buildings may actually help reduce glare issues. These buildings often use bare metal roofing that is known to have the highest specular glare potential. A cool roof is normally defined as having a high Solar Reflectance Index (SRI) value requiring both a high solar reflectance and thermal emittance. Bare metal roofing cannot achieve high SRI values on account of their low thermal emittance so the use of bare metal for roofing can result in a less energy efficient building that potentially produces more glare. By comparison, a cool roof in the Commercial and Industrial market will deliver a more energy efficient building with less potential for visual glare.

The incorrect assumption that high reflectivity equals high glare has resulted in blanket bans on highly reflective roofs in some local communities. Local planning and building policies should be designed to encourage the use of cool roofs for the benefit of the community and environment whilst still limiting the few cases where real glare issues can exist. BlueScope can provide examples of best practice cool roof policies that strike the right balance on request.

    COLORBOND® Coolmax® steel in Whitehaven® has a 9% higher solar reflectance than COLORBOND® steel in Surfmist®. Based on independent roof studies of the solar reflectance of roofing contained in a report by the US Environmental Protection Agency (http://www.epa.gov/hiri/resources/compendium.htm), we calculate this difference could result in cooling energy savings of up to 7.5%. Any savings may vary and depend upon the particular circumstances of your building, including building location, level of insulation, location of air-conditioning ducts, building shape, building function and environmental factors. Based on expectation for a daytime occupied and air-conditioned single storey commercial building in BCA Climate Zone 2.  Based on calculated reduced heat flows, specifying COLORBOND® Coolmax® steel in Whitehaven® over COLORBOND® steel in Surfmist® and ZINCALUME® steel has the potential to save approximately $0.57/m2 and $1.70/m2 of roofing respectively on the cost of HVAC cooling equipment. The actual benefit may be greater when air-conditioning ducts run within the roof space or near the roof as the impact of heat and infiltration on ducting is not taken into account, but any savings may vary and depend upon the particular circumstances of your building, including building location, level of insulation, location of air-conditioning ducts, building shape, building function and environmental factors. Measured in accordance with ASTM E 903-96, Standard test method for solar absorptance, reflectance and transmittance of materials using integrating spheres.

* Warranty subject to application and eligibility criteria. For full terms and conditions and to determine the eligibility of your building for the warranty visit our warranty page or call 1800 022 999.

Download COLORBOND® Coolmax® steel facts brochure