Cool Metal Roof Creek County Energy Savings
Written by Admin
Energy Savings With A Cool Metal Roof
More and more, homeowners are seeking out energy-saving building materials for their renovations and new homes, products that not only secure and improve structures but also provide long-term cost-cutting on energy bills while promoting environmental and economic sustainability in the greater community.
Among the array of possible upgrades, “cool metal roofing” easily answers this consumer demand offering a solid, attractive roofing solution available in multiple colors, textures, and profiles, for steep-slope and low-slope applications, that can save your household up to 40% of its annual energy costs, depending on your geographical region.
The Benefits of Energy Efficient Metal Roofing
As reported by the Cool Metal Roofing Coalition and the Oak Ridge National Laboratory, installation of reflective metal roofing can save your home up to 40% in summer cooling energy costs while highly emissive metal roofs can reduce urban air temperatures by as much as 12 ° F. Combined, these benefits mean less money out of your wallet, less dependence on energy resources and less general air pollution in your neighborhood and across the nation.
|While asphalt traps heat…||Metal Roofs reflect solar energy…||And pigments re-emit heat.|
The secret to metal roofing’s energy savings is in its variety of finishes. As shown above, the basic, unpainted metal roof will reflect much of the solar radiation usually absorbed in your attic and home by an asphalt roof. But, for homes in warmer climates, pre-painted or granular coated metal roofing systems not only reflect solar energy but also cool your home by re-emitting most of what solar radiation is absorbed.Where annual cooling loads dominate, a highly reflective and highly emissive painted or granular-coated metal roof is optimal for reducing energy consumption and can actually re-emit up to 90% of absorbed solar radiation.
Additionally, most metal roofing, including standing seam, is composed of recycled material and can be installed directly onto an existing asphalt roof, reducing landfill waste and promoting quick installation as well as decades of environmentally-sound, maintenance-free strength and beauty.
Cool Pigment Technology – Metal Roofing Creek County
On a building or on a home, the roof has a major impact with the absorption of heat from sunlight (Solar Radiation). The heat is either reflected into the atmosphere or absorbed through conduction into the building. Any solar radiation that is absorbed will heat the roof’s surface. The more the solar radiation is absorbed, the greater the need to find alternative means to dissipate the heat. That’s where emittance comes into play. Emissivity is measures of the roof’s ability to shed absorbed heat.
The roof’s design (type, color, elevation) will determine how the heat is reflected and absorbed heat is emitted. “Cool” coating technology focuses on reflecting solar radiation (Solar Reflectivity), and shedding what heat is absorbed away from the surface (Thermal Emittance).
Conduction – The passing of heat through a roof material into the layer in contact directly beneath the surface.
Convection – The heating of the air that passes over a hot surface.
Heat Flux – The amount of energy flowing through any surface
Coatings colored with conventional pigments tend to absorb infrared radiation. Replacing conventional pigments with “cool” pigments (absorb less infrared radiation) can yield similarly colored coatings with higher solar reflectances. Mainly, cool coatings lower roof surface temperatures, reducing the need for cooling energy in conditioned buildings and making unconditioned buildings more comfortable.
How do the “cool” pigments work
Source: Lawrence Berkley National Laboratory
Pigments provide color by absorbing and reflecting different parts of the sun’s wavelength spectrum based on their chemistry. Color pigments selectively absorb visible light, and what light it reflects appears to the human eye as color. Pigments also have IR characteristics. While nearly 40% of the sun’s energy occurs in the visible light range (400 to 700 nm), more than 50% of the sun’s energy is in the non-visible infrared region (700-2500nm). It’s infrared (IR) that is largely responsible for heat build-up.
There are two types of pigments used in coatings: organic and inorganic. Organic pigments offer very vivid and bright colors but are generally not as lightfast and opaque as inorganic pigments. It is the inorganic pigments that are used for applications that are warranted against color change from sunlight and the elements. For the most demanding applications, like metal roofing, a special group of inorganic pigments known as Complex Inorganic Color Pigments (CICP) are used. Certain pigments within this group exhibit high IR-reflectivity for a given visible color.
Source: Metal Roofing Alliance