Builders and architects are changing the way they select building materials and design for energy performance. The roof can have the greatest impact on the energy use of a building. All of Metal Mart’s Kynar 500® and Silicon Polyester Finishes qualify as a recognized cool roof product.
Buildings consume 1/3 of all energy and 2/3 of all electricity generated. Cool roofs can help reduce energy consumption by lowering cooling loads. Lightly colored, more reflective roofs save up to 40% in cooling energy, as reported by the Heat Island Group of Lawrence Berkeley National Laboratory. Highly emissive roofs can lower urban air temperatures, thereby benefiting the environment by reducing smog formation.
Metal roofing has many attractive features. Its architectural appeal, texture, color, flexibility and durability make it popular for residential and commercial projects, both in low-slope and steep-slope applications. Metal roofing and its finishes are inert, safe materials that don’t pose a health risk. Metal roofing is tested for wind, fire and hail resistance, and is listed with various building codes and entities. Its non-combustibility can reduce the spread of fire in and among buildings.
A building’s cooling and heating costs can be effectively reduced by insulation under the roof surface. Adding increasing amounts of insulation is not always the best way to save energy. As part of total system design, a Metal Mart cool metal roof can be an economical method for better energy efficiency.
Metal Mart cool metal roofing comes standard with oven-baked paint finishes. This family of roofing can achieve solar reflectance of over 70%. Reflected solar energy allows the roof surface to remain cooler, which means less heat is transferred into the building.
The infrared emittance of a roof is a measure of absorbed solar radiation that is remitted from the roof surface to the sky. Emittance of metal roofing varies with the surface finish. Emittance of painted metal roofing can be as high as 90%.
Where annual cooling loads dominate, a highly reflective and emissive painted metal roof is optimal for reducing energy consumption. Where annual heating loads dominate, an unpainted metal roof is more desirable because of its low emittance.