To address the problem of increasing energy consumption, the United States Department of Energy (DOE) encourages consumers who are planning to have their roofs replaced to use green materials. Many eco-friendly products today are made from materials that have the capacity to reflect the heat of the sun, allowing improved building efficiency, power savings, and decreased carbon dioxide emissions.
When thinking about the installation of a “green” and environmentally sound roof, area contractors are the ones to contact about the new cool coating materials. Since this is a product that offers energy-saving benefits, knowing about “green” elements is vital in decreasing monthly power bills.
Energy Efficient Coating
Energy efficient coating is a component that has the ability to reflect the destructive ultraviolet and infrared rays from the sun, thereby decreasing heat transference. It also has high thermal emissivity, which means it has the ability to radiate the absorbed heat radiation back into the environment and therefore maintain a cool surface. The DOE explains that “cool roofs” can deliver savings of up to 15 percent on monthly electric bills. The use of these coatings can also significantly decrease the need to use air-conditioning to provide comfort to the people who occupy the building.
Coating Properties
The degree of “coolness” can be measured by two different properties and their impact on temperatures. The Cool Roof Rating Council (CCRC) refers to these two properties as solar reflectance and thermal emittance.
- Solar Reflectance – Solar reflectance is also known as “albedo” or the reflecting power of the surface. This is shown in the ratio of solar power that hits the surface compared to the amount of power reflected back into the environment. Basically, white or light-colored surfaces have a high solar reflectance, while black or darker colored surfaces have a low solar reflectance although the color of the material is not a reliable determinant of solar deflection.
- Thermal Emittance – Thermal emittance is the ability of the surface to radiate back the absorbed heat radiation. This is rated between zero and one in percentage form.
Benefits of Cool Roofs
Energy efficiency is vital in green building methods because of the cascading benefits they can provide. This is not a new idea in the construction industry, since these methods were utilized in ancient civilizations. A cool roof is essential in achieving an energy-efficient building infrastructure. Highlighted below are few of the positive benefits of a cool roof.
- Decreases urban island heat effect
- Increases energy savings
- Increases comfort of occupants
- Decreases maintenance costs
- Decreases use of air-conditioning
- Decreases carbon dioxide emissions
- Slows down “greenhouse effect”
- Reduces smog and improves air quality
- Improves health by decreasing heat-related and smog-related health concerns.
Again, the coolness of the material is measured by two determining properties which are solar reflectance and emittance. These two are gauged as percentages or fractions; the higher the value, the “cooler” the material. This determines the coolness of the surface when the sun shines directly on it. It is important to remember that a “cool roof” refers to these two determining surface properties. Adequate insulation and ventilation when making changes that allow heat reduction and energy efficiency inside a building must also be considered. With all the available options, there is every reason to think “green” when planning a Woodlands roofing project – the only thing to lose are high energy bills!