Your roof affects energy efficiency. It shields your home from the elements and helps control indoor temperatures. But it does more. Your roof’s insulation, ventilation, color, and material also impact your energy costs. Understanding your roof’s role in energy management is key to making the right choices for your home.
What Makes a Roof Energy Efficient?
According to the Environmental and Energy Study Institute (EESI), up to 90% of roofs in the United States are poorly designed. The reason is that these roofs consist of dark, non-reflective materials that absorb rather than reflect heat. Studies show that rooftop surface temperatures can soar 90 to 100 degrees hotter than the outside air temperature. With a roof that absorbs heat, these high temperatures transfer to your attic and can ultimately alter the conditions of your home. While decent home insulation can offer some protection, it does not prevent the transference of heat from the roof to the attic or ceiling. This excess heat disperses throughout the home and causes the air conditioner to work harder than it should. The extra work subjects your AC unit to wear and tear and can also cause higher utility bills.
Fortunately, there are ways to make a roof more energy efficient by stopping this transference of heat. The two factors that can reduce the absorption and transference of heat are solar reflection and proper ventilation.
Solar Reflection Index (SRI)
The solar reflection index (SRI) is a measurement of a roof’s ability to reject solar heat. This index is also an indicator of how much a roof can release any energy already absorbed. The rejection of solar heat is also known as solar reflection, and the release of absorbed heat is called thermal emissivity. Under the same solar energy exposure, roofs made of materials with a higher SRI are cooler than roofs made of materials with a lower SRI. In other words, the higher the SRI number, the better it is for the energy efficiency of your home.
For example, a study from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory found that raising the SRI from 25 to 40 can reduce the surface temperature of a roof by around 13 degrees. For many homeowners, this can translate into saving 15%-20% on their monthly utility bill. To explore the potential benefits of an improved SRI, talk to your local roofing professional about possible upgrades. Roofing professionals have knowledge about everything from lighter colors to industrial coats that increase and can deflect the sun’s radiation away from your house.
Proper ventilation can also reduce the absorption and transference of heat within the home. According to the National Renewable Energy Laboratory (NREL), the air within attics or upper levels of the home can reach significantly higher temperatures than the air outside. This is because the air within the enclosed space traps heat from the sun. Without proper ventilation, this trapped heat eventually transfers to the rest of the house. And if temperatures get too extreme, this transference will affect more than your energy bill. Much like an oven, the high temperature within this enclosed space can begin to “cook” its surroundings and damage your ceiling and roof.
Fortunately, a professional roofer can help you avoid problems by upgrading the ventilation of your home. Three main types of vents used for residential roofing include static vents, wind-powered vents, or eclectic vents. A roofer can evaluate your home and help you determine the best choice for your circumstances or needs. For example, the general industry rule is to choose a vent ratio of 1:300. This means that a professional may install one square foot of ventilation for every 300 square feet of your roof’s surface area.
What Types of Roofing Materials Are Energy Efficient?
There are several types of energy-efficient roofing materials. Such materials usually comply with the ENERGY STAR performance requirements and test procedures for roofing products. The three most common types of energy-efficient roofing materials are metal, tile, and cool-roof asphalt shingles.
Metal roofs are among the most energy-efficient residential installations. These roofs are simple to install, can last around 50 years, and are easy to maintain. As any scientist can explain, metals contain free electrons that absorb energy and vibrate when they come in contact with light. As a result, metals can reflect almost all wavelengths in the visible region of the spectrum. This high reflectivity not only gives metals their shiny color but also means that metals have a high SRI rating. For this reason, metal is a top choice for homes in sunny climates. In addition to the natural properties of metal, a roofer can also treat metal with additional coatings to produce a higher efficiency rating.
Tile is another popular choice for energy-efficient roofs. This type of roofing has been common for millennia for homes in desert and Mediterranean climates. Tile roofing is usually made of clay, slate, or concrete. In addition, modern roofers can treat tile with special coating for maximum heat reflectivity. Along with the tile’s high SRI, the structure of this material enables optimal airflow. This helps your tile roof release any heat that it absorbs and can help keep your home cool.
Asphalt shingles are the most conventional type of roofing materials used for residential buildings. In the past, asphalt shingles were also the most non-reflective and heat-absorbent roofing options on the market. However, advances in roofing technology mean that you can now find asphalt shingles that are much more reflective and energy efficient. For example, many new variations of asphalt shingles include solar-reflecting granules that raise the SRI value and can even prolong the lifespan of a roof by keeping its average surface temperature low. To explore these energy-efficient options, reach out to a professional company about upgrading the roof of your home.
What Are the Benefits of an Energy-Efficient Roof?
For many homeowners, the primary benefit of an energy-efficient roof is that it can potentially lower monthly utility bills. Lower heat absorption means that your air conditioning system does not have to work as hard to keep your home cool, thereby reducing the strain on your AC unit. However, there are other important advantages as well. The benefits of an energy-efficient roof include the following:
- Lower maintenance costs
- Increased aesthetic appeal
- Improved property or resale value
- Longer lifespan than traditional roofs
Energy-efficient roofs are also more environmentally friendly than their traditional counterparts. By keeping your home cooler, these roofs can reduce the number of times that your AC cycle restarts. The decreased use of energy thereby reduces power plant emissions that deplete the ozone layer. Because efficient roofs can also lower peak electricity demand, they may also help prevent power outages within the home. In addition, an upgraded roof can improve the comfort level of spaces like garages or covered patios that do not normally benefit from air conditioning. Installing an improved roof is one of the best ways to ensure consistent temperatures throughout the home.
Get Help From the Experts Today
An energy-efficient roof is a top home improvement for saving energy. If you have questions or need roofing services in Sanford, FL, Xtreme Roofing & Construction is here to help. We offer standard and custom roof installation, inspections, maintenance, repairs, and upgrades for homes and businesses. Trust us for quality protection, ventilation, and aesthetics. Contact Xtreme Roofing & Construction today for all your roofing needs.