Whether you’re looking to reduce energy costs, boost comfort, or help cool down those pesky urban heat islands, a ‘cool roof’ is one seriously ‘cool’ choice. Not only is it a smart, sustainable option, but research even shows that metal roofs can keep your home cooler than traditional materials like asphalt. In today’s blog post, we’ll dive into what makes a roof truly ‘cool,’ the key benefits, the role of the Cool Roof Rating Council (CRRC), and how you can stay in the know through METALCON Online and at METALCON 2024, just two months away in Atlanta, Georgia!
What is a Cool Roof?
Imagine stepping outside on a hot summer day, choosing between a white T-shirt and a black one. Chances are you pick the white T-shirt, guessing it will reflect more sunlight and absorb less heat. Now, think of your roof as that T-shirt. A cool roof works in much the same way, reflecting sunlight and efficiently releasing any heat it does absorb, keeping the roof — and your building — significantly cooler. Just as fabric type, fit, and airflow influence how cool you stay in a T-shirt, the materials used in your roof play a crucial role in its ability to maintain a cooler temperature.
So, what exactly is a cool roof? In simple terms, it’s a roof designed to reflect more sunlight and release more heat than a standard roof. This means the roof itself stays cooler, which helps reduce the amount of heat that seeps into the building below. For buildings without air conditioning, this can lead to a more stable and comfortable indoor temperature. For those with air conditioning, a cool roof takes some of the strain off your cooling system, potentially lowering energy costs.
And just like your T-shirt choice doesn’t have to be white to keep you cool, a cool roof doesn’t have to be white either. According to the Metal Roofing Alliance, “The secret to metal roofing’s energy savings is in its variety of finishes. The basic, unpainted metal roof will reflect more solar radiation than an asphalt roof, which absorbs and holds heat. For homes in warmer climates, pre-painted or granular coated metal roofing systems reflect solar energy and cool your home by re-emitting most of what solar radiation is absorbed. 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.”
The “coolness” of a roof is determined by two key properties: solar reflectance and thermal emittance. These are measured on a scale from 0 to 1, where 1 represents maximum reflectivity or emittance. The higher these numbers, the cooler your roof will be.
Benefits of a Cool Roof
Choosing a cool roof comes with a range of advantages that go beyond simply keeping your building cooler. According to the CCRC, here are some key benefits to consider:
- Increase occupant comfort by keeping the building cooler during hot summer months.
- Cut costs by reducing the need for air-conditioning and extending the life of cooling equipment. Individual results vary based on a variety of factors related to the climate and installation.
- Decrease roof temperature, which may extend roof service life.
- Address air pollution and global warming concerns by lowering CO2 and other emissions associated with fossil fuel-generated electricity used for air-conditioning.
- Reduce the urban heat island effectby reflecting heat back to the atmosphere. An urban heat island occurs when a city is hotter than the surrounding rural areas due to dark surfaces, like roofs and roads, that absorb heat from the sun and have less shade trees and vegetation.
- Help with local code compliance for building codes that have cool roof requirements
What Makes Metal Roofs “Cooler”
Metal roofs often perform better as cool roofs compared to other roofing materials due to their natural properties and the ability to be coated with reflective finishes. Here’s why:
- High Reflectivity: Metal roofs can be manufactured with highly reflective surfaces or coated with reflective paints, which effectively bounce off a significant portion of the sun’s rays, reducing the amount of heat absorbed.
- Thermal Emittance: Metal roofs also have good thermal emittance properties, meaning they can efficiently release the heat they do absorb, helping to keep the roof — and the building underneath — cooler.
- Durability: Metal roofs are long-lasting and resistant to degradation from weather exposure, which means their cool roof properties can last longer compared to some other materials that might degrade more quickly under harsh sunlight.
- Cool Color Options: Metal roofs are available in a wide range of colors, including “cool colors” that offer the reflective benefits of a cool roof while still allowing for aesthetic flexibility.
Compared to traditional roofing materials like asphalt shingles, metal roofs tend to maintain their cool roof properties over time better, making them a popular choice for energy efficiency and sustainability. Because metal roofing systems are available in a wide range of durable and fade-resistant colors, they can easily achieve cool roof ratings. Metal Roofing systems contain 30-60 percent recycled content and last two to three times longer than other roofing materials, supporting sustainable construction in ways beyond cool roof ratings.
Did you know that metal roofing products make up nearly half of the over 3,000 rated products on the CRRC Rated Roof Products Directory?
What is the Cool Roof Rating Council?
The Cool Roof Rating Council (CRRC) is a nonprofit organization established in 1998 with the mission to develop accurate and credible methods for evaluating and labeling the solar reflectance and thermal emittance of roofing products. The CRRC’s goal is to provide the public, contractors, and regulatory bodies with reliable information that helps them make informed decisions about energy-efficient roofing materials. By maintaining a comprehensive database of rated products, the CRRC promotes the adoption of cool roofs, which contribute to energy savings, improved indoor comfort, and the reduction of urban heat islands. Through its rigorous testing standards and commitment to transparency, the CRRC plays a crucial role in advancing the use of sustainable roofing solutions.
METALCON Online: Demystifying the CRRC Product Rating Process
Learn more about the CRRC Product Rating Process for Metal Roofing with CRRC Program Managers Beth James-Bourgeois and Audrey McGarrell and David Cocuzzi, Technical Director of the National Coil Coating Association. Join this FREE METALCON Online webinar next Wednesday, September 4 at 1:00 pm EST, for a deep dive into navigating the rating process. This interactive webinar will focus on CRRC’s Roof and Wall Color Family Programs, Reference Rating option, and the roles coating manufacturers, coil coaters, and fabricators play in the rating process.
Learn More at METALCON
In addition to this online webinar, Audrey will be on hand at METALCON to provide person to person training. Her session, “Advancements in Cool Roof and Wall Evaluation and Compliance,” is scheduled for Thursday, October 31, at 10:15 am in the Building Performance Learning Center in the Exhibit Hall. With the discontinuation of the U.S. EPA’s ENERGY STAR certification for roofing products in June 2022, architects and builders now face the challenge of finding alternative compliance options. This session will explore new resources and developments, including cool exterior walls, which, like cool roofs, help mitigate urban heat and save energy in various U.S. climate zones. Additionally, it will address opportunities, barriers, and methods for educating customers about the benefits of cool surfaces.
This session is included with your registration and is accredited by both the AIA and the FL DBPR for one continuing education credit each.
REGISTER FOR METALCON TODAY and join us at the Georgia World Congress Center in Atlanta, Georgia, October 30 – November 1. Check out all of the Roofing Events at the METALCON Tradeshow!
