If you have a small business, the wrong type of roofing can make the summer incredibly hot, forcing your HVAC system to work overtime and leaving your employees—and customers—overheated and uncomfortable. Cool roofs help combat rising temperatures in hot climates, offering small businesses opportunities to save on air-conditioning costs while providing a cool work environment.
Cool roofs are designed to reflect sunlight while absorbing less heat. Compared to traditional roofs, a reflective roof has a high albedo, or solar reflectance. A higher albedo means that a roof has a higher ability to reflect the sun’s rays, and thus reflects more sunlight than traditional roofs. Cool roofing systems also have high thermal emittance, which is the ability to radiate absorbed heat back into the air and away from your business.
The primary advantage of a cool roofing system is that business owners can expect to use less energy to cool their small businesses. In hot climates, traditional roofs in the contiguous United States can reach temperatures of 150 to 185 degrees Fahrenheit. A cool reflective roof stays 50 to 60 degrees cooler when exposed to the same summer heat.
Generally speaking, the cost of installing cool roofing during construction is comparable to traditional roofing, as this energy-saving calculator demonstrates, so small business owners may save on energy costs in long-run by installing a cool roof.
Small business owners have a wide selection of cool roofs to choose from, and the type of cool roof you install largely depends on the size and structure of your building, and the slope of your roof. In addition to energy-saving white reflective roofs, other cool roof solutions that small business owners can choose from include roof coatings, single-ply membranes and cool roof shingles.
Traditional roofing is typically dark colored or black—colors that absorb heat faster than brighter colors. However, there are energy-saving benefits to painting your roof white–this increases your roof’s albedo causing more heat reflection, which keeps your small business cooler.
And if you think simply opting for a happy medium—such as gray, for instance—is the answer, consider that it’s not all about white roofs vs. black roofs. For instance, when you compare a white reflective roof with a gray roof, the white roof reflects 80 percent of incoming sunlight compared to the gray roof, which reflects only 20 percent.
The difference means the white roof will stay approximately 55 degrees Fahrenheit cooler than its gray counterpart. Ultimately, painting a roof white to save energy is a great idea, because it’s one of the simplest ways to increase its solar reflectance and thermal emittance properties.
While a flat roof has no gradation, a low-sloped roof is generally defined as a roof that rises at an angle of less than 18.5 degrees. If you have a small business, it is likely that you have a flat or low-sloped roof. To find out the slope of your roof, you can call a professional for accurate estimates and measurements.
Cool roof solutions for flat or low-sloped roofs often come in a variety of materials to reflect thermal heat, and provide flexible solutions for you and your small business.
While there are benefits to painting your roof white to save energy, applying a roof coating provides even better results. These coatings, which resemble thick paint, protect the roof from ultraviolet damage while increasing reflectivity. Some also provide water protection. Cool coatings are the easiest cool roofing solutions available for low-slope roofs.
Single-ply membranes are prefabricated sheets rolled into place on the roof and attached by mechanical means or chemical adhesives. Generally a more expensive cooling solution than coatings, single-ply membranes are sturdier and provide additional protection to the underlying roof. Single-ply membranes come in two categories:
Flat or low-sloped cool roofs can also be used with green roofing systems to help save even more energy. That’s why Constellation’s headquarters uses a flat cool roof, in combination with green roofing, to create an energy-efficient solution that decreases both energy use and greenhouse gas emissions.
Constellation’s cool roofing system has even helped the building earn an overall LEED Gold designation, and the interior was awarded LEED Platinum status. The US Green Building Council awards LEED (Leadership in Energy and Environmental Design) certification to healthy, cost-efficient, sustainable buildings based on a strict set of criteria.
Unlike low-sloped cool roofs, high-sloped roofs generally have a gradation steeper than 18.5 degrees. Because of their slope, it can be difficult to apply most cool reflective roofs to their surfaces.
A professional will be able to determine the slope of your roof, and what cool roofing system will work best. Reflective coatings, for instance, are difficult to apply evenly. Some single-ply membranes may be installed on high-sloped roofs, but the most effective solutions for high-sloped roofs are cool roof shingles and tiles.
Cool roof shingles, tiles and slate may be coated with special granules to give them better solar reflectance. The heavy mass of cool roof shingles and tiles can also provide some degree of thermal protection by absorbing and blocking heat during the day, and releasing heat throughout the night.
Reflective metal roofing may also cool high-slope roofs. For more information, check out Constellation’s post about energy-efficient roof shingles, tiles and metal roofing.
Cool roofs are excellent for keeping small businesses cool during peak summer months or year round in hot climates, but you may be wondering about possible disadvantages. Let’s examine the pros and cons of cool roofs.
Cool roofs have many benefits, from lowering indoor temperatures and improving air quality to reducing cooling costs and greenhouse gas emissions.
Many disadvantages of cool roofs can be offset by your choice of cool roofing system, or by adapting other aspects of your building’s heating/cooling system, but it’s worthwhile to be aware of the possible cons.
Cooling your roof is only one way to improve your small business’s energy efficiency! You can try these other strategies to help you save on your energy use:
As a final note, keep in mind that making changes to your roof or taking steps to reduce your small business’s energy expenditures may qualify you for small business energy tax credits. These incentives allow you to recoup a portion of the expense associated with transitioning to an energy-efficient workplace.
Painting the roof white, or implementing any type of cool roof, is only one step small businesses can make to conserve energy, reduce their carbon footprint and provide a more comfortable workplace for employees and clients alike.
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