Even if you’re hearing the phrase “cool roof construction materials” for the first time, its meaning is clear: It’s possible to construct a roof that will stay cooler than some alternatives and can therefore help to keep temperatures inside the building it tops lower.
The conclusion that logically follows is the possibility of energy savings, since air conditioners won’t have to work as hard in hot weather to keep the interior temperature of that building down. What many people may not realize, though, is just how significant that contrast – and those savings — can be.
If you’ve ever gotten into a car that’s been parked in direct sunlight for a while, you know that objects can get a lot hotter than the ambient air temperature. For highly absorptive materials like asphalt, the difference between the surface temperature and the surrounding air can be startlingly high — as much as 100°F. (The technical term for these substances is “low-albedo.”)
For less absorptive (high-albedo) substances, that gap may be as low as 20°F. Early research found energy savings ranging from 7% to 15%, but more recent studies in California and Florida have found air conditioning loads – and therefore power bills — dropping by as much as 50%. That wide range is probably at least partly the result of differences in location. Regardless, it’s proven that a cool roof coating can reflect up to 90% of the heat from the sun, acting as an added layer of insulation for your roof.
You may have heard of the “heat island” effect. Densely populated urban areas are significantly warmer than the average temperature across a given region. For example, the average temperature across Metro Atlanta is as much as 10°F higher as the average in surrounding areas.
This phenomenon is largely due to the heat absorbed and retained by paved roads and parking lots, but dark roofs also play a role. The temperature difference also makes smog worse and increases rainfall (which might not be a problem if the rain was landing on soil, but instead intensifies runoff). To combat these problems, power companies in some areas now offer cash rebates to customers who install cool roofs.
To sum up, cool roofing materials can save you money in the short term, in the form of rebates on your utility bill, and the long term, as your HVAC system works less hard over the summer. To learn more about your cool roofing options, including liquid roof coatings and installation, contact Energy Seal Coatings.