It’s well-documented that commercial facilities with white roofs save energy. The combination of high reflectivity and high emissivity provides a real return to the bottom line for commercial building owners.
A recent article in Roofing magazine looked at some of the broader economic benefits of cooler buildings (those that incorporate cool roofs and other technologies) and cities, including improved health, air quality, and energy savings.
You can read the entire article at this link, but here’s a brief summary:
Cool Cities Are Energy Savers
In Washington, DC, demand for electricity climbs rapidly above 80°F. When the temperature hits 90°F, the city requires 21 percent more electricity, on average, than on 80°F days. At 95°F, demand spikes by nearly 40 percent over the 80°F baseline. Higher utility charges for peak electricity demand (typically occurring mid-day) are a major expense for commercial and industrial building operators. Also, peak demand is often met by less efficient, more expensive, and dirtier power plants that worsen air quality.
Cool Cities Are Healthier Places
On average, heat kills more people than any other natural disaster, and heat-related deaths tend to be underreported. Cities on dangerously hot days experience 7 to 14 percent spikes in mortality from all causes. Heat puts significant additional stress on people already suffering from various diseases, and a recent study found that every 1.5°F increase in temperatures will kill 5.4 more people per 100,000 every year. Other studies have estimated that switching to reflective and vegetative systems on 25% of flat roof surfaces could reduce mortality by 6 to 7 percent.
Cool Cities Are Engines of Economic Growth
The health, air quality, and energy benefits of modest increases in urban roof reflectivity could generate billions of dollars of economic prosperity for cities. A study of 1,700 cities found that changing only 20 percent of a city’s roofs and half of its pavement to cool options could save up to 12 times what they cost to install and maintain, and reduce air temperatures by about 1.5°F (0.8°C). For the average city, such an outcome would generate over a $1 billion in net economic benefits.
The Roofing magazine article also discusses cool roof performance in cold climates, citing research that shows that the “winter heating penalty” for reflective roofs is significantly less than previously thought and that cool roofs deliver net reductions in annual energy use, even with high roof insulation “R” levels.
A properly built, reflective roofing system is a high-performance option that delivers value for building owners while making hugely positive contributions to the neighborhoods and cities they occupy.