Lower Energy Bills with Cool Roofs

Managers specifying a cool roof only a few years ago found a limited number of product options. Now, based on the growing demand in part by institutional and commercial facilities, managers can choose from among hundreds of cool products.

By reducing the amount of heat transferred to a building’s interior, cool roofs provide a number of additional benefits. These include lower energy bills and longer performance lives for roof systems, as well as cooling equipment.

The environment also benefits from cool roofs. By lowering facilities’ energy use, cool roofs cut down on air pollution — including carbon emissions, which contribute to global warming.

Managers also need to pay attention to the return on investment — an especially important consideration in tough economic times. While some cool-roofing options cost more than standard, non-cool options, a cool roof generally will pay for itself in a relatively short time through savings in energy costs. But managers should note that exact savings depend on a number of factors that include climate zone, product type, building insulation and the type of HVAC equipment used to cool the building.

Understanding the concept behind a cool roof does not fully describe the amount of actual energy savings managers can expect. Savings obviously can vary widely, but the difference in temperature between a cool roof and a regular roof can be large.

Climate, roof performance, insulation and other aspects of the building can cause variations in the exact amount of savings, but cool roofs can yield up to 50 percent savings on cooling loads.

Average savings in the range of 10-30 percent of the cooling energy required is a reasonable expectation for a typical application of cool roofing under normal conditions. This range might equate to a drop in the total electric bill of 3-10 percent. These ranges generally apply to low-rise buildings in regions with significant cooling loads.