The Emergence of Cool Roofs

   Cool roofing is not a new concept. In the mid-1980s, researchers at DOE national laboratories in Tennessee and California were measuring the energy-saving benefits of “solar radiation control coatings” on test roofs. Although energy savings were confirmed in these early studies, they were not sufficient to lead roofing designers and installers to switch away from traditional dark-colored roofing systems.

   A parallel effort was launched to determine the influence of light-colored roofing products on summer urban heat islands. This research demonstrated that solar reflective roofs, solar reflective pavements, and vegetation could lower urban air temperatures, saving additional energy and improving air quality.

Rolling blackouts during the summer of 2001 motivated California’s public utilities to expand the scope of their peak load management programs. They found that cool roofing reduces peak demand for electricity, helping to lower costs and avoid power outages. Twenty years after DOE initiated its work on cool roofs, these products dominate the commercial roofing marketplace in warm and hot climates, partly because the State of California changed its energy code to prescribe cool roofing for most commercial buildings with low-sloped roofs.

Today, both white and “cool color” products are available for low-slope and steep-slope roofs.

Roofing for residential buildings need not be white; cool colors are available for a number of roofing materials.

Thanks to the reflective nature of the Cool Series Shingles, part of the heat radiating from the sun gets reflected, reducing the heat in the attic, and heat going into the house. It may translate into substantial savings on air conditioning bills.

Cool roofs may save residents an avg. 7-15%** of total cooling costs, depending on geography, structure, and climate. In warmer climates, cooling-cost savings may be greater year round.

A cool roof minimizes the solar heat gain of a building by first reflecting incoming sun rays and then by quickly re-emitting the remaining absorbed portion. As a result, the cool roof stays cooler than a traditional roof of similar construction.