Energy Efficiency & Sustainability Consulting

Cool Roofing 101

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What is a Cool Roof?

Cool Roof diagram-400x268A cool roof is one that is designed to maintain a lower roof temperature than traditional roofs while the sun is shining as sunlight is the primary factor affecting the temperature of a roof. Just as wearing light-colored clothing can help keep a person cool on a sunny day, cool roofs use solar-reflective surfaces to maintain lower roof temperatures. A cool roof under the same conditions as a traditional roof can stay as much as 50 degrees cooler.

Cool roofs do not have to be white. Colored roofing materials can be made to reflect sunlight; the lighter the color, the greater the solar-reflectance. For example, a conventional dark roof might reflect 20% of incoming sunlight, a cool dark roof could reflect 40% and a cool light roof could reflect 80%.

What are the benefits of a cool roof?

  • Reduction of energy bills by decreasing air conditioning needs;
  • Improvement of indoor thermal comfort for unairconditioned spaces;
  • Extension of roof service life;
  • Improvement of air quality;
  • Reduction of peak electric power demand;
  • Reduction of power plant emissions; and
  • Decelerating climate change.