A national “cool” roof campaign could save some 5.7 quad of net primary energy valued at $33 billion over the 20-year lifespan of an average roof, according to researchers at the Lawrence Berkeley National Laboratory’s Heat Island Group.
The Case for Cool Roofs recommends a no-cost cool roof upgrade program. It says upgrading commercial and residential roofs at end of service life could, over 20 years, save $15.5 billion in energy costs.
Plus, these cool-colored clay tile, concrete tile and metal roofs cost the same or less than their conventional black asphalt or rubber counterparts.
Cool-colored dark roofs look like traditional dark roofs but better reflect near-infrared light. On a typical summer afternoon, a cool-colored roof that reflects 35 percent of sunlight will stay about 12°C (22°F) cooler than a traditional roof that looks the same but reflects only 10 percent of sunlight the Heat Island Group explains.
A brilliant blue invented by Oregon State University researcher Mas Subramanian could reflect the sunlight and provide a nice roof color, Co.Exist reports. The article says car and building companies are coating their products with the brilliant blue to save money on energy costs.
Additionally, US Recovery and Reinvestment Act funds are available to finance basic research for new reflective pigments that could keep roofs cool.
Online roofing tools can help save money and energy, too. The Oak Ridge National Laboratory has designed a cool roof calculator that shows potential savings for commercial and residential buildings, while roofing manufacturer GAF has developed CREST, the Cool Roof Energy and Sustainability Tool, designed to help contractors, consultants and building owners compare the energy cost savings of different roofing systems options.
CREST is mobile-enabled, with preloaded utility cost information by zip code. It allows users to compare multiple roof design options, varying levels of reflectivity and multiple thicknesses of insulation.
Building professionals can then print a customized report that includes images of the building site from publicly-available, internet-based mapping services and available rebates. It generates a proposal-quality report for immediate free download.
To ease the process of projecting peak energy loads, CREST queries both the Oak Ridge National Labs CoolCalc and CoolCalc Peak calculators in one step, using an app-style format.
CREST was developed in conjunction with GreenOhm, a technology company that maintains one of the largest datasets of energy efficiency rebates, incentives and tax credits and links this information to provide a complete picture to property owners.