Cool Roof Accreditation Caps Architectural Testing’s Solar Testing Capabilities

The Fresno laboratory facility of Architectural Testing, Inc. (ATI), a complete testing center for solar performance of the entire building envelope, has been accredited by the Cool Roof Rating Council (CRRC) as an Accredited Independent Testing Laboratory (AITL) – one of seven nationwide. As such, the laboratory is authorized to test roofing materials of all types for key properties of solar reflectance (the ability to reflect the visible, infrared and ultraviolet wavelengths of the sun) and thermal emittance (the ability to radiate absorbed, or non-reflected, solar energy). Higher readings in these parameters qualifies a roofing system as a “cool roof,” i.e., one capable of reducing solar heat transfer into the building below, resulting in reduced energy costs and longer AC unit life because of reduced air-conditioning load, and increased roof longevity due to reduced thermal flux. The measurements can be combined by calculation to determine the Solar Reflective Index (SRI), a parameter cited by the U.S. Green Building Council and others. For aged ratings, product samples are exposed for three years at a CRRC Approved Test Farm.

A growing number of building codes (e.g., ASHRAE Standard 90.1, California’s Title 24 Building Energy Efficiency Standards, as well as a number of city building codes, including those of Chicago, Houston, and Dallas) include cool roof measures. Green building programs (such as the U.S. Green Building Council’s LEED® and the Green Building Initiative’s GreenGlobes™) offer credits for use of cool roof materials. Consequently, cool roof products are being specified by architects to save energy, satisfy building codes and meet client expectations for comfort, cost and aesthetics. In addition, cool roofs can improve air quality by mitigating the urban heat island effect due to the reduction of ambient air temperatures.

The Cool Roof Rating Council (CRRC), fast becoming to the roofing industry what the National Fenestration Rating Council (NFRC) is to the window industry, has created a rating system for measuring and reporting the solar reflectance and thermal emittance of any roofing product. A manufacturer of any of these materials wishing to establish a cool roof rating applies to CRRC to become a licensee and chooses a CRRC-Accredited Independent Testing Laboratory (AITL), then sends product samples to the lab for initial testing according to designated ASTM and CRRC test methods.

ATI’s Fresno Laboratory uniquely offers a complete delivered package of laboratory testing and exposure farm testing via subcontract (CRRC rules do not permit solar farm testing by the same entity performing laboratory testing) for a total CRRC rating evaluation package.

“You could say that ATI is the nation’s Solar Performance Specialist for the entire building envelope – fenestration and wall materials as well as roofing,” says Project Engineer Tyler Westerling, P.E., pointing out the additional solar-related testing capability, including Solar Heat Gain measurement via the nation’s only – and the world’s largest – accredited solar calorimeter capable of testing specimen as large as seven feet square. “We complete our offerings with tests for visual transmittance (VT) and reflectance, absorption and transmittance in the ultraviolet (UV) range.”

Solar reflectance and thermal emittance are becoming more important performance parameters for building envelope materials as part of the worldwide green building movement. ATI is fully equipped to develop performance data for all such materials as an aid to both R&D and to demonstrate compliance with codes and rating systems.