Other Weathering Services
WE TEST EVERYTHING UNDER THE SUN ®
Window Energy Analysis
Shading Coefficient and U-Value Analysis
The proper determination of the Shading Coefficient (SC) for a window system provides important marketing and technical data for that system. The SC, along with the U-Value of a particular fenestration, permits the designer to perform heat gain and heat loss calculations, important in today's competitive marketplace. By definition, a Shading Coefficient is the ratio of solar heat gain through a glazing system to the solar heat gain through a single lite of double-strength sheet glass, when both are tested under a specific set of conditions. The U-Value is the overall coefficient of heat transmission through a window system.
Calculation of Shading Coefficient and U-Value
Using methods based on the ASHRAE Handbook of Fundamentals, the SC and winter and summer U-Values can be calculated. However, these calculations can only be performed on smooth surface window systems and they require separate measurements of thermal emittance, solar transmittance, and solar reflectance of each window surface.
Window energy analysis testing is offered in accordance with NFRC 200-93 standard. The National Fenestration Rating Council (NFRC) recently began implementing a nationwide energy performance rating and labelling system for all fenestration products, allowing consumers and builders to directly compare window systems energy characteristics. For suppliers seeking to meet the requirements of NFRC 200-93, Atlas Weathering Services Group performs the necessary solar optical property measurements and calculations. NFRC 200-93 specifies a method to calculate Solar Heat Gain Coefficients (SHGC) for fenestration products. Spectrophotometric and color measurement equipment is available for testing to ASTM E903 requirements to determine solar optical properties such as SHGC and daylight transmission. This test applies to spectroradiometric measurements of solar spectral transmittance and reflectance, and calculations of the weighted solar transmittance and reflectance, visible transmittance, and color indices. Average solar properties are required to determine solar heat gain as specified in NFRC 200-93.
Environmental Test Services
Atlas' test capabilities in the field of environmental testing include Temperature/Humidity Cycling, High Temperature, Low Temperature, and Temperature Shock conducted in accordance with the appropriate MIL-STD specifications. Temperature/Humidity Testing (MIL-STD-810D, 202D, etc.) Number of Chambers: 2 Volume: 1.7 m3 (64 ft3) Interior Dimensions: 1.2 x 1.2 x 1.2 m (4 x 4 x 4 ft) Temperature Range: -73¡ C to 175¡ C (-100¡ F to 350¡ F) Humidity Range: 20 to 95%
The Cool Roof Rating Council (CRRC) has designated Atlas Weathering Services Group as the "first" approved Test Farm facility for the CRRC's Product Rating Program. To earn the coveted CRRC rating, roofing manufacturers and sellers must perform weathering tests through Atlas for three years at locations in Florida (hot/humid), Arizona (hot/dry), and Chicago (cold/temperate).
The CRRC's product rating program is designed to provide third-party verification of weathered performance claims to help purchasers in the selection of cool roofs that save energy and reduce a building's impact on the environment.
The CRRC's rating program authorizes manufactures and sellers to label roofing products to indicate their Initial Radiative Properties and Aged Radiative Properties. Certification is a three-stage process:
- All production-line roofing products must be initially tested by an Accredited Independent Testing Laboratory (AITL) in order to assess their Initial Radiative Properties.
- The products must then be weather-tested at the Atlas Approved Test Farms.
- Finally, after weathering the roofing products at Atlas facilities, an Aged Radiative Property can be determined by an AITL.
CRRC schedules four weathering cycles during the year - commencing March 21st, June 21st, September 21st and December 21st. Test Specimens must be provided to Atlas's Arizona facility at least 10 days prior to those dates to ensure timely distribution to all test farm locations.
The Cool Roof Rating Council was created in 1998 to develop accurate and credible methods for evaluating and labeling the solar reflectance and thermal emittance (radiative properties) of roofing products, and to disseminate the information to all interested parties. Based in Oakland, California, the CRRC is incorporated as a non-profit educational organization.
Atlas is proud to offer a solar radiometer calibration service that has been accredited to ISO/IEC 17025 requirements. These radiometers include pyranometers and pyrheliometers, which are used mainly to measure total sunlight which need calibration directly traceable to the World Radiometric Reference (WRR) and radiometers that are used to measure total or narrow-band ultraviolet radiation which need traceability to the National Institute of Standards and Technology (NIST). These calibrations are performed according to ASTM standard methods and a Certificate of Calibration is issued that complies with ISO/IEC 17025 requirements.
Calibrations Available: Method for Transfer of Calibration from Reference to Field Radiometers (E824) and Standard Test Method for Calibration of Pyrheliometer by comparison to Reference Pyrheliometers (E816).
Special Project Testing
Atlas offers specialized custom designed services, thus allowing our clients to evaluate critical items for test performances under various conditions. Atlas understands that each client has his own sophisticated needs. Therefore, we work hard at living up to our motto: "we test everything under the sun." As the need arises, we can provide the test These capabilities range from automotive assemblies such as windshields and bumpers to complete vehicles. We test building industry and construction materials such as doors, windows, skylights, frames, roofing and siding. Special projects at Atlas may vary from leisure items such as toys or golfballs to environmental concerns such as photodegradable plastics.
Custom tests are just one way in which Atlas is dynamic. Equally important is the ability to offer special testing in a broad range of environments. For more information about alternate exposure climates and sites, please read about the Atlas Worldwide Exposure Network.