States that national window rating and labelling programmes in Canada and the U.S. have recently put increased emphasis on the development of consensus test procedures for determining the thermal and solar performance of windows. In support of these activities, a standard test method has been developed for the determination of fenestration solar heat gain coefficient (SHGC) using simulated solar irradiance. To evaluate the new method, SHGC values for nine high-performance windows covering a wide range of commercially available glazing products were measured in a solar simulator test facility. The sensitivity of SHGC performance to the environmental conditions and the simulated solar spectrum encountered in the test facility was also investigated. Supplies the results and finds good agreement with values obtained with the VISION3 and FRAME computer programs.

KEYWORDS: Windows, testing, Canada, solar heat gain, performance.