Evaluation of thermal performance of fenestration system under cooling season is based on heat gains by temperature difference and solar radiation, characterized by thermal transmittance (U-value) and solar heat gain coefficient (SHGC), respectively. However, current test methods are only concerned with nighttime performance, and may not accurately reflect the performance improvements of specific window designs. With nighttime test methods, the thermal performance of a fenestration system is characterized only by the U-value. In this paper, a new test method has been developed to measure the thermal performance of fenestration systems. This method enables the determination of SHGC and U-value for various fenestration systems under cooling season, including integral shading devices and complex frame designs.
