Calibrated Hotbox for Testing Window Systems: Construction, Calibration, and Measurements on Prototype High-Performance Windows

摘要

Windows have the highest thermal conductance (or U-value) of all the elements in a building envelope. A small (3 ft x 4 ft opening) calibrated hotbox was built for studying methods of improving window thermal performance. Generic approaches to window thermal control are compared, novel methods of improving window performance are identified, and the mechanisms by which actual window performance may differ from theoretical are studied. The construction and instrumentation of the hotbox, the methods by which the box was calibrated, and the limits on its accuracy are described. The results of a study of prototype windows which serves the dual purpose of illustrating the methodology and some interesting options for window improvement are presented. (ERA citation 05:033765)