This is the first paper resulting from this joint research project. It outlines the overall project objectives and presents the first set of results. It also provides a summary of the future work planned in the first phase of this project. The results presented in this paper compare overall U-values for seven windows obtained for laboratory testing using a guarded hot box and the U-values obtained using two computer models. The results indicate a reasonable agreement between the guarded hot box measurements and the simulations for overall U-values, but differences exist when comparing the edge-of-glass and frame U-values resulting from computer simulations.

KEYWORDS: research, windows, performance, glazing, Canada, USA, calculating, thermal resistance, comparing, measuring, laboratory testing, window frames, double glazing.