The main objective of the proposed research is to propose a validated and integrated calculation procedure for the prediction of clear-sky solar spectra incident on vertical (or otherwise tilted) windows as a function of local climatic conditions in North America. It is to be used in conjunction with modern fenestration analysis software to dynamically evaluate the peakload optical characteristics of any fenestration system (particularly those that are highly spectrally selective), as a function of window geometry, time, and local climate.

This procedure is aimed at engineers with modest background in radiative transfer or atmospheric sciences, and therefore attempts to reconcile accuracy, flexibility, and ease of use.