Presents a calorimetric measurement of layer-specific, inward-flowing fractions of absorbed solar energy for a number of geometric configurations common in fenestrations with shading. The inward-flowing fractions are found to be relatively insensitive to exterior conditions. Results for an interior venetian blind over double glazing agree with thermal model calculations in the literature and are the first layer-specific verification of these calculations. It is argued that a database of these inward-flowing fractions for a suitably broad class of geometries will make possible the determination of solar heat gain coefficients from non-calorimetric measurements of solar-optical properties of complex fenestration components, a procedure termed solar-thermal separation.

KEYWORDS: year 1996, calorimeters, measuring, solar heat gain, windows, glazing, heat flow, venetian blinds, double glazing, blinds, insulating window films, optical properties