This paper 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 data base of these inward-flowing fractions for a suitably broad class of geometries will make possible the determination of solar heat gain coefficient from non-calorimetric measurements of solar-optical properties of complex fenestration components, a procedure termed solar-thermal separation.

1 aKlems, Joseph, H.1 aKelley, Guy, O. uhttps://facades.lbl.gov/publications/calorimetric-measurements-inward01580nas a2200157 4500008004100000050001400041245008700055210006900142260002500211490001600236520102900252100002201281700002401303700002001327856007501347 1995 eng d aLBL-3703700aA Comparison Between Calculated and Measured SHGC For Complex Fenestration Systems0 aComparison Between Calculated and Measured SHGC For Complex Fene aAtlanta, GAc02/19960 v102, Part 13 aCalorimetric measurements of the dynamic net heat flow through a complex fenestration system consisting of a buff venetian blind inside clear double glazing are used to derive the direction-dependent beam SHGC of the fenestration. These measurements are compared with calculations according to a proposed general method for deriving complex fenestration system SHGCs from bidirectional layer optical properties and generic calorimetric properties. Previously published optical measurements of the same venetian blind and generic inward-flowing fraction measurements are used in the calculation. The authors find satisfactory agreement between the SHGC measurements and the calculation.

Significant dependence on incident angle was found in the measured SHGCs. Profile angle was not found to be a useful variable in characterizing the system performance. The predicted SHGC was found to be inherently dependent on two angles, although only the incident angle variations were observable under the test conditions.

1 aKlems, Joseph, H.1 aWarner, Jeffrey, L.1 aKelley, Guy, O. uhttps://facades.lbl.gov/publications/comparison-between-calculated-and