Defining Daylighting from Windows in Terms of Candlepower Distribution Curves

摘要

This work describes a method for evaluating quantitatively the daylight admittance of windows under any outdoor conditions in terms that make it possible to calculate interior light distribution. The visible daylight flux introduced through a window (or other daylight-admitting aperture) can be considered, from the point of view of the internal space, as being emitted from a point source or from a finite-area uniform source. The photometric properties of those light sources are defined in terms of the well-known candlepower distribution curves. The ways in which this approach can be applied for different window designs are demonstrated. (ERA citation 09:046128)