This paper presents a set of daylighting programs that can be run on a TI-59 hand calculator. The paper gives the program listings, the step-by-step procedures for using the programs, worksheets, and a worked sample problem.

The programs calculate interior horizontal illumination levels or daylight factors from a window. The user can specify the location of the calculation point, or, if a printer is available, the locations of a grid of points. Calculations can be performed for both CIE clear and overcast sky conditions.

The direct sky component calculation uses Riveros approximation for window transmission. The interreflected component calculation uses a split-flux approximation.

PB - Lawrence Berkeley Laboratory CY - Berkeley N1 -Also published in *Lighting Design and Application*.

Windows and Daylighting Group

U2 - LBL-12248 ER -