New Educational Software for Teaching the Sunpath Diagram and Shading Mask Protractor

摘要

The well-known versions of the sunpath diagrams thatappear in the AIA's Architectural Graphics Standards arebased on the equidistant sky dome projections and use ashading mask protractor developed by Olgyay and Olgyayat Princeton University in the 1950s. A designer usingthe AIA's Graphics Standards book, or other printedversions of the sunpath diagram, must select the nearestlatitude, make photocopies of the appropriate sunpathdiagram and shading mask protractor, and then overlaythe shading mask protractor upon the diagram in theproper orientation. The outline of the shading device isthen transcribed upon the shading mask, aligned at theproper orientation for the facade in which the window isbeing analyzed, and placed on top of the sunpath diagramto determine if a point centered at the base of the windowis exposed to direct sunlight.Teaching this process to architects and engineers istedious and error-prone since the students must calculateseveral angles and then mentally translate their cartesiancoordinates onto a sperical coordinate system to determinewhether or not their shading device is going to have theintended effect. As a result of this, the sunpath diagramand shading mask protractor are not widely used becausemany designers either do not understand how to use thetools or do not budget the time to analyze a shading deviceproperly with these tools.This paper describes the new MS-Windows-basededucational software package (Oh and Haberl 1996) thathas been developed to fast-track the learning of thesunpath diagram and shading mask protractor which isbased on previously published equations for plotting thesunpath diagram and shading mask protractor (McWattersand Haberl 1994a, 1994b, 1995). A review of the manualprocess is also provided to compare the computerized toolto the traditional design method.