The goal of this study was to develop a computer model for solar radiation calculation and display and a shaded fenestration design system that can be used by architectural and engineering designers. This computerized model calculates the amount of insolation and transmitted solar radiation through a shaded window as well as the heat transfer through it.
The computer model, called Shaded Fenestration Design (SFD), contains various functions relating to solar simulation such as: display of the sunpath diagrams and the accompanying shading mask protractor, display of the hourly intensity of solar radiation onto the path of the sun for horizontal and vertical surfaces at varying off-south azimuths, and simulating the thermal performance of a shaded fenestration. The model also provides graphical aids for energy-efficient shading device design with use of various kinds of sunpath diagrams and solar radiation diagrams.
The model performs solar radiation simulation using the methods developed in the ASHRAE Handbook, Duffie and Beckman, and Kreider and Rabl. An anisotrophic sky model was applied for the calculation of solar radiation on a titled surface and the transmitted solar radiation through a single-glazed window. A part of the model was validated experimentally using a physical test box and was also compared to simulated results from the DOE-2 program; however, the validation is not included in this paper.