You can use the Sun Path Diagram to determine the angle of the sun at different times of year. I usually use the noon solstice angles to determine the range of appropriate glazing angles.
R Scott wrote:You do have this document, right? http://www.bensoninstitute.org/Publication/Manuals/Walipini.pdf
Keep in mind the design is built for high elevation, low latitudes. Areas that have near vertical sun in winter and summer sun actually north of vertical (for northern hemisphere). When you get out of the tropics, the roof angle doesn't work the same as a pit.
Daniel Pinnell wrote:So I would have to reduce winter solstice sun approx to 75% and increase close to 75% of summer solstice sun?