Solar Geometry:
Solar Charts

Solar Geometry:

Understanding solar geometry is essential in order to be able to design from both a passive as well as sustainable point of view. The sun is able to give us free heating energy in the cold months, but it must be avoided during the hot months to prevent unwanted gain. Control of the sun is also key to achieving successful daylighting strategies as daylight can be used to increase comfort, avoid the use of electric lights and sculpt our architectural forms.

A link to a very cool site that does sun angle calculations:

http://www.susdesign.com/sunangle/

The Basics:

When you are designing shading devices, you must differentiate by orientation (or it is incorrect, dumb, waste of money on shades...)They also need to be verified by checking against the solar angle from due south at summer solstice and winter solstice.

Horizontal shades work for the south.

East and west get no benefit from horizontal shades as the light coming from this direction is somewhat horizontal when it is most offensive. These shades need to be external vertical (trees, trellises, fences...) or vertical baffles at the sides of the windows to cut off light from the south east or south west. The York University building by Busby does a nice sawtooth facade on these sides so that you get north west/north east light, but no direct sun.

North doesn't really need shades, but you do get light in from the north when you get to June 21 as it comes in early in the morning and late in the evening.

To keep out HEAT, shades should be on the outside of the envelope. Shades or drapes on the inside will cut down on glare, but the heat has already entered the building.