Posts Tagged ‘Sun Chart’

Passive Solar Design: Complete Care Chiropractic

Thursday, June 2nd, 2011

One of the oldest tricks of design, is to carefully consider where the sunshine will hit a building in winter and in summer and use that to the best architectural advantage.    In our climate in N. California, Oregon, and Washington, we need to heat buildings in the winter.  The sun can help us with that task, if we make sure it shines into the windows during the winter days.

This “free” heat is called passive solar heating, because there are no moving parts or adjustments to be made, we simply have to situate the windows to catch the wintertime sunshine.

But, if we’re not careful, sunshine hitting those same windows in the summer, can turn a building into an oven.  Here in the Rogue Valley, our summer days are often over 90* and it’s hard enough to stay cool, without creating a greenhouse that captures and holds heat.  So up and down the west coast we should shade our windows in the summer, and the easiest architectural way to do this is with a moderately deep roof eave between 3 and 4 feet deep depending on your location.

The sun’s path through the sky is the same each year, so we can predict the height of the sun for anytime of day during the year.  The easiest way to find this information is download a Sun Chart from University of Oregon.  Here’s an example of Sunchart that shows the sun’s angles in the Rogue Valley, throughout the year.


For Complete Care Chiropractic in Eagle Point, we used a 4′ deep eave to shade the windows during hot summer days, but allow plenty of direct light in during winter days.

January Sun

To see how it works, we have a photo of the sunshine January 10 at 4:30pm.   The sun is low in the sky and shining directly into the windows.

And on May 21 at 3:30, the sun is much higher in the sky and the eaves are shading the windows.

May 21 Sun

Feel free to give our design team a call if you have any questions about Passive Solar design or would like a design for a passive solar building.   The benefit of passive solar designed buildings , are having much lower power bills both in the winter and in summer.  That’s not a bad thing at all.