Passive solar orientation and shade-free zone
I am writing to double-check my thinking on our passive solar building orientation and a shade free zone.
Next week a surveyor will stake out the building layout for our 1,100 sq foot passive solar home at 46 degrees N in Minnesota.
The structure’s southerly, solar-gain wall will be oriented at 210 degrees (30 degrees W of true south). Solar studies I have done show that we will get good sun light penetration into the structure during the winter with this orientation.
My understanding of effective passive solar building orientation is to maintain a zone free of trees or other obstructions so as to prevent shading 45 degrees or more east and west of the south elevation.
Question: Does the shade free zone rotate with the building or does the 45 degrees either side of south elevation remain fixed with orientation of true south at 180 degrees?
See attachment. I have outlined in red an estimated 45 degree obstruction-free zone that rotates with the cabin. Yellow highlights cabin orientation and true south.
I am probably over thinking this. Yet it seems to me that at some point the westerly rotation of the building away from true south the structure would no longer warrant a symmetrical 45 degrees clear zone east AND west of the south elevation
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