Originally Posted by
pstu
Gil_bo, if you are at all considering solar screens for shading they are inexpensive and could affect sizing of your replacement AC. They were quite effective helping a room in my house which got too warm due to east windows. If you are going to do it, then do it before your final load calc, rather than after. Same goes for other energy improvements you plan to make.
It is east and west exposure which is worst case for windows. If it were up to me the major window area would be north and south. I wouldn't feel too bad about your south orientation, as summer comes the sun will be more and more indirect on those windows. In the winter some argue that you benefit from solar heating via the lower sun.
Of the three AC companies I mentioned, Classical/Al/ex-AirServe is likely to have the most skilled technician. You might ask him to inspect your house and give some advice. Seeing as it *might* steer you toward the right AC sizing, that consulting should be worth a pretty penny to you.
Best of luck -- Pstu