Replies

1. 
   Andrew Henry|Sep 29, 2009 12:33pm|#1

   Hi Claire,

   Stephen at Thermotech Fenestration is a guy who has given some thought to glazing and orientation. I learned a great deal from his columns and have even seen them referenced in Energy Design Update, if I recall correctly.

   Here is the link to his columns, I'd start there. Also, the answer to your question will depend on the climate where the house is located, .

   http://www.thermotechfiberglass.com/news.htm

   Andrew

2. GBA Editor
   Martin Holladay|Sep 29, 2009 12:36pm|#2

   Claire,
   Here in northern Vermont, I think high SHGC glass is fine for east windows. It's almost always cool in the morning, even in the middle of summer. In other climates, east glazing should be low SHGC. Of course, if your east elevation has a lot of large windows because of a spectacular view, the glazing choice must be made carefully.

3. 
   Robert Riversong|Sep 29, 2009 05:09pm|#3

   If you're relying on East windows as part of your passive solar strategy and you have little solar shading in that direction for the low morning sun, then high SHGC glazing is the right choice. If, however, you have enough south glazing to meet the 7%-12% of floor area required for a passive solar design, then the additional insolation from the East may be excessive.

   South windows can be well-shaded in the summer with properly-designed overhangs, but East windows cannot (except by deciduous trees) and may contribute to summertime overheating.