Tilting Windows to Save Energy

It's not a new idea; Le Corbusier put bris de soleil on many of his buildings seventy-five years ago. Since the sun in high in the sky in summer and low in winter, one can easily calculate overhangs to let sun in during the winter but shade it in the summer. Greenhouse designers also know that the closer the sun is to perpendicular to the glass, the more sunlight gets through instead of being reflected away.

Architect Jeanne Gang of Chicago's Studio Gang applied these lessons to a new condo in Chicago's Hyde Park. According to Wired, "Gang worked with engineering powerhouse Arup to calibrate the facade. Using a computer model, they gradually angled the glass until they hit the sweet spot — skewed enough to keep living rooms from baking, but not so much that they feel like the inside of a boat. The magic number for Chicago's latitude? Exactly 71 degrees. Which should also be the temperature inside."

So by tilting the glass and utilizing principles that have been around for ages, she designs a building that needs less air conditioning in summer yet gets the heat gain in winter. Thats good design. ::Wired

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