Windows can be coated with an absorptive or reflective film to reduce the amount of light transmitted into a house/office. This is great for keeping your house cool in summer, but will also keep your house cold in winter.

What is needed is a window that reflects summer sunlight and transmits winter sunlight.

My solution is to make windows of relatively high refractive index glass and coat the outside with an anti-reflective layer. Light entering from high/shallow angles (summer sunlight) will travel through the anti-reflective coating and then be reflected (by 'total internal reflection') from the inside face of the window. Light entering from a low angle (winter sunlight) will go straight through without reflection.
-- xaviergisz, Nov 15 2012

illustration https://docs.google...nU-FLVA3V2RHcEVFd2M
[xaviergisz, Nov 15 2012]

...or you could just close the shutters.
-- DrCurry, Nov 15 2012


that would work.
-- sqeaketh the wheel, Nov 15 2012


Could work, seems to be very dependent of latitude.
-- piluso, Nov 15 2012



random, halfbakery