High Solar Gain Windows with Loss Prevention

Here is a window/Shutter design I came up with last week (Click for Full Size):

Here’s how it works.

In winter you want the maximum amount of solar gain on sunny days. The best way to get that done is to have lots of south facing glass. Reflecting more sunlight into the windows can get you even more solar gain. To minimize daytime loss you want to have windows that are double or triple paned.

At night, however, it’s a different case. With no sunlight, the windows become a serious liability because they lose heat much more quickly than the surrounding walls which can be much more heavily insulated.

In addition both during the day and especially at night, air infultration also creates a huge problem allowing heat to be transferred at a high rate from inside the house to outside.