NFRC - Summer Solar Window Performance

Protecting your home from the hot house/greenhouse "syndrome"

For a printable version of the NFRC Window Performance Sheet, Click Here

We've all had the experience of sitting in a room that was hot, stuffy, and uncomfortable, because of too much heat from the sun. Unfortunately, the increased use of large window areas in today's homes has made solar overheating a much bigger problem than it was ten or fifteen years ago. Fortunately, glazing products are now available that can significantly reduce solar heat gain through windows.

Solar control is measured by a value called the solar heat gain coefficient. The solar heat gain coefficient is a relative comparison of solar heat gain with lower values indicating lower levels of heat gain and therefore better solar control. Gilkey Windows cut heat gain in half compared to standard dual pane glass.

You should select a window with a lower solar head gain co-effcient if:

You have air conditioning in your home.
You have large areas of glass facing west, south or east.
You are building in an area with energy codes that require solar control glazings.
You are replacing windows and some areas of your home currently get too hot.