Efficient Windows

Characteristics of Energy Efficient Windows

An energy efficient window in Texas is a window that reduces heat exchange, particularly the solar heat gain. Solar heat on windows is the biggest contributor to air conditioning bills. Energy efficient windows in Texas must have a solar heat gain coefficient (SHGC) of 0.25, although even lower SHGC values are preferable.

What is solar heat gain coefficient?

SHGC is the fraction of solar heat transmitted through a window system. A window with a solar heat gain coefficient (SHGC) of 0.25 means only 25% of the heat from the sun is transmitted through the window.

How is solar heat gain reduced?

Use a window system with a low-E coating on the glass that is designed to block solar heat gain. Low-E glass is a specific type of glass that lowers solar heat gain while allowing most of the visible light to enter.

For a description of the key components that make up an energy efficient window system, select a topic below: