Education

How Does Low-E Glass Block Heat?

Published on January 29, 2026

How Does Low-E Glass Block Heat?

If you live in Dallas, you know how hot it can get in the summer. In many previous articles, we’ve consistently recommended that homeowners upgrade to Low-E, or low emissivity glass, because it can keep heat out of the home.

You may wonder how Low-E glass can actually block heat while it still lets light in. Doesn’t this seem contradictory? The reason this is possible because much of the heating from the sun’s light comes from the invisible spectrums, infrared and ultraviolet light. This means it’s possible to let visible light through, while blocking the heat that comes from invisible infrared and ultraviolet rays.

Low-E glass can block up to 75-99% of ultraviolet rays and 80-88% of infrared rays. Because visible light is still let in, your room can still be brightly illuminated while reducing heat.

If you would like to upgrade your windows to Low-E, simply contact us and we will provide you with a free quote. We have experience installing windows all over the Dallas-Fort Worth metroplex for both residential and commercial clients.