What is Low E glass?

Low-E glass stands for low emissivity glass. It has a coating that helps block out a substantial portion of ultraviolet (UV) light and infrared (IR) light while allowing the majority of visible light to pass through. This is important because of the impact of UV light and IR light on your home.

UV light is typically known for its role in causing skin cancer, which is certainly a good reason to be cautious of it, but that’s not the full extent of damage it can cause. It can also contribute to the fading of various materials - "bleaching" things left in the sun.

IR light is closely associated with heat energy - for the most part, the heat you feel from sunlight is the heat of infrared light. The exact relationship between infrared and heat is complicated, but it’s important to understand that controlling IR light increases control over the passage of heat through your window.

How does Low E work?

Low-E coatings help you to block out the majority of UV and IR wavelengths of light while still allowing most of the visible light through your window. A Low-E coat is microscopically thin and applied during the initial manufacturing process. It’s closely bonded to the glass to the point that you’ll struggle to notice it.

As a bonus, Low-E glass is applied from the manufacturer, so there is no risk in the coating voiding your warranty, which can happen with solar film.

In cold weather, Low-E glass can also help with energy efficiency by reflecting heat back into the home, helping to maintain warmth. In warmer months, it reflects heat away from the home, keeping it cooler.