How does High-Performance™ Low-E4™ glass work?
A microscopic coating of titanium dioxide (TiO2) and Silicone dioxide is applied and bonded to the exterior glass surface during the glass manufacturing process. Sunlight is required to activate the coating. When the coating is activated, it loosens dirt, dust and organic material, which are then washed away by rain. The glass dries faster and reduces water spotting up to 99%.

Will it work on cloudy days and at night?
The unique exterior coating works similarly to a rechargeable battery. Once the coating is activated or "charged", it will hold its activation for some time, regardless of the time of day or weather. The more sunlight it receives, the better the activation. When re-exposed to sunlight, the coating will recharge after periods of lower sunlight levels.

Does it work immediately after being installed?
No, the glass must be activated. Since High-Performance™ Low-E4™ glass is activated by sunlight, results may vary depending on environmental factors, such as seasonality and location.

Will I ever have to wash my windows again?
High-Performance Low-E4 glass does not eliminate the need for washing windows. However, it will make the cleaning process easier. When active, High-Performance Low-E4 glass reduces dirt build-up, dries faster and reduces water spotting by up to 99%. Since the unique low maintenance coating is only applied to the exterior glass pane, the interior glass must be cleaned as normal.

Does High-Performance Low-E4 glass had a different color from Low-E Maximizer Plus® glass?
No, there is no visual difference between High-Performance Low-E4 glass and Low-E Maximizer Plus glass. The color and reflectivity of High-Performance Low-E4 glass meet Eagle's current color and reflectivity specifications.

How long will the benefits of High-Performance Low-E4 glass last?
The exterior coating is highly durable. Eagle will continue to offer the same limited glass warranty. The performance of the low-maintenance exterior coating will not be warranted. Performance results will vary depending on environmental conditions. See Eagle's limited warranty for more information.

Can the coating be damaged?
The low-maintenance exterior coating is highly durable, but it can be scratched. As a general rule, if you have visibly scratched the glass, you have scratched the coating. Razor blades should not be used to clean the glass, and sealants should not contact the glass as they can damage the coating.

Does it require special care or cleaning?
Common households liquid glass cleaner can be used to clean the glass. Ammonia and water or soapy water, are also recommended. Abrasive cleaners should not be used. Most common household chemicals will not damaged the low-maintenance exterior coating. Certain harsh chemicals may impair the coating's performance and/or damage the exterior coating. Razor blades should not be used to clean the glass, and sealants should not contact the glass as they can damage the coating.

How much does it cost?
High-Performance Low-E4 glass is standard. There is no additional charge for this glass.

Are the low maintenance properties on the interior glass pane too?
No, the unique coating is only applied to the exterior glass pane.

How is High-Performance Low-E4 glass different and better than other low maintenance glass products on the market?
Some companies offer low maintenance glass products as an upgrade option. For many of these products, the glass reflects more light and appears "brighter" than regular glass. High Performance Low-E4 glass is avaialble on many of Eagle's glass options and meets Eagle's glass color and reflectivity specifications. High Performance Low-E4 glass is self-activating by exposure to sunlight, unlike other low-maintenance products, which require homeowners to activate the coating.

How is High-Performance Low-E4 glass warranted?
See Eagle's limited warranty for more information.

Learn about the history of Low-E4 glass from the October 15, 2008 Morning Eidtion
Energy-Saving Windows A Legacy Of '70s Oil Crisis- by Richard Harris