It can be difficult to keep up with all the new advancements in window technology. Is this a new improvement or just a passing fad? Does that upgrade have staying power? And most important, is it really going to be worth the investment? In hopes of clearing things up, here is a breakdown on one of the most asked about advancements in the window market—Low-E windows.
What are Low-E Windows?
Glass is one of the most versatile building materials in use today. Unfortunately, by nature, it is highly emissive. This means it readily absorbs or transfers energy without reflecting much back. So during the day, your home would absorb a lot of heat through the windows, then at night, that heat leaches back out. You can guess this isn’t great for comfort or energy efficiency. Low-e, which stands for low emissivity, is a technology that improves the energy efficiency in glass on both windows and doors.
Manufacturers apply a thin layer of reflective material to the surfaces of raw glass to improve thermal efficiency and insulation. And depending on the type of material and the application process, you can get a range of results to help save energy and keep your home more comfortable.
What are the Methods of Application?
There are a couple of different ways manufacturers can apply the coatings. One is called a pyrolytic coating, or hard coat, used when the coatings are on the exposed surfaces of the glass. For this method manufacturers apply a thin metallic coat to the surface of the glass and bake it at high temperatures. The layer is still so thin it will not obstruct the light. And while it is more resistant, it is considered only medium grade when it comes to energy efficiency. This method is also more prone to developing a slight haze over time.
The more effective option is magnetron sputtering or a soft coat. For this method, manufacturers apply thin layers of silver between the panes of glass. It has to be between the glass because the layers are softer and need to be protected from scratching. This is the most effective and common method of improving the emissivity of residential window glass.
How do Low-E Windows Work?
The location of the application depends on what kind of heat transference you want to block or reflect. If you live in an area with hot summers, then you want to keep radiant heat from the sun from entering your home. In this case, you would apply a coat on the outer pane. But if you live in an area with freezing winters you want to trap radiant heat inside, and would want a coating on the inner pane of glass. Or if you live in an area with both hot summers and cold winters, you might consider getting low-E coatings to reflect heat in both directions. In our area, we typically have coatings on the outer pane, with an option to add additional coatings on the inner pane.
Do I Need Low-E Windows in My Home?
Most window manufacturers automatically include low-E coatings on their windows, as it is a very cost-effective way to improve the energy performance of the windows and reduce heating and cooling bills. To learn more, please talk with one of our window professionals. At Home Supply Window and Door we strive to stay abreast of every technology, striving to help you find the right products for your project. You can reach us at 973-949-5401 or visit 160 Van Winkle Ave, Hawthorne, NJ 07506.