When it comes to the overall performance of windows, the glass is critical, especially when it comes to energy efficiency. Low-E coatings also have an important role. They can significantly affect overall light, heating, and cooling costs in your home. But the concept of low-E glass can be confusing. How does it work? Is it really worth the extra cost? Here we explain what low-E means, how manufacturers produce it, how it works, and what is best for your area.
Properties of Glass
By nature, glass is a highly thermal emissive material—especially clear, single pane glass. It typically absorbs and transmits a lot of energy without reflecting much. This is why certain rooms in the house may feel hot during the day and cold at night. As a result, you end up using more energy to heat and cool your home. Low-E glass is one way to solve this issue.
What is Low-E Glass?
Low-E glass stands for “low emissivity.” Initially, it was created to reduce the amount of infrared and ultraviolet light coming through the windows without reducing the amount of visible light. Manufacturers apply a metal coating to surfaces of the raw glass. It is thinner than human hair and transparent. The coating reflects radiant heat either back outside, or back inside the home instead of letting the unwanted energy pass through. In turn, this regulates the indoor temperature of your home and reduces your energy expenses.
What are the Methods for Low-E Coatings?
Manufacturers use a couple of different processes. Some apply passive coatings at extremely high temperatures, baking the metallic coating directly on the glass during manufacturing. These pyrolytic or “hard-coats” are usually tin dioxide. The coat fuses to the surface of the glass and is very durable, so it is often used when additional coatings are needed on a surface of the glass that is exposed.
The other process involves putting the glass in a vacuum chamber and applying several thin layers of silver to the surface. This is called magnetron sputtering. The “soft-coat” is more energy efficient and is applied to the glass surface inside the airspace.
How Do Low-E Windows Work
Most manufacturers put coatings on the inside of the outer pane on double pane windows. It keeps radiant heat on the side of the pane it originates from, so it lets in visible light from the sun but bounces the heat back outside. It also works when you run your heater, reflecting heat back inside your home so it doesn’t transmit through the window.
Should I Get Low-E Windows
Low-E windows work well in both hot and cold climates—perfect for the area. Most companies will offer both hard coat and soft coat products. To figure out which low-E windows are best for your home, talk to one of the experts at Home Supply Windows and Door. We possess detailed product knowledge and will make sure your project is professionally executed from start to finish. We offer an outstanding commitment to our customers with high-quality results. You can call 973-949-5401 or visit our showroom at 160 Van Winkle Ave, Hawthorne, NJ 07506.