Are Low-E Windows Worth It?
Low E glass windows are all the rage today, the gold standard for truly energy efficient homes. But is Low E glass worth it? Do the windows still work? How? Do you know if you already own them?
Learn all this and more in our ultimate guide to Low E glass windows.
What is Low-E glass?
Low-E glass stands for low emissivity. low-E glass is clear glass that has been treated with an invisible metal oxide coating. The coating is invisible to the naked eye. Although the coating is thin, it creates a surface that reflects heat and blocks UV rays while allowing light to pass through.
Windows are a great investment for any home or structure, so whether you're building new, or replacing or upgrading windows in an existing home or building, considering the benefits of Low E glass can literally pay off in a big way.
How does Low-E glass work?
Low-E glass works because of the microscopic layers of reflective coatings applied to the glass. The "E" stands for emissivity, which allows the material (in this case, the coating) to radiate energy. As a result, houses and buildings with low-e glass windows are able to retain heat during the cold winter months and allow it to bounce back during the warm summer months.
Think of Low E glass as the silver lining inside a hot water bottle. When a warm item is inside, heat bounces off the silver lining and reflects back into the container to keep the contents warm. This is like the heat in your home during the colder months of the year. And, when you put cold items inside a hot water bottle, the opposite is true - the heat does not penetrate the silver liner. As a result, in the summer, outdoor heat is reflected or bounced off Low E glass windows, keeping your home cooler and reducing overall cooling costs.
Low-E glass, commonly known as low e glass, has excellent thermal insulation properties. The glass is coated with a special coating that allows only visible light to enter the room, thus protecting it from ultraviolet and infrared rays. This coating, also known as a low-e coating, gives the glass its thermal insulation properties. Low-E glass acts as a barrier between the internal and external temperatures, thus preventing energy transfer.
The low-e coating helps maintain the room temperature by reflecting energy waves back into the room. In the winter, low-e glass does not allow interior heat to escape through the windows and reflects the warmth back into the room. Low e glass also blocks most infrared radiation, thus reducing the amount of heat entering the building in the summer to some extent. As a result, it keeps the room cooler in the summer and helps reduce air conditioning costs. They are widely used in commercial buildings, skyscrapers, glass curtain walls, etc.
There are two types of low-e coatings depending on the method of application; hard-coated and soft-coated.
Hard-coated low-e glass.
Hard coatings, also known as in-line coatings, are done during the glass manufacturing process. The coating is applied when the glass is in the molten state and on a float line where it will gradually cool. When the coating is applied while the glass is in the molten state, the coating is tightly fused to the glass. Hard-coated low-e glass is typically used for glass facades in residential buildings.
Soft Coated Low-E Glass.
Soft coating, also known as off-line coating, is done after the glass is manufactured. The coating is applied at room temperature in a vacuum chamber. Soft-coated low-e glass provides better thermal insulation than hard-coated glass, but is less resistant to scratching. Therefore, soft-coated low-e glass is often used in the form of insulated glass units and double-glazed units.
Are Low-E windows worth it?
While they may be a slightly larger investment than regular glass windows, depending on where you live, Low E glass can be very good value for money. They provide you with a nice, beautiful new window look, with the added benefit of lower energy costs.
When you consider that they're actually only a few dollars more each compared to regular glass, we think they'll pay for themselves pretty quickly once you factor in your yearly savings on heating and cooling costs-round and round. According to Energy.com, 25-30% of heating and cooling use is due to heat loss and heat gain through windows - it's not hard to see how fast the savings can be!
Where are Low E glass windows a good investment?
If you live in a cold northern climate, you can use Low E coatings to stop heat from escaping. If you live in a warm southern climate, Low E coatings can effectively block heat from entering your home. So really, no matter where you live, low-e windows are a solid investment.
As a glass manufacturer, Northglass offers high-performance glass products for most window companies. Ready to learn more about low-E window glass? Contact us today to talk to our team about finding the perfect windows to maximize your home's comfort and energy efficiency.