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You have decided to install new vinyl windows into your house. You make several window estimate appointments. Many sales representatives are gonna come to your house and show you different types of vinyl windows. But what about glass? You should know that the window is as good as it’s glass. About 70% of the window is glass area. Definitely you would want to know types of Low-E coating on the glass in your new vinyl windows.
So what is Low-E? It is special low emissivity coat, that goes on top of the window glass. In other words, when there is some kind of heat source inside your house or outside, the Low-E glass bounces back that heat inside the house or leaves it outside. In winter time, when hot air touches the glass inside the house, the Low-E coat prevents cooling it off. In summer time all the hot air stays outside the house. So at the end of the day you are saving money both in winter and summer times.
When we talk about Low-E we should know that it is not only adds energy efficiency to the vinyl window, but beauty as well. There are two types of Low-E glass coat: hard coat and soft coat. And you might imagine they have different properties. These two coats even look different. The hard coated glass has slightly bluish tint, while soft coated glass has greenish tint to it.
Hard coat Low-E glass is made by pouring a very thin layer of hot tin on to slightly molten glass surface. The glass with hard coating becomes very durable and it is hard to scratch it or remove the coat from the glass.
Soft coat Low-E glass is applied by adding zink, silver or tin. The glass of the window is placed into a vacuum chamber filled with gas and then it is electrically charged. The coating is pretty much delicate, that's why it is called soft.
These two types of Low-E coating have different energy efficiency ratings.
As you can see from the table, soft coat is more energy efficient, than
hard coat. The hard coat adds more durability for the window glass and more beauty. While soft coat adds more insulating qualities. So now you familiar with these two types of Low-E glass coats and you can choose the one you like for your new vinyl windows.