What are the Benefits of Low-E Windows?

For most homeowners, natural light is an asset. It makes living spaces feel brighter and more open. It makes your space inviting. And it can help cut down on the use of electricity for lighting. Unfortunately, when you open up your home with more windows, you also make it more vulnerable to solar heat gain, radiant heat loss, and UV infiltration. Fortunately, there are new technologies on the market that improve efficiency and protect your home. Once such technology is low-E glass.

What are Low-E Windows?

By nature, glass is a highly thermal emissive material. It absorbs and transfers a lot of energy without reflecting much. So not only do you gain a lot of unwanted heat in the summer with plain glass, but you also lose a lot of radiant heat from inside during the winter. As a result, your energy consumption goes up as you try to maintain a comfortable temperature inside your home. Low-E is short for low emissivity, or low thermal emissivity. Manufacturers apply special coatings to one or more surfaces of the windowpanes to reflect radiant heat while still providing plenty of natural light.

When first invented in the 80’s, low-E glass was designed for one purpose: to keep infrared light inside for cold-weather climates. It would let as much light in as possible and then reflect the radiant heat (infrared light) back inside so the heat could not escape. The glaze acted as a thermal insulator and even in the winter, you could feel the warmth bouncing back through the windowpanes.

What are the Types of Low-E Glass?

Today, there are several unique methods manufacturers use to treat the glass so you can be comfortable in both winter and summer conditions. Usually they involve applying a thin metallic coat in or on the glass. There are two main methods:

1. Soft Coats (Magnetron Sputtering)

These have strong reflective capabilities, but because they can’t hold up against wind and rain, manufacturers often apply them to the interior surfaces of window panes. The process is complex. Manufactures must place the glass in a vacuum chamber to apply several thin layers of metallic oxide to the surface. As a result, soft coats are more expensive.

2. Hard Coats (Pyrolytic Coatings)

This low-e glass is mid-grade when it comes to energy efficiency, but can withstand the elements. For this process, the manufacturers apply the metallic coatings at high temperatures. And because they hold up, manufactures can apply them to exterior surfaces. That said, usually they suspend an ultra-thin metallic sheet between the two panes. That works as both a reflective and a thermal insulator, making a double-pane window perform almost like a triple-pane. Unfortunately, this option does have a higher solar gain and it can develop a slight haze over time.

What Kind of Low-E Windows Are Best for Tualatin, OR?

Because ours is a heating-dominated climate with moderate to cool temperatures, you want to look for passive low-e glass. This will let in light and warmth, and keep it in. If you have questions about low-e windows,Tualatin, OR contact EnergyGuard Windows and Doors at 503-554-5500 or visit us at by 516 E. 2nd St., Newberg, OR 97132.