What is Low- Emissivity, or Low-E Glass? And Why Does it Matter for My San Diego Home?

When you buy replacement windows, choosing the correct product for your San Diego home is important. There are several options to choose from and for some homeowners it could be an overwhelming experience. Without any prior knowledge about replacement / retrofit windows and doors you will rely on your own research and the information provided by the San Diego window companies you choose to contact for estimates. You may also find all the window and door lingo to be a little confusing. Our goal is to make the experience as easy as possible while providing you with the information to make educated choices.

One topic you’ll hear most San Diego window and door companies talk about is Low-E glass. But what is Low-E glass?

There are two types of Low-E, or low emissivity glass that San Diegans should know about.

Single Layered Glass

The first type is a single layered glass that if often labeled as LOE, LOE266, LOE2, etc. This glass is basically one layer of silver coating applied on the sheet of glass.

Triple Layered Glass

The second type is a triple layered glass, often called LOE366, triple LOE, etc. There are several different names used by various window and door manufacturers. Each has their own name which can make it confusing to decipher them. But the solution is to simply ask if the window is single layered or triple layered.

Triple layered glass is generally about 30%-40% more energy efficient than single layered glass.

Number of Layers Versus Number of Panes

While discussing single and triple layered replacement windows it’s very important not to confuse this with the number of panes. The layering refers to how many layers of Low-E coating are on each sheet of glass or pane, while terms like single pane and dual pane refer to the number of actual panes in the window. Or more specifically, how many sheets of glass are glazed together in an insulated glass unit.