Understanding How Energy-Efficient Windows Work

If you’re building a new home or remodeling an existing one, you’ve probably thought about installing energy-efficient windows. They look pretty similar to regular windows, so you’ve probably also wondered how exactly they work and how it’s possible that they could save you money and increase the comfort of your home. There are actually a couple of different techniques that manufacturers use to get the desired result.


Low-emissivity coatings, or low-E, reflect the rays of the sun away from your house, keeping a fair amount of heat from getting inside. Regular glass absorbs about 84% of the sun’s heat rays, while glass treated with a low-E coating absorbs less than 35%. These coatings also work to keep the warm air in as well, and since this technology is see-through, it doesn’t obscure your view or the beauty of natural light. There are several glazing options and tints to further maximize the solar reflection of the glass.


The spacer’s main function is separate the two glass panes in the unit, and it helps to provide relief from the stresses that come along with expansion and compression due to differences in temperature. Spacers also provide a moisture barrier, a seal, and an insulation barrier. While they’re still commonly made of metal, they’re also being produced more widely from alternative materials like silicone, vinyl, and fiberglass. Warm-edge spacers have the added bonus of creating a larger thermal effect, expanding the area affected beyond the edge of the window.

Gas Fills

Manufacturers use inert gases, usually argon or krypton, to improve the thermal performance of the unit. These gases aren’t toxic, and they’re also clear and odorless, which makes them the perfect choice for this application. Of the two gases, krypton works better, but it’s more expensive. It’s also the most useful for thinner glazing areas that are less than a half an inch. Argon, on the other hand, works in a normal half-inch glazing. These two gases can also be mixed for a compromise between cost and production. The chosen gas or gases are placed between the two panes as an added barrier between your home and the elements outside.


When deciding on which of the many different kinds of energy-efficient windows available, you’ll also want to think about the kinds of frames you choose as well. You may want to consider a non-metal, thermally improved frame to optimize your investment.

While these home features seem like an obvious choice, understanding exactly how these windows work will help you choose the right ones for your home, your aesthetic, and your lifestyle.

Looking for energy-efficient windows? Portland residents can learn more about their available options by visiting http://www.advancedenergyoregon.com/.