The Anatomy of an Energy Efficient Window
By improving window efficiency, you can dramatically improve your overall home efficiency.
Everyone wishes their home was a little more energy efficient. Not only does this mean more money in your pocket, but it will also mean a more comfortable home, especially during those extreme summer and winter months. Energy efficiency is the goal, but how do you get there? Where do you start?
Money Flying Out the Window
The U.S. Department of Energy (DOE) estimates that as much as 40 percent of the average home’s heating and cooling costs can be attributed to its windows. In fact, your windows are one of the biggest energy wasters in your home. By improving window efficiency, you can dramatically improve your overall home efficiency. But what makes a window energy efficient?
When it comes to your windows, your mother was right – it’s what’s on the inside that counts. In between the panes of glass in double and triple pane windows is a layer of inert gas — typically argon or krypton. These gasses are poor thermal conductors and help slow the passage of heat through the window.
Energy efficient window glass also features what is known as Low-E coating. This special coating covering the panes of glass reduces heat transfer – preventing heat from entering your home in the summer and stopping it from leaving your home in the winter. Low-E coating also reflects infrared and ultraviolet (UV) light, protecting your home from the damaging effects of the sun’s rays.
The window frame represents roughly 25% of the window’s total area, so it is easy to see why it plays such a big role in terms of energy efficiency. Options include wood, fiberglass and vinyl.
- Vinyl frames are good efficiency boosters thanks to their insulated cavities.
- Fiberglass frames have a higher heat transfer resistance than wood or vinyl but are more expensive.
- Wood frames are naturally efficient, but are very high maintenance.
The High Cost of Replacement Windows
Based on a study by HomeAdvisor, “The average national cost of window installation is $4,759, with most homeowners spending between $2,614 and $7,084.” Yet, according to Energy Star, homeowners in Maryland, Washington DC, and Virginia can only expect to save $93 per year by replacing double-pane windows. Even on the low end of the spectrum, it would take the average homeowner more than 28 years to recoup the cost of window replacement.
Even the best windows have a hard time doing everything themselves. So, instead of paying thousands upon thousands of dollars for new windows, homeowners can improve the energy efficiency of their current windows with the right blinds, shades, or shutters. Every window treatment has unique energy saving properties that can help increase the energy efficiency of your windows, providing year-round savings on heating and cooling costs. Take honeycomb shades, for example. While a standard uncovered double-pane window has an R-Value of 1.16, a window with Blackout Honeycombs is around 5.00. The secret is the honeycomb design. Each honeycomb, or cell, produces insulating pockets of inert air – a poor conductor of heat – which can help reduce heat transfer through a window by as much as 55-65%.
According to interior designer Lisa Scheff, honeycomb shades “act as insulation, protecting your home from cold and heat with their energy-saving honeycomb design.”