Selecting Energy Efficient Windows

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Selecting Energy Efficient Windows

Selecting energy efficienct windows not only insures that you are buying a quality window, it also helps lower your energy costs and keeps you more comfortable throughout the year.

Energy Star Program

Well made windows will carry the Energy Star label that indicates that the windows meet certain requirements set by the Federal Government. These also carry a federal tax rebate that you can claim assuming you buy retail. (If you get windows through a company or contractor, they will more often than not benefit from the rebate and hopefully pass the savings onto you.) The Energy Star program requires certain performance numbers that vary based on what part of the country that you live.

By The Numbers

Performance numbers tell the story of how energy efficient your windows are. Here are the three important measures to look for and target numbers to shoot for.

U-factor: This measures the amount of heat loss that occurs through the window. Aim to get a .28 U-factor or better. A .22 U-factor or lower is excellent.

Air Infiltration: This measures how much air gets through the window and/or glass. Aim to get a .12 air infiltration or better. A .06 AI or lower is excellent.

SHGC: This measures the amount of solar heat that passes through a window and the right number will depend on your overall climate. Warm climates require a lower SHGC, while a colder climate requires a higher SHGC number. Ask each of the companies that provide you with a replacement window bid to suggest an ideal SHGC number to get a good idea of what the right number is.

Add Ons And Upgrades

The quality of each component that goes into a window affects how well it will perform both in the short term and the long term. This is why it's so difficult to tell the actual quality when looking at two windows side by side (just like if you looked at two cars side by side, but knew nothing about the guts of the engine). Here are a few add ons or upgrades that will help to make your windows more energy efficient.

A window that uses argon or krypton fills helps to reduce the transfer of heat or cold from the outer glass pane to the inner or vice versa. A quality non metallic spacer helps to lower the heat or cold transfer in double pane glass units. Low-e glass helps prevent heat from entering through the glass pane and there are several grades of low-e glass available. The quality of the frame construction and the glass package of a window are the two most important components in an energy efficient window.

Costs & Prices

Adding better components and upgrades will certainly affect the upfront price of the window. However, homeowners should balance this initial outlay of cash with the long term costs. Better and more energy efficient windows will save you money on energy bills - not a huge amount each month, but over a 20 year period it can more than cover the cost of an upgraded glass package, for instance.

In addition, well made windows will usually last 5 to 10 years longer than poorly made windows and that can add up to long term savings. Get the add on and upgrade costs in each of your bids and see what you can afford in order to make the best decision for your home and budget.