Plan Your Energy Efficient Windows Project

Plan How to Upgrade to Energy Efficient Windows Carefully

When upgrading to energy efficient windows be sure to select a window with the best U-Value, solar heat gain coefficient (SHGC) or air leakage rating for your region of the country. For example, in a hot climate, the sun's energy radiating through windows yields often a significant source of heat gain. As a result, windows that allow more heat gain, which result in your air conditioning system working harder (using more energy) and rooms overheating. Therefore, a window with a SHGC of less than .25 blocks more of the sun’s energy. The window reduces the amount of cooling needed from your air conditioner. In time, this saves real dollars on your air conditioning costs.

Conversely, in colder climates, SHGC makes less of a difference. However, homeowners must leverage the U-Value rating during an energy efficient window upgrade. For example, in cold climates, look for the U-values of .27 or less. Remember, the lower or smaller the U-Value rating, the less heat escapes from your windows. Think of low U-value windows as windows with "invisible insulation" in them.

Watch Out for Air Leakage During Energy Efficient Window Upgrades

Air leakage measures how much air enters your home through the window itself. The air leakage rating of windows should be .3 cfm/ft2 or less in any climate. Additionally, reducing air leakage minimizes cold, drafty air or hot, humid air from entering your home.

In addition to the NFRC Air Leakage rating through new windows, the amount of air leakage coming from AROUND windows remains critically important. However, typically the amount of air leakage entering your home from AROUND the window unit is not part of the NFRC or ENERGY Star labels. Therefore, homeowners must ensure air tight window installation. Plus, the amount of air leakage entering a home from around a window has nothing to do with the window itself. Rather, air leakage relates to how well the window is installed. As a result, if new windows aren’t installed properly, it is quite possible you can still experience problems. Typically, these potential problems include excessive air leaks, moisture problems, drafts and excessive exterior noise coming from your new windows.

Many industry experts agree, proper window installation remains one of the single most important aspects of an upgrade. As a result, homeowners must work with an experienced installer. Quality window installers know the importance of thoroughly air sealing windows with low expanding spray foam. This ensures you receive the maximum benefit from your new windows. Finally, discuss U-Values, SHGC values, air leakage ratings and installation procedures with any potential window installer.