In addition to insulation and heat loss regulation, air leakage is one of the most critical qualities to take into account when choosing new windows. In this article, our experts discuss everything you need to know about air leakage and why it is so important.

What Is Air Leakage?

Also known as air infiltration, air leakage is the measurement of air that passes through the cracks or gaps in the window structure. This measurement is determined prior to installation. In order to maintain that number and prevent drafts from occurring, the unit must be installed by a licensed and certified professional.

Air leakage is measured on a scale of 0.1 to 0.3. 0.1 is the least amount of air that infiltrates a window, although as long as the rating is below 0.3, the National Fenestration Ratings Council® (NFRC) deems it energy-efficient. The organization, however, does not recognize ratings below 0.1 because they believe that the difference is so unremarkable that it cannot be distinguished.

Why Is It an Important Rating?

If you are in the market for new windows, you will want to know how much outside air the window unit would allow to leak into your home. Knowing as much as possible about the windows is a safety measure you want to take before making such an important decision. However, since air leakage is not a required rating for windows, some manufacturers leave it out of the discussion completely. You should take this as a red flag.

For more information on energy-efficient replacement windows, contact Exterior Building Solutions. You can reach us at (314) 470-8783 or through our online form. Our team will work with you closely and present you with a wide range of options so you can make the best decision for your home.