When you search for your replacement windows, be sure to look for industry certifications. These certifications help ensure that manufacturers produce quality products with high energy efficiency. When you compare replacement windows, the major labels you’ll encounter are:

• AAMA certification (American Architectural Manufacturers Association)
• NFRC certification (National Fenestration Rating Council).

AAMA Certification and AAMA Windows

American Architectural Manufacturers Association (AAMA), is an organization comprised of companies that manufacture, service and consult on:

• Curtain walls
• Doors
• Skylights
• Storefronts
• Windows.

Together, members create and develop standards for providing third-party validation of product performance and quality of replacement windows and other building components.

Windows with AAMA certification have an AAMA label with the organization’s logo on the far left. In order for replacement windows to be categorized as “AAMA windows”, they must be found to demonstrate superior performance and meet the standards outlined by the AAMA.

AAMA certification labels specify certain information about various replacement windows in a four-part code, specifying:

• Product type
• Performance class
• Performance grade
• Maximum size tested.

Customers who purchase replacement windows can rest assured that these units are up to par with industry standards. These findings are determined by independent laboratory testing and followed up on-site.

Here are just a few of the manufacturers of replacement windows with AAMA certification:

• Acadia Windows & Doors, Inc.
• Burris Windows
• Champion Window and Door
• International Window Corporation
• Pella Vinyl-Portland Operations.

NFRC Certification and NFRC Window Ratings

The NFRC is a non-profit collaboration of groups that focus on the energy efficiency of:

• Doors
• Skylights
• Windows.

These groups include:

• Building trade associations
• Consumer organizations
• Government agencies
• Manufacturers
• Suppliers
• Utility companies.

NFRC window ratings are a labeling system, also used on doors and skylights, to establish energy performance. The group uses a fair, accurate, reliable and credible method to determine energy efficiency.

Replacement windows feature labels with their NFRC window ratings. NFRC Certification considers a replacement window’s performance during both winter and summer:

• SHGC: In the summer, NFRC windows block solar heat from entering the home. This blockage is measured and denoted as a Solar Heat Gain Coefficient (SHGC), and is expressed as a number between zero and one.
• U-Factor: In the winter, replacement windows with NFRC certification allow the least amount of heat to escape, with the amount expressed as a “U-factor”, typically between 0.20 and 1.20.

Additional ratings on a NFRC certification label may include air leakage and visible transmittance.

To help consumers find replacement windows with NFRC certification, this organization publishes books with all the products they have tested. Some of the products listed in the book include:

• Acadia Windows & Doors
• Burris Windows
• Continental Window & Glass
• Pella Corporation
• Window Corporation.

Many replacement window companies, including some of those listed above, have numerous certifications. Look for replacement windows with both AAMA certification and NFRC certification, as well as other window ratings, as they are usually the best options.