Certifications such as the National Fenestration Rating Council®, National Accreditation & Management Institute® and ENERGY STAR® show that a window has met important performance requirements. These certifications are important and intended to provide unbiased facts that homeowners can use to evaluate different window products.

However, when shopping for windows, don’t accept a verbal promise that a company’s windows are certified. Ask to see a copy or documentation of the certification and make sure each window you are planning on purchasing has a certification label affixed to it.

Unfortunately, some companies will test a modified window for a “high performance” label, but unless the window you purchase has the certification label attached to it, it isn’t certified and may not be the same window that was represented during the sale. 

1. This is the name or logo of the window manufacturer.

2. Look for this label for assurance that this window has been independently rated using a procedure established by the NFRC. Although other labels may be present, the NFRC label is your best source of energy performance information.

3. The NFRC rating is a numerical value which represents the applicable energy performance characteristic. Residential (or "AA”) and Non-Residential (or “BB”) are NFRC size designations. Representative test sizes are compared among different manufacturers.

4. U-factor is a measure of heat transfer by the entire window (frame, sash and glass), either into or out of the building. A smaller U-factor will provide a window which is more comfortable to sit next to on cold days. Try to purchase a window with the lowest U-Factor.

5. Solar Heat Gain Coefficient (SHGC) is a measure of the solar energy entering the building through the entire window. A lower SHGC will reduce air conditioning costs and provide a more comfortable window to sit next to on hot days.

6. Visible Light Transmission (VLT) is a measure of the amount of visible light entering through the window. This measurement is not a percentage, but rather a rating between 0 and 1 with zero blocking out visible light and one allowing all visible light to enter the room. (A double pane of clear insulated glass has a VLT of .59)

7. This is the manufacturer’s description of the labeled product.

The National Accreditation & Management Institute label certifies the window has passed all structural performance tests conforming to NFRC and AAMA standards, including forced-entry resistance, resistance to air infiltration, resistance to water infiltration and design pressure

For more information on rating systems, visit https://www.nfrc.org/energy-performance-label/

Or, you can view a factsheet PDF https://www.nfrc.org/wp-content/uploads/2020/04/Energy_Performance_Label_Zone_Official.pdf

It's frustrating when you notice that your home's windows are no longer functioning properly.

No one wants to look out their window and be unable to see through the glass because of a permanently foggy window or feel drafts on a cool fall night when the window is completely closed.

So why do windows fail in the first place?

Windows, like most man-made objects, don't last forever.  There are several factors that can cause residential windows to fail prematurely and they can be broken down into three main categories:

• The quality and materials of the original window.
• How the window was installed.
• How well the window has been cared for.

Purchasing quality windows made with superior materials to help keep your home secure and comfortable year-round, should be a major consideration instead of just price.

Sure, cheap windows are less expensive up front, but you'll end up replacing them decades sooner than quality-made windows and you'll more than likely end up paying more to heat and cool your home over time than if you were to purchase quality, energy-efficient windows like Kehl Windows, in the beginning.