Shopping for new windows can be confusing. Where do you begin? How do you decide which window will perform better than others? Where do you obtain unbiased facts?
Well, these are all questions that have been asked by many consumers. The window industry is finally responding. The voluntary performance rating and labeling system is designed to provide accurate information to homeowners.
Do you remember comparing fuel economy stickers on automobiles? It showed you how many miles per gallon the car would get in the city and highway. Companies that have their windows tested and certified, both structurally and thermally, are assuring you that the products being installed in your home are identical to the tested products in both construction and performance. Be sure to buy a window that is tested, certified and labeled.
NAMI Certification Label
The National Accreditation and Management Institute (NAMI) is an independent company which provides third party certification and inspection services to the fenestration industry. This gold label is a "guarantee" from the manufacturer that the product satisfies the requirements through AAMA standards. Therefore, the products must meet the applicable standards, and second, prove continuous compliance to the standards.
This certification label indicates the standard to which the product was tested, a code or name (to provide traceability) of the manufacturing facility, the structural performance level achieved, the series or model name of the product and other information pertinent to that product.
CAUTION: ONLY PRODUCTS BEARING CERTIFICATION LABELS ARE CONSIDERED CERTIFIED PRODUCTS.
NFRC Label
The National Fenestration Rating Council is a non-profit organization created to provide accurate information to measure and compare the energy performance of window, door or skylight products.
To the bottom is an example of a NFRC Label with each section clearly explained. Shopping for windows can be confusing. Use this label to truly compare energy performance ratings.
FACT: Architects purchase only windows that are certified and labeled.
- This is the name of the window manufacturer.
- Look for this label as your 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.
- 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.
- 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.
- 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.
- 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)
- This is the manufacturer’s description of the labeled product
