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April-May-June 2002

Fenestration Focus

Reaching New Levels
        Industry Groups Advise Companies to Seek NFRC Certification
by Werner Lichtenberger

Consumers consider energy performance to be the single most important factor in deciding which windows to buy, according to a recent National Fenestration Rating Council (NFRC) survey. Based on this finding, energy-efficient products should be the manufacturer’s number-one priority. It’s not enough to tout your windows as energy-efficient: they need to be certified as energy-efficient by the NFRC.

Already a hot topic for most manufacturers, certified energy-efficient products will soon take on a new level of importance with the recent mandate from the National Association of Home Builders (NAHB). Much like the ENERGY STAR® Program and the Efficient Windows Collaborative, the NAHB is now advising members to use NFRC-certified products. It will be years before the full implications of this mandate are realized, but window manufacturers need to be even more aware of the importance of NFRC certification.

NFRC Certification
The NFRC has established a certification procedure for window thermal performance in the United States: The NFRC 100. This testing procedure determines an energy performance rating for your products.

For example, to receive NFRC certification a manufacturer’s window would first undergo thermal performance computer simulation by an accredited simulator. A random sample would then be taken from the manufacturer’s line of windows to be taken through physical testing. Once the testing facility determines an agreement between the two tests, the manufacturer will receive its product ratings. The manufacturer also must agree to periodic, unannounced technical audits by an inspection agency to ensure ongoing compliance.

The manufacturer is authorized to attach a temporary and permanent label to all products in the product line once the certification process is complete.

NFRC Compliance and Recertification
Most window manufacturers realize the importance of the NFRC and thermal efficiency, so they look to upgrade the components they use in their products continually. A great concern for many manufacturers is maintaining NFRC compliance when changing components and upgrading windows.

According to NFRC Technical Interpretation TI-200-96010: “component substitutions can be made as long as a simulator uses the approved NFRC simulation tools to verify the performance improvements.” This means that as long as the component is a better performer, you can substitute without changing your label.

In addition, to maintain compliance, the original certified U-values must be used to represent the new product. This is the one down side of retaining your label—you can’t show the improvement in the product. For that, you would have to redo the simulated testing process, which would be costly.

Cost is another factor to consider when dealing with the NFRC recertification process. To improve a window’s thermal performance, it can be quite expensive for the window maker in regards to updating label certification. To keep these costs down, upgrade at the time of recertification.

Also, keep in mind that for insulating glass spacer substitutions, only the spacer needs to be modeled. For glazing system changes, only the center of glass must be modeled.

Energy efficiency will continue to grow as a market trend as consumer preference and government regulations drive the demand for these products. As a manufacturer, you need to ensure your products are not only energy efficient, but also “certified” energy efficient.    

Werner Lichtenberger, P. Eng., serves as special projects manager for TruSeal Technologies Inc., based in Beachwood, Ohio.


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