DOE Implements Performance-based Ratings for South and South Central Regions

Speaking before members of the Window and Door Manufacturers Association (WDMA) at the association's annual technical conference in Chicago in May, Mark LaFrance, technology development manager for the U.S. Department of Energy (DOE) announced a change to the DOE's ENERGY STAR™ program.

The DOE has implemented a performance-based rating system for the South and South/Central (excluding California) areas of the United States, thus allowing trade-offs in these areas. According to LaFrance, trade-offs deliver equivalent average energy performance when integrated over the specific region. He added that the DOE's rationale for this announcement includes the following:

  • In the South/Central zone limited trade-offs work, but U-factors required are below most aluminum windows in the NFRC database, opportunity for investment.
  • In the Southern zone, trade-offs work and allow for hurricane windows to be compliant. For example, laminated low-E glass for constructing impact-resistant hurricane windows have higher U-factors. These windows cannot routinely meet the perspective U-factor criteria, but can deliver equivalent energy performance with lower solar heat gain coefficients.

LaFrance noted that the rationale excludes the Northern and North/Central zones, which allow no latitude for trade-offs. He also pointed out that California is excluded from the South/Central because viable trade-offs did not work when it was included. Additionally, California has very large populations living in moderate climates.

LaFrance also added that this change offers equal or greater average energy savings than the current perspective criteria, while providing greater flexibility in U-factor performance ratings. It also meets or exceeds prescriptive building energy codes in the applicable regions, while enhancing the value of the program.

While the changes made by DOE appear to result in equivalent energy savings, many WDMA members believe that the ENERGY STAR changes will complicate the otherwise simple rating system, and cost more energy by allowing lower performing products to claim ENERGY STAR ratings.

"The products actually labeled as ENERGY STAR often exceed the required minimum values," said Jeff Lowinski, WDMA's acting president. "Using the new trade offs, some WDMA members are concerned that the minimum product may be allowed to be used, instead of the higher-efficiency product."

Lowinski acknowledges, however, that ENERGY STAR trade-offs may be needed in the future to give credit for dynamic glazing systems.


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