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Volume 6   Issue 6                July  2005


Energy Star Loses Luster
by Michael Fischer

Since 1992, when the U.S. Environmental Protection Agency (EPA) introduced Energy Star as a voluntary labeling program aimed at reducing the emission of greenhouse gases through the use of energy-efficient appliances and products, the program has symbolized the best in new technology. The Energy Star label told consumers the product stood above the rest and represented cutting-edge energy efficiency. With the latest revision to the Energy Star window program, however, that perception is being challenged. 

Energy Star Usage Increases
The percentage of Energy Star windows in new construction has increased steadily since the window program’s inception in 1998. Consumer demand and window manufacturer supply trends have combined to create a dramatic increase in the use of high-performance, energy-efficient windows. As technologies improve, and the exception becomes the rule, we feel this is not the time to lower the bar. 

As the EPA stated in 2000 in the High Performance Windows Fact Sheet, “In recent years, many technological advances have been made that significantly enhance the thermal performance of windows ... these technologies include improved framing materials, low-emissivity and solar control coatings, low-conductance gas fills, improved thermal breaks and edge spacers, and better edge sealing techniques.” 

During an address at the Window and Door Manufacturers Association (WDMA) technical conference, Marc LaFrance of the U.S. Department of Energy’s (DOE) building technologies program presented a session titled “Windows R&D and Energy Star.” In his presentation, LaFrance reviewed the window roadmapping program and outlined the DOE’s goal of Zero-Energy-Homes (ZEH) by the year 2020. He also discussed changes in window technology from single-glazed clear windows in 1973 to today’s double-glazed, low-E product and the corresponding energy savings of 30 to 65 percent. Looking forward to the advent of the ZEH, LaFrance outlined potential new window technologies including highly insulated products, dynamic solar control and daylight redirecting windows. 

New Trade-Offs Announced
The most significant part of the presentation for the near future, however, was the unveiling of new trade-offs to current performance-based requirements that will go into effect on September 19, 2005 in the Southern and South/Central Zones of the Energy Star windows program (see June DWM, page 57). The DOE decision to allow windows that feature lower solar heat gain coefficient (SHGC) values to have higher U-factors in those two regions may seem on the surface to be a reasonable approach to window performance, but I believe it is fraught with inconsistencies and represents a step back in the evolution of high-performance windows. 

The Energy Star window requirements have been simple and have promoted clarity in adoption, interpretation and enforcement. The addition of trade-offs add unnecessary complexity to a simple user-friendly program. There will actually be five Energy Star window zones instead of the three that existed in 2002 with the exclusion of California from these latest changes (see chart and map, page 16).

In 2003, the Energy Star windows program changed from a three-zone to a four-zone approach despite opposition from the majority of the window industry including public comments from both WDMA and the American Architectural Manufacturers Association (AAMA), after lobbying from special material interests within the building products industry. For example, the “Keep Aluminum Windows” (KAW) initiative formed in 2002 by the Aluminum Extruder’s Council (AEC) expended significant effort to protect aluminum material interests. The KAW mission, as stated on the AEC website, is “to keep aluminum windows as a viable and preferred component within the residential and commercial construction markets.” Further activities of the KAW include “Aggressively opposing all Department of Energy (DOE)-Energy Star proposed changes detrimental to aluminum interests.” None of the stated goals of the AEC’s KAW efforts include promoting energy-efficient windows; rather KAW appears to be focused on protecting the interests of the aluminum industry.

Performance-based Approach 
WDMA has taken a material-neutral stance to the development of codes and standards by advocating a performance-based approach to product requirements. That stance extends to the use of non-mandatory programs like Energy Star. In releasing the new performance trade-offs, the DOE rationale includes the statement that impact-resistant hurricane windows cannot meet the existing Energy Star U-factor criteria. In fact, there are hundreds of available window products that meet impact protection, high wind load requirements as well as U-factor and SHGC requirements in effect from the Texas Gulf Coast through the Florida Keys to the tip of Long Island. 

Some Misconceptions
There is another popular misconception regarding the conflict between hurricane windows and energy performance. The DOE news release regarding the revised performance criteria mixes impact and wind resistance within the Florida market. Only windows found along the coastal zones in close proximity to open water need to meet impact provisions, but the new Energy Star performance measures extend across the width of the country. 

If impact protection requirements did in fact create a conflict between structural and energy performance requirements, it is limited only to those areas within the coastal zones. In a comment filed with the DOE, however, the AEC does not recommend that the performance trade-offs be limited to impact-resistant products despite using their need as a basis to justify modifying the program. There is no need to sacrifice thermal performance to achieve structural integrity unless material interests are the only yardstick applied.

The implementation of the new Energy Star provisions that allow less efficient windows to trade off SHGC takes a simple approach to a complicated design scenario. By lowering the bar and broadening the number of products that will qualify for the Energy Star label under the guise of inclusion, the DOE has weakened the value of the Energy Star brand. Currently, available products that meet both U-factor and SHGC performance values and that meet coastal impact requirements will be lumped in with those that barely qualify. 

The DOE states that “The availability of Energy Star qualified products will ensure a greater proportion of hurricane-resistant windows sold are also energy-efficient.” In fact, however, this relaxation of the Energy Star standards will simply ensure that more products that currently meet both structural and energy-code requirements will also carry the Energy Star label. 

Where do we go from here? As the DOE moves forward with window roadmapping, and towards the goal of the ZEH, it is important that energy efficiency—rather than the special interests of market segments—be paramount. While the future of windows may well include more stringent structural requirements, Energy Star should continue to represent the best of available products, not the average. In particular, the use of material-neutral criteria that will spur investment in new technologies and guarantee the future energy savings critical to the future U.S. energy demand should be the basis for the Energy Star program as the building industry moves to the next generation of windows. 

Michael Fischer serves as director of codes and regulatory compliance for the Window and Door Manufacturers Association based in Des Plaines, Ill. 

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