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September - October 2003

Carl Wagus AAMA Analysis

At Long Last
DOE Announces New Energy Star® Window Requirements; 
Some in the Industry Still Unhappy
by Carl Wagus


After the Department of Energy (DOE) proposed changes to its Energy Star® windows program in October of 2001, the DOE has finally announced its new criteria. Since the initial proposals, there has much discussion between DOE and the window and door industry as many in the industry were not happy with some of the proposed changes (see July-August 2002 DWM, page 42). Some, including many aluminum manufacturers, are still unhappy. 
New Criteria Announced
The definition of Energy Star-qualifying windows and doors (and skylights, which are also included) is based on their U-factors and solar heat gain coefficients (SHGC). The allowable limits for these parameters have been based on three climatic regions: a Southern “mostly cooling” zone, a Central zone and a Northern “mostly heating” zone.
On May 28, 2003, the DOE announced new, more stringent requirements for windows to qualify for the Energy Star rating, which are expected to:
• More accurately reflect actual climatic conditions across the country;
• Increase energy savings beyond those achievable with the old criteria and lower consumer energy bills; and 
• Set Energy Star criteria at a level consistent with, but more 
stringent than code (e.g., the 2000 International Energy Conservation Code’s [IECC]), wherever practical.

The final new criteria are based on four climatic zones, defined by ranges of total annual Heating Degree Days (HDD) and Cooling Degree Days (CDD). (See box below).

New Four Zone Energy Star Map

Windows & Doors Skylights
  U-Factor SHGC U-Factor SHGC
Northern  ³ 5,400 HDD  £ 0.35  Any  £ 0.60 Any
North Central 3,600 - 5,400 HDD  £ 0.40  £ 0.55  £ 0.60  £ 0.40
South Central 6,300 - 4,500 CDD  £ 0.40  £ 0.40  £ 0.60  £ 0.40
Southern  ³ 6,300 CDD  £ 0.65  £ 0.40  £ 0.75  £ 0.40

Previous map showing 3 zones. New map showing four zones. Manufacturers Express Concern
The responses from window manufacturers have been mixed, based variously on the potential impact on the market for their products, increased cost of labeling and handling, relative complexity of the four-zone approach and a perceived short timeline for implementation that would upset sales and marketing programs. 

The aluminum window segment of the industry is particularly concerned that the stringent U-factor requirement of < 0.40 in certain zones will limit the area where aluminum windows will qualify for the Energy Star program. 

Another recurring concern reflected in the comments received by DOE from AAMA members is the exclusion or diminished importance of high solar gain products, particularly in the Northern zone.

“The benefits of solar heat gain in significantly reducing heating costs in the North were ignored … by favoring products that actually block out the sun’s warmth in winter,” said Arthur Van Nostrand, president of Atofina Chemicals, in a statement posted on the DOE website. “One solution is to consider a minimum solar heat gain coefficient (SHGC) in the North [instead of a maximum], [but] the best solution is a true performance-based standard that appropriately reflects the tradeoffs between U-factor and SHGC in each region.” 

Jim DiBacco, executive vice president for Astro Shapes, pointed out in similar comments to DOE that the long-term durability of the product should also be considered. DOE should “review the results and evaluate the total energy performance of a product,” he noted. 

DOE Responds
To its credit, DOE seriously considered these concerns and made several adjustments to the program in its final form:

The criticized “short fuse” implementation date of August 29, 2003, prompted the addition of a 90-day transition period until November 30, 2003.

With regard to potential confusion among suppliers and consumers in understanding the new criteria, DOE will provide “resources and educational materials to ease the transition.” 
Addressing concerns over increased implementation cost, DOE noted that they “expect most manufacturers will offer products qualifying in two or more regions, reducing the need for more complicated product offerings and labeling.”

Finally, DOE’s response to the inability of aluminum-framed < 0.40 U-factor required for the Central zones was that it is “unfortunate,” pointing out that Energy Star program criteria were intended to be more stringent than applicable code. 

It was not much of an adjustment, but an olive branch was offered in the form of DOE’s expressed desire to “explore the concept of a ‘performance-based’ approach” involving SHGC/U-factor tradeoffs in certain areas, air leakage and product durability attributes. A workshop to explore this possibility is promised “in the coming months.” 

From the beginning, AAMA has worked closely with the DOE in the development of the Energy Star window criteria. As a key participant in the upcoming workshop, we will represent the interests of all market segments and framing materials in the fenestration

Pilkington Supports New Energy Star Guidelines

While some may not be happy with the new requirements, one company that says it is pleased is Pilkington. In a press release issued on July 3, 2003, the company said that the DOE’s decision to establish a new four-zone map allows window manufacturers to offer homeowners energy-efficient windows suited to their needs. Pilkington wasn’t as supportive of the DOE’s earlier proposals (see July-August 2002 DWM, page 42). 

“For the first time, the DOE guidelines for Energy Star criteria will recognize the benefits of passive solar heat when the criteria takes effect Aug. 29, 2003,” said Stephen Weidner, vice president of sales and marketing for Pilkington Building Products North America. “The criteria for each of the four zones recognize the unique cooling and heating days ratio of each region. The announcement will not only benefit Pilkington and other pyrolytic low-E suppliers, but it also enables many window manufacturers to offer an Energy Star window.”

Carl Wagus serves as technical director for the American Architectural Manufacturers Association in Schaumburg, Ill. 

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