EPA Issues Draft Energy Star Changes

July 26, 2012

Taking the next step to finalizing new criteria for Energy Star windows, doors and skylights, the Environmental Protection Agency has issued its  Version 6.0 Draft 1 Specification, along with an in-depth criteria and analysis report. With a tentative effective date of January 1, 2014, the new proposed criteria include a maximum U-factor of 0.27 for the Northern climate zone, a move likely to lessen the pressure on manufacturers to offer triple-glazed products.

EPA developed the latest draft, which also includes new air infiltration rating and installation instruction requirements, based on feedback received on an initial specification framework document released in October 2011. Before it determines the final 2014 requirements, the agency will again accept written comments on its new draft criteria and is also planning an in-person stakeholder meeting and concurrent webinar on Monday, August 27.


Proposed Criteria
In its initial proposals, EPA said it was considering a maximum U-factor of 0.25 to 0.27 for the Northern climate zone. In opting for the 0.27 number, EPA notes that in its analysis of the National Fenestration Rating Council certified products directory, double-pane windows dominate those offerings with a 0.27 U-factor, while triple-glazed units become more dominant below that level.

"Double-pane windows are typically much more cost effective than triple-pane windows," the document states, adding that "EPA is interested in promoting enhanced performance of double-pane windows while also acknowledging those manufacturers who have already made the shift to triple-pane windows, especially those that have found a way to do so in a cost-effective manner."

Window criteria changes initially proposed for other climate zones generated much less industry discussion. For the North Central region, EPA is now proposing that the maximum U-factor be decreased from the current 0.32 to 0.29 level. In the South Central zone, the same number declines from 0.35 to 0.31. For the Southern region, EPA is bringing the U-factor maximum down from 0.60 to 0.40.  

These proposed revisions, as well as lower SHGC requirements, are based on EPA's goal to have Energy Star U-value and SHGC maximums to be equal to or more stringent than code, it notes.


Door and Skylight Performance   
The draft U-factor criteria for doors fall in the middle range of EPA's October 2011 proposals.  U-factor requirements for opaque doors will be ratcheted down from the current 0.21 for opaque doors to 0.17. Doors with less than a half-lite of glazing will see U-factor requirements go from the current 0.27 to 0.23, while doors with more than a half lite of glass will see those numbers go from 0.32 to 0.30.  SHGC maximums for non-opaque doors will head down from 0.30 to 0.25.    

To determine technological feasibility, EPA says it reviewed the door data in NFRC's certified product directory and found that at the proposed criteria levels approximately 77 percent of opaque, half-lite, and quarter-lite doors would qualify. Of the greater-than-half-lite doors, about 67 percent would qualify, it reports. EPA also notes that the four major core materials would be able to qualify.

For skylights, EPA is proposing more stringent U-factor and SHGC requirements for all climate zones. The latest draft also notes that despite some suggestions for separate criteria for tubular daylighting devices, these products can continue to qualify under the skylight criteria.


Air Infiltration
As noted, the next round of Energy Star criteria will include some new requirements, including an air leakage rating. EPA is proposing that windows, sliding doors, and skylights must have an air leakage rating of 0.3 cfm/ft² and swinging doors must have an air leakage rating of 0.5 cfm/ft².

"EPA has opted to match the air leakage requirements of the 2012 IECC to help ensure that Energy Star qualified products help consumers avoid unnecessary additional heating and cooling costs," the analysis report. 

For testing purposes, EPA proposes allowing either NFRC 400 or ASTM E283 to determine air leakage ratings. The agency plans to work with NFRC to develop an air leakage labeling methodology.

Installation Instructions
Another important addition is a requirement for installation instructions. The Draft 1 specification states that to qualify for Energy Star, "products shall have installation instructions readily available online or packaged with the product. Electronic versions of instructions may be provided on the website of a retailer, manufacturer, and/or industry association."

According to the draft, these instructions shall include:

  • A list of hardware and tools required for installation, including those provided by the manufacturer and those not provided by the manufacturer.
  • Diagrams/pictures and descriptions of the product and parts provided by the manufacturer.
  • General guidance on safely removing old products and preparing the frame for installation, including proper management of lead paint when applicable. (Inclusion of diagrams/pictures is preferred, but optional.)
  • Detailed flashing instructions including diagrams/pictures or reference to the applicable flashing manufacturer’s instructions.
  • Instructions on properly shimming the product to achieve an installation that is flush, level, and plumb. (Inclusion of diagrams/pictures is preferred, but optional.)
  • Guidance on sealing and weatherproofing to prevent air and water infiltration. (Inclusion of diagrams/pictures is preferred, but optional.)
  • Variations of the above based on whether the job is a pocket installation, rough opening installation with exterior sheathing intact, and/or rough opening installation with exterior sheathing removed (e.g. new construction installation), as applicable to the product.

The EPA report notes that several other program elements–such as special Energy Star criteria for products to be installed at high-altitude and for impact-resistant products–were considered for adoption, but that there is still insufficient data and/or little justification for at this time.  Most significant of these potential program changes was a requirement that products must be tested and certified for structural performance, which EPA says it will consider for the Energy Star Version 7. 

Most Efficient
In its discussion of the new window performance criteria, the report also raises the prospect of a "Most Efficient" program.  EPA currently offers such a program, designed to recognize the highest levels of energy efficiency, in several product categories.  "If a Most Efficient program for windows is put into place in the coming year," the current report says, "it could have a dramatic impact on future criteria revisions for the mainstream Energy Star program. Having Most Efficient criteria that highlight the very top performers, allows Energy Star for Windows, Doors, and Skylights to focus on less aggressive criteria levels. At the same time, a Most Efficient program could drive program innovation forward in such a way that more aggressive criteria levels are much more feasible than they would otherwise have been. Most Efficient also allows the opportunity to explore other program criteria or options, which may later be adopted into the Version 7.0 specification." 

EPA is soliciting feedback on the proposed criteria. Comments may be submitted to windows@energystar.gov and must be received by Friday, September 28, 2012.  Details on the in-person stakeholder meeting and concurrent webinar scheduled for August 27 will be provided at a later date.