Industry Debates Code Proposal to Lower SHGC in Climate Zones 1-3
October 28, 2010

Energy efficiency is a major part of the International Code Council's 2010 Final Action Hearings, which are underway this week at the Charlotte Convention Center in Charlotte, N.C. A number of proposals relate directly to fenestration, and the outcome of the hearings will result in the 2012 International Energy Conservation Code (IECC), which will be published early next year.

Proposal EC25, for example, which was submitted by Bill Fay, representing the Energy Efficient Coalition, would lower the solar heat gain coefficient (SHGC) in climate zones 1, 2 and 3 from .30 to .25. During this morning's hearings the committee action up for debate was for disapproval, and several from the glass and fenestration industry spoke out both for and against the motion.

Speaking on behalf of the Window and Door Manufacturers Association, Jeff Inks said EC13 (the Department of Energy's residential energy code proposal that covered many areas, including more stringent envelope requirements), which was approved, already "gets us as close to 30 percent [energy savings] as we can get reasonably at this time. There's no need for what's proposed in EC25."

Inks added that the association was particularly concerned about SHGC.

"Not only is it different for some vertical fenestration products, but especially skylights. One of the things we don't see here is consideration for daylighting," said Inks, who added that a lower SHGC would lead to a reduction in visible light, in turn leading to having more light switches turned on and, consequently, more electricity usage.

Thom Zaremba, who spoke on behalf of Pilkington and AGC, also urged disapproval of EC25. He noted that the committee statement says the proposal takes an aggressive approach to increasing the stringency of the provisions well beyond EC13 and this would be too restrictive. "This one goes way beyond reasonable. The committee got it right [that this should be disapproved]," he said. "The 0.25 SHGC in the South will block 50 to 60 percent of the visible light. If that happens people will start turning lights on."

Tom Culp, speaking for the Glazing Industry Code Committee and the Aluminum Extruders Council, was also opposed to EC25, saying not only was it unnecessary, it contains flaws.

"Where are the skylights? Look at the prescriptive table. The skylight column is gone and there's no replacement provision." Culp said it also removes hurricane products, "which raises a real life safety structural issue. You cannot ignore or treat structural issues separate from energy … this promotes material that has a 30 to 35 percent lower design pressure."

Speaking on behalf of the American Architectural Manufacturers Association, Julie Ruth also urged disapproval. She addressed the cost-effectiveness of going to .25 in climate zone 3 and climate zone 2.

"These are parts of the country where buildings are traditionally built with some openness to the outside because there are certain times of the day where you want to take advantage of the outdoors to condition the indoor space," Ruth said. "We have no information that these changes would be cost-effective in these climate zones."

Others, including Chris Mathis of Mathis Consulting, spoke to approve EC25.

"Low solar heat gain glazing is available from every manufacturer and it does not mean a reduction in visible light transmittance," said Mathis, adding, "this code change has no technological advances in it … it uses technology we have today."

Mike Fisher with the Kellen Co. spoke on the issue of life safety.

"Please understand this proposal in no way changes any requirements for windows or doors or other penetrations to meet requirements for impact-resistance," he said. "There are products out there that meet the structural code and meet this code."

After rounds of comments and rebuttal, the committee's motion to disapprove carried.

The IECC code hearings continue in Charlotte, N.C., until October 31. Stay tuned to USGNN.com™ for more reports and updates.

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