EC22: Part One Disapproved; Part Two Approved as Modified by Public Comment Two

After drawing much debate during the ICC code hearings this week in Minneapolis, EC22 part one was disapproved as previously recommended by the code committee. Part two, however, was approved as modified by public comment two.

Part one called for changing glazed fenestration solar heat gain coefficient (SHGC) requirements in zones one and two from 0.37 to 0.30 and zone three from 0.40 to 0.30 as well. Original and primary reasons included the impact low SHGC windows have by reducing cooling energy use and increasing heating energy use. The committee's basis for recommending disapproval was in anticipation of consideration of more aggressive values in EC24 and EC26.

Several spoke in favor of the committee's motion to disapprove part one, many agreeing that changes in EC26 represented a suitable alternative.

"I support the committee, but I do think that some of the proposals in EC22 part one would be improvements over the current energy code, but I think EC26 does a better job and was approved by the committee," said Garrett Stone representing Cardinal Glass. "I would therefore suggest it instead."

Tom Zaremba, speaking on his own behalf, pointed out differences in EC22 and EC26 regarding hurricane protection.

"This particular proposal, EC22, has a hurricane exemption," Zaremba said. "EC26, as it was modified, does not. I urge you disapprove the committee's recommendation and move on to the opportunity to consider the public comments."

Tom Culp, representing the Aluminum Extruders Council, spoke in opposition to the committee's recommendation. One of Culp's points referenced what he saw as an oversight in previous discussions involving skylights.

"I agree, there are a large number of products available to meet the 0.30 requirement," Culp said. "However, the bulk of the products in the NFRC are your standard, double-hung windows. But this code and its requirements apply to all products and we need to account for that. It also applies to skylights and I think a lot of people forgot about skylights when this was being debated."

Culp argued that a 0.30 requirement represented a conflict of interest, based on the purpose of installing and using skylights. "The whole purpose of a skylight is to bring in light and, yet, the 0.30 requirement will tend to decrease visible light transmittance," he said. "It's going against the whole purpose of having a skylight."

Culp suggested the 0.30 level was a suitable goal for the future, but perhaps a bit premature. "The 0.30 requirement does save energy, but it's a little too far at this time," he said. "The 0.35 is more reasonable. The way to do that is to overturn the committee and then you get consistency with some of the public comments regarding EC22."

The committee also motioned for disapproval of EC22 part two. Suggested changes in part two also included adjusting SHGC ratings for insulation and fenestration requirements by component to 0.30 in zones one through three. Public comment two called for softening those requirements to 0.35, which was ultimately approved as submitted.

In summary, following are the final decisions regarding U-factor and SHGC:

U-Factor
Zone 1 stayed at 1.20
Zone 2 moved from 0.75 to 0.65. Products with impact rated glazing stay at 0.75.
Zone 3 moved from 0.65 to 0.50. Products with impact rated glazing stay at 0.65.
Zone 4 moved from 0.40 to 0.35.
Zone 5-8 stayed at 0.35.

Note: these apply to all fenestration besides skylights. None of the skylight U-factors changed from the 2006 IECC values.

SHGC
In the IECC, zones 1-3 moved from 0.40 to 0.30.
In the IRC, zones 1-3 moved from 0.40 to 0.35. Products with impact rated glazing stay at 0.40.
In both, there continues to be no requirement for zones 4-8, and also not in Marine 3.

Note: these apply to all fenestration, including skylights.

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