GANA Voices Industry's Objections to ASHRAE 90.1 Committee
June 29, 2010

Representatives from Glass Association of North America (GANA) attended last week's meeting of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1 Committee in Albuquerque, N.M. Urmilla Sowell, GANA's technical director and Dr. Tom Culp, energy code consultant for GANA and the Aluminum Extruders Council (AEC), spoke to the committee at length about a proposed 30-percent window-to-wall ratio (WWR) limit included in the standard, as well as other items.

"We presented our concerns regarding the 30-percent WWR limit, lack of connection between the Visible Transmittance (VT)/Solar Heat Gain Coefficient (SGHC) requirement and lighting controls, U-factor and SHGC criteria inconsistent with the National Buildings Institute proposal to the International Energy Conservation Code, and the lack of glazing representation," said Culp. "There were also presentations from other groups objecting to some of the wall and metal building requirements."

"The presentations were well received, but it did not change the outcome," explained Culp. The vote to accept the proposal was 33-5-2. Oddly enough, the committee then heard a proposal to increase the WWR ratio to 40 percent with daylighting controls.

"The committee voted on final publication of this other addendum with 'knowledge of unresolved objections,'" explained Culp. "This time, the objections came from some of the envelope subcommittee members, but to no avail. Ironically, the vote was also 33-5-2."

With opposing proposals included in the standard, GANA noted in its statement that " the future may lead to a murky conclusion."

"Both addenda will move forward for final approval by a few overseeing committees and the ASHRAE board of directors," said Culp. "This is expected to happen at the end of July. There is a small chance one or the other could be rejected, but this is very uncommon. Therefore, pending any successful appeals, the 2010 version of ASHRAE 90.1 would include both aspects: a prescriptive limit of 30 percent WWR, but also the prescriptive option to use 40 percent WWR with daylighting controls. Larger glass areas would have to use the performance path."

GANA says such a result would be a success for glazing manufacturers.

"Although the added controls are expensive and may limit use of this option, this is a significant achievement," explained Culp. "This gives us more options, and also sets a precedent that more glass is not 'always bad,' preventing any further reductions in glass area in the future."

In related news, ASHRAE named Sowell as "consultant" to the Envelope Subcommittee, a non-voting position that allows her to participate freely in subcommittee discussions, as well as Culp who is a full voting member of the Envelope Subcommittee and full 90.1 committee.

CLICK HERE for more information on GANA and these efforts.

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