Proposed changes designed to improve the energy efficiency of buildings covered by ASHRAE Standard 90.1 are open for public comment.

The standard provides minimum requirements for the energy-efficient design of most buildings. Currently, 18 proposed addenda to the standard are open for review.

“As we move toward publication of the 2010 standard, the 90.1 committee is considering many changes to reduce building energy use and cost,” said Mick Schwedler, chairman of the American Society of Heating, Refrigeration and Air-Conditioning Engineers Society committee handling the revisions. “The proposed addenda that are out for review move toward our goal of 30 percent energy-cost savings.”

Among the proposals is an addendum that would require a supply air temperature reset in multiple-zone HVAC systems. Balancing the reset with an increase in fan energy can substantially reduce system energy use, Schwedler said.

“A preliminary energy analysis indicates that the whole building energy savings for buildings affected by this requirement is between 2.5 and 3 percent,” he said.

Another proposed addendum would provide new requirements for continuous air barriers. Schwedler noted that while performance requirements have existed for fenestration and door products, evidence suggests that the opaque envelope is the source of the majority of air leakage in buildings.

“A working group comprised of many interested parties developed an energy saving proposal that we hope will lead to acceptance and adoption,” Schwedler said.

The proposed addenda are available during the public review period. To read the addenda or to comment, visit www.ashrae.org/publicreviews.