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

ANSI/ASHRAE/IESNA Standard 90.1-2007, Energy Standard for Buildings Except Low-Rise Residential Buildings, provides minimum requirements for the energy-efficient design of buildings except low-rise residential buildings.  Currently, 18 proposed addenda to the standard are open for public 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,” Chair Mick Schwedler said. “The proposed addenda that are out for review move toward our goal of 30 percent energy cost savings.”

Among the proposed addendum out for public review is addendum bh, which would require 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%,” he says.

Proposed addendum bf provides 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 says.

Other addenda include "f," which would allow a number of paths to reduce building roof load; "bq," which reduces additional lighting power allowances by reducing both lighting energy and the energy needed to cool the space; and "bn," which requires orientation of fenestration to be considered to reduce thermal loads.

The proposed addenda to ASHRAE/IESNA Standard 90.1 are available during their public review period. To read the addenda or to comment, visit ashrae.org/publicreviews.