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Changes to Standard 90.1 to Lighten Energy Use

Requirements to “lighten up” energy use and costs through fenestration, parking-lot lighting, and other measures are being recommended for ANSI/ASHRAE/IESNA Standard 90.1-2007, Energy Standard for Buildings Except Low-Rise Residential Buildings. Currently, 15 proposed addenda to the standard are open for public review.

“As the industry continues to call for buildings and systems that use less energy, the Standard 90.1 committee is striving to find ways to reduce energy uses and costs,” Mick Schwedler, chair of the Standard 90.1 committee, said. “The proposed changes not only reduce energy use but move the standard closer to the work plan goal of a 2010 standard with 30 percent energy-cost savings compared to the 2004 standards.”

Among the proposed addenda out for public comment is addendum cd, which would require active exterior control rather than just require the control capability; add bi-level control for general all-night applications, such as parking lots to reduce lighting when not needed; and add control for façade and landscaping lighting not needed after midnight.

Eric Richman, chair of the standard’s lighting subcommittee, noted that studies from the California Lighting Technology Center at the University of California at Davis found that control strategies reduce lighting energy use by significant amounts during nighttime hours. A study by Polytechnic State University showed that parking-lot lighting operates in a low mode 68 percent of the time.

Additional information from a study by Navigant Consulting shows that parking lots account for 22 twh out of a total 57 twh used for outdoor lighting annually nationwide. While this estimate includes all lit parking areas, the potential for energy savings in parking areas that are directly associated with specific building projects are significant and should be supported by the standard.

A second public review of proposed addendum bn would reduce solar loads by orienting the fenestration in more appropriate directions. Changed in response to comments during the first public review, this approach gives flexibility to building design teams to work with siting and fenestration and orientation as well as fenestration area to comply with the requirement.

Proposed addendum bb updates building-envelope requirements for opaque elements, such as walls and rooms, and fenestration (windows and skylights). A number of changes were made in response to public comments during the first public review.

The proposed addenda to Standard 90.1 are available for comment only during their public review period. Addenda <i>aq, bs, ca, cb, cc, cd, ce</i>, and <i>cf</i> are available for review until Dec. 6; addenda <i>am, bb, bf, bi, bn, bt,</i> and <i>bx</i> are available for review until Jan. 4. To read the addenda or to comment, visit

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