Energy Manager

Final energy savings figures announced for 2010 Energy Standard

More than 30 percent energy savings can be achieved using the recently published 2010 version of Standard 90.1 vs. the 2004 standard, said Ashrae at its 2011 Winter Conference, which ran Jan. 29-Feb. 2 in Las Vegas, Nev.

February 3, 2011  By  Alyssa Dalton

ANSI/ASHRAE/IES Standard 90.1-2010, Energy Standard for Buildings Except Low-Rise Residential Buildings, which provides minimum requirements for the energy-efficient design of buildings except low-rise residential buildings, was published in November 2010.

Ashrae received the final results of analysis work from Pacific Northwest National Laboratories in support of the U.S. Department of Energy (DOE) Building Energy Codes Program on addenda included in the standard. Without plug loads, site energy savings are 32.6 percent and energy cost savings 30.1 percent. Including plug loads, the site energy savings are estimated at 25.5 percent and energy cost savings 24 percent

“Three years ago, the 90.1 project committee set an aggressive goal of 30 percent savings for the 2010 version,” president Lynn G. Bellenger said. “That the target was met and exceeded is a testament to the talent and dedication of the men and women from Ashrae and the Illuminating Engineering Society who developed and evaluated over 119 change proposals to increase the stringency of our flagship energy conservation standard.”

On a nationally aggregated level, building type energy savings ranged from 8.8 to 38.3 percent and energy cost savings from 7.9 to 33.6 percent. These figures include energy use and cost from plug loads.


Research analysts used 16 different building prototypes were modeled in 17 different climate zones for a total of 272 building types and climate zone combinations.

How was the energy reduction achieved? Here are a few examples:

• The Scope was expanded so that 90.1 covers receptacles and process loads, including data centers. This allows future addenda to the standard to address energy consuming equipment and systems previously outside its scope.

• Building Envelope: Continuous air barrier and cool/high albedo roof requirements were added.

• Lighting: Most interior Lighting Power Densities were lowered, and additional occupant sensing controls and mandatory daylighting requirements were added for specific spaces, along with a new five-zone exterior Lighting Power Density table.

• Mechanical: Most equipment efficiencies are higher, energy recovery is required in more applications, economizers are required in more climates and more energy-conserving controls are required.

• Modeling requirements were clarified and expanded so that building modelers could more accurately compare energy cost of their building project with an appropriate baseline building as defined by the standard.


“The 90.1 standard is a fluid document,” said Mick Schwedler, former chair of the 90.1 committee. “As technology evolves, the project committee is continually considering new changes and proposing addenda for public review. The rigorous, open, public review process following Ashrae and American National Standards Institute procedures, results in a document that is both technically sound and reaches consensus.”

The standard is written in mandatory code language and offers code bodies the opportunity to improve the energy efficiency of new buildings, additions and renovations.

Papers are now being accepted for the Ashrae 2012 Winter Conference, which runs Jan. 21-25 in Chicago, Ill. CLICK HERE for more information.

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