New ASHRAE 90.1 means big energy savings

The standard used throughout Canada for energy efficient buildings has been tightened up and made 30% more rigorous in the 2010 version.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) confirmed the savings after receiving analysis from Pacific Northwest National Laboratories.

ANSI/ASHRAE/IES Standard 90.1-2010, “Energy Standard for Buildings Except Low-Rise Residential Buildings” was launched 35 years ago and has become the benchmark for building energy design in Canada and many parts of the world, as well as in the U.S.

Using the 2010 version compared to the 2004 version of the standard, site savings without plug loads are 32.6% and energy cost savings are 31%.  When plug loads are taken into account, the site energy savings are estimated at 25.5% and energy cost savings at 24%.

ASHRAE cited some of the changes in the 2010 version of the standard that produce the energy savings:

• 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 have been clarified and expanded so that building modelers can more accurately compare energy cost of their building project with an appropriate baseline building as defined by the standard.

“Three years ago, the 90.1 project committee set an aggressive goal of 30 percent savings for the 2010 version,” ASHRAE 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 (IES) who developed and evaluated over 119 change proposals to increase the stringency of our flagship energy conservation standard. At the 35th anniversary of Standard 90.1, it continues to lead the way in our industry as the minimum standard for energy efficiency.”

The analysis work to see how effective the new standard would actually be was done by Pacific Northwest National Laboratories in support of the DOE Building Energy Codes Program. Sixteen different building prototypes were modeled in 17 different climate zones for a total of 272 building types and climate zone combinations.