Pacific Northwest National Laboratories (PNNL), in support of the Department of Energy’s Building Energy Codes Program, conducted the energy savings analysis on 110 addenda included in the standard.

PNNL’s analysis shows that the site and energy cost savings are 37.7% and 37.8%, respectively, by using the 2004 standard as baseline for the regulated loads only.  For the whole building energy consumptions, national aggregated site energy savings are 29.5% and energy cost savings are 29.0%. 

According to ASHRAE, on a nationally aggregated level, building-type energy savings range from 19.3% to 51.9% and energy-cost savings from 18.6% to 50.6%. These figures include energy use and cost from the whole building energy consumptions including plug and process loads.

 “ASHRAE is committed to continually improving building energy performance, so we are pleased with this confirmation that the 2013 standard achieves significant energy savings over its predecessor,” said William Bahnfleth, ASHRAE president. “As we approach the 40th anniversary of the publication of the standard, these new savings underscore Standard 90.1’s key role in promoting energy efficiency in buildings in the United States by establishing successively more stringent — but cost effective — minimum requirements and we look forward to further advances in future revisions.”

ASHRAE officials said extensive analysis work was performed by a team from Pacific Northwest National Laboratories. Sixteen different building prototypes were modeled in 17 different climate locations for a total of 272 building types and climate zone combinations

The energy reduction was achieved through 33 addenda related to major changes to requirements regarding building envelope, lighting, mechanical, and the energy cost budget.

Another important change for the 2013 standard is the first alternate compliance path in Chapter 6.  Section 6.6 was added to the 2010 edition to provide a location for alternate methods of compliance with the standard. The first such alternate path has been developed for computer room systems and was formulated with the assistance of ASHRAE technical committee 9.9, Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment. This path uses the Power Usage Effectiveness (PUE) metric established by the datacom industry. This alternate efficiency path format provides a framework that could be considered for other energy using facets of buildings not easily covered in the prescriptive provisions of the standard.

The standard is written in mandatory code language and offers code bodies the opportunity to make a significant improvement in the energy efficiency of new buildings, additions, and major renovations.