Code crafters are lauding a significant process change in reference-standard development that provides markers for progress along the way, directional signals for reaching goals and validation of the standard’s potential impact on energy use and cost. The process, based on energy modeling and analysis, helped the developers of the 2010 edition of the commercial-building energy standard reach their goal of providing a standard that, if followed, could result in a whopping 30% reduction in both energy use and costs compared with use of the standard’s 2004 edition.
Crafters of the next edition of the energy standard already are using the process again, this time to reach an even more ambitious “50% goal.” Crafters of the next two editions of the model residential energy code—targeting a 30% goal and then a 50% goal, respectively—also are using the process.
Use of ANSI/ASHRAE/IES Standard 90.1-2010, published by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Atlanta, can result in buildings that use more than 30% less energy than those designed to the 2004 standard, according to the Pacific Northwest National Laboratory (PNNL), which performed the energy modeling analyses under contract with the U.S. Dept. of Energy’s Building Energy Codes Program (BECP).
“The 30% goal, set by DOE, was very challenging to reach,” says Bing Liu, senior research engineer at the Richland, Wash.-based PNNL and the one credited with the idea of the progress indicators. “It’s a huge change that has changed the expectation of other building energy-efficiency codes,” adds Liu, who also served on 90.1’s mechanical subcommittee.
PNNL analyzed the impact of the 109 changes to the standard during the 2007-2010 development period, reporting quarterly to ASHRAE committees, as well as after 90.1’s publication in October (ENR 11/15/10 p. 7). PNNL is also under contract with DOE to provide progress indicators for the 90.1-2013 and the International Energy Conservation Code.
PNNL modeled 16 building types in 17 climate zones for a total of 272 building types and climate-zone combinations, representing 80% of U.S. commercial buildings constructed annually. On a nationally aggregated level, compared with 90.1-2004, building-type energy savings ranged from 8.8% to 38.3% and energy-cost savings from 7.9% to 33.6%.
PNNL’s work was “important and essential to enable us to measure progress,” says Steve Skalko, manager of regional codes, in Macon, Ga., for the Portland Cement Association and chairman of 90.1 committee. Without PNNL’s final analysis, “we would never have known if we had reached our goal,” adds Skalko, vice chairman of the 90.1 committee until July.
The analysis was a big help when, in January of last year—only nine months before the standard’s publication—the PNNL team informed the committee it had reached only half of its 30% goal. “When we heard the “15% report,” we did not panic,” says Skalko, because addenda still in process hadn’t been counted.
But the committee decided to prioritize remaining addenda according to energy impact, and give the high-impact ones special care, so they would win approval. One given extra attention, called the “title, purpose and scope” change, would allow the standard, for the first time, to address plug and process loads, which offered big conservation potential, especially in data centers. “We realized how important that particular addendum was to get savings in 2010 and future standards,” says Skalko.
The next challenge for DOE is getting the states, especially the reluctant ones, to adopt 90.1-2010, says Diana Shankle, manager of DOE’s BECP at PNNL. “We have a strategy for how to target each state,” she says.