PNNL

Energy efficiency rules and requirements for buildings may not make a splash on the nightly news, but they have gained favor in the Biden Administration and are helping slash energy consumption, carbon emissions, and costs.

The administration’s efforts to advance ambitious national decarbonization goals through better, more efficient buildings and building systems have resulted in substantial Department of Energy (DOE) research investments in multiple areas. The areas range from rulemaking and building energy codes to performance standards for existing buildings.

Pacific Northwest National Laboratory’s (PNNL’s) longstanding technical capabilities and expertise, as well as its partnerships with DOE, codes and standards organizations, and a diverse set of other stakeholders, are delivering on the DOE investments. PNNL is helping improve the performance of federal and non-federal commercial buildings, manufactured homes, water heaters, and more.

Some recent advances and PNNL’s contributions are summarized below.

Federal buildings

As of April, all new buildings and major retrofits constructed by the federal government must comply with more stringent building energy codes. DOE expects the approach will save more than $4 million in operating costs within the first year of implementation.

“To support development of this new requirement, PNNL conducted analysis based on DOE Building Energy Codes Program (BECP) models to determine cost-effectiveness,” said Erik Mets, a PNNL building research engineer. “We also characterized the federal building stock to make sure our analysis of codes aligned with the commercial and residential sector. And, we helped write the requirement.”

Manufactured homes (MFHs)

MFHs represent nearly 10 percent of the residential building market and often provide housing for underserved communities. In late May 2023, a new rule was published for energy conservation standards for newly built MFHs. The rule will save energy, cut utility costs, and improve indoor air quality and comfort.

“PNNL contributed our deep understanding of energy codes to the rule, as well as high-quality, large-scale modeling analysis,” said Vrushali Mendon, PNNL‘s technical lead on the effort. “Our study of efficiency measures and impacts was instrumental in establishing the technical foundation for the standards.”

National model building energy codes

PNNL’s technical expertise in the development of energy codes has been instrumental in helping prepare for the achievement of net-zero operational energy emissions in buildings by 2030. PNNL’s efforts support ASHRAE standard 90.1 for commercial buildings and the International Energy Conservation Code (IECC) for residential buildings.

“PNNL has helped develop new performance-based compliance pathways and an extensive library of energy and load management credits that are preparing energy codes to achieve net-zero by 2030,” said Michael Rosenberg, who manages BECP activities at PNNL.

Water heaters

New efficiency standards that recently went into effect for commercial water heaters are expected to save businesses nationwide nearly $150 million per year on energy costs and reduce carbon emissions by an estimated 38 million metric tons. The standards require condensing technology in new commercial water heaters in 2026.

“We’ve provided our longstanding expertise in appliance standards toward developing and finalizing this rule,” said Michelle Niemeyer, manager of the Appliance and Commercial Equipment Standards program at PNNL. “It was rewarding to see it adopted.”

Heating, ventilation, and air conditioning (HVAC) systems

PNNL has developed system performance approaches that assess the efficiency of the entire HVAC system. The methodology, which will drive substantial energy savings in buildings, applies PNNL’s Total System Performance Ratio, which is a simplified energy simulation tool. The approach has been incorporated in ASHRAE standard 90.1 and the 2022 Washington State Code. It also is expected to be adopted by the IECC and New York’s NYStretch Code.

“This technique assesses the overall performance of the entire HVAC system, including controls. It compares the annual heating and cooling load of a building to the annual energy consumed by the building’s HVAC system,” said PNNL’s Michael Rosenberg. “This helps assure energy efficiency while saving building owners and managers time and money.”

Building Performance Standards (BPS)

BPS save energy and reduce carbon. The standards are similar to building energy codes, but instead of regulating design and construction of new buildings, the standards regulate actual energy use in existing buildings. PNNL provides technical assistance to a range of BPS efforts, including the recent development of a seminal technical resource guide.

“PNNL’s knowledge of national and international BPS efforts, involvement in national building decarbonization strategies, and longstanding codes and building technologies expertise, have been central to advancing BPS objectives,” said Bing Liu, PNNL’s buildings sector manager.

Performance-based codes

PNNL is wrapping up the second phase of a pilot project in New York City that’s testing performance-based energy codes in about 20 buildings. Performance-based codes measure compliance based on projected energy performance of a whole building or its systems, rather than the longstanding practice of prescribing codes for individual components.

“The pilot project, which has helped improve tools and codes that support the performance-based approach, could significantly impact use of codes to improve building performance. We have several other jurisdictions who are now interested in working with PNNL on similar studies,” said PNNL’s Michael Tillou, a technical advisor.

Building Re-tuning™

PNNL’s formative work in Building Re-tuning™ has helped inform new city-driven mandates in Seattle, WA, and Philadelphia, PA. Re-tuning™ is a technique to identify and correct operational problems in existing buildings to reduce energy waste. In Seattle, for example, commercial building owners and operators must tune energy and water systems in certain buildings every five years.

“PNNL advises cities and states interested in mitigating climate change through improved efficiency,” says PNNL’s Srinivas Katipamula, a senior staff scientist. “We have shown significant energy savings are possible if commercial building owners periodically look for and correct operational problems such as air-conditioning systems running too long.”