The final rule, announced Dec. 17, applies to small, large, and very large air-cooled commercial-package air conditioning, heating equipment and commercial warm-air furnaces. According to a prepublication Federal Register notice, the standards are more stringent than the applicable levels prescribed by American Society of Heating, Refrigerating and Air Conditioning Engineers/Illuminating Engineering Society Standard 90.1

The standards will adopt ASHRAE 90.1-2013 efficiency levels in 2018 and a higher level in 2023 as recommended by the group working on the rule. The standards ultimately will bring about a 28% improvement in energy efficiency by 2023, according to DOE.

To finalize the rule, DOE convened 17 stakeholders, including ASHRAE, some manufacturers, utilities and efficiency organizations. “These standards are a direct result of the Energy Dept.’s negotiated rulemaking process, which brings diverse stakeholders to the negotiating table and supports industry innovation, demonstrating how government and business can work together to meet U.S. carbon-reduction goals,” said Energy Secretary Ernest Moniz in a statement.

The DOE sponsored a High Performance Rooftop Unit Challenge in 2011 to encourage manufacturers to develop more efficient cost-effective rooftop air conditioners. With the commercialization of many of these innovations, businesses already have upgraded more than 40,000 rooftop units, DOE asserts.

According to Kateri Callahan, president of the Alliance to Save Energy, the energy and dollar savings from the latest standards are more than double that of any standard that has been issued to date. “DOE continues its aggressive and focused campaign to save business and consumers money on their energy bills,” she said in a statement.  

The rule will become effective 120 days after publication in the Federal Register.