New Air Compressor Efficiency Standards: Good, but Not Great

Credit: DOE

The U.S. Department of Energy’s (DOE) just-released standard for commercial and industrial compressors succeeds in lowering the energy use of these machines and, consequently, reduces the pollution output necessary to run them, but still falls short of what we and other researchers believe is possible.

What’s a compressor? Compressors are used to increase the pressure of gases for a variety of applications, such as pressurizing natural gas for distribution, refrigerants that are used in residential and commercial HVAC equipment, to power pneumatic tools like jackhammers, and even equipment cleaning. If you’ve used one of those machines at gas stations to put more air in your tires, you’ve interacted with a compressor. DOE’s new standards apply only to equipment used to compress air.

It is the first time DOE has released standards for compressors, and they’ve been hard at work on this rule since 2012. The rule covers only the lubricated rotary type of compressor, which can be found in commercial and industrial products including robots used in manufacturing and large paint sprayers. Other types of compressors are not covered by this rule—I’ll get to that in a moment. Compressor manufacturers in the United States and abroad will have five years to bring their products into compliance if they are to be sold in the United States.

DOE estimates the new standard will save commercial and industrial consumers $36 million to $45 million on their utility bills each year, or $200 to $400 million over the lifespan of the machines.  Customers will see a payback on their investment in a new compressor within the first 2.5 to 5 years, which is well within the 13-year lifespan of the compressor. Meanwhile, the lifetime energy savings for air compressors purchased in the 30-year period that begins with the first full year of compliance (2022) will amount to 0.16 quads, or more than 15 billion kilowatt-hours, equivalent to a year’s worth of electricity use in 1.6 million homes.

Reducing the energy use of compressors is another step toward meeting President Obama's goal of saving 3 billion metric tons of carbon emissions from standards by 2030. The new standards will avoid almost one million metric tons of carbon by 2030. That’s equivalent to emissions resulting from the annual electricity use of more than 95,000 homes.

Better, stronger standards still possible

When the proposed US standards were announced in May, we commended DOE for addressing compressor energy use but also argued the rule could be more demanding and could cover a wider share of the market.

DOE initially considered higher standards for lubricated rotary compressors, which would have more than doubled the savings to 0.49 quads of energy savings, $1.6 billion in net consumer savings, and 29 million metric tons of carbon pollution reductions over 30 years. In addition to ultimately choosing a lower efficiency level, this standard only covers lubricated rotary compressors rated between 10 and 200 nominal horsepower. This means the standard affects a small share of the market, but a high share of the energy use: DOE notes that compressors of 25 horsepower and above account for less than 1 percent of annual sales but represent 80 percent of the annual electricity consumption. The standard does not cover reciprocating compressors, which are generally smaller but account for the vast majority of compressors sold each year. DOE analyzed reciprocating compressors, but did not have enough data to feel confident that standards would be economically justified. Given that they comprise such a high proportion of the market, we strongly urge DOE to work to gather the necessary data for reciprocating compressors before developing the next compressor standard.

Credit: DOE

European Union standards

In a letter to the DOE in August from NRDC, the Appliance Standards Awareness Project, the American Council for an Energy Efficient Economy and other stakeholders, we urged DOE to review the benefits of harmonizing compressor standards with those pending in the European Union (EU). 

The DOE standards released this week have a more narrow scope than the EU's. While the EU standards cover reciprocating compressors, the DOE standard does not, despite the fact that reciprocating compressors represent a larger share of the air compressors market in the United States. Working with the EU on a common standard in the future would benefit manufacturers in both the U.S. and abroad by better harmonizing markets.

While this latest standard did not go as far as we would have liked, setting a standard is an important first step to removing the least efficient models from the market. And it will lower utility costs for businesses and industry while reducing the pollution driving climate change.