Air conditioning unit on a rooftop.

Image courtesy of Daikin.

Commercial air conditioners, often referred to as rooftop units (RTUs), are commonly used across commercial building sectors such as schools, restaurants, big box retailers, and small office buildings. These heating, ventilation and air conditioning units condition almost half of all U.S. commercial floor space. But commonly they are old and inefficient, wasting anywhere from $900 to $3,700 per unit annually.

To take advantage of this energy and cost savings opportunity, the Department of Energy (DOE) partnered with manufacturers and businesses to launch a multi-faceted program that has transformed an entire market—from a time not long ago, when zero high efficiency RTUs were commercially available, to a historic standard that ensures all businesses will have access to energy-saving RTUs. Learn about the process step-by-step below.

Step 1: Challenge Manufacturers to Develop Innovative, Efficient Rooftop Units

DOE convened building operators and manufacturers to lay out a high-efficiency performance specification, initiating the High-Performance Rooftop Unit Challenge to produce units that would cut energy use by up to 50% compared to the existing standard. DOE issued a supporting announcement documenting Better Buildings Alliance members’ interest in high efficiency RTUs that met the specification. Based on the illustrated market demand for these units, manufacturers quickly responded to the challenge. Daikin’s Rebel and Carrier’s WeatherExpert rooftop unit systems became the first to meet the challenge. Today, manufacturers are offering more than 20 RTU models that exceed this specification.

Step 2: Prove New Technologies Work in Real-World Settings

However, many businesses were still hesitant to adopt this new technology without more information on how the technology performed in real world situations, beyond manufacturer’s data sheets and laboratory testing. Throughout 2013 and 2014, DOE supported third-party verification of performance for the winning units in partnership with building owners/operators and other federal agencies, measuring and sharing their performance. These demonstrations proved that the high efficiency units save significant energy in a real-world setting, reducing the risk for owners to adopt them.

Step 3: Encourage Widespread Adoption through Industry Partnerships

To stimulate broader savings, DOE initiated the Advanced RTU Campaign in partnership with ASHRAE and the Retail Industry Leaders Association, to spur widespread adoption. Through the Campaign, more than 200 public- and private-sector organizations have upgraded more than 43,000 rooftop units. To date, these upgrades have saved businesses and organizations a combined $37 million annually on their energy bills, while cutting carbon pollution by 356 million pounds. The Campaign recently set a new goal to upgrade 75,000 total RTUs.

Building owners can either commit to replace their old RTUs with more efficient units, or retrofit them with advanced controls, depending on which option makes best financial sense. DOE provides recognition for best practices — along with a peer-to-peer network, validated data on energy savings, and access to technical assistance — awarding those businesses for taking advantage of promising, verified energy savings solutions.

Step 4: Lock In Massive Energy Savings with Historic Efficiency Standard

The success of the Campaign and the Challenge motivated DOE to investigate issuing new standards for commercial RTUs that would set the minimum efficiency level. DOE used its consensus rulemaking process to bring together industry, utilities, and environmental groups in forming the new standard. In December 2015, DOE announced the final standard, which will save more energy than any other standard issued by DOE to date. Over the lifetime of the products, businesses will save $167 billion on their utility bills and carbon pollution will be reduced by 885 million metric tons.

The Office of Energy Efficiency and Renewable Energy (EERE) success stories highlight the positive impact of its work with businesses, industry partners, universities, research labs, and other entities.