Global energy consumption from air conditioning and refrigeration may increase more than 450 percent by 2050, and the Energy Department’s Building Technologies Office (BTO) is looking for ways to reduce this energy usage while improving performance.
Most systems currently rely on a process called vapor compression to cool and heat buildings, using a compressor to circulate liquid refrigerants—typically hydrofluorocarbons (HFCs). Phasing down HFCs, which are are hundreds to thousands of times more potent than carbon dioxide and can last for centuries when released into the atmosphere, could avoid up to 0.5 C of global warming by the end of the century.
Buildings in the United States consume 38.5 quads of energy annually, of which, nearly half is used for heating, ventilation, air conditioning, and refrigeration (HVAC&R). In October, the global community committed to the Kigali Agreement, an amendment to the Montreal Protocol that will avoid rampant growth of HFC emissions and phase out their usage over time, replacing them with climate-friendly, energy-efficient alternatives.
BTO conducted performance testing of low global warming potential (GWP) alternative refrigerants in very hot climates, providing evidence to the international community that they could use viable replacements without affecting HVAC&R energy efficiency or cooling performance.
“Our performance testing work was just a part of BTO’s comprehensive strategy to advance HVAC&R technologies,” said Tony Bouza, technology manager for BTO’s HVAC, Water Heaters, and Appliances program. “We’re working to create a revolutionary new class of technologies that are energy efficient, and have it become common across the world. We’ve already seen some success.”
BTO’s strategy seeks to bring low-GWP refrigerants to market, improve the performance and costs of existing technologies, and develop next-generation technologies that push the United States toward a zero-GWP refrigerant future.
Several energy-saving, climate-friendly refrigeration technologies developed through BTO-funded industry lab partnerships are already available on the market.
For example, in 2014, Hillphoenix and Oak Ridge National Laboratory debuted their Second Nature Advansor System—a supermarket refrigeration system that lowers energy consumption by 25 percent and uses climate-friendly alternative refrigerants, reducing greenhouse gas emissions by 78 percent.
Further, BTO is supporting next-generation technologies, such as the first home water heater that uses zero-GWP refrigerants. Xergy’s electrochemical compressor prototype is a potentially transformative technology that uses water, which has no global warming impact, as the refrigerant.