Replacement for Freon Discovered, Air Conditioners and Refrigerators Set to Change
Scientists have developed a new cooling technology that could potentially reduce dependence on hydrofluorocarbon (HFC)-based refrigerants, or freon. The technology uses salt as a main component in the cooling system, making it more environmentally friendly.
According to a report from IFL Science, typical cooling systems use special heat-conducting liquids. The liquid is then evaporated into a gas and circulated through a closed system before being condensed back into a liquid to repeat the cooling process. This process is so effective that it has become the standard technology for refrigerators, air conditioners, and water dispensers. The problem is that the materials used pose an environmental hazard.
Researchers from the Lawrence Berkeley National Laboratory at the University of California, Berkeley, have developed a new way to absorb and transfer heat energy. The model they used harnesses the way energy is stored and released when a material changes form, for example, when ice turns into water. If the room temperature rises, the ice will melt. At the same time, the melting ice absorbs heat from its surroundings, cooling the room.
To find an alternative cooling process, the researchers focused on finding a way to ‘melt ice’ without increasing the temperature. The method they found involves adding energy-containing particles known as ions. An example of this melting process using ion particles is when salt is used to prevent ice from forming on roads during winter in four-season countries. This cycle of changing form is called the ionocaloric cycle.
‘No alternative solution has yet successfully created cooling that works efficiently, meets safety aspects, and does not have a negative impact on the environment. We think the ionocaloric cycle has potential,’ said Drew Lilley from the Lawrence Berkeley National Laboratory.
The research team has tested a salt made using iodine and sodium to melt ethylene carbonate. The liquid produced utilises carbon dioxide and is also used in lithium-ion batteries. This means the manufacturing process is not only zero-emission but carbon-negative. In the trial, the temperature changed by up to 25 degrees Celsius with just a 1-volt charge.
The researchers are now working to create a practical system that can be applied commercially. One development involves finding the most effective ‘salt’ for drawing heat from a space. In 2025, researchers found that the most efficient salt is nitrate-based.