Replacement for Freon Found, Air Conditioners and Refrigerators Set to Change

Air conditioners and refrigerators are set to change in the future. After decades of relying on Freon as a refrigerant, a more environmentally friendly cooling substance has now been found. This change is driven by global efforts to reduce greenhouse gas emissions, as the Freon used in air conditioners and refrigerators is said to be a potential cause of global warming. Researchers have successfully developed an alternative method to lower room temperature without relying on risky chemicals such as hydrofluorocarbons (HFCs), long known widely as Freon. Instead, the research utilises salt as the main component of the cooling system. Conventional cooling technology essentially works by absorbing and then expelling heat from a room using a special heat-conducting liquid. 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 even water dispensers. The problem is that the materials used pose a danger to the environment. Researchers from the Lawrence Berkeley National Laboratory at the University of California, Berkeley, have developed a new way to absorb and transfer heat energy. Their model utilises 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, making the room cooler. 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-charged 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 phase-change cycle is named the ionocaloric cycle. ‘There has yet to be an alternative solution that successfully creates cold, 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. This liquid, produced using carbon dioxide, is also used in lithium-ion batteries. This means the manufacturing process is not only zero-emission but emission-negative. In the trial, the temperature changed by up to 25 degrees Celsius with just a 1-volt charge. Researchers are now creating 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 salts are nitrate-based.