Researchers from the Chinese Academy of Sciences have discovered that saturating water with ammonium thiocyanate salt and pressurizing it, and then suddenly releasing the pressure, would allow it to cool by 30 degrees C (54 degrees F) at room temperatures, even going as far as a 50-degree C (122 degrees F) drop in warmer environments. The research paper, published in Nature [PDF], presents this as a greener alternative to current refrigerants, with its theoretical efficiency hitting almost 80% — much higher than conventional refrigerants — making it a great solution for the thermal issues that data centers face.
The researchers compare the system to a wet sponge, with water acting as the sponge and salt acting as the absorbed fluid. When you apply pressure on the sponge (the water), the fluid (the ammonium thiocyanate salt) will be squeezed out and release heat. But when you reduce the pressure, it will quickly reabsorb the solution and reabsorb the heat from its environment, causing a quick temperature drop.
