England. Scientists from the National Physical Laboratory (NPL) and Imperial College London are working on a new cooling method, using the electrocaloric effect, which can offer multiple advantages over current systems without the need for polluting refrigerants.
The electrocaloric effect is a phenomenon in which a material changes temperature under an applied electric field.
Today's domestic refrigeration is based on a continuous cycle of compression and expansion of chemicals – known as 'vapor compression'. Freon gas, for example, can be cooled and condensed into a liquid. This liquid then absorbs heat from the cooling zone, causing re-evaporation, where the cycle begins again.
These chemicals can be harmful to the environment when discarded or filtered. They have a fairly low efficiency, which requires a high energy input to create adequate cooling. They also require bulky appliances, which makes them unsuitable for smaller applications, such as refrigeration electronics.
Thermoelectric and magnetic cooling technologies have been proposed as environmentally friendly alternatives to vapor compression. However, these technologies have a hard time competing with vapor compression due to low energy efficiency (maximum 10%), and the need for large, expensive magnets to generate the necessary magnetic fields and run magnetic coolers.
Maciej Rokosz, a PhD student at NPL and Imperial College London, explains: "An electrocaloric cooler could potentially offer higher vapor compression efficiency – as creating an electric field requires less energy than the compression process to create the same level of cooling It could also offer reduced size and weight, so it is viable for applications such as refrigeration electronics."
