The BBC reports a new approach to refrigeration and cooling could make for high-efficiency, portable, and quiet refrigerators in the future. This new method works by applying an electric field to long molecules called polar polymers.
Advocates of the method say it will achieve a ten-fold increase of efficiency over conventional cooling.
Traditional refrigeration works by compressing a refrigerant, which grows cold as it is allowed to rapidly expand. The refrigerant is then circulated around to remove heat from fridges or air that is then used for cooling.
While environmentally unfriendly chemicals have been removed from almost all refrigerators these days, the process is still noisy and fairly inefficient.
The new method instead takes its cooling power from the ordering and disordering of the polymers, which are distributed in a thin film just a millionth of a metre thick. In an electric field, the molecules spontaneously line up, creating heat. Removing the field causes the polymers to cool down again as a result of the electrocaloric effect. This energy-from-order is evidenced when stretching and releasing a rubber band; stretching it lines up the mess of its constituent long molecules, warming it up.
If the temperature at which these transitions occur is near the temperature of the desired cooling, the effect can be exploited.
Though the temperature range of the new work is still too high to result in ice-cold beer, it has achieved a cooling of +12˚C (+22˚F), showing that polar polymers might just do the trick.
So, we don't think that we'll be seeing this technology anytime soon and that it has to achieve a stable -18˚C to be used in a freezer and around +5˚C for a fridge. If anything we may see it used on top end refrigeration, especially built-in or integrated as it would help massively with heat build up problems on that sort of refrigeration.