The days of the rackety, energy-gobbling refrigerator may be numbered with the advent of more efficient systems that cool with the use of magnets. The idea has been around almost as long as your standard gas-compression fridge, but it hasn't yet been viable for the household and commercial markets. Now, Cooltech Applications has launched the first magnetic refrigeration system (MRS) for commercial use.
The system is based on the magnetocaloric effect, which states that the temperature of a material can be changed by exposing it to a magnetic field. As magnetocaloric materials in the system are put through a cycle of magnetization and demagnetization, a water coolant is pumped through them, transferring the heat from the interior of the fridge to the outside air.
The basic structure of the system sounds similar to that of conventional refrigerators, which use chemical refrigerants and a compressor to keep your milk from spoiling. But that system comes at a high cost: even with recent advances in energy efficiency, they still guzzle a lot of electricity, and are running 24 hours a day. Not to mention they can be quite loud, and the gases used pose an environmental hazard.
According to Cooltech, the lack of a gas compression system means the MRS consumes only half the energy of a standard fridge, produces less noise and vibration, and requires less maintenance. And being known pollutants, these refrigerant gases are under constant scrutiny by environmental agencies and regulations, so from a commercial point of view, it makes sense to avoid the whole issue. Magnetic emissions are a potential concern, but the levels surrounding its devices are reportedly far lower than even an individual magnet you'd stick on the fridge.
The idea of magnetic cooling itself isn't entirely new, but this is the first time the technology has become available to the public. Previous machines were too big for common use, and nowhere near as effective as conventional refrigerators. GE managed to shrink the system down a few years ago, and was able to reduce the temperature of a fluid by 80° F (a total of 44.4° C) by having it pass by magnets arranged into 50 different cooling stages, but this prototype was still complex and bulky.
Cooltech's first commercial system, the MRS400, boasts 400 W of cooling power, keeping the internal temperature between 35.6° F and 41° F (2° C and 5° C), which is within the recommended levels for safe food storage. Its first applications will be in the commercial sector, for use in refrigerated retail display cases, wine cellars, and medical facilities. It's currently being beta-tested in three locations, using various configurations. Larger industrial systems, capable of 20 KW of cooling power, are also in development.
Source: Cooltech Applications
