Researchers at POLO (Research Laboratories for Emerging Technologies in Cooling and Thermophysics) at the Federal University of Santa Catarina are developing an energy-efficient magnetocaloric air conditioner, which does not rely on flammable refrigerants or environmentally harmful substances.
The working principle is based on the magnetocaloric effect, which is the thermal response of some materials to the variation of a magnetic field. Thus, when a magnetic field is applied, the material temperature increases and, reversibly, the removal of the magnetic field reduces the temperature of the material.
The Active Magnetic Regenerators (or AMRs) are responsible for generating the refrigerating effect. Together with the magnet, they play a role similar to the compressor and expansion device in a conventional refrigerator. The magnetic refrigeration cycle uses water to remove heat from the refrigerated room, lowering its temperature. The AMR itself consists of a porous solid metal that undergoes a temperature variation under the action of the magnetic field, alternatingly cooling down and heating up the flowing water.
In the present development stage, the system is equipped with flow, pressure, temperature, magnetic field, and electrical power sensors to enable mapping the performance of the refrigeration unit. The project's ultimate goal is to achieve temperature and cooling capacity specifications of a 9000 Btu/h domestic air conditioner with an energy consumption compatible with that of a conventional appliance."