Heating and cooling devices are typically based on vapor-compression technology, relying on refrigerants that contribute to global carbon emissions. An alternative being pursued by researchers from U.S. Ames National Laboratory and Iowa State University is magnetocaloric heat pump technology, which can eliminate refrigerant emissions and require less energy to operate.

These systems operate by changing the magnetic field applied to a magnetocaloric material while pumping fluid to move heat. A baseline device designed by the researchers involves spinning permanent magnets relative to the magnetocaloric material and using magnetic steel to keep the magnetic field contained. Gadolinium and lanthanum-iron-silicon-hydride-based magnetocaloric materials were included to boost the power density of the heat pump.

The research published in Applied Energy confirms that the performance and mass of the magnetocaloric heat pump can match that of conventional compressors. The baseline device demonstrated thermal powers ranging from 37 W to 44 kW at a nominal 10 K temperature span, and system power density was estimated to improve from 6 W/kg to 81 W/kg. The magnetocaloric heat pump can therefore compete with the power, efficiency, size and cost of off-the-shelf compressors.

To contact the author of this article, email shimmelstein@globalspec.com