Now engineers at Berkeley Lab have developed a new technology that heats and cools by switching a material between solid and liquid states, inducing a large temperature change from a small voltage.

Most air conditioning and refrigeration systems currently in use work through vapor compression, where a refrigerant cycles between a liquid and a gas. In its liquid form, the refrigerant absorbs heat from a room or space and becomes a vapor, which is then compressed and condensed back into a liquid, transferring the heat away in the process. The liquid eventually re-enters the evaporator and the cycle continues.