That means you need somewhere to move the heat to, and the thermoynamics of heat...

mensetmanusman on June 18, 2022 | parent | context | favorite | on: DOE announces breakthrough in residential cold cli...

That means you need somewhere to move the heat to, and the thermoynamics of heat capacity are not forgiving if you are trying to make something lightweight. You need atoms and lots of entropic states to store heat :)