I can imagine having modular heat sinks apart from the heat pumps which your various household heat pumps could tap into: a warmth sink your cooling devices dum

I can imagine having modular heat sinks apart from the heat pumps which your various household heat pumps could tap into: a warmth sink your cooling devices dump to and warming devices draw from; a coolth sink that does the reverse. It would likely be expensive and you'd need a way to dump the surplus of either outside the building, but I don't imagine there would be much maintenance cost. You wouldn't need moving parts, just a liquid to move heat quickly within the sink via convection. Or maybe a chunk of aluminum would do.