There would be decreased costs for the entire house as you then no longer need a heat pump in you fridge, water heater, etc if you tried to emulate current hot/

There would be decreased costs for the entire house as you then no longer need a heat pump in you fridge, water heater, etc if you tried to emulate current hot/cold use. If I designed the system, it would just be a hot and a cold loop that goes throughout the building, with a standard outlet that had both the hot and cold lines present. For residential, you could install faucets that had a internal heat exchanger that would let you have actually cold or hot water for cheaper than a traditional on-demand water heater. HVAC would be better as individual control of the heat for each room wouldn't add much extra cost, so your south facing rooms can get more cooling without having to freeze everyone in the other rooms. For restaurants, the system would be particularly attractive as they can have heated/chilled food holding (and work surfaces) and they would be able to be swapped between the two by flicking a switch, so the winter menu (or the lunch menu even) could feature more hot items, and the summer (or dinner) menu more cold things without wasting capital (and space) on equipment that isn't used all the time.