They would need to be constantly pumped. In our neck of the woods if the pump stops, anything 3 feet or above freezes solid.
I would think you would need some fort of antifreeze running.
It’s just a dream that everyone north of the Mason Dixon line has to eliminate snow shoveling, lol.
We have here in Florida companies that make such a system for home COOLING and HEATING.
PVC pipes are buried about 4 or more feet underground in a grid pattern, and a pump moves water through the CLOSED system to a heat exchanger in the house............