Given a lot of room, talking hundreds of feet of piping, and potentially hundreds of square meters for equipment, how fast can you drop an input ranging from 50-100C down to 5-10C? It can also be partially underground (shallow). In this case, I could use the waste heat, especially if it's in a couple specific locations (i.e. a solar water heater, and a refrigerator/heat exchanger). In a closed loop system, I would assume that dropping the temperature down to ~25C wouldn't be difficult given some distance. But with flowing pipes, how fast could you feasibly 'flash cool' a fairly large volume of water/heat transfer fluid from ~25C to ~5C, or potentially 50C to 5C given a shorter distance?