Why would you need to use the refrigerant itself for heat transfer from end users? Couldn't you just use water for that; like they do for central heating? (E.g.

Why would you need to use the refrigerant itself for heat transfer from end users? Couldn't you just use water for that; like they do for central heating? (E.g. Chill water using centralized AC, then pump the cold water through pipes to cool homes and businesses?)