Water treatment system and treating water for abating bacterial growth

1 . A water treatment system for treating water to abate bacterial growth and comprising: a cold water supply conduit that receives input cold water and communicates the input cold water to a water treatment container; the water treatment container in thermal communication with a heater and that: receives the input cold water at cold water temperature TC, receives main heat from the heater, increases cold water temperature TC of the input cold water by the main heat from the heater, produces container heated water at high water temperature TH from the input cold water by increasing cold water temperature TC to high water temperature TH, and communicates the container heated water, such that high water temperature TH is greater than or equal to kill temperature TK for bacteria to kill bacteria in the container heated water, and such that the container heated water does not contain viable bacteria; a hot water delivery conduit comprising a transitional cooling zone and a delivery zone in fluid communication with the transitional cooling zone, such that the transitional cooling zone is arranged along the hot water delivery conduit; the transitional cooling zone in thermal communication with a fluid-isolated heat exchanger, such that the transitional cooling zone: receives the container heated water from the water treatment container, transfers thermal energy from the container heated water to the fluid-isolated heat exchanger while maintaining hydraulic isolation preventing mass transfer of the container heated water into the fluid-isolated heat exchanger, decreases high water temperature TH of the container heated water by transfer of second heat from the container heated water to the fluid-isolated heat exchanger in an absence of fluid communication between the hot water delivery conduit and the fluid-isolated heat exchanger, produces transitionally cooled water at hot water delivery temperature TD from the container heated water by decreasing high water temperature TH to hot water delivery temperature TD, and communicates the transitionally cooled water as delivery hot water to the delivery zone; and the fluid-isolated heat exchanger in thermal communication with the transitional cooling zone and that: provides heat flow from the transitional cooling zone while maintaining fluid isolation between the transitional cooling zone and the cold water conduit, such that the transitional cooling zone does not contain viable bacteria from the water treatment container or the cold water supply conduit, wherein the fluid-isolated heat exchanger contacts the transitional cooling zone of the hot water delivery conduit but is physically separated from and devoid of contact with the cold water supply conduit.

2 . The water treatment system of claim 1 , further comprising a flow controller in fluid communication with the transitional cooling zone and that prevents delivery hot water from flowing unless a temperature of the delivery hot water is less than or equal to a safe delivery temperature TS.

3 . The water treatment system of claim 2 , wherein the safe delivery temperature TS is less than 49° C.

4 . The water treatment system of claim 3 , wherein the pathogenic bacteria comprises Legionella bacteria.

5 . The water treatment system of claim 1 , wherein the bacteria comprises pathogenic bacteria.

6 . The water treatment system of claim 1 , wherein the water treatment container comprises a tankless water heater.

7 . The water treatment system of claim 1 , wherein the cold water temperature TC is for liquid water from greater than 0° C. to 16° C.

8 . The water treatment system of claim 1 , wherein the high water temperature TH is greater than or equal to a kill temperature TK for bacteria.