Method and apparatus for providing on-demand hot water

A device for providing on-demand hot water comprising:

• a) an on-demand water heater comprising:
• i) a steam infeed conduit,
• ii) a steam flow regulator cooperating with said steam infeed conduit to regulate the flow of steam through said steam infeed conduit according to a trigger signal,
• iii) a steam-to-water heat exchanger operatively connected in fluid communication with said steam feed conduit and having a steam infeed and a steam outlet downstream of said steam infeed for channelling steam from said steam feed conduit through said steam-to-water beat exchanger, said steam-to-water heat exchanger having a cold water infeed and a hot water outlet downstream of said cold water infeed for channelling water to be heated through said steam-to-water heat exchanger,
• iv) a hot water conduit operatively connected in fluid communication with said hot water outlet,
• v) a temperature sensor cooperating with said hot water conduit for sensing the temperature of hot water leaving said steam-to-water heat exchanger and for sending corresponding temperature information,
• vi) a means for generating said trigger signal when the temperature of said hot water leaving said steam-to-water heat exchanger falls below a threshold temperature;
• b) means for providing pressurized steam to said steam infeed conduit from a steam boiler so as to re-capture waste heat in a steam circuit of said steam boiler wherein said pressurized steam is otherwise not in demand in said steam circuit within a facility containing said steam boiler;
• c) means for causing hot water to flow to an end use from said hot water outlet upon demand from the end use so as to draw water through said steam-to-water heat exchanger from said cold water infeed;
• d) means for causing said steam flow regulator to open steam flow upon said trigger signal to allow flow of steam from said boiler through said steam-to-water heat exchanger upon detection by said temperature sensor of a hot water temperature below the threshold temperature;
• e) means for causing said steam flow regulator to close off steam flow to said steam-to-water heat exchanger upon detection by said temperature sensor of a hot water temperature at or above said threshold temperature.