Tankless heater instant hot water

Abstract

This invention consists of a heat exchanger, a heating element, and a return line from a remote faucet to provide a constant circulatory flow of hot water through hot water distribution lines in a building utilizing a tankless water heater, such that hot water is available instantly at remote faucets in the building. The invention will eliminate the waste of water and heat while waiting for hot water to arrive at the outlets. A second benefit is to heat the mass of cold water known as the cold sandwich that results from the time delay for the heating element in the tankless heater to achieve its operating temperature. A third benefit is the convenience of not having to wait for hot water to arrive at remote faucets.

1 . A heat exchanger device that includes an outer housing, a water tank including a thermostatically controlled heating mechanism, an inner heat tube, and a return line from remote faucets. 
   
   
       2 . A system as in  claim 1  that will provide instant hot water to remote faucets in residential and small commercial buildings that use tankless water heaters for domestic water heating. 
   
   
       3 . A system as in  claim 1  that will eliminate the phenomenon called Cold Water Sandwich in water systems using tankless water heaters. 
   
   
       4 . A system as in  claim 1  that eliminates the wait for hot water to reach faucets remote from a tankless water heater. 
   
   
       5 . A heat exchanger device that utilizes a heat source other than standard electrical or gas supplies or conversion units. 
   
   
       6 . A heat exchanger unit that establishes a circulation flow of hot water to remote faucets for the purpose of providing instant hot water. 
   
   
       7 . A heat exchanger as in  claim 6  that uses convective pressures to circulate hot water from a heat exchanger to remote faucets 
   
   
       8 . A heat exchanger unit that uses a electromechanical pump to circulate hot water from a heat exchanger to remote faucets for the purpose of providing instant hot water. 
   
   
       9 . A return line as in  claim 1  that interfaces with the hot water distribution line proximate a remote hot water faucet, that terminates at its opposite end into a check valve that prohibits entry of water from the water jacket. 
   
   
       10 . A return line as in  claim 9  that contains a neutral buoyancy check valve poppet to provide the necessary sensitivity to respond to small differential pressures.