Commercial Hot Water Control Systems

Abstract

A commercial hot water system includes a hot water source, and a hot water delivery line connected between the hot water source and at least one plumbing fixture. A pump, enables circulation of hot water to and from the fixtures. A controller provides for turning on the pump in conjunction with an external signal, and a detector, preferably a temperature sensor, in conjunction with the controller, is effective in stopping the pump to prevent heated water from being circulated.

What is claimed is: 
     
         1 . A hot water recovery system comprising:
 a) a feed line supplying cold water to a boiler;   b) a hot water delivery line circulating hot water directly or indirectly from said boiler to one or more plumbing fixture dispersed throughout a building, and returning unused water;   c) a pump circulating water in a closed loop directly or indirectly from said boiler to said plumbing fixture and returning unused water from said fixture;   d) a controller, for turning on the pump in accordance with an external signal, and turning off the pump in accordance with information received from a detector, connected thereto and disposed in a water line, indicating a decreased use of hot water.   
     
     
         2 . The hot water recovery system of  claim 1  wherein said detector is a temperature sensor, and said temperature sensor and controller are configured to detect a selected temperature increase and in response thereto cause the controller to turn off the pump to prevent heated water from being circulated. 
     
     
         3 . The hot water recovery system of  claim 1  wherein said temperature increase is from about one to about two degrees F. 
     
     
         4 . The hot water recovery system of  claim 1  comprising a hot water storage tank fluidly connected between said boiler and said at least one plumbing fixture. 
     
     
         5 . The hot water system of  claim 2  wherein a timer, connected to said controller, causes said controller to turn on said pump at a present time. 
     
     
         6 . A method of controlling the circulation of hot water in a building comprising:
 a) receiving cold water from a cold water source through a feed line;   b) heating said hot water;   c) circulating said hot water through a hot water line in a closed loop to and from one or more plumbing fixture using a pump;   d) turning the pump on or off using a controller according to hot water demand;   wherein said controller is connected to a detector disposed in said hot water line and turns off said pump when it receives a first signal from said detector indicating a lack of hot water demand, said pump is turned on when said controller receives a second signal indicating a demand for hot water.   
     
     
         7 . The method of  claim 6  wherein said heating step comprises directing water into a boiler. 
     
     
         8 . The method of  claim 6  wherein said second signal is generated by a timer connected to said controller. 
     
     
         9 . The method of  claim 6  wherein said first signal is received from a detector disposed in said hot water line. 
     
     
         10 . The method of  claim 7  wherein said detector is a temperature sensor and said controller shuts down the pump when a temperature increase in said hot water line is detected. 
     
     
         11 . The method of  claim 10  wherein said temperature increase is from about 1 to about 2 degrees F. 
     
     
         12 . The method of  claim 8  wherein said first signal is received from a detector disposed in said hot water line. 
     
     
         13 . The method of  claim 7  wherein said detector is a temperature sensor and said controller shuts down the pump when a temperature increase in said hot water line is detected. 
     
     
         14 . The method of  claim 12  wherein said temperature increase is from about 1 to about 2 degrees F.