Method and Controller to Operate a Domestic Hot Water System and Domestic Hot Water System

Abstract

A method may measure a respective temperature at a respective remote location or at the respective water pipe with the respective temperature sensor. A method may determine from the respective temperature measured by the respective temperature sensor a water usage event at the respective remote location. A method may determine during a determined water usage event a temperature profile from the temperature measured by the respective temperature sensor. A method may determine from the temperature profile determined during the water usage event a risk factor of microbiological growth at the respective remote location or of microbiological growth within the respective water pipe. A method may execute a disinfection cycle for the respective remote location or the respective water pipe if the respective risk factor of microbiological growth is above a respective risk threshold.

1 . A method to operate a domestic hot water system, the domestic hot water system having a tank to store hot potable water, the domestic hot water system having at least one remote location being remote from the tank at which water stored within the tank can be provided to a respective water consumer, wherein the respective remote location is connected to the tank through a respective water pipe, wherein a temperature sensor is assigned to the respective remote location or to the respective water pipe guiding the water stored within the tank to the respective remote location, the method comprising
 measuring a respective temperature at a respective remote location or at the respective water pipe with the respective temperature sensor;   determining from the respective temperature measured by the respective temperature sensor a water usage event at the respective remote location;   determining during a determined water usage event a temperature profile from the temperature measured by the respective temperature sensor;   determining from the temperature profile determined during the water usage event a risk factor of microbiological growth at the respective remote location or of microbiological growth within the respective water pipe; and   executing a disinfection cycle for the respective remote location or the respective water pipe if the respective risk factor of microbiological growth is above a respective risk threshold.   
     
     
         2 . The method of  claim 1 , wherein the respective water usage event is automatically determined on basis of a change rate of the respective temperature measured by the respective temperature sensor. 
     
     
         3 . The method of  claim 1 , wherein the risk factor is automatically increased if, within the determined temperature profile, the measured temperature or a temperature depending on the measured temperature is above a first, lower temperature and below a second, upper temperature threshold. 
     
     
         4 . The method of  claim 3 , wherein the risk factor is automatically decreased if, within the determined temperature profile, the measured temperature or the temperature depending on the measured temperature is above the second, upper temperature threshold. 
     
     
         5 . The method of  claim 3 , wherein the risk factor is automatically kept constant or is automatically decreased if, within the determined temperature profile, the measured temperature or the temperature depending on the measured temperature is below the first, lower temperature threshold. 
     
     
         6 . The method of  claim 1 , wherein the disinfection cycle is automatically executed in such a manner that water having a defined disinfection water temperature is flowing from the tank through the respective water pipe towards the respective remote location for a defined disinfection time interval. 
     
     
         7 . The method of  claim 6 , wherein for the disinfection cycle at least a portion of the water stored within the tank is automatically heated to the defined disinfection water temperature if the respective risk factor is above the respective risk threshold and if the temperature of the water stored within the tank is below said disinfection water temperature. 
     
     
         8 . The method of  claim 1 , further comprising:
 determining a time interval of no water usage at a respective remote location; and   executing a disinfection cycle for the respective remote location or the respective water pipe if the duration of the time interval of no water usage is above a respective threshold.   
     
     
         9 . The method of  claim 1 ,
 wherein at least one tank temperature sensor is assigned to the water tank for measuring the temperature of the water stored within the tank; and   further comprising:
 determining from the temperature measured by said at least one tank temperature sensor a risk factor of microbiological growth within the tank; and 
 executing a disinfection cycle for the tank if the respective risk factor of microbiological growth is above a respective risk threshold. 
   
     
     
         10 . A controller to operate a domestic hot water system, the domestic hot water system having a tank to store hot potable water, the domestic hot water system having at least one remote location being remote from the tank at which water stored within the tank can be provided to a respective water consumer, wherein the respective remote location is connected to the tank through at least one water pipe, wherein a temperature sensor is assigned to the respective remote location or to the respective water pipe guiding the water to the respective remote location;
 wherein the controller is configured to:
 receive a respective temperature measured at a respective remote location or at the respective water pipe by the respective temperature sensor; 
 determine from the respective temperature measured by the respective temperature sensor a water usage event at the respective remote location; 
 determine during a determined water usage event a temperature profile from the temperature measured by the respective temperature sensor; 
 determine from the temperature profile determined during the water usage event a risk factor of microbiological growth at the respective remote location or of a microbiological growth within the respective water pipe; and 
 initiate and control execution of a disinfection cycle for the respective remote location or the respective water pipe if the respective risk factor of microbiological growth is above a respective risk threshold. 
   
     
     
         11 . The controller of  claim 10 , being configured to automatically operate the potable water system according to the method of  claim 1 . 
     
     
         12 . A domestic hot water system comprising:
 a tank to store hot potable water;   at least one remote location being remote from the tank at which water stored within the tank can be provided to a respective water consumer,
 wherein the respective remote location is connected to the tank through at least one water pipe; 
 wherein a temperature sensor is assigned to the respective remote location or to the respective water pipe guiding the water to the respective remote location; and 
   the controller according to  claim 10 .