Dual Mode Water Heating Systems and Methods

Abstract

A water heating system is disclosed. The water heating system may include a water tank configured to store water, a heating element configured to heat the water inside the water tank, and a sensor configured to measure water temperature in the water tank. The water heating system may further include a controller configured to determine a difference between a target water temperature and the water temperature. The controller may activate the heating element when the determined difference is greater than a differential temperature threshold value. The controller may be further configured to detect a trigger event, and decrease the differential temperature threshold value from a first value to a second value responsive to detecting the trigger event.

That which is claimed is: 
     
         1 . A water heating system, comprising:
 a water tank configured to store water;   a heating element configured to heat the water inside the water tank;   a sensor configured to measure water temperature in the water tank; and   a controller communicatively coupled with the sensor and the heating element, wherein the controller is configured to:
 obtain a target water temperature and the water temperature in the water tank; 
 determine a difference between the target water temperature and the water temperature; 
 activate the heating element when the difference is greater than a differential temperature threshold value; 
 detect a trigger event; and 
 decrease the differential temperature threshold value from a first value to a second value, responsive to detecting the trigger event. 
   
     
     
         2 . The water heating system of  claim 1 , wherein the first value is in a range of about 7-9 degree Fahrenheit and the second value is in a range of about 3-6 degree Fahrenheit. 
     
     
         3 . The water heating system of  claim 2 , wherein the first value is about 8 degree Fahrenheit and the second value is about 4 degree Fahrenheit. 
     
     
         4 . The water heating system of  claim 1 , further comprising a memory configured to store the target water temperature and the differential temperature threshold value. 
     
     
         5 . The water heating system of  claim 4 , wherein the memory is further configured to store a historical water usage information. 
     
     
         6 . The water heating system of  claim 5 , wherein the controller is further configured to:
 obtain the historical water usage information from the memory;   predict a time duration when a water temperature drop rate is greater than a first water temperature drop threshold based on the historical water usage information, wherein the time duration comprises a start time and an end time; and   store the time duration in the memory.   
     
     
         7 . The water heating system of  claim 6 , wherein the controller comprises a timer configured to:
 obtain the time duration from the memory;   generate a first trigger signal at the start time; and   generate a second trigger signal at the end time.   
     
     
         8 . The water heating system of  claim 7 , wherein the detection of the trigger event comprises generation of the first trigger signal. 
     
     
         9 . The water heating system of  claim 8 , wherein the controller is further configured to increase the differential temperature threshold value from the second value to the first value at the end time, responsive to generation of the second trigger signal. 
     
     
         10 . The water heating system of  claim 1 , wherein the controller is further configured to:
 obtain the water temperature from the sensor;   determine that a water temperature drop rate is greater than a second water temperature drop rate threshold, based on the water temperature; and   detect the trigger event when the water temperature drop rate is greater than the second water temperature drop rate threshold.   
     
     
         11 . The water heating system of  claim 10 , wherein the controller is further configured to:
 determine that the water temperature drop rate is less than a third water temperature drop rate threshold, based on the water temperature; and   increase the differential temperature threshold value from the second value to the first value, responsive to a determination that the water temperature drop rate is less than the third water temperature drop rate threshold.   
     
     
         12 . A water heating method, comprising:
 obtaining, by a controller, a target water temperature from a memory and a water temperature in a water tank from a sensor, wherein the water tank is configured to store water and the sensor is configured to measure water temperature in the water tank;   determining, by the controller, a difference between the target water temperature and the water temperature;   activating, by the controller, a heating element when the difference is greater than a differential temperature threshold value, wherein the heating element is configured to heat the water inside the water tank;   detecting, by the controller, a trigger event; and   decreasing, by the controller, the differential temperature threshold value from a first value to a second value responsive to detecting the trigger event.   
     
     
         13 . The water heating method of  claim 12 , wherein the first value is about 8 degree Fahrenheit and the second value is about 4 degree Fahrenheit. 
     
     
         14 . The water heating method of  claim 12 , further comprising storing the target water temperature, the differential temperature threshold value, and a historical water usage information in the memory. 
     
     
         15 . The water heating method of  claim 14 , further comprising:
 obtaining the historical water usage information from the memory;   predicting a time duration when a water temperature drop rate is greater than a first water temperature drop threshold based on the historical water usage information, wherein the time duration comprises a start time and an end time; and   storing the time duration in the memory.   
     
     
         16 . The water heating method of  claim 15 , further comprising:
 obtaining the time duration from the memory;   generating a first trigger signal at the start time, wherein detecting the trigger event comprises generation of the first trigger signal; and   generating a second trigger signal at the end time.   
     
     
         17 . The water heating method of  claim 16 , further comprising increasing the differential temperature threshold value from the second value to the first value at the end time, responsive to generation of the second trigger signal. 
     
     
         18 . The water heating method of  claim 12 , further comprising:
 obtaining the water temperature from the sensor;   determining that a water temperature drop rate is greater than a second water temperature drop rate threshold, based on the water temperature; and   detecting the trigger event when the water temperature drop rate is greater than the second water temperature drop rate threshold.   
     
     
         19 . The water heating method of  claim 18 , further comprising:
 determining that the water temperature drop rate is less than a third water temperature drop rate threshold, based on the water temperature; and   increasing the differential temperature threshold value from the second value to the first value, responsive to a determination that the water temperature drop rate is less than the third water temperature drop rate threshold.   
     
     
         20 . A non-transitory computer-readable storage medium having instructions stored thereupon which, when executed by a processor, cause the processor to:
 obtain a target water temperature from a memory and a water temperature in a water tank from a sensor, wherein the water tank is configured to store water and the sensor is configured to measure water temperature in the water tank;   determine a difference between the target water temperature and the water temperature;   activate a heating element when the difference is greater than a differential temperature threshold value, wherein the heating element is configured to heat the water inside the water tank;   detect a trigger event; and   decrease the differential temperature threshold value from a first value to a second value responsive to detecting the trigger event.