Method of controlling the temperature of water in a water heater

• US 6,633,726 B2
• Filed: 01/02/2001
• Issued: 10/14/2003
• Est. Priority Date: 07/27/1999
• Status: Expired due to Term

• Current Assignee: AOS Holding Company (A O Smith Corporation)
• Original Assignee: Kenneth A. Bradenbaugh
• Inventors: Bradenbaugh, Kenneth A.
• Primary Examiner(s): CAMPBELL, THOR S
• Application Number:
  US09/752,477
• Publication Number:
  US 20010009609A1
• Time in Patent Office: 1,015 Days
• Field of Search: 219/497, 219/488, 219/490, 219/491, 219/494, 392/463, 392/441, 392/449
• US Class Current: 392/463
• CPC Class Codes: F24H 15/144 Measuring or calculating energy consumption
• CPC Class Codes: F24H 15/156 Reducing the quantity of energy consumed; Increasing efficiency
• CPC Class Codes: F24H 15/174 Supplying heated water with desired temperature or desired range of temperature
• CPC Class Codes: F24H 15/225 at different heights of the tank
• CPC Class Codes: F24H 15/242 Pressure
• CPC Class Codes: F24H 15/254 Room temperature
• CPC Class Codes: F24H 15/281 Input from user
• CPC Class Codes: F24H 15/37 of electric heaters
• CPC Class Codes: F24H 15/395 Information to users, e.g. alarms
• CPC Class Codes: F24H 15/407 using electrical switching, e.g. TRIAC
• CPC Class Codes: F24H 15/414 using electronic processing, e.g. computer-based
• CPC Class Codes: F24H 9/2021 Storage heaters
• CPC Class Codes: G05D 23/1909 whose output amplitude can only take two discrete values
• CPC Class Codes: H05B 1/0283 For heating of fluids, e.g. water heaters
• CPC Class Codes: H05B 3/82 Fixedly-mounted immersion heaters

Abstract

A method of controlling the temperature of water in a water heater. The water heater includes a tank for storing water and a heating element capable of being powered by a power source. In one embodiment, the method includes the acts of determining an element characteristic of the heating element, sensing a temperature of the water in the tank, calculating an amount of power to be provided to the heating element based on the element characteristic and water temperature, and transmitting the amount of power from the power source to the heating element.

Claims

1. A method of controlling a temperature of water in a water heater including a tank for storing water and a heating element capable of being powered by a power source, the method comprising the acts of:

determining an element characteristic of the heating element;

sensing a temperature of the water in the tank;

calculating an amount of power to be provided to the heating element based at least in part on the element characteristic and water temperature;

transmitting the amount of power from the power source to the heating element;

sensing an ambient temperature; and

wherein the act of calculating an amount of power is based at least in part on the ambient temperature.

2. A method of controlling a temperature of water in a water heater including a tank for storing water and a heating element capable of being powered by a power source, the method comprising the acts of:

sensing an ambient temperature exterior to the water heater;

sensing a temperature of the water in the tank;

calculating an amount of power to be provided to the heating element based at least in part on the ambient temperature and the water temperature; and

transmitting the amount of power from the power source to the heating element.

3. A method as set forth in claim 2, the method further comprising the acts of:

determining an element characteristic of the heating element; and

wherein the act of calculating the amount of power is based at least in part on the element characteristic.

4. A method as set forth in claim 2, the method further comprising:

determining a tank characteristic of the tank; and

wherein the act of calculating the amount of power is based at least in part on the tank characteristic.

5. A method as set forth in claim 2, further comprising:

sensing a second temperature of the water in the tank; and

wherein the act of calculating the amount of power is based at least in part on the second temperature.

6. A method as set forth in claim 5, wherein the first temperature is sensed by a first sensor, and wherein the second temperature is sensed by a second sensor.

7. A method as set forth in claim 5, wherein the second temperature is sensed after the first temperature.

8. A method as set forth in claim 7, further comprising:

calculating a slope of a line based at least in part on the first and second temperatures; and

wherein the act of calculating the amount of power is based at least in part on the calculated slope.

9. A method as set forth in claim 2, further comprising:

repeating the act of sensing an ambient temperature;

storing each sensed temperature, the storing act results in a usage pattern; and

wherein the act of calculating an amount of power is based in part on the usage pattern.

10. A method as set forth in claim 9, further comprising:

repeating the act of sensing a temperature of the water;

storing each sensed ambient temperature.

11. A method as set forth in claim 2, wherein the act of transmitting power comprises transmitting power from the power source to the heating element in a burst.

12. A method of controlling a temperature of water in a storage-type water heater, the storage-type water heater including a tank for storing water and a heating element capable of being powered by a power source, the method comprising the acts of:

determining an element characteristic of the heating element;

establishing a strategy to heat the water, the strategy being based on the element characteristic and including at least two conditions, each condition specifying a ratio of a maximum power deliverable to the heating element, at least one of the ratios being between zero and one hundred percent;

sensing a temperature of the water in the tank;

determining an amount of power to be provided to the heating element based on the strategy and the water temperature; and

transmitting the amount of power to the heating element.

13. A method as set forth in claim 12 wherein the determining act includes determining the ratio of the maximum power to be provided by the heating element based on the water temperature, and wherein the transmitting act includes transmitting an amount of power corresponding to the determined ratio.

14. A method as set forth in claim 13 wherein a first ratio is one hundred percent of the maximum power deliverable to the heating element and a second ratio is zero percent of the maximum power deliverable to the heating element.

15. A method as set forth in claim 13 wherein a first condition includes a first temperature range and a second condition includes a second temperature range, and wherein determining a ratio of the maximum power includes determining whether the water temperature is within the first temperature range.

16. A method as set forth in claim 13 wherein a first condition includes a first state of the water heater and wherein the second condition includes a second state of the water heater.

17. A method as set forth in claim 16 wherein the first state is a draw-down state and the second state is a recovery state.

18. A method as set forth in claim 16 further comprising:

sensing a second temperature of the water in the tank; and

wherein the act of determining an amount of power is further based on the second temperature.

19. A method as set forth in claim 18 wherein the first temperature is sensed by a first sensor and wherein the second temperature is sensed by a second sensor.

20. A method as set forth in claim 18 wherein the second temperature is sensed after the first temperature.

21. A method as set forth in claim 20 wherein the method further comprises calculating a slope of a line based on the first and second temperatures, wherein the calculated slope signifies a current water heater state, and wherein determining a ratio of the maximum power includes determining whether the current water heater state is within the first state.

22. A method as set forth in claim 20 wherein the method further comprises comparing the first and second temperatures, wherein the comparison signifies a current water heater state, and wherein the determining a ratio of the maximum power includes determining whether the current water heater state is within the first state.

23. A method as set forth in claim 13 wherein the at least two conditions include one or more temperature ranges and one or more states.

24. A method as set forth in claim 23 wherein the one or more temperature ranges is a subset of the one or more states.

25. A method as set forth in claim 12 and further comprising:

repeating the act of sensing a temperature of the water;

storing multiple sensed temperatures, the storing act results in a usage pattern; and

wherein the act of determining an amount of power is further based on the usage pattern.

26. A method as set forth in claim 12 and further comprising:

repeating the act of sensing a temperature of the water;

storing multiple sensed temperatures, the storing act results in a water use history; and

wherein the act of determining an amount of power is further based on the water use history.

27. A method as set forth in claim 12 wherein the element characteristic includes an element type.

28. A method as set forth in claim 12 wherein the element characteristic includes an element wattage.

29. A method as set forth in claim 12 wherein the element characteristic includes an element voltage.

30. A method as set forth in claim 12 wherein the element characteristic includes the location of the element within the tank.

31. A method as set forth in claim 12 wherein the water heater further includes a second heating element capable of being powered by the power source, wherein the method further comprises the act of determining a second element characteristic of the second heating element, and wherein the strategy is further based on the second element characteristic.

32. A method as set forth in claim 31 and further comprising:

determining a second amount of power to be provided to the second heating element based on the strategy and the water temperature; and

transmitting the second amount of power from the power source to the second heating element.

33. A method as set forth in claim 32 wherein the act of transmitting power from the power source to the first element comprises transmitting power from the power source to the first heating element in a first set of bursts, and wherein the act of transmitting power from the power source to the second element comprises transmitting power from the power source to the second heating element in a second set of bursts.

34. A method as set forth in claim 12 wherein the method further comprises determining a tank characteristic of the tank, and wherein the strategy is further based on the tank characteristic.

35. A method as set forth in claim 34 wherein the tank characteristic includes a tank capacity.

36. A method as set forth in claim 34 wherein the tank characteristic includes a tank diameter, tank radius, tank circumference, or tank cross-sectional area.

37. A method as set forth in claim 34 wherein the tank characteristic includes a tank height.

38. A method as set forth in claim 12 wherein the transmitting act includes transmitting power to the heating element in bursts.

39. A method as set forth in claim 38 each ratio of the maximum power defines a duty cycle for the bursts and wherein the determining act includes determining the duty cycle for the bursts based on the strategy and the water temperature.

40. A method as set forth in claim 12 wherein the method further comprises sensing an ambient temperature and wherein the determining act includes determining an amount of power to be provided to the heating element based on the strategy, water temperature, and ambient temperature.

41. A method as set forth in claim 12 wherein the determining act includes the acts of

transmitting a voltage to the heating element, and

calculating an element wattage for the heating element.

42. A method as set forth in claim 12 wherein the water heater includes a memory unit having a table, the table includes a plurality of stored water heater codes and respective stored strategies, and wherein the establishing act includes the acts of

determining a water heater code based on the element characteristic, and

obtaining the strategy from the table with the water heater code.

43. A method of controlling a temperature of water in a storage-type water heater, the storage-type water heater including a tank for storing water and a heating element capable of being powered by a power source, the method comprising the acts of:

determining a tank characteristic of the tank;

establishing a strategy to heat the water, the strategy being based on the tank characteristic and including at least two conditions, each condition specifying a ratio of a maximum power deliverable to the heating element, at least one of the ratios being between zero and one hundred percent;

sensing a temperature of the water in the tank;

determining an amount of power to be provided to the heating element based on the strategy and the water temperature; and

transmitting the amount of power to the heating element.

44. A method as set forth in claim 43 wherein the determining act includes determining the ratio of the maximum power to be provided by the heating element based on the sensed temperature, and wherein the transmitting act includes transmitting an amount of power corresponding to the determined ratio.

45. A method as set forth in claim 44 wherein a first ratio is one hundred percent of the maximum power deliverable to the heating element and a second ratio is zero percent of the maximum power deliverable to the heating element.

46. A method as set forth in claim 44 wherein a first condition includes a first temperature range and a second condition includes a second temperature range, and wherein determining a ratio of the maximum power includes determining whether the water temperature is within the first temperature range.

47. A method as set forth in claim 44 wherein a first condition includes a first state of the water heater and wherein the second condition includes a second state of the water heater.

48. A method as set forth in claim 47 wherein the first state is a draw-down state and the second state is a recovery state.

49. A method as set forth in claim 46 further comprising:

sensing a second temperature of the water in the tank; and

wherein the act of determining an amount of power is further based on the second temperature.

50. A method as set forth in claim 49 wherein the first temperature is sensed by a first sensor and wherein the second temperature is sensed by a second sensor.

51. A method as set forth in claim 49 wherein the second temperature is sensed after the first temperature.

52. A method as set forth in claim 51 wherein the method further comprises calculating a slope of a line based on the first and second temperatures, wherein the calculated slope signifies a current water heater state, and wherein determining a ratio of the maximum power includes determining whether the current water heater state is within the first state.

53. A method as set forth in claim 51 wherein the method further comprises comparing the first and second temperatures, wherein the comparison signifies a current water heater state, and wherein the determining a ratio of the maximum power includes determining whether the current water heater state is within the first state.

54. A method as set forth in claim 44 wherein the at least two conditions include one or more temperature ranges and one or more states.

55. A method as set forth in claim 54 wherein the one or more temperature ranges is a subset of the one or more states.

56. A method as set forth in claim 43 and further comprising:

repeating the act of sensing a temperature of the water;

storing multiple sensed temperatures, the storing act results in a usage pattern; and

wherein the act of determining an amount of power is further based on the usage pattern.

57. A method as set forth in claim 43 and further comprising:

repeating the act of sensing a temperature of the water;

storing multiple sensed temperatures, the storing act results in a water use history; and

wherein the act of determining an amount of power is further based on the water use history.

58. A method as set forth in claim 43 wherein the tank characteristic includes a tank capacity.

59. A method as set forth in claim 43 wherein the tank characteristic includes a tank diameter, tank radius, tank circumference or tank cross-sectional area.

60. A method as set forth in claim 43 wherein the tank characteristic includes a tank height.

61. A method as set forth in claim 43 wherein the transmitting act includes transmitting power from the power source to the heating element in bursts.

62. A method as set forth in claim 61 wherein each ratio of the maximum power defines a duty cycle for the bursts and wherein the determining act includes determining the duty cycle for the bursts based on the strategy and the water temperature.

63. A method as set forth in claim 43 wherein the method further comprises sensing an ambient temperature and wherein the determining act includes determining an amount of power to be provided to the heating element based on the strategy, water temperature, and ambient temperature.

64. A method as set forth in claim 43 wherein the water heater includes a memory unit having a table, the table includes a plurality of stored water heater codes and respective stored strategies, and wherein the establishing act includes the acts of

determining a water heater code based on the tank characteristic, and

obtaining the strategy from the table with the water heater code.

65. A method of controlling a temperature of water in a storage-type water heater, the storage-type water heater including a tank for storing water, a heating element capable of being powered by a power source, and a memory having a heating strategy, the heating strategy including at least two conditions, each condition specifying a ratio of a maximum power deliverable to the heating element, at least one of the ratios being between zero and one hundred percent, the method comprising the acts of:

sensing a temperature of the water in the tank;

determining the ratio of the maximum power to be provided by the heating element based on the heating strategy and the water temperature; and

transmitting an amount of power corresponding to the determined ratio to the heating element.

66. A method as set forth in claim 65 wherein the heating strategy is based on at least one of an element characteristic and a tank characteristic.

67. A method as set forth in claim 65 wherein the memory further includes a table having a plurality of stored water heater codes and respective stored strategies and wherein the method further comprises the acts of:

providing a water heater code; and

obtaining the heating strategy from the table with the water heater code.

68. A method as set forth in claim 67 wherein the water heater code is based on at least one of an element characteristic and a tank characteristic.

69. A method as set forth in claim 65 wherein one of the ratios of the maximum power deliverable to the heating element is one hundred percent of the maximum power deliverable to the heating element.

70. A method as set forth in claim 65 wherein a first condition includes a first temperature range and a second condition includes a second temperature range, and wherein the determining act includes determining whether the water temperature is within the first temperature range.

71. A method as set forth in claim 65 wherein a first condition includes a first state of the water heater and wherein the second condition includes a second state of the water heater.

72. A method as set forth in claim 71 wherein the first state is a draw-down state and the second state is a recovery state.

73. A method as set forth in claim 71 further comprising:

sensing a second temperature of the water in the tank; and

wherein the act of determining the ratio of the maximum power to be provided by the heating element is further based on the second temperature.

74. A method as set forth in claim 73 wherein the first temperature is sensed by a first sensor and wherein the second temperature is sensed by a second sensor.

75. A method as set forth in claim 73 wherein the second temperature is sensed after the first temperature.

76. A method as set forth in claim 75 wherein the method further comprises calculating a slope of a line based on the first and second temperatures, wherein the calculated slope signifies a current water heater state, and wherein determining the ratio of the maximum power to be provided by the heating element includes determining whether the current water heater state is within the first state.

77. A method as set forth in claim 75 wherein the method further comprises comparing the first and second temperatures, wherein the comparison signifies a current water heater state, and wherein the determining the ratio of the maximum power to be provided by the heating element includes determining whether the current water heater state is within the first state.

78. A method as set forth in claim 65 wherein the at least two conditions include one or more temperature ranges and one or more states.

79. A method as set forth in claim 78 wherein the one or more temperature ranges is a subset of the one or more states.

80. A method as set forth in claim 65 and further comprising:

repeating the act of sensing a temperature of the water;

storing multiple sensed temperatures, the storing act results in a usage pattern; and

wherein the act of determining a ratio of the maximum power to be provided by the heating element is further based on the usage pattern.

81. A method as set forth in claim 65 and further comprising:

repeating the act of sensing a temperature of the water;

storing multiple sensed temperatures, the storing act results in a water use history; and

wherein the act of determining a ratio of the maximum power to be provided by the heating element is further based on the water use history.

82. A method as set forth in claim 65 wherein the transmitting act includes transmitting power to the heating element in bursts.

83. A method as set forth in claim 82 wherein each ratio of a maximum power defines a duty cycle for the bursts and wherein the determining act includes determining the duty cycle for the bursts based on the strategy and the water temperature.

84. A method as set forth in claim 65 wherein the method further comprises sensing an ambient temperature and wherein the determining act includes determining a ratio of the maximum power to be provided by the heating element based on the water temperature and ambient temperature.