Water heater controller

• US 5,056,712 A
• Filed: 10/09/1990
• Issued: 10/15/1991
• Est. Priority Date: 12/06/1989
• Status: Expired due to Fees

• Current Assignee: Harry J. Enck
• Original Assignee: Harry J. Enck
• Inventors: Enck, Harry J.
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US07/595,789
• Time in Patent Office: 371 Days
• Field of Search: 392/463, 236/9 R, 236/20 R, 236/25 R, 236/25 A, 236/23, 236/24, 236/46 R, 236/46 A, 236/46 F, 236/47, 236/91 R, 236/91 G, 236/91 F, 237/8 R, 237/19, 126/351, 219/330, 219/334, 364/557
• US Class Current: 236/20.00R
• CPC Class Codes: F23N 1/082 using electronic means
• CPC Class Codes: F23N 2223/08 Microprocessor; Microcomputer
• CPC Class Codes: F23N 2241/06 Space-heating and heating water
• CPC Class Codes: F24D 17/0078 Recirculation systems
• CPC Class Codes: G05D 23/1904 variable in time

Abstract

A water heater controller including hot water supply temperature sensor, a return water temperature sensor, a cold water flow sensor, a recirculation loop ambient temperature sensor, and a processor and control unit for controlling the heating of water and the circulation of water. The processor and control unit controlling the water heater to permit the hot water supply temperature to decrease to within a first supply setback temperature range defined by a calculated first setback temperature during non-use of hot water that is within a historically indicated hot water use period, (2) selectively controlling the water heater and recirculation apparatus to permit the hot water supply temperature to decrease to within a second supply setback temperature range defined by a second setback temperature and to permit the return water temperature to decrease to within a return setback temperature range during hot water non-use that is within a historically indicated hot water non-use period, and (3) controlling the water heater and recirculating means during hot water use so that the hot water supply temperature is controlled relative to a predetermined maximum temperature. The first setback temperature is calculated relative to system heat loss and a minimum return water temperature.

Claims

1. A controller for a hot water heater system having a heater for heating water, a hot water outlet for supplying hot water, a cold water inlet for receiving cold water, and a return line for returning non-used supplied hot water for reheating, the controller comprising:

recirculating means for circulating the supplied hot water to points of usage and back to the heater via the return line;

means coupled to the hot water outlet for sensing the temperature of the hot water supply and providing hot water supply temperature data;

means coupled to the return line for sensing the temperature of the return water and providing return water temperature data;

means for sensing use and non-use of hot water;

means for storing historical data indicative of time periods of hot water use and non-use; and

control means responsive to said hot water supply temperature sensing means, said return temperature sensing means, and said use sensing means for (a) calculating a first setback temperature, (b) controlling the heater to permit the hot water supply temperature to decease to and remain within a first supply setback temperature range based on said calculated setback temperature during sensed non-use that is within a historically indicated hot water use period based on said historical use and non-use data, (c) selectively controlling the heater and said recirculating means to permit the hot water supply temperature to decrease to and remain within a second supply setback temperature range based on a second setback temperature that is lower than said first setback temperature and to permit the return water temperature to decrease to within a return setback temperature range based on said second setback temperature during non-use that occurs within a historically indicate non-use period based on said historical non-use data, (d) controlling the water heater and said recirculating means during sensed use of hot water so that the hot water supply temperature is controlled relative to a predetermined maximum temperature which is greater than said first setback temperature.

2. The controller of claim 1 wherein said first setback temperature is calculated as a function of the heat loss of the hot water heater system and a predetermined minimum return water temperature.

3. The controller of claim 2 further including means for sensing an ambient temperature representative of the ambient temperatures to which the recirculation loop is exposed and providing ambient temperature data, and wherein the heat loss of the hot water system is calculated as a function of the loop ambient temperature sensed by said ambient temperature sensing means.

4. The controller of claim 1 wherein said sensing means comprises flow sensing means for sensing the flow of cold water into the water heater system.

5. The controller of claim 4 wherein said flow sensing means comprises a temperature sensor located at the hot water migration zone of the cold water inlet.

6. The controller of claim 1 wherein said control means calculates a projected time of day for the start of hot water usage and controls said hot water supply temperature so as to be at about said first setback temperature at said projected time of start of hot water usage.

7. The controller of claim 6 wherein said control means determines a temperature ramp-up start time when heating of water is to start so as to control said hot water supply temperature to be at about said first setback temperature at said projected time of start of hot water usage.

8. The controller of claim 7 wherein said ramp-up start time is determined as a function of the difference between a predetermined minimum return water temperature and the sensed return water temperature.

9. The controller of claim 7 wherein said recirculating means includes a recirculation pump controlled by said control means.

10. The controller of claim 1 wherein said recirculating means includes diverting means controlled by said control means for selectively diverting return water directly into the hot water outlet.

11. The controller of claim 10 wherein said diverting means comprises an electrically operated diverter valve.

12. The controller of claim 10 wherein said recirculating means further includes a recirculation pump located upstream of said diverting means.

13. The controller of claim 1 wherein said second supply setback temperature range comprises the range between the second setback temperature and a higher temperature, and wherein said return setback temperature range comprises the range between the second setback temperature and a lower temperature.

14. The controller of claim 1 wherein said historical data comprises manually entered data.

15. The controller of claim 1 wherein said historical data comprises historical use and non-use data.

16. A controller for a hot water heater system having a heater for heating water, a heater pump, a hot water outlet for supplying hot water, a cold water inlet for receiving cold water, and a return line for returning non-used supplied hot water for reheating, the controller comprising:

recirculating means for circulating the supplied hot water back to the heater via the return line;

means coupled to the hot water outlet for sensing the temperature of the hot water supply and providing hot water supply temperature data;

means coupled to the return line for sensing the temperature of the return water and providing return water temperature data;

means for sensing the temperature of the input water to the heater;

means for sensing the temperature of the output water to the heater;

means for sensing use and non-use of hot water;

means for storing historical data indicative of time periods of hot water use and non-use; and

control means responsive to said hot water supply temperature sensing means, said return temperature sensing means, and said use sensing means for (a) calculating a first setback temperature, (b) controlling the heater to permit the hot water supply temperature to decease to and remain within a first supply setback temperature range based on said calculated setback temperature during sensed non-use that is within a historically indicated hot water use period based on said historical use and non-use data, (c) selectively controlling the heater and said recirculating means to permit the hot water supply temperature to decrease to and remain within a second supply setback temperature range based on a second setback temperature that is lower than said first setback temperature and to permit the return water temperature to decrease to within a return setback temperature during non-use that occurs within a historically indicated non-use period based on said historical non-use data, (d) turning on the heater pump when said heater output water temperature is greater than said heater input water temperature, and (e) controlling the water heater and said recirculating means during sensed use of hot water so that the hot water supply temperature is controlled relative to a predetermined maximum temperature which is greater than said first setback temperature.

17. The controller of claim 16 wherein said first setback temperature is calculated as a function of the heat loss of the hot water heater system and a predetermined minimum return water temperature.

18. The controller of claim 17 further including means for sensing an ambient temperature representative of the ambient temperatures to which the recirculation loop is exposed and providing ambient temperature data, and wherein the heat loss of the hot water system is calculated as a function of the loop ambient temperature sensed by said ambient temperature sensing means.

19. The controller of claim 16 wherein said sensing means comprises flow sensing means for sensing the flow of cold water into the water heater system.

20. The controller of claim 19 wherein said flow sensing means comprises a temperature sensor located at the hot water migration zone of the cold water inlet.

21. The controller of claim 16 wherein said control means calculates a projected time of day for the start of hot water usage and controls said hot water supply temperature so as to be at about said first setback temperature at said projected time of start of hot water usage.

22. The controller of claim 21 wherein said control means determines a temperature ramp-up start time when heating of water is to start so as to control said hot water supply temperature to be at about said first setback temperature at said projected time of start of hot water usage.

23. The controller of claim 22 wherein said ramp-up start time is determined as a function of the difference between a predetermined minimum return water temperature and the sensed return water temperature.

24. The controller of claim 16 wherein said recirculating means includes a recirculation pump controlled by said control means.

25. The controller of claim 16 wherein said recirculating means includes diverting means controlled by said control means for selectively diverting return water directly into the hot water outlet.

26. The controller of claim 25 wherein said diverting means comprises an electrically operated diverter valve.

27. The controller of claim 25 wherein said recirculating means further includes a recirculation pump located upstream of said diverting means.

28. The controller of claim 16 wherein said second supply setback temperature range comprises the range between the second setback temperature and a higher temperature, and wherein said return setback temperature range comprises the range between the second setback temperature and a lower temperature.

29. The controller of claim 16 wherein said historical data comprises manually entered data.

30. The controller of claim 16 wherein said historical data comprises historical use and non-use data.

31. A controller for a hot water heater system having a heater for heating water, a hot water outlet for supplying hot water, and a cold water inlet for receiving cold water, the controller comprising:

means coupled to the hot water outlet for sensing the temperature of the hot water supply and providing hot water supply temperature data;

means for sensing use and non-use of hot water; and

control means responsive to said hot water supply temperature sensing means and said use sensing means for (a) controlling the heater to permit the hot water supply temperature to decrease to and remain within a first supply setback temperature range defined by a first setback temperature during sensed non-use that is within a predetermined hot water use period, (b) controlling the heater to permit the hot water supply temperature to decrease to and remain within a second supply setback temperature range defined by a second setback temperature during sensed non-use that is within a predetermined heater off periods, and (c) controlling the water heater during sensed use of hot water so that the hot water supply temperature is controlled relative to a predetermined maximum temperature which is greater than said first setback temperature.

32. The controller of claim 31 wherein said sensing means comprises flow sensing means for sensing the flow of cold water into the water heater system.

33. The controller of claim 32 wherein said flow sensing means comprises a temperature sensor located at the hot water migration zone of the cold water inlet.

34. The controller of claim 31 wherein said first setback temperature is a fixed value.

35. A controller for a hot water heater system having a heater for heating water, a hot water outlet for supplying hot water, a cold water inlet for receiving cold water, and a return line for returning non-used supplied hot water for reheating, the controller comprising:

recirculating means for circulating the supplied hot water to points of usage and back to the heater via the return line;

means coupled to the hot water outlet for sensing the temperature of the hot water supply and providing hot water supply temperature data;

means coupled to the return line for sensing the temperature of the return water and providing return water temperature data;

means for sensing use and non-use of hot water;

means for storing historical data indicative of time periods of hot water use and non-use; and

control means responsive to said hot water supply temperature sensing means, said return temperature sensing means, and said use sensing means for (a) controlling the heater to permit the hot water supply temperature to decease to and remain within a first supply setback temperature range based on a first supply setback temperature during sensed non-use that is within a historically indicated hot water use period based on said historical use and non-use data, (c) selectively controlling the heater and said recirculating means to permit the hot water supply temperature to decrease to and remain within a second supply setback temperature range based on a second setback temperature that is lower than said first setback temperature and to permit the return water temperature to decrease to within a return setback temperature range based on said second setback temperature during non-use that occurs within a historically indicated non-use period based on said historical non-use data, (d) controlling the water heater and said recirculating means during sensed use of hot water so that the hot water supply temperature is controlled relative to a predetermined maximum temperature which is greater than said first setback temperature.

36. The controller of claim 35 wherein said sensing means comprises flow sensing means for sensing the flow of cold water into the water heater system.

37. The controller of claim 36 wherein said flow sensing means comprises a temperature sensor located at the hot water migration zone of the cold water inlet.

38. The controller of claim 35 wherein said control means calculates a projected time of day for the start of hot water usage and controls said hot water supply temperature so as to be at about said first setback temperature at said projected time of start of hot water usage.

39. The controller of claim 38 wherein said control means determines a temperature ramp-up start time when heating of water is to start so as to control said hot water supply temperature to be at about said first setback temperature at said projected time of start of hot water usage.

40. The controller of claim 39 wherein said ramp-up start time is determined as a function of the difference between a predetermined minimum return water temperature and the sensed return water temperature.

41. The controller of claim 35 wherein said recirculating means includes a recirculation pump controlled by said control means.

42. The controller of claim 35 wherein said recirculating means includes diverting means controlled by said control means for selectively diverting return water directly into the hot water outlet.

43. The controller of claim 42 wherein said diverting means comprises an electrically operated diverter valve.

44. The controller of claim 42 wherein said recirculating means further includes a recirculation pump located upstream of said diverting means.

45. The controller of claim 35 wherein said second supply setback temperature range comprises the range between the second setback temperature and a higher temperature, and wherein said return setback temperature range comprises the range between the second setback temperature and a lower temperature.

46. The controller of claim 35 wherein said historical data comprises manually entered data.

47. The controller of claim 35 wherein said historical data comprises historical use and non-use data.

48. A controller for a hot water heater system having a heater for heating water, a heater pump, a hot water outlet for supplying hot water, a cold water inlet for receiving cold water, and a return line for returning non-used supplied hot water for reheating, the controller comprising:

recirculating means for circulating the supplied hot water back to the heater via the return line;

means coupled to the hot water outlet for sensing the temperature of the hot water supply and providing hot water supply temperature data;

means coupled to the return line for sensing the temperature of the return water and providing return water temperature data;

means for sensing the temperature of the input water to the heater;

means for sensing the temperature of the output water to the heater;

means for sensing use and non-use of hot water;

means for storing historical data indicative of time periods of hot water use and non-use; and

control means responsive to said hot water supply temperature sensing means, said return temperature sensing means, and said use sensing means for (a) controlling the heater to permit the hot water supply temperature to decease to and remain within a first supply setback temperature range based on a first supply setback temperature during sensed non-use that is within a historically indicated hot water use period based on said historical use and non-use data, (c) selectively controlling the heater and said recirculating means to permit the hot water supply temperature to decrease to and remain within a second supply setback temperature range based on a second setback temperature that is lower than said first setback temperature and to permit the return water temperature to decrease to within a return setback temperature range based on said second setback temperature during non-use that occurs within a historically indicated non-use period based on said historical non-use data, (d) turning on the heater pump when said heater output water temperature is greater than said heater input water temperature, and (e) controlling the water heater and said recirculating means during sensed use of hot water so that the hot water supply temperature is controlled relative to a predetermined maximum temperature which is greater than said first setback temperature.

49. The controller of claim 48 wherein said sensing means comprises flow sensing means for sensing the flow of cold water into the water heater system.

50. The controller of claim 49 wherein said flow sensing means comprises a temperature sensor located at the hot water migration zone of the cold water inlet.

51. The controller of claim 48 wherein said control means calculates a projected time of day for the start of hot water usage and controls said hot water supply temperature so as to be at about said first setback temperature at said projected time of start of hot water usage.

52. The controller of claim 51 wherein said control means determines a temperature ramp-up start time when heating of water is to start so as to control said hot water supply temperature to be at about said first setback temperature at said projected time of start of hot water usage.

53. The controller of claim 52 wherein said ramp-up start time is determined as a function of the difference between a predetermined minimum return water temperature and the sensed return water temperature.

54. The controller of claim 48 wherein said recirculating means includes a recirculation pump controlled by said control means.

55. The controller of claim 48 wherein said recirculating means includes diverting means controlled by said control means for selectively diverting return water directly into the hot water outlet.

56. The controller of claim 55 wherein said diverting means comprises an electrically operated diverter valve.

57. The controller of claim 55 wherein said recirculating means further includes a recirculation pump located upstream of said diverting means.

58. The controller of claim 48 wherein said second supply setback temperature range comprises the range between the second setback temperature and a higher temperature, and wherein said return setback temperature range comprises the range between the second setback temperature and a lower temperature.

59. The controller of claim 48 wherein said historical data comprises manually entered data.

60. The controller of claim 48 wherein said historical data comprises historical use and non-use data.