Hot water recirculation system technologies

• US 10,036,572 B1
• Filed: 02/15/2017
• Issued: 07/31/2018
• Est. Priority Date: 08/12/2013
• Status: Active Grant

• Current Assignee: Lawrence Halff
• Original Assignee: Lawrence Halff
• Inventors: Halff, Lawrence
• Primary Examiner(s): Bertheaud, Peter J
• Application Number:
  US15/433,295
• Time in Patent Office: 531 Days
• Field of Search: 417 12, 417 43
• CPC Class Codes: F24D 17/0078 Recirculation systems
• CPC Class Codes: F24D 19/1051 for domestic hot water
• CPC Class Codes: F24H 15/238 Flow rate
• CPC Class Codes: F24H 15/265 Occupancy
• CPC Class Codes: F24H 15/269 Time, e.g. hour or date
• CPC Class Codes: F24H 15/281 Input from user
• CPC Class Codes: F24H 15/335 Control of pumps, e.g. on-off control control of compressors of heat pumps F24H15/38
• CPC Class Codes: F24H 15/45 remotely accessible
• CPC Class Codes: Y10T 137/6497 Hot and cold water system having a connection from the hot to the cold channel

Abstract

Technologies for use with a hot water recirculation system containing a hot water source, a booster pump downstream from the sensor, a conduit connecting the booster pump and water source, a flow sensor external to the conduit for sensing water flow within the conduit, and a plumbing fixture downstream from the pump are provided. The technologies enable a controller to couple to the sensor and the pump, and operate in a calibration mode and a control mode. Such operations can increase energy efficiency of the pump and increase operational longevity of the pump.

Claims

1. A device for use with a hot water recirculation system containing a hot water source, a conduit connecting the booster pump and hot water source, a flow sensor external to said conduit for sensing flow within said conduit, a booster pump downstream from said sensor, and a plumbing fixture downstream from said pump, said device comprising:

a controller configured for coupling to said sensor and said pump, said controller operative in one of a calibration mode and a control mode when coupled to said sensor and said pump,

in said calibration mode, said controller determines a resting flow state and an in-use flow state via said sensor, said resting state determined when said pump avoids pumping water and said fixture avoids drawing water, said in-use state determined when said pump pumps water and said fixture draws water pumped via said pump, said controller determines a first time period indicative of time for returning from at least said in-use state to said resting state when said pump avoids pumping water and said fixture avoids drawing water, said controller receives an input from a user for a second time period,

in said control mode, said controller controls said pump to pump water for duration of said second period based on said input in response to sensing at least said in-use state via said sensor, said controller controls said pump to avoid pumping water immediately after expiration of said second period for duration of at least said first period, and

wherein in said control mode, said controller selectively periodically enters a refresh mode and activates the pump, not in response to sensing at least said in-use state via said sensor.

2. The device of claim 1, wherein the hot water recirculation system includes a proximity sensor, and wherein the controller does not initiate the refresh mode when the proximity sensor determines that the user is not present.

3. The device of claim 2, wherein during the refresh mode, the controller activates the pump for a refresh time of substantially one minute.

4. The device of claim 3, wherein following the refresh mode, the controller avoids pumping water for duration of at least said first period.

5. The device of claim 2, wherein, in said calibration mode, said resting state is determined for duration of a third time period, said resting state is sensed via said flow sensor during said third period.

6. The device of claim 2, wherein, in said calibration mode, said in-use state is determined via said user operating said fixture for duration of a fourth time period after said third period, said in-use state sensed via said flow sensor during said fourth period, said controller receiving an indication from said user before determining said first period, said indication indicative that a process for determining said in-use state is complete.

7. The device of claim 6, wherein, in said calibration mode, said first period is determined via said controller controlling said pump to pump water for duration of a fifth time period after said fourth period, said fifth period is sufficiently long to induce flow back to at least said source, said first period corresponding to time as determined via said controller for flow state as determined via said flow sensor to return to said resting state.

8. The device of claim 7, wherein, in said calibration mode, said first period is determined via iteration such that flow variation is accounted for, said first period corresponding to a longest reading taken during said iteration via said controller, wherein, in said control mode, said controller is configured for controlling said pump via a switch coupled to said controller and said pump.

9. The device of claim 2, wherein said controller containing a user interface configured for operation via said user, said controller is operative for receiving said input via said interface from said user in said calibration mode.

10. The device of claim 2, wherein said controller is configured to receive a wireless signal, said controller is operative for receiving said input via said signal in said calibration mode.

11. A hot water recirculation system comprising:

a hot water source;

a first conduit connected to the hot water source;

a second conduit connected to the first conduit;

a flow sensor located externally to the first and second conduit for sensing water flow within said conduits;

a booster pump connected to the second conduit;

a plumbing fixture downstream from said pump;

a controller coupled to said sensor and said pump, said controller operative in one of a calibration mode and a control mode,

in said calibration mode, said controller determines a resting flow state and an in-use flow state via said sensor, said resting state determined when said pump avoids pumping water and said fixture avoids drawing water, said in-use state determined when said pump pumps water and said fixture draws water pumped via said pump, said controller determines a first time period indicative of time for returning from at least said in-use state to said resting state when said pump avoids pumping water and said fixture avoids drawing water, said controller receives an input from a user for a second time period,

in said control mode, said controller controls said pump to pump water for duration of said second period based on said input in response to sensing at least said in-use state via said sensor, said controller controls said pump to avoid pumping water immediately after expiration of said second period for duration of at least said first period, and

wherein in said control mode, said controller selectively periodically enters a refresh mode and activates the pump, not in response to sensing at least said in-use state via said sensor.

12. The system of claim 11, wherein the hot water recirculation system includes a proximity sensor, and wherein the controller does not initiate the refresh mode when the proximity sensor determines that the user is not present, and wherein following the refresh mode, the controller avoids pumping water for duration of at least said first period.

13. The system of claim 12, wherein, in said calibration mode, said resting state is determined for duration of a third time period, said resting state is determined by the flow sensor at a maximum flow during said third period.

14. The system of claim 13, wherein, in said calibration mode, said in-use state is determined via said user operating said fixture for duration of a fourth time period after said third period, said in-use state is a minimum flow sensed via said flow sensor during said fourth period, said controller receiving an indication from said user before determining said first period, said indication indicative that a process for determining said in-use state is complete.

15. The system of claim 14, wherein, in said calibration mode, said first period is determined via said controller controlling said pump to pump water for duration of a fifth time period after said fourth period, said fifth period is sufficiently long to induce flow back to at least said source, said first period corresponding to time as determined via said controller for flow as determined via said flow sensor to return to said resting state.

16. The system of claim 15, further comprising a switch coupled to said controller and said pump, said controller controlling said pump via said switch in said control mode, wherein, in said calibration mode, said first period is determined via iteration such that flow variation is accounted for, said first period corresponding to a longest reading taken during said iteration via said controller.

17. A method for use with a hot water recirculation system, for use by a user, containing a hot water source, and a plumbing fixture downstream from said pump, a conduit connecting the booster pump to hot water source, a flow sensor external to said conduit for sensing water flow within said conduit, a booster pump downstream from said flow sensor, and a proximity sensor for detecting presence of the user, said method comprising:

coupling a controller to said flow sensor and said pump, said controller programmed for operation in one of a calibration mode and a control mode;

operating said controller in said calibration mode such that said controller determines a resting flow state and an in-use flow state via said flow sensor, said resting state determined when said pump avoids pumping water and said fixture avoids drawing water, said in-use state determined when said pump pumps water and said fixture draws water pumped via said pump, said controller determines a first time period indicative of time for returning from at least said in-use state to said resting state when said pump avoids pumping water and said fixture avoids drawing water, said controller receives an input from a user for a second time period;

operating said controller in said control mode such that said controller controls said pump to pump water for duration of said second period based on said input in response to sensing at least said in-use state via said flow sensor, said controller controlling said pump to avoid pumping water immediately after expiration of said second period for duration of at least said first period, and said controller controls said pump to periodically pump water for a refresh period unless said proximity sensor determines that the user is not present, not in response to sensing at least said in-use state via said flow sensor.

18. The method of claim 17, wherein, in said calibration mode, said resting state is determined for duration of a third time period, said resting state is determined by the flow sensor during said third period.

19. The method of claim 18, wherein, in said calibration mode, said in-use state is determined via said user operating said fixture for duration of a fourth time period after said third period, said in-use state sensed via said flow sensor during said fourth period, said controller receiving an indication from said user before determining said first period, said indication indicative that a process for determining said in-use state is complete.

20. The method of claim 19, wherein, in said calibration mode, said first period is determined via said controller controlling said pump to pump water for duration of a fifth time period after said fourth period, said fifth period is sufficiently long to induce flow back to at least said source, said first period corresponding to time as determined via said controller for flow as determined via said flow sensor to return to said resting state.

21. The method of claim 20, wherein, in said calibration mode, said first period is determined via iteration such that flow variation is accounted for, said first period corresponding to a longest reading taken during said iteration via said controller, wherein, in said control mode, said controller is configured for controlling said pump via a switch coupled to said controller and said pump.

22. The method of claim 17, wherein said controller includes at least one of a user interface configured for operation via said user and a wireless signal receiver, said controller is operative for at least one of receiving said input via said interface from said user in said calibration mode and receiving said input via said receiver in said calibration mode.