Electronically controlled hot water recirculation pump with data logging

Abstract

A water pump controlled by a microcontroller and operated to pump hot water for specific recirculation periods during a multi-day cycle. The recirculation periods are determined from hot water usage data logged by the microcontroller during a logging period occurring in the previous multi-day cycle. A preferred cycle is during a seven-day, or one-week, period.

1 - 4 . (canceled) 
     
     
         5 . A method for controlling the flow of hot water in a building hot water system, the hot water system comprising a source of hot water, a piping system for containing a flow of hot water, a water pump mechanism operatively connected to the piping system for causing the flow of hot water from the source through the piping system, a sensor for detecting the flow of hot water through the hot water system by sensing a temperature change in the hot water system, a microcontroller operatively connected to the sensor to receive a signal indicating the flow of hot water, the microcontroller also being capable of logging and recording the signal during a pre-defined data logging period, and for controlling the pump to cause hot water flow during a subsequent data logging period, the method comprising: during a pre-defined data logging period, logging and recording on the microcontroller, signals from the sensor indicating the times for the periods of a flow of hot water through the hot water system during each day of the data logging period to obtain usage patterns data during the data logging period; and during a succeeding pre-defined data period controlling the operation of the water pump mechanism with the microcontroller to operate the water pump mechanism to maintain a flow of hot water in accordance with the logged usage pattern data obtained during the previous defined data logging period. 
     
     
         6 . The method of  claim 5  further comprising:
 during the succeeding pre-defined data period, logging and recording on the microcontroller, signals from the sensor indicating the times for the periods of a flow of hot water through the hot water system during each day of the succeeding data period to obtain usage pattern data during the succeeding data logging period, updating the logged usage pattern data obtained during the previous defined data logging period, representing the water usage patterns upon expiration of the succeeding pre-defined data logging period; and 
 operating the water pump mechanism during a second succeeding data period. 
 
     
     
         7 . The method of  claim 5  where each succeeding pre-defined data period comprises one or more recirculation periods each day of the pre-defined data period, each recirculation period including a start usage cycle and an end usage cycle, as defined from the previously logged and recorded data. 
     
     
         8 . The method of  claim 5  where the microcontroller is programmed to place the smart pump into an idle mode when no hot water usage is detected for a pre-defined period of time during any data period. 
     
     
         9 . The method of  claim 8  where the pre-defined period of time is 36 hours. 
     
     
         10 . The method of  claim 7  where the sensor signals a start usage cycle determined by a time rate of change of water temperature of K degrees per L minutes after the water pump mechanism has been off for M minutes where K, L and M are pre-defined variables representing real numbers greater than zero. 
     
     
         11 . The method of  claim 7  where a start usage cycle occurs when the water pump mechanism has been off for P minutes and the water remains hot, where P is a variable representing a real number greater than zero. 
     
     
         12 . The method of  claim 7  where the end usage cycle occurs when no hot water usage is detected for a pre-defined period of time, Z, where Z is a variable representing a real number greater than zero. 
     
     
         13 . The method of  claim 12  where Z equals 2.8 hours. 
     
     
         14 . The method of  claim 7  where a pre-run time X and a post-run time Y are applied to the start usage cycles and to the end usage cycles respectively where X and Y are variables representing time periods in minutes, hours, seconds or any combination thereof. 
     
     
         15 . The method of  claim 5  further comprising operating the water pump mechanism in a pulse mode based on a selection made with an automatic switch, where desired. 
     
     
         16 . The method of  claim 5  further comprising maintaining sufficient power to the microcontroller to maintain operating status during a power outage, such that upon restoration of power after a power outage the water pump mechanism returns to its operating status immediately prior to the power outage. 
     
     
         17 . The method of  claim 5  where, upon restoration of power after a power outage, the water pump mechanism starts a new data logging period. 
     
     
         18 . The method of  claim 5  where the data logging period is 7 calendar days. 
     
     
         19 . (canceled)