| 主权项 |
1. A device for use with a hot water recirculation system containing a hot water source, a flow sensor downstream from said source, 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 rate and an in-use flow rate via said sensor, said resting rate determined when said pump avoids pumping water and said fixture avoids drawing water, said in-use rate 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 rate to said resting rate 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 rate 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. |
