System and method for improving a water heating cycle in a multi-purpose hvac system

Abstract

A method for improving a water heater cycle in a system for heating water and conditioning an interior space by operating a water pump at a first rate of speed until the entering water temperature is within a desirable range, or the water pump has operated at the first rate of speed for a predetermined time, then operating the water pump at a second rate of speed.

What is claimed is: 
     
         1 . A method for improving a water heating cycle in a multi-purpose HVAC system including an outdoor unit assembly operably coupled to a water heater module, the water heater module including at least one valve, a pump, and a temperature sensor, the multi-purpose HVAC system further including an indoor unit assembly operably coupled to the water heater module, the method comprising the steps of:
 (a) operating the multi-purpose HVAC system in a water heating mode;   (b) operating the pump at a first rate of speed;   (c) determining if a predetermined condition has been satisfied; and   (d) if the predetermined condition has been satisfied, operating the pump at a second rate of speed.   
     
     
         2 . The method of  claim 1 , wherein the at least one valve comprises a pair of three way valves. 
     
     
         3 . The method of  claim 1 , wherein step (a) comprises operating one or more of the at least one valve to configure a refrigerant circuit. 
     
     
         4 . The method of  claim 3 , wherein:
 the at least one valve comprises:
 a first valve coupled to an inlet of a heat exchanger via a first conduit; 
 a second valve coupled to an outlet of the heat exchanger via a second conduit; 
 a third valve coupled to the first valve via a third conduit; 
 a fourth valve coupled to the second valve via a fourth conduit; and 
   step (a) comprises opening the first and second valves and closing the third and fourth valves.   
     
     
         5 . The method of  claim 3 , wherein the refrigerant circuit circulates a refrigerant from the outdoor unit assembly, through the water heater module, and returns to the outdoor unit assembly. 
     
     
         6 . The method of  claim 1 , wherein the first rate of speed is less than or equal to four gallons per minute. 
     
     
         7 . The method of  claim 1 , wherein the second rate of speed is greater than  4  gallons per minute. 
     
     
         8 . The method of  claim 1 , wherein step (c) further comprises operating the temperature sensor to measure a first water temperature and the predetermined condition comprises the first water temperature being greater than or equal to a predetermined water temperature. 
     
     
         9 . The method of  claim 1 , wherein the predetermined condition comprises operating the pump at the first rate of speed for a predetermined duration of time. 
     
     
         10 . The method of  claim 8 , wherein the predetermined water temperature is between approximately 100° F. and approximately 120° F. 
     
     
         11 . A multi-purpose HVAC system comprising
 an outdoor unit assembly;   an indoor unit assembly;   a water heater module including at least one valve, a pump, and a temperature sensor;   a plurality of conduits operatively coupling the water heater module to the outdoor unit assembly and the indoor unit assembly; and   a controller in electrical communication with, the at least one valve, the pump, and the temperature sensor;   wherein the controller is configured to:   (a) operate the multi-purpose HVAC system in a water heating mode;   (b) operate the pump at a first rate of speed;   (c) determine if a predetermined condition has been satisfied; and   (d) operate the pump at a second rate of speed, if the predetermined condition has been satisfied.   
     
     
         12 . The multi-purpose HVAC system of  claim 11 , wherein the at least one valve comprises a pair of three way valves. 
     
     
         13 . The multi-purpose HVAC system of  claim 11 , wherein step (a) comprises the controller operating one or more of the at least one valves to configure a refrigerant circuit to circulate a refrigerant from the outdoor unit assembly through the water heater module, and returns to the outdoor unit assembly. 
     
     
         14 . The multi-purpose HVAC system of  claim 13 , wherein the at least one valve comprises:
 a first valve;   a first conduit coupling the first valve to an inlet of the heat exchanger;   a second valve;   a second conduit coupling the second valve to an outlet of the heat exchanger;   a third valve;   a third conduit coupling the third valve to the first valve;   a fourth valve;   a fourth conduit coupling the fourth valve to the second valve;   wherein the controller is configured to open the first and second valves and close the third and fourth valves to configure the refrigerant circuit.   
     
     
         15 . The multi-purpose HVAC system of  claim 11 , wherein the first rate of speed is less than or equal to four gallons per minute. 
     
     
         16 . The multi-purpose HVAC system of  claim 11 , wherein the second rate of speed is greater than 4 gallons per minute. 
     
     
         17 . The multi-purpose HVAC system of  claim 11 , wherein the controller operates the pump at the second rate of speed when the temperature sensor measures a first water temperature and the predetermined condition comprises the first water temperature being greater than or equal to a predetermined water temperature. 
     
     
         18 . The multi-purpose HVAC system of  claim 11 , wherein the controller operates the pump at the second rate of speed when predetermined condition comprises operating the pump at the first rate of speed for a predetermined duration of time. 
     
     
         19 . The multi-purpose HVAC system of  claim 17 , wherein the predetermined water temperature is between approximately 100° F. and approximately 120° F.