Control System for Bottom Freezer Refrigerator with Ice Maker in Upper Door

Abstract

A refrigerator includes a main body defining a compartment, the compartment having an access opening and a first wall, a door supported by the main body for selectively closing at least part of the access opening, a sub-compartment on the door, the sub-compartment including a second wall having an opening, a heat exchanger supported by the first wall and positioned so that when the door is closed the heat exchanger is exposed to an interior of the sub-compartment through the opening. The heat exchanger includes a heat exchanging plate. A sealed refrigeration system contains a working medium for cooling the heat exchanger and has one or more segments attached to the heat exchanging plate. A fan is configured to force air over the heat exchanging plate and into the interior of the sub-compartment. A thermistor is coupled to the heat exchanging plate for monitoring a temperature of the heat exchanging plate. A controller is configured to adjust a speed of the fan in dependence of the temperature of the heat-exchanging plate detected by the thermistor.

What is claimed is: 
     
         1 . A method, comprising:
 detecting a temperature of a heat exchanging plate, the heat exchanging plate positioned adjacent an ice sub-compartment, the ice sub-compartment disposed on a fresh food compartment door of a bottom freezer refrigerator; and   activating a fan in order to move air across the heat exchanging plate and into the ice sub-compartment in response to the temperature of the heat exchanging plate.   
     
     
         2 . The method of  claim 1 , further comprising adjusting a speed of the fan to a first speed when the temperature of the heat exchanging plate is less than a predetermined temperature setpoint or to a second speed when the temperature of the heat exchanging plate is greater than the predetermined temperature setpoint, the first speed being less than the second speed. 
     
     
         3 . The method of  claim 2 , further comprising:
 detecting that the temperature of the heat exchanging plate is greater than a second predetermined temperature setpoint; and   increasing the speed of the fan and activating a refrigeration system of the bottom freezer refrigerator when the temperature of the heat exchanging plate is greater than the second predetermined temperature setpoint.   
     
     
         4 . The method of  claim 3 , wherein activation of the refrigeration system occurs independently of a temperature requirement for a fresh food or freezer compartment of the refrigerator. 
     
     
         5 . The method of  claim 1 , further comprising activating the fan only when a refrigeration system for the refrigerator is in a cooling mode. 
     
     
         6 . The method of  claim 1 , further comprising:
 detecting that a state of an ice maker in the ice sub-compartment is in an ice formation cycle;   increasing a speed of the fan and activating a refrigeration system for the refrigeration to detecting that the state of the ice maker is the ice formation cycle.   
     
     
         7 . The method of  claim 6 , further comprising:
 determining a pre-determined time period from a start of the ice formation cycle; and   setting the speed of the fan in dependence of the temperature of the heat exchanging plate.   
     
     
         8 . The method of  claim 1 , further comprising using a single thermistor coupled to the heat exchanging plate to detect the temperature of the heat exchanging plate. 
     
     
         9 . The method of  claim 1 , further comprising:
 detecting a defrost mode of the heat-exchanging plate; and   deactivating the defrost mode when the temperature of the heat-exchanging plate is greater than a pre-determined defrost temperature setpoint.