Vending machine and method for defrosting

Abstract

A method includes sensing an exposure of a refrigerated compartment of a vending machine to ambient air and, in response, sensing an initial temperature of the refrigerated compartment. The method also includes, responsive to sensing the exposure to ambient air, selecting a procedure from a plurality of procedures according to the sensed initial temperature, and controlling a refrigeration system of the vending machine using the selected procedure during an initial period. The method may include sensing a current temperature of the vending machine and, once the refrigerated compartment reaches a second predetermined temperature, controlling the refrigeration system according to the sensed current temperature, monitoring an operational characteristic of a compressor of the refrigeration system, and performing a defrost procedure according to the monitored operational characteristic.

1 . A method, comprising:
 sensing an exposure of a refrigerated compartment of a vending machine to outside air; and   responsive to sensing the exposure of a refrigerated compartment to outside air,   sensing an initial temperature of the refrigerated compartment,   according to the sensed initial temperature, selecting a procedure from a plurality of procedures, and   controlling a refrigeration system of the vending machine using the selected procedure during an initial period.   
     
     
         2 . The method of  claim 1 , wherein the step of sensing an exposure of a refrigerated compartment of a vending machine to ambient air comprises sensing an opening of a door of the refrigerated compartment. 
     
     
         3 . The method of  claim 1 , wherein the procedure is selected according to whether the initial temperature of the vending machine is above a first predetermined temperature. 
     
     
         4 . The method of  claim 1 , wherein the step of controlling the refrigeration system during the initial period further comprises:
 activating a compressor of the refrigeration system for a first predetermined length of time; and   deactivating the compressor for a second predetermined length of time,   where the first and second predetermined lengths of time are selected according to the sensed initial temperature.   
     
     
         5 . The method of  claim 1 , further comprising:
 sensing a current temperature of the vending machine; and   during a second period:
 controlling the refrigeration system according to the sensed current temperature, 
 monitoring an operational characteristic of a compressor of the refrigeration system, and 
 performing a defrost procedure according to the monitored operational characteristic. 
   
     
     
         6 . The method of  claim 5 , wherein the defrost procedure is performed according to one of an accumulated length of time the compressor has been activated and a number of activations of the compressor. 
     
     
         7 . The method of  claim 5 , wherein the second period begins when a second predetermined temperature of the vending machine is sensed. 
     
     
         8 . The method of  claim 7 , wherein the step of controlling a refrigeration system according to the sensed current temperature further comprises activating an evaporator fan of the refrigeration system for a third predetermined length of time after the temperature of the vending machine reaches the second predetermined temperature. 
     
     
         9 . The method of  claim 8 , wherein the step of controlling a refrigeration system according to the sensed current temperature further comprises, after the third predetermined length of time, deactivating the evaporator fan when the compressor is deactivated. 
     
     
         10 . A vending machine, comprising:
 a controller;   a temperature probe communicatively coupled to the controller; and   a refrigeration system communicatively coupled to the controller,   wherein the controller is adapted to:
 sense an exposure of a refrigerated compartment of a vending machine to outside air; and 
 responsive to sensing the exposure of a refrigerated compartment to outside air,
 sense an initial temperature of the refrigerated compartment, 
 according to the sensed initial temperature, select a procedure from a plurality of procedures, and 
 control a refrigeration system of the vending machine using the selected procedure during an initial period. 
 
   
     
     
         11 . The vending machine of  claim 10 , wherein the controller is further adapted to select the procedure according to whether the initial temperature of the vending machine is above a first predetermined temperature. 
     
     
         12 . The vending machine of  claim 10 , wherein the controller is further adapted to, during the initial period:
 activate a compressor of the refrigeration system for a first predetermined length of time;   deactivate the compressor for a second predetermined length of time; and   select the first and second predetermined lengths of time according to the sensed initial temperature.   
     
     
         13 . The vending machine of  claim 10 , wherein the controller is further adapted to:
 sense a current temperature of the vending machine; and   during a second period:
 control the refrigeration system according to the sensed current temperature, 
 monitor an operational characteristic of a compressor of the refrigeration system, and 
 perform a defrost procedure according to the monitored operational characteristic. 
   
     
     
         14 . The vending machine of  claim 13 , wherein the controller is further adapted to perform the defrost procedure according to one of an accumulated length of time the compressor has been activated and a number of activations of the compressor. 
     
     
         15 . The vending machine of  claim 13 , wherein the controller is further adapted to begin the second period when a second predetermined temperature of the vending machine is sensed. 
     
     
         16 . The vending machine of  claim 15 , wherein the controller is further adapted to, when the second period begins, activate an evaporator fan of the refrigeration system for a third predetermined length of time. 
     
     
         17 . The vending machine of  claim 16 , wherein the controller is further adapted to, during the second period, after the third predetermined length of time, deactivate the evaporator fan when the compressor is deactivated. 
     
     
         18 . A method, comprising:
 sensing an opening of a door of a refrigerated compartment of a vending machine; and   responsive to sensing the opening of the door,
 sensing an initial temperature of the refrigerated compartment, and 
 during an initial period, operating a compressor of a refrigeration system of the vending machine in a plurality of cycles of activation and deactivation, where the compressor is activated and deactivated for predetermined lengths of time selected according to whether the initial temperature of the vending machine is above a first predetermined temperature. 
   
     
     
         19 . The method of  claim 18 , further comprising:
 sensing a current temperature of the vending machine; and   during a second period that begins when a second predetermined temperature of the vending machine is sensed:
 controlling the refrigeration system according to the sensed current temperature, 
 monitoring an operational characteristic of a compressor of the refrigeration system, and 
 performing a defrost procedure according to the monitored operational characteristic. 
   
     
     
         20 . The method of  claim 19 , wherein the defrost procedure is performed according to one of an accumulated length of time the compressor has been activated and a number of activations of the compressor. 
     
     
         21 . The method of  claim 19 , wherein the step of controlling the refrigeration system according to a sensed current temperature further comprises:
 activating an evaporator fan of the refrigeration system for a predetermined length of time after the second predetermined temperature is sensed; and   subsequently, activating the evaporator fan when the compressor is activated and deactivating the fan when the compressor is deactivated.