Frost sensor, defrost system, and defrost methods

Abstract

A frost sensor, or a frost/ice/water sensor, and systems and methods of using the same, are provided herein. The frost sensor includes a body including a measurement circuit, and a capacitance sensor including two or more co-planar plates coupled to and extending laterally from the body. The measurement circuit is configured to measure a capacitance sensed by the capacitance sensor, the measurement representing a change of material between the plates over time. The frost sensor also includes at least one mounting component coupled to and extending laterally from the body. In some instances, the frost sensor is coupled to evaporator coils of a cooling system.

What is claimed is: 
     
         1 . A method of controlling a defrost cycle for an evaporator, the method comprising:
 measuring, using a frost sensor coupled to an evaporator coil of the evaporator, a capacitance over time;   based on the measured capacitance, determining an amount of ice buildup on the frost sensor; and   initiating a defrost cycle when the amount of ice buildup reaches a threshold amount.   
     
     
         2 . The method of  claim 1 , wherein initiating the defrost cycle comprises transmitting a defrost initiation signal to a motor operating a fan associated with the evaporator coil. 
     
     
         3 . The method of  claim 2 , further comprising generating the defrost initiation signal including control parameters, the control parameters including one or more of a cycle initiation time, a cycle duration, a cycle temperature or magnitude, or a cycle periodicity. 
     
     
         4 . The method of  claim 1 , further comprising monitoring trends in the amount of ice buildup on the frost sensor. 
     
     
         5 . The method of  claim 4 , further comprising adjusting a defrost schedule based on the trends. 
     
     
         6 . The method of  claim 4 , further comprising identifying an aberrant change in an accumulation of ice buildup on the frost sensor. 
     
     
         7 . The method of  claim 6 , further comprising initiating the defrost cycle at a sooner or later time based on the aberrant change in accumulation. 
     
     
         8 . The method of  claim 1 , further comprising determining, based on the measured capacitance, a ratio of ice buildup, water, and air at the frost sensor. 
     
     
         9 . The method of  claim 1 , wherein initiating the defrost cycle comprises automatically initiating the defrost cycle. 
     
     
         10 . The method of  claim 1 , wherein initiating the defrost cycle comprises:
 transmitting, to an external computing device, an alert indicating the amount of ice buildup has reached or exceeded the threshold amount;   receiving, from the external computing device, a command to initiate the defrost cycle; and   in response to receiving the command, initiating the defrost cycle.   
     
     
         11 . A method of controlling a defrost cycle for an evaporator, the method comprising:
 measuring, using a frost sensor coupled to an evaporator coil of the evaporator, a capacitance over time;   based on the measured capacitance, determining an amount of ice buildup on the frost sensor over time; and   generating a defrost schedule for the evaporator based on the determinations.   
     
     
         12 . The method of  claim 11 , wherein generating the defrost schedule comprises:
 accessing an existing defrost schedule for the evaporator;   identifying, based on the determinations, an aberrant change in an accumulation of ice buildup on the frost sensor; and   updating the existing defrost schedule to accommodate the aberrant change in accumulation of ice buildup.   
     
     
         13 . A method of controlling a defrost cycle for an evaporator, the method comprising:
 receiving, from a frost sensor coupled to an evaporator coil of the evaporator, a capacitance measurement of capacitance at the frost sensor over time;   based on the measured capacitance, determining an amount of ice buildup on the frost sensor; and   initiating a defrost cycle when the amount of ice buildup reaches a threshold amount.   
     
     
         14 . The method of  claim 13 , wherein initiating the defrost cycle comprises transmitting a defrost initiation signal to a motor operating a fan associated with the evaporator coil. 
     
     
         15 . A defrost system comprising:
 a frost sensor coupled to an evaporator, the frost sensor comprising:
 a body comprising a measurement circuit; 
 a capacitance sensor comprising two or more coplanar plates coupled to and extending laterally from the body, wherein the measurement circuit is configured to measure a capacitance sensed by the capacitance sensor; and 
 at least one mounting clip coupled to and extending laterally from the body; and 
   an external device configured to receive the measured capacitance from the frost sensor.   
     
     
         16 . The defrost system of  claim 15 , wherein the external device is further configured to:
 based on the measured capacitance, determine an amount of ice buildup on the frost sensor; and   initiate a defrost cycle at the evaporator when the amount of ice buildup reaches a threshold amount.   
     
     
         17 . The defrost system of  claim 16 , wherein the external device is further configured to initiate the defrost cycle by transmitting a defrost initiation signal to a motor operating a fan associated with the evaporator coil. 
     
     
         18 . The defrost system of  claim 17 , wherein the external device is further configured to generate the defrost initiation signal including control parameters, the control parameters including one or more of a cycle initiation time, a cycle duration, a cycle temperature or magnitude, or a cycle periodicity. 
     
     
         19 . The defrost system of  claim 15 , wherein the external device is further configured to monitor trends in an amount of ice buildup on the frost sensor. 
     
     
         20 . The defrost system of  claim 15 , wherein the external device includes a user interface configured to display the capacitance measurements.