Washing machine appliance and methods for drying a wash chamber

Abstract

A washing machine appliance may include a cabinet, a tub, a wash basket, a ventilation line, a humidity sensor, and a controller. The ventilation line may define an air path from the tub through the cabinet. The humidity sensor may be mounted along the ventilation line to detect humidity therein. The controller may be in operative communication with the humidity sensor. The controller may be configured to direct a dry cycle that includes detecting a humidity level at the humidity sensor reaching a predetermined level target, measuring an elapsed time period to detecting the humidity level, determining the elapsed time period exceeds a baseline time period, recording an excess instance in response to determining the elapsed time period exceeds the baseline time period, determining a previous excess instance corresponding to a prior dry cycle, and determining a fault condition based on the excess instance and previous excess instance.

What is claimed is: 
     
         1 . A washing machine appliance comprising:
 a cabinet;   a tub positioned within the cabinet;   a wash basket rotatably mounted within the tub;   a ventilation line defining an air path from the tub through the cabinet;   a humidity sensor mounted along the ventilation line to detect humidity therein; and   a controller in operative communication with the humidity sensor, the controller being configured to direct a dry cycle comprising
 detecting a humidity level at the humidity sensor reaching a predetermined level target, 
 measuring an elapsed time period to detecting the humidity level, 
 determining the elapsed time period exceeds a baseline time period, 
 recording an excess instance in response to determining the elapsed time period exceeds the baseline time period, 
 determining a previous excess instance corresponding to a prior dry cycle, and 
 determining a fault condition based on the excess instance and previous excess instance. 
   
     
     
         2 . The washing machine appliance of  claim 1 , further comprising:
 a vent damper positioned along ventilation line in fluid communication therewith, the vent damper being selectively movable between a first position restricting airflow through the ventilation line and a second position permitting airflow through the ventilation line,   wherein the dry cycle further comprises moving the vent damper to the second position prior to detecting the humidity level.   
     
     
         3 . The washing machine appliance of  claim 1 , further comprising:
 a fan positioned in fluid communication with the ventilation line to motivate an airflow therethrough,   wherein the dry cycle further comprises directing rotation of the fan during detecting the humidity level.   
     
     
         4 . The washing machine appliance of  claim 1 , wherein the elapsed time period is measured from a start point of the dry cycle. 
     
     
         5 . The washing machine appliance of  claim 1 , wherein determining the elapsed time period exceeds the baseline time period comprises determining the elapsed time period exceeds the baseline time period by at least 10%. 
     
     
         6 . The washing machine appliance of  claim 1 , wherein the baseline time period comprises an average cycle time period of a plurality of prior dry cycles. 
     
     
         7 . The washing machine appliance of  claim 6 , wherein the plurality of prior dry cycles comprises a fixed number of prior dry cycles. 
     
     
         8 . The washing machine appliance of  claim 7 , wherein the plurality of prior dry cycles is a rolling plurality of consecutive dry cycles. 
     
     
         9 . The washing machine appliance of  claim 1 , wherein the prior dry cycle is limited to an immediately prior dry cycle such that the dry cycle is consecutive with the prior dry cycle. 
     
     
         10 . A method of operating a washing machine appliance, the washing machine appliance comprising a cabinet, a tub positioned within the cabinet, a ventilation line defining an air path from the tub through the cabinet, and a humidity sensor positioned along ventilation line in fluid communication therewith, the method comprising:
 detecting a humidity level at the humidity sensor reaching a predetermined level target;   measuring an elapsed time period to detecting the humidity level;   determining the elapsed time period exceeds a baseline time period;   recording an excess instance in response to determining the elapsed time period exceeds the baseline time period;   determining a previous excess instance corresponding to a prior dry cycle; and   determining a fault condition based on the excess instance and previous excess instance.   
     
     
         11 . The method of  claim 10 , wherein the washing machine appliance further comprises a vent damper positioned along ventilation line in fluid communication therewith, the vent damper being selectively movable between a first position restricting airflow through the ventilation line and a second position permitting airflow through the ventilation line, and
 wherein the method further comprises moving the vent damper to the second position prior to detecting the humidity level.   
     
     
         12 . The method of  claim 10 , wherein the washing machine appliance further comprises a fan positioned in fluid communication with the ventilation line to motivate an airflow therethrough, and
 wherein the method further comprises directing rotation of the fan during detecting the humidity level.   
     
     
         13 . The method of  claim 10 , wherein the elapsed time period is measured from a start point of the dry cycle. 
     
     
         14 . The method of  claim 10 , wherein determining the elapsed time period exceeds the baseline time period comprises determining the elapsed time period exceeds the baseline time period by at least 10%. 
     
     
         15 . The method of  claim 10 , wherein the baseline time period comprises an average cycle time period of a plurality of prior dry cycles. 
     
     
         16 . The method of  claim 15 , wherein the plurality of prior dry cycles comprises a fixed number of prior dry cycles. 
     
     
         17 . The method of  claim 16 , wherein the plurality of prior dry cycles is a rolling plurality of consecutive dry cycles. 
     
     
         18 . The method of  claim 10 , wherein the prior dry cycle is limited to an immediately prior dry cycle such that the dry cycle is consecutive with the prior dry cycle.