Appliance configured to circulate air during a wash cycle

Abstract

An appliance such as a dishwasher is configured to re-circulate air to reduce the amount of air with high moisture content that is expelled from the dishwasher. In one embodiment, the dishwasher comprises a wash zone in which objects are positioned to be washed and a door assembly, secured to the dishwasher in sealing engagement. Air from an upper region of the wash zone is drawn into a door cavity in the door assembly and re-circulated to a lower region of the wash zone. Inside of the door cavity is a thermal sink with a surface on which vapor in the air condenses, thereby lowering the relative humidity of the air that is ejected from the door assembly and into the lower region of the wash zone.

1 . A door assembly, comprising:
 a peripheral wall surrounding a door cavity, the peripheral wall having a first opening and a second opening exposing the door cavity to the environment;   a thermal sink disposed in the door cavity; and   an air moving device that is configured to draw air through the first opening and into the door cavity,   wherein the thermal sink is configured with a surface on which condenses vapor in the air.   
     
     
         2 . A door assembly according to  claim 1 , further comprising a pathway disposed in the door cavity through which air flows from the first opening to the second opening, wherein the pathway exposes the air to the thermal sink. 
     
     
         3 . A door assembly according to  claim 2 , wherein the pathway comprises a duct coupled to each of the first opening and the second opening. 
     
     
         4 . A door assembly according to  claim 3 , wherein the duct is formed by a tube. 
     
     
         5 . A door assembly according to claim I, further comprising a conduit through which the condensed vapor flows out of the door cavity. 
     
     
         6 . A door assembly according to  claim 1 , wherein the thermal sink comprises a phase change material. 
     
     
         7 . A door assembly according to  claim 6 , wherein the phase change material is proximate the surface of the thermal sink. 
     
     
         8 . An appliance, comprising:
 a wash zone in which objects can be positioned to be washed; and   a door assembly configured to seal the wash zone, the door assembly having a peripheral wall surrounding a door cavity in which is disposed a thermal sink with a surface on which condenses vapor in the air,   wherein the door assembly is configured to draw air into the door cavity from an upper region of the wash zone and to expel the air from the door cavity into a lower region of the wash zone.   
     
     
         9 . An appliance according to  claim 8 , further comprising a sump zone proximate the lower region and in which a washing fluid is collected, wherein the door assembly is configured to flow the condensed vapor from the thermal sink into the sump zone. 
     
     
         10 . An appliance according to  claim 8 , wherein the door assembly comprises a duct in flow communication with the upper region and the lower region and through which flows the air. 
     
     
         11 . An appliance according to  claim 10 , wherein the duct comprises a conduit that extends from a first opening to a second opening in the peripheral wall. 
     
     
         12 . An appliance according to  claim 10 , wherein the duct is configured to expose the air to the thermal sink. 
     
     
         13 . An appliance according to  claim 8 , further comprising an air moving device proximate the upper region, wherein the air moving device is configured to move air from the upper region into an opening in the peripheral wall. 
     
     
         14 . An appliance according to  claim 13 , wherein the air moving device comprises a fan. 
     
     
         15 . A method of operating a dishwasher, said method comprising:
 activating an air moving device located proximate an upper region of the dishwasher, wherein the air moving device is configured to generate an outward flow of air from inside the dishwasher into a door cavity;   regulating a heating element from a first power level to a second power level in response to a change in a characteristic of the environment of the dishwasher,   wherein the air passes through the door cavity in thermal relation to a thermal sink.   
     
     
         16 . A method according to  claim 15 , wherein the air is ejected into a lower region of the dishwasher. 
     
     
         17 . A method according to  claim 15 , wherein the first power level is less than the second power level. 
     
     
         18 . A method according to  claim 15 , wherein the characteristic is temperature of air in the appliance. 
     
     
         19 . A method according to  claim 15 , wherein the characteristic is relative humidity of air in the appliance. 
     
     
         20 . A method according to  claim 15 , farther comprising regulating a speed of the air moving device in response to changes in one or more of the characteristic of the environment.