Refrigerator

Abstract

A refrigerator has a fresh food compartment ( 3 ) adapted for maintaining the contents at a temperature above freezing. A vapour compression refrigeration system is operable in one mode so that an evaporator ( 7 ) is operated at a temperature within 10° C. of the temperature desired in the fresh food compartment ( 3 ) and a supply of air is maintained over the evaporator ( 7 ) and in to the compartment ( 3 ). The vapour compression system is used in a defrost mode in which the vapour compression refrigeration system is stopped or allowed to operate without significant heat extraction at the evaporator ( 7 ), and a supply of air above 0° C. is past over it. Operating the fresh food compartment evaporator ( 7 ) at such a high temperature (close to 0° C.) reduces the rate of frost build up and the under cooling of frost. Frost may be adequately removed by an ambient air flow without heater supplementation.

1 . A refrigerator having a fresh food compartment adapted for maintaining the contents thereof at a temperature above freezing, a vapour compression refrigerator system, air circulation means for causing a circulating airflow between said compartment and the evaporator of said refrigerator system, and a controller for controlling said air circulation means and said refrigerator system, characterised in that in a refrigeration mode with said refrigeration system and air circulation means active, said evaporator operates with a surface temperature within 10° C. of the temperature desired in the said fresh food compartment and a supply of air is maintained over said evaporator and into said fresh food compartment, and in a defrost mode said controller deactivates said vapour compression refrigeration system, or operates it without significant heat extraction at said evaporator, and activates said air circulation means to circulate air above 0° C. over said evaporator, and there is no other means of heating said evaporator.  
     
     
         2 . A refrigerator as claimed as  claim 1  wherein said refrigerator includes only said fresh food compartment.  
     
     
         3 . A refrigerator as claimed in  claim 1  including a frozen food compartment and a separate vapour compression refrigeration system for each said compartment, the evaporator of said vapour compression refrigeration system of said frozen food compartment operating at a much lower temperature than the evaporator of said vapour compression system for said fresh food compartment.  
     
     
         4 . A refrigerator as claimed in  claim 1  including a frozen food compartment, said vapour compression system including said evaporator for said fresh food compartment and a second evaporator adapted to operate at a lower temperature for cooling the frozen food compartment.