Patent ID: 7322204

Claim:
A low temperature zone forming system including an upward-open case body for displaying commodities, the case body confining a space surrounded by a floor face and four side walls, to be used for maintaining freshness of fresh marine products in a wholesale market, wherein a thermally stratified low temperature zone having temperature distribution in a vertical direction is formed above said floor face, and further wherein said floor face constitutes a cooling heat exchanger having heat transfer faces on both sides thereof, one of the heat transfer faces forming a cooling floor face and the other of the heat transfer faces forming a heat transfer face to perform heat exchange in a cold air producing chamber formed in a rear face side of the floor face, wherein warm air in a warm air zone in an upside opening region of said case body is introduced into said cold air producing chamber to be cooled therein, and cold air produced in the chamber is introduced into the low temperature zone formed above said one of the heat transfer faces to form a new cold air stratified zone.