Refrigerated display case

Claim 1

A REFRIGERATED CASE HAVING A PRODUCT AREA WITH AN ACCESS OPENING, COMPRISING A REFRIGERATION SYSTEM HAVING EVAPORATOR MEANS FOR REFRIGERATING AIR, AIR DISTRIBUTION MEANS INCLUDING A DELIVERY DUCT FROM SAID EVAPORATOR MEANS TO SAID PRODUCT AREA AND A RETURN DUCT FROM SAID PRODUCT AREA TO SAID EVAPORATOR MEANS, AND AIR MOVING MEANS FOR CIRCULATING REFRIGERATED AIR ACROSS SAID EVAPORATOR MEANS AND THROUGH SAID DELIVERY DUCT TO COOL SAID PRODUCT AREA AND FOR FORMING A WALL OF AIR ACROSS SAID ACCESS OPENING TO PROJECT SAID PRODUCT AREA FROM AMBIENT AIR EXTERNAL OF SAID CASE AND FOR RETURNING SAID AIR FROM SAID PRODUCT AREA AND ACCESS OPENING TO SAID EVAPORATOR MEANS FOR RECOOLING AND RECIRCULATION, A FLUE SEPARATED FROM SAID RETURN DUCT MEANS BY AN INSULATED WALL, SAID RETURN DUCT AND SAID FLUE HAVING ADJACENT INLET ENDS, AND FAN MEANS FOR CREATING A NEGATIVE PRESSURE IN SAID FLUE TO DRAW INTO SAID FLUE AMBIENT AIR THAT IS ENTRAINED AND COOLED BY SAID WALL OF AIR, SAID REFRIGERATION SYSTEM INCLUDING A CONDENSER POSITIONED IN HEAT EXCHANGING RELATION WITH THE AMBIENT AIR ENTRAINED AND COOLED BY SAID WALL OF AIR, THERE BEING AN AIR INLET OPENING THROUGH WHICH ADDITIONAL AMBIENT AIR MAY FLOW TO THE NEGATIVE PRESSURE SIDE OF SAID FAN MEANS TO OBVIATE INTERFERENCE WITH THE CIRCULATION OF SAID REFRIGERATED AIR TO SAID RETURN DUCT.