Field-installable refrigerated cabinet kit, refrigerated merchandiser, and methods of use

A refrigerated storage or display device comprising;

• a cabinet having an interior and an exterior;
• an evaporator enclosure comprising an insulated wall separating an interior of the evaporator enclosure from the exterior, the insulated wall defining a pressure relief valve opening;
• an evaporator coil in the evaporator enclosure;
• a refrigeration system for cooling the interior of the cabinet, the refrigeration system including an evaporator assembly in the evaporator enclosure;
• a frosting chamber in the evaporator enclosure between the insulated wall and the evaporator assembly, the frosting chamber having a chilled interior frosting surface, the frosting chamber being adjacent to the evaporator assembly such that the frosting chamber is cooled by the evaporator assembly;
• an evaporator drain pan below the evaporator assembly and the frosting chamber;
• a pressure relief valve in the pressure relief valve opening, the pressure relief valve comprising a valve heater configured to heat the pressure relief valve to prevent frost from forming inside the pressure relief valve, the pressure relief valve configured to open in response to pressure of the interior of the cabinet being less than pressure of the exterior of the cabinet whereby outside air containing moisture is introduced into the refrigeration system and then into the interior of the cabinet through the pressure relief valve until the pressure of the interior of the cabinet equalizes with the pressure of the exterior of the cabinet, the pressure relief valve configured to direct the outside air into the interior of the cabinet through the frosting chamber such that the moisture in the outside air introduced through the pressure relief freezes as frost on the chilled interior frosting surface of the frosting chamber;
• and
• a defrost heater configured to periodically conduct defrost cycles during which the defrost heater defrosts the evaporator assembly, wherein the frosting chamber is located in relation to the defrost heater such that frost formed on the chilled interior frosting surface defrosts and drains into the evaporator drain pan during the defrost cycles;
• wherein the frosting chamber has a bottom end a top end and a frosting chamber height extending from the bottom end to the top end;
• wherein the bottom end is enclosed by the evaporator drain pan;
• wherein the top end is enclosed by the evaporator enclosure;
• wherein the frosting chamber comprises first, second, and third enclosed vertical sides;
• wherein each of the first, second, and third enclosed vertical sides extends from the bottom end to the top end;
• wherein the first enclosed vertical side extends alongside the evaporator coil;
• wherein the second enclosed vertical side extends along the evaporator enclosure opposite the first enclosed vertical side;
• wherein the pressure relief valve opens through the second enclosed vertical side;
• wherein the third enclosed vertical side extends between the first enclosed vertical side and the second enclosed vertical side;
• and
• wherein the frosting chamber further comprises a fourth open vertical side opposite the third enclosed vertical side.