Abstract: An open front refrigerated display case having an improved ambient air defrost system which includes a housing with a display compartment area for displaying articles therein and an open front area to facilitate placement and removal of the articles, a main refrigeration duct extends throughout the housing having a primary inlet above the open front area and a primary outlet defined below the front area, a primary refrigeration coil is positioned within the primary refrigeration duct for cooling of air passing therethrough and a primary fan device is positioned within the primary refrigeration duct to facilitate drawing of air through the air inlet and expelling of refrigerated air through the air outlet in such a manner as to form an air curtain across the open front area. An ambient air defrost system is included having an ambient air circulation device such as a fan and an ambient air drive means for powering thereof.

Abstract: An opened front refrigerated display case having multiple front refrigeration control air curtains and a supplemental refrigerated air curtain passing over the bin area thereof to aid in maintaining of the bin area of the display area of the case in an efficiently refrigerated condition and to minimize the accumulation of frost therein. The display case includes multiple inlets in the upper area above the opened front area and multiple outlets in the lower area below the opened front area to facilitate multiple curtains of controlled air passing thereover. The innermost lower inlet is adapted to also receive therein refrigerated air from a bin cooling air curtain which passes approximately horizontally over the bin area. Air is admitted into the curtain by a bin outlet positioned immediately adjacent to the main refrigeration flow duct path positioned immediately behind the bin area.

Abstract: A refrigerated display case, of the reach-in type having a door normally closing a customer access opening, utilizes ambient air for defrost purposes by channeling it through an inlet conduit at the bottom of the case. The air is introduced into the normal air circulation pattern that obtains during the refrigerating cycle of the case, at the intake sides of the otherwise conventional primary circulating fan and its adjacent evaporator coil. The arrangement avoids reversal of the normal air circulation pattern and maintains a small but noticeable air flow, during a defrost cycle, through the product display area and along the inside of the glass door surface. The inflow of ambient defrost air is directed into the case through a defrost air inlet conduit having at its outlet end a continuously open air supply port, which opens into the primary air duct to provide for said introduction of defrost air into the normal air pattern.