Abstract: A refrigerated case (20) has a housing containing an interior volume (36) for storing items. Along an air flow path (510) through the case, a refrigerant-to-air heat exchanger (60) has an evaporator section (112) and a reheat section (114). A preconditioning section (110) may be upstream of the evaporator section (112) and the evaporator section is upstream of the reheat section (114). Along a refrigerant flow path (520), the reheat section (114) is downstream of the preconditioning section (110) (if any) and upstream of the evaporator section (112) and an expansion device (62) is between the reheat (114) and evaporator (112) sections.

Abstract: Cooled air is drawn into a display case (12) from a cooler (18). Products (160) are stacked on shelves (14) in the case. A fan system (50) at the bottom front of the display case draws the air through a return grill (56). The fan system blows the air through a grille and back into the cooler. A deflector (64) is installed between the shelves and a lower case front (58) that houses the fan system. The deflector provides a barrier to prevent stray air that flows from the grille from diffusing upwardly to lower shelves in the case and warming the product on the lower shelves. The deflector also stops the stray air from recirculating back through the fan system.

Abstract: A refrigerated case (20) has a housing containing an interior volume (36) for storing items. Along an air flow path (510) through the case, a refrigerant-to-air heat exchanger (60) has an evaporator section (112) and a reheat section (114). A preconditioning section (110) may be upstream of the evaporator section (112) and the evaporator section is upstream of the reheat section (114). Along a refrigerant flow path (520), the reheat section (114) is downstream of the preconditioning section (110) (if any) and upstream of the evaporator section (112) and an expansion device (62) is between the reheat (114) and evaporator (112) sections.

Abstract: A compressor control system for a commercial refrigeration system includes a variable speed compressor and multiple fixed speed compressors. The control system calculates a variable which fluctuates according to the desired capacity of the system and is calculated as a function of the difference between a variable indicative of the refrigeration load on the system, such as compressor suction pressure, and a target value. A "PID" proportional-integral-differential (PID) controller is used in which terms have been added which fluctuate as a function of the square of the difference between the sensed variable and the target value and as a function of the second derivative of the control variable with respect to time. Fixed speed compressors are turned on or off and the speed of the variable speed compressor is adjusted to bring the actual refrigeration capacity of the system in line with the system refrigeration requirements.

Abstract: In an island type refrigeration display cabinet, a top aperture containing two oppositely disposed louvers for discharging oppositely directed coplanar air curtain sections, to form a single air curtain of multiple section in the top aperture of the display cabinet. Preferably, the cabinet also includes means for withdrawing air from the interior display space of the cabinet and forcing the air through a bifurcated conduit. Each bifurcation of the conduit is flowably connected to one of the respective louvers in the top opening of the display cabinet. Each bifurcation of the conduit also includes means for refrigerating the air flowing through the conduit to the louvers.

Abstract: A refrigeration system for a display case including electronic means for controlling an expansion valve and a refrigerant compressor used in the system. The expansion valve is cycled between open and close positions to modulate refrigerant flow into an evaporator coil. A microprocessor controls the operation of the expansion valve in response to: (a) the relationship of the temperature of air that has passed over the evaporator coil to multiple upper and lower limits (b) time integrated temperature deviations beyond preselected limits (c) upward or downward trend of the differential in temperature in the refrigerant during its flow through the evaporator coil, and (d) extreme deviation of the temperature of air that has passed over the evaporator coil. Compressor cut-in and cut-out pressures are also adjusted by the control in response to these air and refrigerant temperatures.