Abstract: A temperature-controlled display device includes a temperature-controlled space and a refrigeration circuit configured to provide cooling for the temperature-controlled space. The refrigeration circuit is configured to operate in multiple cooling modes including a normal refrigeration mode and an anti-ingression mode. A proximity sensor is configured to detect an object such as a human hand or forearm within a detection zone adjacent to a door handle of the temperature-controlled display device. A controller estimates a distance between the handle and the detected object using an input from the proximity sensor. The controller causes the refrigeration circuit to transition between the multiple cooling modes based on the estimated distance.

Abstract: A temperature-controlled display device includes a temperature-controlled space and a refrigeration circuit configured to provide cooling for the temperature-controlled space. The refrigeration circuit is configured to operate in multiple cooling modes including a normal refrigeration mode and an anti-ingression mode. A proximity sensor is configured to detect an object such as a human hand or forearm within a detection zone adjacent to a door handle of the temperature-controlled display device. A controller estimates a distance between the handle and the detected object using an input from the proximity sensor. The controller causes the refrigeration circuit to transition between the multiple cooling modes based on the estimated distance.

Abstract: In general the present invention provides a refrigeration system and a method of controlling the refrigeration system. The system includes a coolant circuit having in series a compressor, a metering device, an evaporator coil, and sensors for determining the coolant temperature and pressure within the circuit. The system also includes a defrost system that includes a fan and/or a resistive heating element. The present invention also provides a method of operating the refrigeration system to protect the individual components such as the compressor from damage from flooding with liquid coolant. Additionally, the operating method provides a more efficient operation by using a self-adaptive defrost sequence and rapid startup sequences after the defrost periods.

Abstract: The invention provides an apparatus and a method for detecting low refrigerant condition in a closed loop refrigeration system. Separate pressure transducers are installed to measure the suction and discharge pressures of the refrigeration system. When the compressor is shut off, usually to remove the frost from the evaporator coils, the pressure difference between the discharge and suction pressures is measured by a microprocess-based control circuit. A low refrigerant alarm or indicator is activated if the pressure difference is below a predetermined value programmed in the control circuit.