The invention relates to an enclosure for refrigerating chambers, suitable for closing an access (3) to a refrigerating chamber and comprising: —a sliding refrigerating door (1), and —a quick-opening door (2), both assembled on the same side of the chamber, comprising a frame with vertical posts (4), comprising: —on an outer face, at least one mouth (42) wherein a fan (6) is coupled which introduces air in the corresponding vertical post (4); —on the inside thereof, a deflector plate (61) which directs the air towards electrical resistors (7) for heating the air, situated underneath the deflector plate and, —on an inner face, an outlet (43) for supplying hot air on one of the surfaces, inner or outer, of the flexible sheet (21) exposed to the cold of the chamber and removing frost from said flexible sheet (21).

A refrigerator a duct arranged to partition an inner space of a storage chamber body into a storage chamber and an air flow channel, wherein the duct has an ejection hole defined therein; a roll-bond evaporator disposed in the air flow channel, wherein the roll-bond evaporator has a top and a bottom, a left end and a right end; a blowing fan configured to draw air from the storage chamber to blow the air into the air flow channel; and a defrost sensor closer to one of the top and bottom than the other of the top and the bottom, wherein said one is closer to the blowing fan than the other, wherein the sensor is closer to one of the left end and the right end than the other of the left end and the right end.

An air handling system for a heating, ventilation, and air conditioning system of a motor vehicle includes a conduit configured to convey air from the air handling system to a vent of the air handling system. A control door is rotatably disposed in the conduit. The control door selectively rotates between a first position and a second position. The first position blocks passage of the air flowing through the conduit. The second position blocks passage of the air flowing through a first portion of the conduit and allows the air to flow through a second portion of the conduit. A control feature is disposed in the second portion of the conduit to control at least one of a volumetric flow rate and a pressure of the air flowing through the second portion.

A refrigerator is provided that includes a low energy defrost system and method for melting frost formed on an evaporator of a cooling system for the refrigerator. The low energy defrost system includes using air from the refrigerator compartment or external air adjacent the refrigerator to be directed to the evaporator and passed adjacent the evaporator coils to melt any frost formed thereon. As the air is above freezing temperature, it will melt any frost formed on the coils without the need of use an electrical heater. Re-cooled air from the melted frost may then be directed back into the refrigerator compartment to be used to aid in cooling the refrigerator compartment or keeping the refrigerator compartment at the programmed or predetermined temperature.

A door assembly for a refrigeration door system with a defrosting feature. The door assembly also includes a door frame. The door frame may include a top member having a first end and a second end opposite the first end, and the top member may have a top conduit therein. The door frame may also include a first side member coupled transversely to the first end of the top member and having a first conduit therein, the first conduit being fluidly coupled to the top conduit, and a second side member coupled transversely to the second end of the top member and having a second conduit. The second conduit may be fluidly coupled to the top conduit. The door frame may further have orifices positioned along the top member, the first side member, and the second side member. The door assembly also includes a positive pressure source.

A door assembly for a refrigeration door system with a defrosting feature. The door assembly also includes a door frame. The door frame may include a top member having a first end and a second end opposite the first end, and the top member may have a top conduit therein. The door frame may also include a first side member coupled transversely to the first end of the top member and having a first conduit therein, the first conduit being fluidly coupled to the top conduit, and a second side member coupled transversely to the second end of the top member and having a second conduit. The second conduit may be fluidly coupled to the top conduit. The door frame may further have orifices positioned along the top member, the first side member, and the second side member. The door assembly also includes a positive pressure source.

A refrigeration system includes at least one low-temperature evaporator, at least one medium-temperature evaporator, one or more low-temperature compressors, and one or more medium-temperature compressors. A controllable valve positioned downstream from the one or more low-temperature compressors directs flow of refrigerant from the low-temperature compressor(s) to one or both of (i) the medium-temperature compressor(s) and (ii) one or more evaporators based on an operation mode of evaporators. A controller is communicatively coupled to the controllable valve. A controller determines that operation of a first evaporator in a defrost mode is indicated and causes the first evaporator to operate in the defrost mode by adjusting the controllable valve to direct a portion of the received compressed refrigerant to the first evaporator.

A refrigeration system includes a controllable valve positioned downstream from one or more low-temperature compressors. The controllable valve receives compressed refrigerant from the low-temperature compressors and directs flow of the refrigerant to one or both of (i) medium-temperature compressors downstream from the controllable valve and (ii) one or more evaporators based on an operation mode of the evaporators. A pressure-regulating valve is disposed in refrigerant conduit coupling a first flash tank to a second flash tank. After determining to operate a first evaporator in a defrost mode, a controller adjusts the controllable valve to direct a portion of refrigerant to the first evaporator and adjusts the pressure-regulating valve to increase a pressure of the first flash tank relative to that of the second flash tank.

A refrigeration system includes pressure-regulating valve positioned between two flash tanks and a heat exchanger is positioned downstream from a medium temperature compressor. After determining that operation of an evaporator in a defrost mode is indicated, the system causes the evaporator to operate in the defrost mode by adjusting the pressure-regulating valve to increase a pressure of a first flash tank relative to a pressure of a second flash tank, allowing flow of refrigerant from the first flash tank to the heat exchanger, and allowing refrigerant heated by the heat exchanger to flow to the first evaporator.

A refrigeration cycle apparatus includes a refrigerant circuit, a fan configured to send air to a heat exchanger, and a controller. The controller is configured to switch among a first operation, a second operation, and a third operation. In the first operation, the heat exchanger is caused to act as an evaporator. In the second operation, the heat exchanger is caused to act as a radiator to defrost the heat exchanger. In the third operation that is performed after the second operation, a compressor is stopped and the fan is operated at a constant rotational speed. The controller is configured to finish the third operation and start the first operation when a physical value positively correlated with electric power supplied to the fan falls to or below a threshold value during the third operation.